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ASTM A380 A380M

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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: A380/A380M − 17
Standard Practice for
Cleaning, Descaling, and Passivation of Stainless Steel
Parts, Equipment, and Systems1
This standard is issued under the fixed designation A380/A380M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revis
revision.
ion. A number in parentheses
parentheses indicates the year of last reapproval.
reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1.1.1.2
1.1.1.
2 Pas
Passiv
sivatio
ation
n is rem
remova
ovall of exo
exogen
genous
ous iro
iron
n or iro
iron
n
compounds from the surface of a stainless steel by means of a
chemica
che
micall dis
dissol
soluti
ution,
on, mos
mostt typ
typica
ically
lly by a trea
treatme
tment
nt wit
with
h an
acid solution that will remove the surface contamination but
willl not sig
wil
signifi
nifican
cantly
tly af
affec
fectt the sta
stainle
inless
ss stee
steell itse
itself.
lf. Thi
Thiss
process is described in a general way in 6.2.11 and defined
precisely in 6.4 with further reference to the requirements of
Annex A2 and Part II of the table on acid cleaning of steel.
Unless otherwise specified, it is this definition of passivation
thatt is tak
tha
taken
en as the meaning
meaning of a spe
specifie
cified
d req
requir
uireme
ement
nt for
passivation.
passiv
ation. (See also Specific
Specification
ation A967/A967M
A967/A967M.)
.)
1.1.1.3
1.1.1
.3 Passiv
Passivation
ation is the chemical treatment of a stainless
steel with a mild oxidant, such as a nitric acid solution, for the
purpose of enhancing the spontaneous formation of the protectivee pa
tiv
pass
ssiv
ivee met
metal
al ox
oxid
idee fil
film.
m. Su
Such
ch ch
chem
emica
icall tr
treat
eatme
ment
nt is
generally not necessary for the formation of the passive metal
oxide film.
1.1.1.4
1.1.1
.4 Passiv
Passivation
ation does not indicate the separate process
process of
descaling as described in Section 5
5,, although descaling may be
necessary before passivation can be effective. Depending on
the application, chemical descaling (acid pickling) as described
in 5.2.1 may pro
provid
videe suf
suffficie
icient
nt pas
passiv
sivatio
ation
n as defi
defined
ned in
1.1.1.2..
1.1.1.2
1. Sco
Scope*
pe*
1.1 This practice covers recommendations
recommendations and precau
precautions
tions
for cleaning, descaling, and passivating of new stainless steel
parts,
par
ts, asse
assembl
mblies
ies,, equ
equipm
ipment
ent,, and ins
install
talled
ed sys
systems
tems.. The
These
se
recommendati
recomm
endations
ons are presen
presented
ted as proce
procedures
dures for guida
guidance
nce
when it is recognized that for a particular service it is desired
to remove surface contaminants that may impair the normal
corrosion resistance, or result in the later contamination of the
particular stainless steel grade, or cause product contamination.
The selection of procedures from this practice to be applied to
the pa
the
part
rtss ma
may
y be sp
spec
ecifie
ified
d up
upon
on ag
agre
reem
emen
entt be
betw
twee
een
n th
thee
supp
su
ppli
lier
er an
and
d th
thee pu
purc
rcha
hase
serr. Fo
Forr ce
cert
rtai
ain
n ex
exce
cept
ptio
iona
nall
applications, additional requirements which are not covered by
this practice
practice may be spe
specifi
cified
ed upo
upon
n agr
agreeme
eement
nt bet
betwee
ween
n the
supplier and the purchaser. Although they apply primarily to
materials in the composition ranges of the austenitic, ferritic,
martensitic,
martens
itic, and duple
duplex
x stainles
stainlesss steels, the practic
practices
es descri
described
bed
may also be useful for cleaning other metals if due consideration is given to corrosion and possible metallurgical effects.
1.1.1 The term passivation
passivation is commo
commonly
nly applied to several
distinctly different operations or processes relating to stainless
stee
st
eels
ls.. In or
orde
derr to av
avoi
oid
d am
ambi
bigu
guit
ity
y in th
thee se
sett
ttin
ing
g of
requirements, it may be necessary for the purchaser to define
precise
pre
cisely
ly the int
intend
ended
ed mea
meanin
ning
g of pas
passiv
sivatio
ation.
n. Som
Somee of the
various meanings associated with the term passivation that are
1.2 This practice does not cover decontaminatio
decontamination
n or cleaning of equipment or systems that have been in service, nor does
in common usage include the following:
1.1.1.1
1.1.1
.1 Passiv
Passivation
ation is the process by which a stainles
stainlesss steel
will spontaneously form a chemically resistant surface when
exposed to air or other oxygen-containing environments. It was
at one time considered that an oxidizing treatment was necessary to establish this passive metal oxide film, but it is now
accepted that this film will form spontaneously in an oxygencontaining
contain
ing environment
environment provi
providing
ding that the surfa
surface
ce has been
thoroughly cleaned or descaled.
it
cover
descaling
and
cleaning
of may
materials
at the mill.
the
other
hand,
some of
the
practices
be applicable
forOn
these
purposes.
purp
oses. While the practic
practicee provi
provides
des recomm
recommendati
endations
ons and
information concerning the use of acids and other cleaning and
descaling agents, it cannot encompass detailed cleaning procedure
du
ress fo
forr sp
speci
ecific
fic ty
type
pess of eq
equi
uipm
pmen
entt or in
inst
stall
allati
ation
ons.
s. It
therefore in no way precludes the necessity for careful planning
and judgment
judgment in the sele
selectio
ction
n and implement
implementatio
ation
n of suc
such
h
procedures.
1.3 The
These
se pra
practic
ctices
es may be app
applied
lied when free iro
iron,
n, oxi
oxide
de
scale, rust, grease, oil, carbonaceous or other residual chemical
films,
film
s, soi
soil,
l, par
particl
ticles,
es, met
metal
al chip
chips,
s, dir
dirt,
t, or oth
other
er non
nonvol
volatil
atilee
deposits
depos
its might adversely affect
affect the metallu
metallurgic
rgical
al or sanitar
sanitary
y
condition or stability of a surface, the mechanical operation of
a part, component, or system, or contaminate a process fluid.
1
This practice is under the jurisd
jurisdiction
iction of ASTM Committee A01 on Steel
Steel,,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.14 on Methods of Corrosion Testing.
Current edition approved Sept. 1, 2017. Published September 2017. Originally
approved in 1954. Last previous edition approved in 2013 as A380/A380M – 13.
DOI: 10.1520/A0380_A0380M-17.
The degree of cleanness required on a surface depends on the
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
A380/A380M − 17
application. In some cases, no more than degreasing or removal
of gro
gross
ss con
contam
taminat
ination
ion is nec
necess
essary
ary.. Oth
Others
ers,, suc
such
h as foo
fooddhandli
han
dling
ng,, pha
pharma
rmaceu
ceutic
tical,
al, aer
aerosp
ospace
ace,, and cer
certai
tain
n nu
nucle
clear
ar
applications, may require extremely high levels of cleanness,
including
includ
ing removal of all detectable residual chemical films and
contaminants that are invisible to ordinary inspection methods.
F22 Test Meth
Method
od for Hyd
Hydrop
rophob
hobic
ic Sur
Surfac
facee Fil
Films
ms by the
Water-Break Test
2.2 ISO Standards:3
ISO 14644-1 Cleanrooms and associated controlled environments -- Part 1: Classification of air cleanliness by particle
concentration
ISO 14644-2 Cleanrooms and associated controlled environments
men
ts -- Pa
Part
rt 2: Mo
Moni
nito
tori
ring
ng to pr
prov
ovid
idee ev
evid
iden
ence
ce of
cleanroom performance related to air cleanliness by particle concentration
NOTE 1—The term “iron,” when hereinafter referred to as a surface
contaminant, shall denote free iron.
contaminant,
1.4 Att
Attain
ainmen
mentt of sur
surfac
faces
es that are fre
freee of iro
iron,
n, meta
metallic
llic
deposits, and other contamination depends on a combination of
properr design
prope
design,, fabri
fabrication
cation methods, cleaning and descali
descaling,
ng,
and protection to preve
prevent
nt recon
recontaminati
tamination
on of cleaned surfaces.
surfaces.
Meanin
Mea
ningfu
gfull test
testss to est
establi
ablish
sh the degree of clea
cleanne
nness
ss of a
surface are few, and those are often difficult to administer and
to eva
evalua
luate
te obj
objecti
ectivel
vely
y. Visu
isual
al ins
inspec
pection
tion is sui
suitab
table
le for the
detection of gross contamination, scale, rust, and particulates,
but may not reveal the presence of thin films of oil or residual
chem
ch
emica
icall film
films.
s. In ad
addi
ditio
tion,
n, vi
visu
sual
al in
insp
spect
ectio
ion
n of in
inter
terna
nall
surfaces is often impossible because of the configuration of the
item. Methods are described for the detection of free iron and
transparent chemical and oily deposits.
3. Desig
Design
n
3.1 Con
Consid
sidera
eratio
tion
n sho
should
uld be giv
given
en in the design of par
parts,
ts,
equipment, and systems that will require cleaning to minimize
the pre
presen
sence
ce of cre
crevic
vices,
es, poc
pockets
kets,, blin
blind
d hol
holes,
es, und
undrain
rainable
able
cavities, and other areas in which dirt, cleaning solutions, or
sludge
slu
dge might lod
lodge
ge or bec
become
ome tra
trappe
pped,
d, and to pro
provid
videe for
effec
ef
fectiv
tivee cir
circula
culatio
tion
n and rem
remova
ovall of clea
cleanin
ning
g sol
solutio
utions.
ns. In
equipment and systems that will be cleaned in place or that
cannot be immersed in the cleaning solution, it is advisable to
slope lines for drainage: to provide vents at high points and
drain
dr
ainss at lo
low
w po
poin
ints
ts of th
thee ite
item
m or sy
syst
stem
em;; to ar
arra
rang
ngee fo
forr
removal or isolation of parts that might be damaged by the
cleanin
clea
ning
g sol
soluti
ution
on or fum
fumes
es fro
from
m the clea
cleanin
ning
g sol
soluti
utions
ons;; to
provid
pro
videe mea
means
ns for atta
attachi
ching
ng temp
tempora
orary
ry fill and cir
circula
culatio
tion
n
lines; and to provide for inspection of cleaned surfaces.
1.5 This practice provides definitions
definitions and descr
describes
ibes practices for cleaning, descaling, and passivation of stainless steel
parts.
par
ts. Test
estss with acc
accepta
eptance
nce cri
criter
teria
ia to dem
demons
onstrat
tratee tha
thatt the
passivation
passiv
ation procedures
procedures have been successful
successful are listed in 7.2.5
and 7.3.4
7.3.4,, an
and
d can al
also
so be fo
foun
und
d in Sp
Speci
ecific
ficati
ation
on A967/
A967M..
A967M
3.2 In a co
3.2
comp
mple
lex
x pi
pipi
ping
ng sy
syst
stem
em it ma
may
y be di
diffficu
icult
lt to
determine how effective a cleaning operation has been. One
method of designing inspectability into the system is to provide
a sh
shor
ortt fla
flang
nged
ed len
lengt
gth
h of pipe (that
(that is
is,, a sp
spoo
ooll pi
piece
ece)) at a
location where the cleaning is likely to be least effective; the
spool piece can then be removed for inspection upon completion of cleaning.
1.6 The values stated in either SI units or inch-pound
inch-pound units
are to be regarded separately as standard. The values stated in
each system may not be exa
exact
ct equ
equiva
ivalen
lents;
ts; the
theref
refore
ore,, each
system shall be used independently of the other. Combining
values from the two systems may result in non-conformance
with the standard.
1.7 This standar
standard
d doe
doess not purport
purport to add
addre
ress
ss all of the
safet
sa
fetyy co
conc
ncer
erns
ns,, if an
anyy, as
asso
socia
ciate
ted
d wit
with
h its us
use.
e. It is th
thee
responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific
4. Precle
Precleaning
aning
safety precautions
precautions see 7.2.5.3
7.2.5.3,, 7.3.4
7.3.4,, Section 8, A1.7
A1.7,, and
A2.11..)
A2.11
1.8 This int
intern
ernati
ationa
onall sta
standa
ndard
rd was dev
develo
eloped
ped in acc
accor
or-dance with internationally recognized principles on standardizatio
iza
tion
n es
esta
tabl
blis
ishe
hed
d in th
thee De
Decis
cisio
ion
n on Pr
Prin
incip
ciple
less fo
forr th
thee
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
Material
Mater
ialss are us
usua
ually
lly pr
precl
eclean
eaned
ed be
befo
fore
re ho
hot-f
t-for
ormin
ming,
g,
anneali
ann
ealing,
ng, or oth
other
er hig
high-t
h-temp
empera
eratur
turee ope
operat
ration
ion,, bef
before
ore any
descaling operation, and before any finish-cleaning operation
wher
wh
eree th
thee pa
parts
rts wi
will
ll be imm
immer
erse
sed
d or wh
wher
eree th
thee cl
clean
eanin
ing
g
solu
so
lutio
tions
ns wi
will
ll be re
reus
used
ed.. It
Item
emss th
that
at ar
aree su
subj
bjec
ectt to se
seve
vera
rall
redraws or a series of hot-forming operations, with intermediate anneals, shall be cleaned after each forming operation, prior
to ann
anneali
ealing.
ng. Pre
Precle
cleanin
aning
g may be acco
accompl
mplish
ished
ed by vap
vapor
or
degreasing; immersion in, spraying, or swabbing with alkaline
or emulsi
emulsion
on cleane
cleaners;
rs; steam; or highhigh-press
pressure
ure water-jet (see
6.2).
6.2
).
4.1 Preclea
Precleaning
ning is the removal of grease,
grease, oil, paint, soil, grit,
and oth
other
er gro
gross
ss con
contami
taminati
nation
on pre
prepar
parato
atory
ry to a fab
fabrica
ricatio
tion
n
process or final cleaning. Precleaning is not as critical and is
generally not as thorough as subsequent cleaning operations.
2. Referenc
Referenced
ed Documents
Documents
2.1 ASTM Standards:2
A967/A967M Specification for Chemical Passivation Treatments for Stainless Steel Parts
F21 Test Met
Method
hod for Hyd
Hydrop
rophob
hobic
ic Sur
Surfac
facee Film
Filmss by the
Atomizer Test
5. Desc
Descaling
aling
5.1 General—Des
Descali
caling
ng is the rem
remova
ovall of hea
heavy
vy,, tig
tightl
htly
y
adhere
adh
erent
nt ox
oxide
ide film
filmss res
result
ulting
ing fr
from
om hot
hot-fo
-form
rming
ing,, hea
heatttreatment,
treatme
nt, weldin
welding,
g, and other high-temperatur
high-temperaturee operat
operations.
ions.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3
Availab
vailable
le from Intern
Internationa
ationall Orga
Organizati
nization
on for Stan
Standardiz
dardization,
ation, ISO Centr
Central
al
Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland.
2
A380/A380M − 17
Because
use mil
milll pro
produc
ducts
ts are usu
usually
ally supplied
supplied in the des
descale
caled
d
Beca
condition, descaling (except removal of localized scale resulting from welding) is generally not necessary during fabrication
of equipment or erection of systems (see 6.3
6.3).
). When necessary,
scale may be removed by one of the chemical methods listed
below, by mechanical methods (for example, abrasive blasting,
sanding,
sandin
g, grinding, power brushing),
brushing), or by a combi
combination
nation of
these.
tions (such as the presence of crevices). If used, neutralization
is usually also followed by rinsing with clean water to remove
all tra
traces
ces of the neu
neutral
tralizin
izing
g age
agent
nt and tho
thorou
rough
gh dry
drying
ing.. To
mini
mi
nimiz
mizee sta
stain
inin
ing,
g, su
surf
rfac
aces
es sh
shall
all no
nott be pe
perm
rmitt
itted
ed to dr
dry
y
betwee
bet
ween
n suc
success
cessive
ive step
stepss of the acid des
descali
caling
ng and rin
rinsin
sing
g
procedure (see A1.5
A1.5).
).
5.2.6 Chemical descaling methods, factors in their selection,
and
an
d pr
prec
ecau
autio
tions
ns in th
their
eir us
usee ar
aree de
desc
scri
ribe
bed
d in th
thee Metals
Handbook.4 When chemical descaling is necessary, it should
5.2 Chem
Chemical
ical Des
Descali
caling
ng (Pic
(Picklin
kling)—
g)—Chem
Chemical
ical desc
descalin
aling
g
agents include aqueous solutions of sulfuric acid, or nitric and
hydrofl
hyd
rofluor
uoric
ic acid
acids,
s, as des
describ
cribed
ed in Anne
Annex
x A1
A1,, Tab
Table
le A1.1
A1.1,,
molten alkali or salt baths, and various proprietary formulations. The safety precautions of 8.6 shall be observed in the use
of the
these
se meth
methods
ods.. Par
Particu
ticular
lar car
caree sha
shall
ll be exe
exercis
rcised
ed whe
when
n
pickling
pick
ling closed sys
systems
tems and item
itemss wit
with
h cre
crevic
vices
es or int
intern
ernal
al
voids to prevent retention of pickling solutions and residues.
5.2.1 Acid Pick
Nitricric-hyd
hydrofl
rofluor
uoric
ic acid sol
soluti
ution
on is
Pickling
ling—
—Nit
most widely used by fabricators of stainless steel equipment
and rem
remove
ovess bot
both
h met
metalli
allicc con
contam
tamina
ination
tion,, and weld
welding
ing and
heat-treating scales. Its use should be carefully controlled and
is not recommended for descaling sensitized austenitic stainless steels or hardened martensitic stainless steels or where it
can com
comee into contact
contact wit
with
h carb
carbon
on ste
steel
el par
parts,
ts, ass
assemb
emblies
lies,,
equipment, and systems. See also A1.3
A1.3.. Solutions of nitric acid
be
done
while thefabrication
part is in its
possible
geometry,
before
subsequent
or simplest
installation
steps create
internal cre
crevic
vices
es or und
undrai
rainab
nable
le spa
spaces
ces tha
thatt may trap descaling
descaling
agents
age
nts,, slu
sludge
dge,, par
particl
ticles,
es, or con
contam
tamina
inated
ted rin
rinse
se wat
water
er that
might either result in eventu
eventual
al corro
corrosion
sion or adver
adversely
sely affect
affect
operation of the item after it is placed in service.
alone are usually not effective for removing heavy oxide scale.
5.2.2 Surfa
Surfaces
ces to be descale
descaled
d shall be precleaned to remove
oils and greases prior to acid treatment (see A1.5
A1.5)), and are
usually precleaned prior to other chemical treatments.
5.2.3 When size and shape of product permit,
permit, total immersion in the pickling solution is preferred. Where immersion is
impractical,
impract
ical, descaling may be accomp
accomplished
lished by ( 1) wetting the
surfaces by swabbing or spraying, or ( 2) by partially filling the
item with picklin
pickling
g solution and rotating or rocki
rocking
ng to slosh the
solutio
sol
ution
n so tha
thatt all sur
surfac
faces
es rec
receiv
eivee the req
requir
uired
ed che
chemica
micall
treatment. The surface should be kept in contact with agitated
solution for about 15 to 30 min or until inspection shows that
comp
co
mplet
letee sca
scale
le rem
remov
oval
al ha
hass be
been
en acc
accom
ompl
plish
ished
ed.. With
ithou
outt
agitation, additional exposure time may be required. If rocking
or rotation are impracticable, pickling solution may be circu-
martensiti
marten
siticc sta
stainle
inless
ss stee
steels
ls whe
when
n in the har
harden
dened
ed con
condit
dition
ion,,
mechanical
mechan
ical descaling may be the only suitable method. Grinding is usually the most effective means of removing localized
scale such as that which results from welding. Disadvantages
of mec
mechan
hanical
ical des
descali
caling
ng are cos
cost,
t, as com
compar
pared
ed to che
chemica
micall
descaling, and the fact that surface defects (for example, laps,
pits, slivers) may be obscured, making them difficult to detect.
5.3.1
5.3
.1 Sur
Surfac
faces
es to be descaled
descaled may have to be pre
preclea
cleaned
ned..
Particular care must be taken to avoid damage by mechanical
methods when descaling thin sections, polished surfaces, and
closeclo
se-tol
toleran
erance
ce par
parts.
ts. Aft
After
er mec
mechan
hanical
ical des
descali
caling,
ng, sur
surfac
faces
es
shou
sh
ould
ld be cl
clean
eaned
ed by scr
scrub
ubbi
bing
ng wi
with
th ho
hott wa
water
ter an
and
d fib
fiber
er
brushes, followed by rinsing with clean, hot water.
5.3.2
5.3
.2 Gri
Grindi
nding
ng whe
wheels
els and san
sandin
ding
g mate
materia
rials
ls sho
should
uld not
contain iron, iron oxide, zinc, or other undesirable materials
lated through the item or system until inspection shows that
descaling has been accomplished.
5.2.4 Over
Over-pick
-pickling
ling must be avoid
avoided.
ed. Uniform removal of
scale
sca
le wi
with
th ac
acid
id pi
pick
cklin
ling
g de
depe
pend
ndss on th
thee aci
acid
d us
used
ed,, ac
acid
id
concen
con
centra
tratio
tion,
n, sol
soluti
ution
on tem
temper
peratu
ature,
re, and con
contact
tact time (se
(seee
Annex
Ann
ex A1
A1).
). Con
Contin
tinuou
uouss exp
exposu
osure
re to pic
picklin
kling
g sol
soluti
utions
ons for
more than 30 min is not recommended. The item should be
drained and rinsed after 30 min and examined to check the
effective
ef
fectiveness
ness of the treatment. Additional
Additional treatme
treatment
nt may be
required. Most pickling solutions will loosen weld and heattreating scale but may not remove them completely. Intermittent scrubbing with a stainless steel brush or fiber-bristle brush,
in conjunction with pickling or the initial rinse, may facilitate
thee re
th
remo
mova
vall of sca
scale
le pa
part
rticl
icles
es an
and
d pr
prod
oduc
ucts
ts of ch
chem
emica
icall
reaction (that is, pickling smut).
that may cause contamination of the metal surface. Grinding
wheels, sanding materials, and wire brushes previously used on
other metals should not be used on stainless steel. Wire brushes
shou
sh
ould
ld be of a st
stain
ainle
less
ss st
steel
eel wh
which
ich is eq
equa
uall in co
corr
rros
osio
ion
n
resistance to the material being worked on.
5.3.3
5.3
.3 Clean, pre
previo
viousl
usly
y unu
unused
sed abr
abrasiv
asives,
es, suc
such
h as gla
glass
ss
beads or iron-free silica or alumina sand, are recommended for
abrasiv
abr
asivee bla
blastin
sting.
g. Ste
Steel
el sho
shott or gri
gritt is gen
genera
erally
lly not rec
recomommended because of the possibility of embedding iron particles.
The use of stainless steel shot or grit reduces the danger of
rusting and iron contamination, but cannot completely eliminate the possi
possibility
bility of embed
embedding
ding residues of ironiron-oxide
oxide scale.
5.3.4 If a totally iron and scale free surface
surface is required,
required, most
abrasiv
abr
asivee bla
blastin
sting
g may be fol
follow
lowed
ed by a bri
brief
ef acid dip (se
(seee
Annex A2)
A2) or passivation treatment (see 6.4
6.4)).
5.3 Mechanical Descaling—Mechanical descaling methods
include abrasive blasting, power brushing, sanding, grinding,
and chi
chippi
pping.
ng. Pro
Proced
cedura
urall req
requir
uiremen
ements
ts and pre
precaut
caution
ionss for
some of these methods are given in the Metals Handb
Handbook
ook.4
Mechanical descaling methods have the advantage that they do
not pro
produc
ducee suc
such
h phy
physica
sicall or che
chemic
mical
al con
conditi
ditions
ons as inte
interrgranular
granu
lar attack, pitting, hydr
hydrogen
ogen embrittlement,
embrittlement, cracks
cracks,, or
smut deposits. For some materials, in particular the austenitic
stain
st
ainle
less
ss st
steel
eelss wh
when
en in th
thee sen
sensit
sitize
ized
d co
cond
nditi
ition
on an
and
d th
thee
5.2.5 After chemical
chemical descaling, surfaces
surfaces shall be thoro
thoroughly
ughly
rinsed
rinse
d wi
with
th cl
clean
ean wa
water
ter to re
remo
move
ve al
alll tr
trace
acess of re
resid
sidua
uall
chemicals and thoroughly dried after the final water rinse. A
neutralization treatment may be necessary under some condi-
4
“Surface
“Surf
ace Clean
Cleaning,
ing, Finis
Finishing,
hing, and Coati
Coating,”
ng,” Metals Handb
Handbook,
ook, Am. Soc.
Metals, 9th ed., Vol 5, 1982.
3
A380/A380M − 17
6.2.2 Emulsio
Emulsion
n Cleanin
Cleaning
g is a pr
proc
oces
esss fo
forr re
remo
movi
ving
ng oi
oily
ly
deposits and other common contaminants from metals by the
use of com
common
mon or
organ
ganic
ic sol
solven
vents
ts dis
disper
persed
sed in an aqu
aqueou
eouss
solution with the aid of a soap or other emulsifying agent (an
emulsif
emu
lsifyin
ying
g age
agent
nt is one which increases
increases the stab
stabilit
ility
y of a
dispersion of one liquid in another). It is effective for removing
a wi
wide
de va
vari
riety
ety of co
cont
ntam
amin
inan
ants
ts in
inclu
cludi
ding
ng pi
pigm
gmen
ente
ted
d an
and
d
unpigme
unp
igmented
nted draw
drawing
ing comp
compoun
ounds
ds and lubr
lubrican
icants,
ts, cutti
cutting
ng
fluids,, and residues resul
fluids
resulting
ting from liquid penetrant
penetrant inspec
inspection.
tion.
6. Clea
Cleaning
ning
6.1 General—Cleaning includes all operations necessary for
the removal of surface contaminants from metals to ensure (1)
maximum corrosion resistance of the metal, (2) prevention of
product contamination, and (3) achievement of desired appearance. Cleanness is a perishable condition. Careful planning is
necessary to achieve and maintain clean surfaces, especially
where
whe
re a hig
high
h deg
degree
ree of clea
cleanne
nness
ss is req
requir
uired.
ed. Selection
Selection of
cleaning processes is influenced mainly by the type of contaminant to be removed, the required degree of cleanness, and
cost. If careful control of fabrication processes, sequencing of
cleaning and fabrication operations, and measures to prevent
recontamination of cleaned surfaces are exercised, very little
spec
sp
ecia
iall cl
clea
eani
ning
ng of th
thee fin
finis
ishe
hed
d it
item
em or sy
syst
stem
em ma
may
y be
necessary to attain the desired level of cleanness. If there is a
question
questio
n concer
concerning
ning the ef
effective
fectiveness
ness of cleanin
cleaning
g agents or
procedures, or the possible adverse effects of some cleaning
agents or procedures on the materials to be cleaned, trial runs
using test specimens and sensitive inspection techniques may
be desira
desirable.
ble. Descriptions,
Descriptions, processes, and precau
precautions
tions to be
obse
ob
serv
rved
ed in cl
clean
eanin
ing
g ar
aree gi
give
ven
n in th
thee Metals Hand
Handbook
book.4
Proprietary cleaners may contain harmful ingredients, such as
chlorides or sulfur compounds, which could adversely affect
the performance of a part, equipment, or system under service
Emulsion cleaning is used when rapid, superficial cleaning is
required and when a light residual film of oil is not objectionable.
6.2.3 Solvent Cleaning is a process for removing contaminants
nan
ts fro
from
m met
metal
al sur
surfac
faces
es by imm
immers
ersion
ion or by spr
sprayi
aying
ng or
swabbing with common organic solvents such as the aliphatic
petroleums, chlorinated hydrocarbons, or blends of these two
classes of solvents. Cleaning is usually performed at or slightly
above
abo
ve roo
room
m temp
temperat
erature
ure.. Exc
Except
ept for par
parts
ts with ext
extrem
remely
ely
heavy contamination or with hard-to-reach areas, or both, good
agitation will usually eliminate the need for prolonged soaking.
Virtually all metal can be cleaned with the commonly used
solvents unless the solvent has become contaminated with acid,
alkali, oil, or other foreign material. Chlorinated solvents are
not recommended for degreasing of closed systems or items
with crevices or internal voids.
6.2.4 V
Vapor
apor Degreasing is a ge
gene
neri
ricc te
term
rm ap
appl
plie
ied
d to a
cleaning process that employs hot vapors of a volatile chlorinated
nat
ed sol
solven
ventt to rem
remove
ove con
contami
taminan
nants,
ts, and is par
particu
ticular
larly
ly
effective against oils, waxes, and greases. The cleanness and
chemical stability of the degreasing solvent are critical factors
in the efficiency of the vapor and possible chemical attack of
the metal. Water in the degreasing tank or on the item being
cleaned may react with the solvent to form hydrochloric acid,
which is usually harmful to the metal. No water should be
present in the degreasing tank or on the item being cleaned.
Acids, oxidizing
oxidizing agents
agents,, and cyanides must be prevented from
contaminating the solvent. Materials such as silicones cause
foam
fo
amin
ing
g at th
thee liq
liqui
uidd-va
vapo
porr in
inter
terfa
face
ce an
and
d may re
resu
sult
lt in
recontamination of the workpiece as it is removed from the
degreaser. Vapor degreasing with chlorinated solvents is not
recommended for closed systems or items with internal voids
or crevic
crevices.
es.
6.2.5 Ultrasonic Cleaning is often used in conjunction with
certain solvent and detergent cleaners to loosen and remove
contaminants from deep recesses and other difficult to reach
areas,
are
as, par
particu
ticularl
larly
y in smal
smalll wor
work-p
k-piece
ieces.
s. Cavi
Cavitati
tation
on in the
liquid
liq
uid pro
produc
duced
ed by the hig
high
h fre
freque
quency
ncy sou
sound
nd cau
causes
ses micr
micro
o
agitation of the cleaner in even tiny recesses of the workpiece,
making the method especially desirable for cleaning parts or
assemblies
assemb
lies havin
having
g an intric
intricate
ate config
configuratio
uration.
n. For extremely
high levels of surface cleanness, high-purity solvents (1 ppm
total nonvolatile residue) are required.
condition
condit
ions.
s. It is reco
recomme
mmende
nded
d tha
thatt the man
manufa
ufactu
cturer
rer of the
cleaner be consulted if there is reason for concern.
NOTE 2—Instances are known where stainless steel vessels have stress
cracked
crack
ed be
befo
fore
re st
star
artt-up
up du
duee to st
stea
eami
ming
ng ou
outt or bo
boil
ilin
ing
g ou
outt wi
with
th a
chloride-containing detergent.
6.2 Cleanin
Cleaning
g Method
Methods—
s—Deg
Degrea
reasin
sing
g and gen
genera
erall clea
cleanin
ning
g
may be acc
accomp
omplis
lished
hed by imm
immers
ersion
ion in, swa
swabbi
bbing
ng wit
with,
h, or
spraying with alkaline, emulsion, solvent, detergent, chelate, or
acid cleaners or a combination of these; by vapor degreasing;
by ultrasonics using various cleaners; by various mechanical
methods
meth
ods;; by steam, with or with
without
out a clea
cleaner
ner;; or by hig
highhpressure water-jetting. The cleaning method available at any
given time during the fabrication or installation of a component
or system is a function of the geometric complexity of the item,
the type of contamination present, the degree of cleanliness
requir
req
uired,
ed, and cos
cost.
t. Met
Method
hodss com
common
monly
ly use
used
d for rem
removi
oving
ng
deposi
dep
osited
ted con
contami
taminan
nants
ts (as opp
oppose
osed
d to sca
scale)
le) are des
descri
cribed
bed
briefly
bri
efly below and in gre
greater
ater detail (includin
(including
g fac
factor
torss to be
considered
consid
ered in their selectio
selection
n and use) in the Metals Handbook4
and the SSPC Steel Structures Painting Handbook.5 The safety
precautions
precau
tions of 8.6 sh
shal
alll be ob
obse
serv
rved
ed in th
thee us
usee of th
thes
esee
methods
meth
ods.. Par
Particu
ticular
lar care sha
shall
ll be exe
exercis
rcised
ed whe
when
n clea
cleanin
ning
g
closed systems and items with crevices or internal voids to
prevent retention of cleaning solutions and residues.
6.2.1 Alkaline Cleanin
Cleaning
g is us
used
ed fo
forr th
thee re
remo
mova
vall of oi
oily
ly,,
semisol
semi
solid,
id, and sol
solid
id con
contami
taminan
nants
ts fro
from
m meta
metals.
ls. To a gre
great
at
extent the solutions used depend on their detergent qualities for
cleaning action and effectiveness.
effectiveness. Agitation and temperature of
the solution are important.
6.2.6 Synthetic Detergents are extensively used as surfaceactive agents because they are freer rinsing than soaps, aid in
soils dispersion, and prevent recontamination. They are effective for softening hard water and in lowering the surface and
interfacial
interf
acial tensions of the solutio
solutions.
ns. Synth
Synthetic
etic deter
detergents,
gents, in
5
Steell Struc
Structures
tures Painting Council, Vol
Vol 1, 1982,
Good Paint
Painting
ing Prac
Practices
tices,, Stee
Chapters 2.0–2.9, 3.1–3.2.
4
A380/A380M − 17
particu
ticular
lar,, sho
should
uld be che
checke
cked
d for the pre
presen
sence
ce of har
harmfu
mfull
par
ingredients as noted in 6.1
6.1..
6.2.7 Chelate Cleaning—Chelates are chemicals that form
soluble, complex molecules with certain metal ions, inactivating the ions in solution so they cannot normally react with
another element or ions to produce precipitates or scale. They
enhance the solubility of scales and certain other contaminants,
do not precipitate different scales when the cleaning solution
becomes spent, and can be used on some scales and contami-
shall not be permitted to dry between successive steps of the
acid cleaning
cleaning and rin
rinsin
sing
g pro
proced
cedure
ure.. Aci
Acid
d clea
cleanin
ning
g is not
recommended
recomm
ended where mechan
mechanical
ical cleanin
cleaning
g or other chemical
methods will suffice on the basis of intended use and, as may
be necessary, on inspection tests (see 7.2 and 7.3
7.3).
). Requirements for superfluous cleaning and inspection testing can result
in excessive costs. Acid cleaning, if not carefully controlled,
may damage the surface and may result in further contamination of the surface.
6.2.12 Rinsing—After cleaning with an aqueous chemical
cleanin
clea
ning
g sol
soluti
ution,
on, sur
surfac
faces
es sha
shall
ll be tho
thorou
roughl
ghly
y rin
rinsed
sed wit
with
h
clean
clea
n wat
water
er to rem
remove
ove all tra
traces
ces of res
residu
idual
al che
chemica
micals
ls and
thoroughly dried after the final water rinse. A neutralization
treatment may be necessary under some conditions (such as the
presen
pre
sence
ce of cre
crevice
vices).
s). If use
used,
d, neu
neutra
traliza
lizatio
tion
n is usu
usually
ally als
also
o
followed by rinsing with clean water to remove all traces of the
neutralizing agent and thorough drying. (See A2.10
A2.10.)
.)
nants
thatelating
even
acids
willcon
not
attack.
properly
used
use
d (ch
(chelat
ing mineral
agents
age
nts mus
must
t be
contin
tinuou
uously
sly When
circul
cir
culated
ated
and
must be maintain
maintained
ed within carefully controlled
controlled temper
temperature
ature
limits), intergranular attack, pitting, and other harmful effects
aree min
ar
minima
imal.
l. Ch
Chela
elatin
ting
g ag
agen
ents
ts ar
aree pa
part
rticu
icular
larly
ly us
usef
eful
ul fo
forr
cleaning installed equipment and systems.
6.2.8 M
Mechanica
echanicall Cleanin
Cleaning
g (al
(also
so see 5.3
5.3)) — Abrasive
blastin
blas
ting,
g, vap
vapor
or bla
blastin
sting
g usi
using
ng a fine abr
abrasi
asive
ve sus
suspen
pended
ded in
water
wa
ter,, gr
grin
indi
ding
ng,, or wi
wire
re br
brus
ushi
hing
ng ar
aree of
often
ten de
desi
sira
rabl
blee fo
forr
removing surface contaminants and rust. Cleanliness of abrasives and cleaning equipment is extremely important to prevent
recontamination of the surfaces being cleaned. Although surfaces may appear visually clean follo
following
wing such proce
procedures
dures,,
residual films which could prevent the formation of an optimum
mu
m pa
pass
ssiv
ivee co
cond
nditi
ition
on ma
may
y st
still
ill be pr
pres
esen
ent.
t. Su
Subs
bseq
eque
uent
nt
6.3 Cleaning of Welds and Weld-Joint Areas—
Areas—The joint area
and surrounding metal for several inches back from the joint
prepar
pre
paratio
ation,
n, on bot
both
h fac
faces
es of the weld, sho
should
uld be clea
cleaned
ned
immediately before starting to weld. Cleaning may be accomplis
pl
ishe
hed
d by br
brus
ushi
hing
ng wi
with
th a cle
clean
an sta
stain
inle
less
ss st
steel
eel br
brus
ush
h or
scrubbing with a clean, lint-free cloth moistened with solvent,
or both. When the joint has cooled after welding, remove all
treatment
treatm
ent suc
such
h as add
additio
itional
nal iro
iron-f
n-free
ree abr
abrasi
asive
ve cle
cleani
aning
ng
methods, acid cleaning, passivation, or combinations of these
is, therefore, required for stainless steel parts, equipment, and
systems to be used where corrosion
corrosion resistance
resistance is a prime factor
to sat
satisf
isfy
y per
perfor
forman
mance
ce and ser
servic
vicee req
requir
uireme
ements
nts,, or whe
where
re
product contamination must be avoided.
6.2.9 Steam Cleanin
used
d mos
mostly
tly for cleaning
cleaning bul
bulky
ky
Cleaning
g is use
objects
obj
ects that are too lar
large
ge for soak tan
tanks
ks or spr
sprayay-was
washin
hing
g
equi
eq
uipm
pmen
ent.
t. It ma
may
y be us
used
ed wi
with
th cle
clean
anin
ing
g ag
agen
ents
ts su
such
ch as
emulsions, solvents, alkalis, and detergents. Steam lances are
frequently
frequ
ently used for cleaning piping assemblies. Steam pressures from 345 to 515 kPa [50 to 75 psi] are usually adequate
(see 6.1
6.1).
).
6.2.10 Water-Jetting at water pressures of up to 70 MPa
[10 000 psi] is effective for removing grease, oils, chemical
accessible weld spatter
accessible
spatter,, weldin
welding
g flux, scale, arc strikes
strikes,, etc., by
grindi
gri
nding.
ng. Accordi
According
ng to the app
applica
lication
tion,, som
somee scal
scalee or hea
heatt
temper may be permissible on the nonprocess side of a weld,
but should be removed from the process side if possible. If
chemical cleaning of the process side of the weld is deemed
necessary, the precautions of this standard shall be observed.
Austenitic
Austen
itic stainle
stainless
ss steels in the sensitized condition should
generally not be descaled with nitric-hydrofluoric acid solutions. Welds may also be cleaned as described in Table A2.1,
A2.1,
Part III, Treatment
Treatment P and Q (also see 5.2.4 and 5.2.5
5.2.5).
).
deposits (except adsorbed chemicals), dirt, loose and moderately
ate
ly ad
adhe
here
rent
nt sc
scale
ale,, an
and
d ot
othe
herr co
cont
ntam
amin
inan
ants
ts th
that
at ar
aree no
nott
actua
act
ually
lly bo
bond
nded
ed to th
thee me
metal
tal.. Th
Thee me
meth
thod
od is pa
part
rtic
icul
ular
arly
ly
applicable for cleaning piping assemblies which can withstand
the high pressures involved;
involved; self-p
self-propell
ropelled
ed nozzles or “moles
“moles””
are generally used for this purpose.
6.2.11 Acid Cleaning is a process in which a solution of a
mineral or organic acid in water, sometimes in combination
with
wit
h a we
wetti
tting
ng ag
agen
entt or de
dete
terg
rgen
entt or bo
both
th,, is em
empl
ploy
oyed
ed to
remove
rem
ove iro
iron
n and oth
other
er met
metalli
allicc con
contam
taminat
ination
ion,, ligh
lightt oxi
oxide
de
films, shop soil, and similar contaminants. Suggested solutions,
contact times, and soluti
solution
on temperatures
temperatures for various alloys are
given in Annex A2.
A2. Acid cleaning is not generally effective for
removal of oils, greases, and waxes. Surfaces shall be precleaned to remove oils and greases before acid cleaning. (See
by a ho
hott-wa
water
ter ri
rins
nsee to re
remo
move
ve re
resid
sidua
uall ch
chem
emica
icals.
ls. Sp
Spot
ot
cleaning
cleanin
g to remov
removee localiz
localized
ed contamination
contamination may be accomplished by wiping with a clean, solvent-moistened cloth. If the
purchaser specifies passivation, the final cleaning shall be in
accordance with the requirements of T
Table
able A2.1
A2.1,, Part II, or one
of the treatments listed in Specification A967/A967M
A967/A967M.. Unless
specified by the purchaser, the chemical treatment applied to
the parts shall be selected by the supplier from among the listed
passivation treatments. When the stainless steel parts are to be
used
use
d for app
applica
lication
tionss whe
where
re cor
corros
rosion
ion res
resist
istanc
ancee is a pri
prime
me
factor
fac
tor to ach
achiev
ievee sat
satisf
isfact
actor
ory
y per
perfo
forma
rmance
nce and ser
servic
vicee
requ
re
quir
ireme
ement
nts,
s, or wh
where
ere pr
prod
oduct
uct co
cont
ntami
aminat
nation
ion mu
must
st be
avoide
avo
ided,
d, pas
passiv
sivatio
ation
n fol
follow
lowed
ed by tho
thorou
rough
gh rin
rinsin
sing
g sev
severa
erall
times with hot water and drying thoroughly after the final water
rinse is recommended, whenever practical.
A2.10.) Common techniques for acid cleaning are immersion,
A2.10.
swabbi
swa
bbing,
ng, and spr
sprayi
aying.
ng. Max
Maximu
imum
m sur
surfac
facee qua
quality
lity is bes
bestt
achieved by using a minimum cleaning time at a given acid
concentration and temperature. To minimize staining, surfaces
6.5 Precision Cleaning—Certain nuclear, space, and other
especially
especia
lly cri
critica
ticall app
applica
licatio
tions
ns may req
requir
uiree that onl
only
y ver
very
y
high-p
hig
h-puri
urity
ty alco
alcohol
hols,
s, acet
acetone
one,, ket
ketone
ones,
s, or oth
other
er precision
used
d for final clea
cleanin
ning
g or recl
reclean
eaning
ing of
cleaning
cleani
ng agents be use
6.4 Final Cleaning or Passivation, or Both—If proper care
hass be
ha
been
en tak
taken
en in ear
earlie
lierr fa
fabr
brica
icatio
tion
n an
and
d cle
clean
anin
ing,
g, fin
final
al
cleaning may consist of little more than scrubbing with hot
water or hot water and detergent (such as trisodium phosphate,
TSP), using fiber brushes. Detergent washing shall be followed
5
A380/A380M − 17
critical
ical sur
surfac
faces
es aft
after
er fab
fabric
ricatio
ation
n adv
advanc
ances
es to the poi
point
nt tha
thatt
crit
internal crevices, undrainable spaces, blind holes, or surfaces
that are not acce
accessi
ssible
ble for tho
thorou
rough
gh scr
scrubb
ubbing
ing,, rin
rinsin
sing,
g, and
inspection are formed. Such items are often assembled under
clean-room conditions (see 8.5.5
8.5.5)) and require approval, by the
purchaser, of carefully prepared cleaning procedures before the
start of fabrication.
6.6.4 When cleaning critical
critical installed systems, do not permit the process surfaces to dry between successive cleaning
and rinsing steps, or between the final rinse and filling with the
layup solution.
7. Inspe
Inspectio
ction
n After Cleaning
Cleaning
7.1 General— Ins
Inspecti
pection
on tech
techniqu
niques
es shou
should
ld repr
represen
esentt
careful, considered review of end use requirements of parts,
equi
eq
uipm
pmen
ent,
t, an
and
d sy
syst
stems
ems.. Th
Ther
eree is no su
subs
bstit
titut
utee fo
forr go
good
od,,
unifor
uni
form,
m, clea
cleanin
ning
g pra
practic
ctices
es whi
which
ch yie
yield
ld a meta
metallur
llurgic
gically
ally
sound and smooth surface, followed by adequ
adequate
ate prote
protection
ction to
preserve that condition. Establishment of the most reliable tests
and test sta
standa
ndards
rds for clea
cleanne
nness
ss are hel
helpfu
pfull in atta
attaini
ining
ng the
desired performance of parts, equipment, and systems. Testing
should be sufficiently extensive to ensure the cleanness of all
surf
su
rfac
aces
es ex
expo
posed
sed to pr
proc
oces
esss flu
fluid
idss wh
when
en in se
serv
rvice
ice.. Th
Thee
follow
fol
lowing
ing rep
repres
resent
ent som
somee test
testss tha
thatt hav
havee bee
been
n suc
succes
cessfu
sfully
lly
applied to stainless steels. The purchaser shall have the option
of spe
specif
cifyin
ying
g in his purchase
purchase doc
docume
uments
nts that any of thes
thesee
quality assurance tests be used as the basis for acceptability of
the cleanness of the stainless steel item, the absence of iron on
the surface, or both.
6.6 Clea
Cleaning
ning of Ins
Install
talled
ed Sys
Systems
tems—
—Th
Ther
eree ar
aree tw
two
o ap
ap-proaches to cleaning installed systems. In the first, which is
probably adequate for most applications, cleaning solutions are
circulated through the completed system after erection, taking
care to remove or protect items that could be damaged during
the cleaning operation. In the second approach, which may be
required for gaseous or liquid oxygen, liquid metal, or other
reactive-process solutions, piping and components are installed
in a manner to avoid or minimize contamination of processsolu
so
lutio
tion
n su
surf
rfac
aces
es du
duri
ring
ng er
erect
ectio
ion
n so th
that
at lit
little
tle ad
addi
ditio
tiona
nall
cleaning is necessary after erection; post-erection flushing, if
necessary, is done with the process fluid. If process surfaces are
coated with an appreciable amount of iron oxide, a chelating
treatmentt or hightreatmen
high-pressu
pressure
re water
water-jettin
-jetting
g treatme
treatment
nt shou
should
ld be
considered in place of acid treatment (see 6.2.7 aand
nd 6.2.10
6.2.10).
).
6.6.1 Post-Erection Cleaning—Circula
Circulate
te hot water to which
a detergent has been added, for at least 4 to 8 h. A water
temperature of at least 60 to 70°C [140 to 160°F] is recommended (see 6.1
6.1).
). Rinse by circulating clean hot water until the
effluent is clear. If excessive particulate matter is present, the
cleaning cycle may be preceded with a high-pressure steam
blow, repeating as necessary until a polished-aluminum target
on the outlet of the system is no longer dulled and scratched by
particulates loosened by the high-velocity steam. Valves and
similar items must be protected from damage during a steam
blow.
6.6.
6.
6.2
2 If me
metal
tallic
lic ir
iron
on is de
detec
tected
ted by on
onee of th
thee me
meth
thod
odss
suggested in Section 7
7,, it can be removed by circulating one of
the acid passivation solutions
solutions sugg
suggested
ested in 6.4 until laboratory
determination for iron, made on samples of the solution taken
hourly, indicates no further increase in iron content, after which
7.2.1 Visual—Items cleaned in accordance with this practice
should
shou
ld be fr
free
ee of pa
pain
int,
t, oi
oil,
l, gr
grea
ease
se,, we
weld
ldin
ing
g flu
flux,
x, sl
slag
ag,,
heat-tr
hea
t-treati
eating
ng and hot
hot-fo
-formi
rming
ng sca
scale
le (ti
(tight
ghtly
ly adh
adhere
erent
nt sca
scale
le
resulting
result
ing from weldin
welding
g may be permissible on some surfaces),
surfaces),
dirt, trash, metal and abrasive particles and chips, and other
gross contamination.
contamination. Some depo
deposited
sited atmospheric dust will
normal
nor
mally
ly be pre
presen
sentt on ext
exterio
eriorr sur
surfac
faces
es but sho
should
uld not be
present on interior surfaces. Visual inspection should be carried
out under a lighting level, including both general and supplementary lighting, of at least 1080 lx [100 footcandles], and
prefer
pre
ferabl
ably
y 270
2700
0 lx [25
[250
0 foo
footcan
tcandle
dles]
s] on the sur
surfac
faces
es bei
being
ng
inspec
ins
pected
ted.. Visu
isual
al ins
inspec
pectio
tion
n sho
should
uld be sup
supple
plemen
mented
ted wit
with
h
borescopes, mirrors, and other aids, as necessary, to properly
examine inaccessible or difficult-to-see surfaces. Lights should
be positioned to prevent glare on the surfaces being inspected.
circulation may be stopped and the system drained. After this
treatment, circulate clean hot water (that is, without detergent)
through the system for 4 h to remove all traces of acid and
corrosion product resulting from the acid treatment, or until the
pH of the rinse water returns to neutral.
6.6.3 In critical systems where
where post-erection
post-erection cleaning is not
desir
de
sirab
able
le (f
(for
or ex
exam
ampl
ple,
e, li
liqu
quid
id ox
oxyg
ygen
en or nu
nucl
clear
ear re
react
actor
or
primary coolant systems), on-site erection may be conducted
under clean-room conditions. Erection instructions may require
that wrapping and seals of incoming materials and equipment
be kept intact until the item is inside the clean area, and that
careful surveillance be exercised to prevent foreign materials
(for example, cleaning swabs or tools) from being dropped or
leftt in th
lef
thee sy
syst
stem.
em. Wh
Wher
eree co
cont
ntam
amin
inati
ation
on do
does
es oc
occu
curr, th
thee
cleaning procedure usually is developed through consultation
7.2.1.1 Gro
Gross
ss Indic
Indication
ationss of Iro
Iron—
n—When iron contam
contaminaination is clearly visible, items should be cleaned in accordance
with this practice.
7.2.2 Wipe Tests—Rubbing of a surface with a clean, lintfree, white cotton cloth, commercial paper product, or filter
paper moistened (but not saturated) with high-purity solvent
(see 6.5
6.5),
), may be used for evaluating the cleanness of surfaces
not accessible for direct visual inspection. Wipe tests of small
diameter tubing are made by blowing a clean white felt plug,
slightly larger in diameter than the inside diameter of the tube,
throug
thr
ough
h the tub
tubee with clea
clean,
n, dry
dry,, filte
filtered
red com
compre
presse
ssed
d air
air..
Cleanness in wipe tests is evaluated by the type of contamination rubbed off on the swab or plug. The presence of a smudge
on the cloth is evidence of contamination. In cases of dispute
concerning the harmful nature of the contamination, a sample
between the erector and the purchaser (or his site representative). Frequently,
Frequently, postpost-erectio
erection
n flushin
flushing
g is accomp
accomplished
lished by
circulating the process fluid through the system until contamination is reduced to tolerable levels.
of the smudg
smudgee may be transferred
transferred to a clean quart
quartzz microscope
slide for infrared analysis. The wipe test is sometimes supplemented
men
ted by rep
repeati
eating
ng the test with a blac
black
k clot
cloth
h to dis
disclos
closee
contaminants that would be invisible on a white cloth.
7.2 Gross Inspection:
6
A380/A380M − 17
Residua
iduall Patter
Pattern—
n—Dr
Dry
y th
thee cl
clea
eane
ned
d su
surf
rfac
acee af
afte
terr
7.2.3 Res
finish-cleaning at 50°C [120°F] for 20 min. The presence of
stain
sta
inss or wa
water
ter sp
spot
otss on th
thee dr
dried
ied su
surf
rface
acess in
indi
dicat
cates
es th
thee
presence of residual soil and incomplete cleaning. The test is
rapid but not very sensitive.
7.2.4 W
Water-Break
ater-Break Test— This is a test for the presence of
hydrophobic contaminants on a cleaned surface. It is applicable
only for items that can be dipped in water and should be made
with high-purity water. The test procedure and interpretation of
copper
copp
er su
sulfa
lfate
te in th
thee fo
follo
llowi
wing
ng pr
prop
opor
ortio
tions
ns (Warning—
Always add acid to cold water.):
Distilled water
95–100 % Sulfuric acid (H2SO4)
Copper sulfate pentahydrate (CuSO4·5H2O)
7.3 Precision Inspection:
7.3.1 Solvent-Ring Test is a test to reveal the presence of
tightly adherent transparent films that may not be revealed by
visual
vis
ual ins
inspec
pection
tion or wip
wipee test
tests.
s. A com
compar
pariso
ison
n stan
standar
dard
d is
prepared by placing on a clean quartz microscope slide a single
drop of high-purity solvent and allowing it to evaporate. Next
place another drop on the surface to be evaluated, stir briefly,
and transfer, using a clean capillary or glass rod, to a clean
quartz microscope slide and allow the drop to evaporate. Make
as many test slides as necessary to give a reasonable sample of
thee su
th
surf
rface
ace be
bein
ing
g ex
exam
amin
ined
ed.. If fo
fore
reig
ign
n ma
mate
teria
riall ha
hass be
been
en
dissolved by the solvent, a distinct ring will be formed on the
outer
ou
ter edge of th
thee dr
drop
op as it ev
evap
apor
orat
ates.
es. The na
natu
ture
re of th
thee
contaminant can be determined by infrared analysis, comparing the infrared analysis with that of the standard.
7.3.2 Bl
Black
ack Lig
Light
ht Ins
Inspec
pectio
tion
n is a te
test
st su
suit
itab
able
le for th
thee
detection of certain oil films and other transparent films that are
not detectable under white light. In an area that is blacked out
to white light, inspect all visible accessible surfaces with the
aid of a new
new,, floo
flood-t
d-type
ype,, ult
ultrav
raviol
iolet
et lamp
lamp.. For inac
inacces
cessib
sible
le
areas, use a wipe test as described in 7.2.2 and subject the used
cloth or plug to ultraviolet lamp inspection in a blacked-out
area. Fluorescence of the surface, cloth, or plug indicates the
presence of contaminants. The nature of the contamination can
be determined by subjecting a sample of the contaminant, that
has been tra
transf
nsferr
erred
ed to a clea
clean
n qua
quartz
rtz micr
microsc
oscope
ope slide, to
infrared
infrar
ed analys
analysis.
is. The test will not detect straig
straight-ch
ht-chain
ain hydrocarbons such as mineral oils.
7.3.3 Atomizer Test is a test for the presence of hydrophobic
films. It is applicable to both small and large surfaces that are
accessi
acce
ssible
ble for dir
direct
ect vis
visual
ual exa
examin
minatio
ation,
n, and is abo
about
ut 100
100×
×
more sensitive than the water-break test. The test procedure
and interpretation of results are described in Test Method F21
F21..
High-purity water should be used for the test.
7.3.4 Ferroxyl Test for Free Iron is a hypersensitive
hypersensitive test and
should be used only when even traces of free iron or iron oxide
might be objectionable. The test can be used on stainless steel
to detect iron contamination from sources including, but not
limited to, ironiron-tool
tool marks, residu
residual-iro
al-iron
n salts from picklin
pickling
g
soluti
sol
utions
ons,, iro
iron
n dus
dust,
t, atmo
atmosph
spheric
eric exp
exposu
osure,
re, iro
iron
n dep
deposi
osits
ts in
welds,
wel
ds, embedded
embedded iro
iron
n and iron oxi
oxide.
de. The tes
testt sol
soluti
ution
on is
prepared by first adding nitric acid to distilled water and then
adding potassium ferricyanide, in the following proportions:
results
are described
in Test Method F22
F22.. The test is moderately sensiti
sensitive.
ve.
7.2.5 Tests for Free Iron:
7.2.5.1 Water-Wetting and Drying— Formation of rust stains
may be accelerated by periodically wetting the surface with
preferably distilled or deionized water or clean, fresh, potable
tap water. Application via a hand held sprayer or atomizer that
produces small droplets that do not coalesce is optimal. The
sampl
sam
plee sh
shou
ould
ld be re
rewe
wett as ne
need
eded
ed bu
butt all
allow
owed
ed to ai
airr dr
dry
y
comp
co
mple
letel
tely
y at lea
least
st 8 tim
times
es,, re
remai
maini
ning
ng dr
dry
y fo
forr at lea
least
st 45
minutes each, and totaling 7 to 9 h in a 24-h test period. After
completion
comple
tion of this test, the surface should show no eviden
evidence
ce of
rust stains or other corrosion products.
7.2.5.2 High-Humidity Test—Su
Subj
bjec
ectt th
thee su
surf
rfac
acee to 95 to
100 % humidity at 40 to 45°C [100 to 115°F] in a suitable
humidity cabinet for 24 to 26 h. After completion of this test,
the surface should show no evidence of rust stains or other
corrosion products.
7.2.5.3 Copper Sulfate Test—This highly sensitive method
is recommended for the detection of metallic iron or iron oxide
on the surface of austenitic 200 and 300 Series, duplex, the
precip
pre
cipitat
itation
ion har
harden
dening
ing allo
alloys,
ys, and the fer
ferriti
riticc 400 Ser
Series
ies
stainless steels containing 16 % chromium or more. It is not
recommended for the martensitic and lower chromium ferritic
stainless steels of the 400 Series since the test may show a
positive reaction on these materials irrespective of the presence
or absence of anodi
anodicc surfa
surface
ce contam
contaminants
inants.. The test solution is
prepared by first adding sulfuric acid to distilled water and then
dissol
dis
solvin
ving
g cop
copper
per sul
sulfat
fatee in the fol
follow
lowing
ing pro
propor
portio
tions
ns
(Warning—
Warning—Always
Always add acid to cold water.):
Distilled water
95–100 % Sulfuric acid (H2SO4)
Copper sulfate pentahydrate (CuSO4·5H2O)
90 mL
5.4 mL
4g
250 mL
1 mL
4g
Appl
Ap
ply
y th
thee tes
testt so
solu
lutio
tion
n to th
thee su
surf
rfac
acee to be in
insp
spect
ected
ed,,
applying additional solution if needed to keep the surface wet
for a period of 6 min. The specimen shall be rinsed and dried
in a manner not to remove any deposited copper. A copper
deposit indicates the presence of free iron.
7.2.5.4 Martensitic Grade Adherent Copper Sulfate Test—
The copper sulfate test as set forth in 7.2.5.3 is not applicable
to surgical and dental instruments made of hardened martensitic stainless steels. Instead,
Instead, a specia
specialized
lized copper sulfate test is
extensi
exte
nsivel
vely
y use
used
d for the pur
purpos
posee of det
detecti
ecting
ng fre
freee iro
iron
n and
determining overall good manufacturing practice. Copper deposi
po
sits
ts on th
thee su
surf
rfac
acee of su
such
ch in
inst
stru
rume
ment
ntss ar
aree wi
wipe
ped
d wi
with
th
Distilled water
Nitric acid (60–67 %)
Potassium ferricyanide
94 weight %
3 weight %
3 weight %
1000 mL
20 mL
30 g
[1 gal]
[0.2 pt]
[4 oz]
The test solution shall be mixed fresh the day the tests are
made since it changes color on standing. Apply solution with
an aluminum, plastic, glass, or rubber atomizer having no iron
or steel parts, or a swab (atomizer spray is preferred).
modera
mode
rate
te vi
vigo
gorr to de
dete
term
rmin
inee if th
thee co
copp
pper
er is ad
adhe
here
rent
nt or
nonadherent. Instruments with nonadherent copper are considered acceptable. The specialized test solution is prepared by
first adding sulfuric acid to distilled water and then dissolving
7.3.
7.
3.4.
4.1
1 Th
Thee ap
appe
pear
aran
ance
ce of a bl
blue
ue st
stai
ain
n wi
with
thin
in 15 s of
application is evidence of surface iron contamination. Several
minute
min
utess may be req
requir
uired
ed for detection
detection of oxi
oxide
de scal
scale.
e. The
soluti
sol
ution
on sho
should
uld be rem
remove
oved
d fro
from
m the sur
surfac
facee as qui
quickly
ckly as
7
A380/A380M − 17
possible after testing using water or, if necessary, white vinegar
or a solution of 5 to 20 weight % acetic acid and scrubbing
with a fiber brush. Flush the surface with water several times
after use of vinegar or acetic acid.
sludge in the bottom of cleaning tanks; the formation of oil,
scums,
scu
ms, and und
undiss
issolv
olved
ed mat
matter
ter on liq
liquid
uid sur
surfac
faces;
es; and hig
high
h
concentrations of emulsified oil, metal or chemical ions, and
suspended solids in the liquids. Periodic cleaning of vats and
degreasing
degre
asing tanks
tanks,, decanti
decanting,
ng, period
periodic
ic bottom
bottom-drain
-drain,, agitatio
agitation
n
of solutions, and similar provisions are essential to maintain
the effectiveness of solutions. Care must be taken to prevent
water contamination
contamination of trichlo
trichloroethy
roethylene
lene and other halogenated solvents, both while in storage and in use. Redistillation
NOTE 3—Potassium ferricyanide is not a dangerous poison as are the
simple cyanides. However, when heated to decomposition or in contact
with concentrated acid, it emits highly toxic cyanide fumes.
NOTE 4—Ru
4—Rubber
bber gloves, clothing,
clothing, and face shield
shieldss shoul
should
d be worn
when applying the test solut
solution,
ion, and inhala
inhalation
tion of the atomized spray
should
shoul
d be avoid
avoided.
ed.
NOTE 5—The test is not recommended for process-surfaces of equipment that will be used for processing food, beverages, pharmaceuticals, or
other products for human consumption unless all traces of the test solution
can be thoro
thoroughly
ughly removed.
and
filterin
filte
ring
g of reuse.
solven
sol
vents
ts and vap
vapor
or-de
-degre
greasin
asing
g to
agents
age
nts are
necessary
before
Makeup
is often
required
maintain
concentrations and pH of cleaning solutions at effective levels.
Do not ove
overus
rusee che
chemica
micall clea
cleaner
ners,
s, par
particu
ticular
larly
ly acid
acidss and
vapor-degreasing solvents; if light films or oily residues remain
on th
thee me
metal
tal su
surf
rfac
aces
es af
after
ter us
usee of su
such
ch ag
agen
ents,
ts, ad
addi
ditio
tiona
nall
scrubbing with hot water and detergent, followed by repeated
rinsing with large quantities of hot water, may be necessary.
8. Pre
Precaut
cautions
ions
8.1 Minimizing Iron Contamination— Iron contamination on
stainless steel parts, components, and systems is almost always
confi
co
nfine
ned
d to th
thee su
surf
rfac
ace.
e. If re
reas
ason
onab
able
le ca
care
re is ta
take
ken
n in
fabrication, simple inexpensive cleaning procedures may suffice for its removal, and very little special cleaning should be
required.
requir
ed. Fabrication
Fabrication should be confin
confined
ed to an area where only
the one grade of mate
material
rial is bei
being
ng wor
worked
ked.. Pow
Powder
der cutting
cutting
should be minimized or prohibited. Handling equipment such
as slings, hooks, and lift-truck forks should be protected with
8.3 Rinse Water—Ordinary industrial or potable waters are
usually suitable for most metal-cleaning applications. Biologically tested potable water should be used for final rinsing of
food-handling, pharmaceutical, dairy, potable-water, and other
sanitar
san
itary
y equ
equipm
ipment
ent and sys
systems
tems.. Rin
Rinsin
sing
g and flus
flushin
hing
g of
critica
cri
ticall com
compon
ponent
entss and sys
systems
tems aft
after
er fini
finishsh-clea
cleanin
ning
g oft
often
en
requires
requi
res highhigh-purity
purity deionized water, having strict controls on
clean wood, cloth, or plastic buffers to reduce contact with the
iron surfa
surfaces.
ces. Walking on corro
corrosion-r
sion-resistan
esistantt alloy surfa
surfaces
ces
should be avoided; where unavoidable, personnel should wear
clean shoe covers each time they enter. Kraft paper, blotting
paper
pap
er,, pap
paperb
erboar
oard,
d, flan
flannel
nel,, vin
vinylyl-bac
backed
ked adh
adhesi
esive
ve tape or
paper, or other protective material should be laid over areas
where personnel are required to walk. Shearing tables, press
breaks
bre
aks,, lay
layout
out stan
stands,
ds, and oth
other
er car
carbon
bon-st
-steel
eel wor
work
k sur
surfac
faces
es
should be covered with clean kraft paper, cardboard, or blotting
paper to reduce the amount of contact with the carbon steel.
Hand
Ha
nd to
tool
ols,
s, br
brus
ushe
hes,
s, mo
mold
ldin
ing
g to
tool
ols,
s, an
and
d ot
othe
herr to
tool
olss an
and
d
supplies
suppl
ies requir
required
ed for fabrication should be segreg
segregated
ated from
similar items used in the fabrication of carbon steel equipment,
and should be restricted to use on the one material; tools and
supplies used with other materials should not be brought into
halide content, pH, resistivity, turbidity, and nonvolatile residues. Analytical
Analytical methods that may be used for establishing
establishing the
puri
pu
rity
ty of ri
rins
nsee wa
wate
terr sh
shou
ould
ld be de
demo
mons
nstr
trate
ated
d to ha
have
ve th
thee
sensitivity
sensiti
vity necessary to detect specified impurity
impurity levels; the
analy
an
alytic
tical
al met
metho
hods
ds gi
give
ven
n in th
thee An
Annu
nual
al Bo
Book
ok of AS
ASTM
TM
Standards, Vol 03.05, are recommended for referee purposes in
casee of dis
cas
disput
pute.
e. To min
minimi
imize
ze the use of cos
costly
tly hig
high-p
h-puri
urity
ty
water, preliminary rinses can often be made with somewhat
lesser quality water, followed by final rinsing with the highpurity water. It is also possible in many cases to use effluent or
overflow
overfl
ow from the final rinse operation
operation for preliminary
preliminary rinsin
rinsing
g
of other items.
the fab
fabric
ricatio
ation
n area
area.. Tool
oolss and fixtures
fixtures sho
should
uld be mad
madee of
hardened tool steel or chrome-plated steel. Wire brushes should
be stainless steel, or of an alloy composition similar to the steel
being cleaned, and should not have been previously used on
other materials. Only new, washed sand that is free of iron
particles should be used for casting.
high-velocity
high-veloci
ty,, turbu
turbulent
lent flow of cleanin
cleaning
g soluti
solutions
ons and rinse
water may be necessary to provide the scrubbing action needed
for effective cleaning and rinsing. The velocity required is a
function of the degree of cleanness required and the size of
particles that are permissible in the system after the start of
operation. For example, if particles between 500 and 1000 µm
[0.002 and 0.004 in.] are acceptable to remain, a mean flushing
velocity of 0.3 to 0.6 m/s [1 to 2 ft/s] may be sufficient for pipe
diameters of DN 50 [NPS 2] and smaller; to remove 100 to
200 µm [0.004 to 0.008 in.] particles, a mean flushing velocity
of 0.9 to 1.2 m/s [3 to 4 ft/s] may be required.
8.4 Circulation of Cleaning Solutions and Rinse Water—For
restricted internal surfaces (for example, small diameter piping
syst
sy
stem
emss or th
thee sh
shel
elll or tu
tube
be si
side
de of a he
heat
at ex
exch
chan
ange
ger)
r),,
8.2 Reu
Reuse
se of Clea
Cleanin
ning
g and Pick
Pickling
ling Sol
Soluti
utions
ons—
—Cleaning
and pickling agents are weakened and contaminated by materials and soil being removed
removed from surfaces as they are cleaned.
Solutions
Solutio
ns may become spent or deplet
depleted
ed in concen
concentratio
tration
n after
extended use, and it is necessary to check concentrations and to
replace or replenish solutions when cleaning or pickling action
slows. A1.2 and A2.6 give limits for iron content in descaling
and passivation solutions respectively. It may be impractical or
uneconomical to discard solutions after a single use, even in
8.5 Pr
Protectio
otection
n of Cleaned Surfaces—Measu
Measures
res to prote
protect
ct
cleaned surfaces should be taken as soon as final cleaning is
completed,
comple
ted, and shoul
should
d be maintained during all subseq
subsequent
uent
fabrication,
fabric
ation, shipp
shipping,
ing, inspec
inspection,
tion, storag
storage,
e, and install
installation.
ation.
8.5.1
8.5
.1 Do not remove
remove wra
wrappi
ppings
ngs and seal
sealss fro
from
m inc
incomi
oming
ng
materials and components until they are at the use site, ready to
be used or installed. If wrappings and seals must be disturbed
for receiving inspection, do not damage them, remove no more
precision cleanin
precision
cleaning
g operat
operations
ions (that is, finish
finish-cleani
-cleaning
ng using
very high-purity solvents and carried out under clean-room and
rigidly controlled environmental conditions). When solutions
are re-used, care shall be taken to prevent the accumulation of
8
A380/A380M − 17
than necessar
y to car
carry
ry out the ins
inspec
pection
tion,, and rewrap
rewrap and
necessary
reseal as soon as the inspection is complete. For critical items
that were cleaned by the supplier, and that will not be given
furt
fu
rthe
herr cle
clean
anin
ing
g at th
thee us
usee sit
sitee or af
afte
terr in
inst
stall
allat
atio
ion,
n, th
thee
condition of seals and wrappings should be inspected regularly
and at fairly short intervals while the item is in storage.
8.5.2 Finish
Finish-cleane
-cleaned
d materia
materials
ls and components
components shou
should
ld not
be stored directly on the ground or floor, and should not be
permitt
per
mitted,
ed, ins
insofa
ofarr as pra
practic
cticabl
able,
e, to com
comee in con
contact
tact with
8.5.7 Instal
Installed
led piping systems
systems are often laid up wet, that is,
they ar
they
aree fill
filled
ed wi
with
th wa
water
ter (o
(orr pr
proc
oces
esss flu
fluid
id)) af
after
ter in
in-p
-pla
lace
ce
cleanin
clea
ning
g unt
until
il rea
ready
dy to be plac
placed
ed in ser
servic
vice.
e. Sto
Storag
ragee wat
water
er
should be of the same quality as the makeup water for the
system, and should be introduced in a manner that it directly
replaces the final flush water without permitting the internal
surfaces of the system to dry.
8.5.8
8.5
.8 Equ
Equipm
ipment
ent and asse
assembl
mblies
ies for cri
critica
ticall app
applica
licatio
tions
ns
may be sto
stored
red and shi
shippe
pped
d wit
with
h pre
pressu
ssuriz
rized,
ed, dry
dry,, filte
filtered
red,,
asphalt,
galvanized
or carbon
mercury,
zinc,
lead,
low-me
low
-meltin
lting
g poi
point
nt meta
metals,
ls, orsteel,
alloys
allo
ys
or com
compou
pounds
nds
ofbrass,
such
suc
h
materials. Acid cleaning of surfaces that have been in contact
with such materials may be necessary to prevent failure of the
item when subsequently heated. The use of carbon or galvanized steel wire for bundling and galvanized steel identification
tags should be avoided.
8.5.3 Store materials
materials and equip
equipment,
ment, when in process, on
wood
wo
od sk
skid
idss or pa
palle
llets
ts or on met
metal
al su
surf
rface
acess th
that
at ha
have
ve be
been
en
protected to prevent direct contact with stainless steel surfaces.
Keep openings of hollow items (pipe, tubing, valves, tanks,
pumps, pressure vessels, and so forth) capped or sealed at all
times except when they must be open to do work on the item,
using polyethylene,
polyethylene, nylon
nylon,, TFE-fl
TFE-fluoro
uorocarbon
carbon plastic, or stainless steel cap
caps,
s, plu
plugs,
gs, or seal
seals.
s. Whe
Where
re clea
cleanne
nness
ss of ext
exteri
erior
or
oil-fr
oil-free
ee nitrogen
prevent
preve
corrosion
they are ready
to be
installed.
Means to
shall
bent
provided
foruntil
maintaining
and monitoring the gas press
pressure
ure during shipping
shipping and storag
storage.
e. If the item
is to be shipped to or through mountains or other areas where
the altitude varies greatly from that where it was pressurized,
consideration must be given to the effect of that change in
altitudee on the pressure inside
altitud
inside the item, and possible rupture or
loss of seals.
8.5.9
8.5
.9 Pre
Pressu
ssurere-sen
sensit
sitive
ive tap
tapee is oft
often
en use
used
d for seal
sealing
ing or
protec
pro
tectiv
tivee cov
covers
ers,, sea
seals,
ls, cap
caps,
s, plu
plugs,
gs, and wra
wrapp
pping
ings.
s. If
possible, the gummed surface of the tape should not come in
contact with stainless steel surfaces. If tape has come in contact
with the metal, clean it with solvent or hot water, and vigorous
scrubbing.
8.5.10
8.5.1
0 Protec
Protective
tive adhesive papers
papers or plastic
plasticss are often used
to protect the finish of sheet stock and parts. These materials
may
ma
y ha
hard
rden
en or de
deter
terio
iora
rate
te wh
when
en su
subj
bject
ected
ed to pr
pres
essu
sure
re or
sunlight, and damage the surface. These materials may also
decompose in time to form substances as described in 8.5.3
8.5.3..
Protect
Pro
tective
ive mat
materia
eriall sho
should
uld be rem
remove
oved
d whe
when
n its fun
functio
ction
n is
comple
com
plete
te or its con
condit
dition
ion mon
monitor
itored
ed for dec
decomp
omposi
ositio
tion
n or
deterioration until it is removed.
surface
surf
acess is im
impo
port
rtan
ant,
t, ke
keep
ep th
thee ite
item
m wr
wrap
appe
ped
d wi
with
th cl
clear
ear
polyet
pol
yethyl
hylene
ene or TFETFE-fluo
fluoroc
rocarb
arbon
on pla
plastic
stic she
sheet
et at all time
timess
except
exc
ept whe
when
n it is actu
actually
ally being wor
worked
ked on. Avoi
Avoid
d asp
asphal
halttcontaining materials. Canvas, adhesive paper or plastics such
as po
poly
ly(v
(vin
inyl
yl ch
chlo
lori
ride
de)) may de
deco
comp
mpos
osee in tim
timee to fo
form
rm
corrosive substances, for example, when exposed to sunlight or
ultra
ul
travi
viol
olet
et lig
light
ht.. Th
Thee re
reus
usee of ca
caps
ps,, pl
plug
ugs,
s, or pa
pack
ckag
agin
ing
g
material
mate
rialss sho
should
uld be avo
avoide
ided
d unl
unless
ess the
they
y hav
havee bee
been
n clea
cleaned
ned
prior to reuse.
8.5.
8.
5.4
4 Cle
Clean
an st
stain
ainles
lesss ste
steel
el wi
wire
re br
brus
ushe
hess an
and
d ha
hand
nd to
tool
olss
before reuse on corrosion-resistant materials; if they have not
been cleaned and if they could have been used on electrolytically different
different materials, the surf
surfaces
aces contacted by the tools
should be acid-cleaned. The use of soft-face hammers or terne
(lead)-coated, galvanized, or unprotected carbon steel tables,
8.6 Safety—Clea
Cleanin
ning
g ope
operat
ration
ionss oft
often
en pre
presen
sentt num
numero
erous
us
hazards to both personnel and facilities. [Material] Safety Data
Sheets
She
ets (MS
(MSDS/
DS/SDS
SDS)) sho
should
uld be con
consul
sulted
ted to dete
determi
rmine
ne the
hazards of handling specific chemicals.
8.6.1
8.6
.1 Precau
Precautio
tions
ns sha
shall
ll be tak
taken
en to pro
protec
tectt per
person
sonnel
nel,,
equipment,
equip
ment, and faciliti
facilities.
es. This includ
includes
es prov
provisions
isions for ventin
venting
g
of explosive or toxic reaction-product gases, safe disposal of
used solutions,
solutions, prov
provision
ision of barrie
barriers
rs and warnin
warning
g signs
signs,, prov
provii-
jigs, racks, slings, or fixtures should be avoided (see 8.5.2
8.5.2).
).
8.5.
8.
5.5
5 If clo
close
se co
cont
ntro
roll of pa
part
rticu
iculat
latee co
conta
ntamin
minati
ation
on is
required, particularly of internal surfaces, the latter stages of
assembly and fabrication may have to be carried out in a clean
room. For most large items, an air cleanliness class (see ISO
14644-1 and ISO 14644-2) at the work surface of Class 8 (that
is, a maximum of 3 520 000 per m 3 [100 000 per ft 3] particl
particles
es
0.5 µm [20 µin.] or larger suspended in the air) is probably
sufficient.
sions for saf
sions
safee tran
transfe
sferr of dan
danger
gerous
ous che
chemic
micals,
als, and main
maintetenance of constant vigilance for hazards and leaks during the
cleaning operation.
8.6.2
8.6
.2 The physica
physicall cap
capabi
ability
lity of the item or sys
system
tem to be
cleaned, together with its foundations, to withstand the loads
produced by the additional weight of fluids used in the cleaning
operati
ope
ration,
on, sha
shall
ll be est
establ
ablish
ished
ed bef
before
ore the star
startt of clea
cleanin
ning
g
operations.
8.6.3 Insof
Insofar
ar as possib
possible,
le, chemicals having explosive,
explosive, toxic,
or obnoxious fumes should be handled out of doors.
8.6.4
8.6
.4 The area in whi
which
ch the cleaning
cleaning ope
operati
ration
on is bein
being
g
conducted should be kept clean and free of debris at all times,
and should be cleaned upon completion of the operation.
NOTE 6—C
6—Clean
lean room is a specia
specially
lly constructed
constructed enclos
enclosure
ure in which
intake air is filtered so that the air at a work station contains no more than
a specified number of particles of a specified size; special personnel and
housekeeping procedures are required to maintain cleanness levels in a
clean room (see ISO 14644-1 and ISO 14644-2).
8.7 Disposal of Used Solutions and Water—Federal, state,
and local safety and water pollution control regulations should
be con
consul
sulted
ted,, par
particu
ticular
larly
ly whe
when
n lar
large
ge vol
volume
umess of che
chemic
mical
al
soluti
sol
utions
ons mus
mustt be dis
dispos
posed
ed of. Con
Contro
trolled
lled rel
release
ease of lar
large
ge
volumes of rinse water may be necessary to avoid damaging
sewers or stream beds.
8.5.6 Workme
orkmen
n handl
handling
ing finished cleaned surfaces of critical items should wear clean lint-free cotton, nylon or dacron
cloth or polyethylene film gloves. Rubber or plastic gloves are
suitabl
sui
tablee dur
during
ing pre
preclea
cleanin
ning
g ope
operat
ration
ionss or clea
cleanin
ning
g of non
non-critical surfa
surfaces.
ces.
9
A380/A380M − 17
9. Keyw
Keywords
ords
9.1 austen
austenitic
itic stainless steels; cleaning; corrosion;
corrosion; corrosive
service applications;
applications; descali
descaling;
ng; duple
duplex
x stainle
stainless
ss steels; ferritic
stainless steels; martensitic stainless steels; pickling; stainless
steels
ANNEXES
(Mandatory Information)
A1. RECOMMEND
RECOMMENDA
ATIONS AND PRECAUTIONS FOR ACID DESCALING (PICKLING) OF ST
STAINLESS
AINLESS STEEL
(See Table A1.1.
A1.1.)
A1.1 Whe
A1.1
Where
re size and shape
shape per
permit,
mit, immersio
immersion
n in the acid
solution is preferred; when immersion is not practicable, one of
the following room-temperature methods may be used:
heat treatment or by welding. Crevices resulting from intergranul
gra
nular
ar atta
attack
ck can col
collect
lect and con
concen
centra
trate
te hal
haloge
ogens
ns und
under
er
service conditions or during cleaning or processing with certain
chemicals; these halogens can cause stress-corrosion cracking.
These alloys should generally not be acid-pickled while in the
sensitized condition. Consideration should be given to stabilized or low-carbon grades if acid pickling after welding is
unavoidable.
A1.1.1
A1.1.
1 For interior
interior surfaces, partially
partially fill item with solution
and rock, rotate,
rotate, or cir
circul
culate
ate so tha
thatt all ins
inside
ide surfaces
surfaces are
thoroughly wetted. Keep surfaces in contact with acid solution
unti
un
till in
insp
spec
ectio
tion
n sh
show
owss th
that
at sc
scale
ale is co
comp
mple
letel
tely
y re
remo
move
ved.
d.
Additional exposure without agitation may be needed. Treat
exterior surfaces in accordance with A1.1.2
A1.1.2..
A1.4
A1
.4 Some
Some la
lati
titu
tude
de is pe
perm
rmis
issi
sibl
blee in ad
adju
just
stin
ing
g ac
acid
id
concentrations,
concentration
s, tempera
temperatures,
tures, and contac
contactt times. In gener
general,
al,
lower values in this table apply to lower alloys, and higher
values to higher alloys. Close control over these variables is
nece
ne
cess
ssar
ary
y on
once
ce pr
prop
oper
er va
valu
lues
es ar
aree es
estab
tablis
lishe
hed
d in or
orde
derr to
preserve desired finishes or close dimensional tolerances, or
both.
A1.1.2 Sur
A1.1.2
Surfac
faces
es tha
thatt can
cannot
not be pic
pickle
kled
d by filling the item
may be descaled by swabbing or spraying with acid solution
forr ab
fo
abou
outt 30 min
min,, or un
until
til in
insp
spect
ectio
ion
n sh
show
owss th
that
at sc
scale
ale is
completely removed.
A1.2 Severe pitting
pitting may result from prolonged
prolonged exposure
exposure to
certain acid solutions
solutions if the solution becomes depleted
depleted or if the
concentration of metallic salts becomes too high as a result of
prolonged
prolo
nged use of the solutio
solution;
n; the concen
concentration
tration of iron shou
should
ld
not exceed 5 weight %; take care to prevent over-pickling.
A1.5 Materi
Materials
als shall be degre
degreased
ased before acid pickling,
pickling, and
shall be thoroughly rinsed after completion of pickling; pH of
final
fin
al ri
rin
nse wa
wate
terr sh
sho
oul
uld
d be be
betw
twee
een
n 6 an
and
d 8 fo
forr mo
most
st
applica
app
licatio
tions,
ns, or 6.5 to 7.5 for crit
critical
ical app
applica
lication
tions.
s. Whe
When
n
applicable, materials may be vigorously brushed with hot water
A1.3 NitricNitric-hydr
hydrofluor
ofluoric
ic acid solutions may inter
intergranu
granularly
larly
corrode certain alloys if they have been sensitized by improper
TABLE A1.1 Acid Descaling (Pickling) of Stainless Steel
AlloyA
ConditionB
Treatment
200, 300, and 400 Series, duplex, precipitation
hardening,
harden
ing, and maragi
maraging
ng alloys (except freemachining alloys)
fully annealed only
A
H2SO4, 8–11 %D , Follow by
treatment D or F, Annex A2,
A2,
as appropriate
65–80 [150–180]
Time,
Minutes
5–45E
200 and 300 Series, 400 Series containing Cr
16 % or more, duplex, and precip
precipitatio
itation-hard
n-hardening
ening
alloys (except free-machining alloys)
fully annealed only
B
HNO3, 15–25 % plus HF,
1–8 %F,G
20–60 [70–140]
5–30E
All free-machining alloys and 400 Series
containing less than Cr 16 %
fully annealed only
C
HNO3, 10–15 % plus HF,
0.5–1.5 %F,G
20 (up to 60 with caution)
[70–140]
5–30E
C
Code
Co
de
Solu
So
luti
tion
on,, Vol
olum
ume,
e, %
A
Temperature °C [°F]
This table is also applicable to the cast grades equivalent to the families of wrought materials listed.
Other heat treatments may be acceptable if proven by experience: see 5.2.1
5.2.1,, A2.4
A2.4,, and A2.5 for further information.
C
Solution prepared from reagents of following weight %: H 2SO4, 98 %; HNO 3, 67 %; HF, 70 %.
D
Tight scale may be removed by a dip in this solution for a few minutes followed by water rinse and nitric-hydrofluoric acid treatment as noted.
E
Minimum contact times necessary to obtain the desired surface should be used in order to prevent over-pickling. Tests should be made to establish correct procedures
for specific applications.
F
For reasons of conven
convenience
ience and handli
handling
ng safety, commercial
commercial formulations
formulations contai
containing
ning fluoride salts may be found useful in place of HF for preparing nitric-hydroflu
nitric-hydrofluoric
oric
acid solutions.
G
After pickling and water rinsing, an aqueous caustic permanganate solution containing NaOH, 10 weight % and KMnO 4, 4 weight %, 70 to 80°C [160 to 180°F], 5 to 60
min, may be used as a final dip for removal of smut, followed by thorough water rinsing and drying.
B
10
A380/A380M − 17
and a bristle brush or with high-pressure water jet on completion of pickling; an initial low pressure rinse to minimize acid
splashing is permissible. To minimize staining, surfaces shall
not be permitted to dry between successive steps of the acid
descali
des
caling
ng and rin
rinsin
sing
g pro
proced
cedure
ure.. Tho
Thorou
rough
gh dry
drying
ing sho
should
uld
follow the final water rinse.
mended where possible. If acid pickling is unavoidable, parts
should be heated at 120 to 150°C [250 to 300°F] for 24 h
immediately following acid treatment to drive off the hydrogen
and reduce the susceptibility to embrittlement.
A1.7 Proper perso
personnel
nnel protection,
protection, includ
including
ing face shields
shields,,
rubber
rub
ber glo
gloves
ves,, and rub
rubber
ber pro
protec
tective
tive clo
clothi
thing,
ng, mus
mustt be pro
pro-vided
vid
ed whe
when
n han
handli
dling
ng acid
acidss and oth
other
er cor
corros
rosive
ive che
chemica
micals.
ls.
Adequate ventilation and strict personnel-access controls must
A1.6
A1.
6 Har
Harden
denabl
ablee 400 Ser
Series
ies allo
alloys,
ys, mar
maragi
aging
ng allo
alloys,
ys, and
precipitation-hard
precipitation
-hardening
ening alloys in the harden
hardened
ed condit
condition
ion are
subject to hydrogen embrittlement or intergranular attack by
pickling
pick
ling acid
acids.
s. Des
Descali
caling
ng by mech
mechani
anical
cal meth
methods
ods is rec
recomom-
be maintained in areas where such chemicals are being used.
A2.1.)
A2. RECOMMEND
RECOMMENDA
ATIONS AND PRECAUTIONS FOR ACID CLEANING OF STAINLESS
STAINLESS STEEL (See Table A2.1.)
A2.1 Trea
Treatments
tments shown are generally
generally adequate for removal
of contamination without seriously changing surface appearance of parts. Passivated parts should exhibit a clean surface
and should show no etching, pitting, or frosting. The purchaser
shall
sha
ll spe
specif
cify
y whe
whethe
therr a slig
slight
ht dis
discol
colora
oration
tion is acc
accepta
eptable
ble..
Passivated parts should not exhibit staining attributable to the
presence of free iron particles embedded in the surface when
subjected to one of the tests described in 7.2.5 or 7.3.4
7.3.4.. For
specific requirements for items to be used in corrosive service
or wh
wher
eree su
surf
rfac
acee ap
appe
pear
aran
ance
ce is cr
criti
itical
cal,, tr
trial
ialss sh
shou
ould
ld be
conducted
condu
cted to establ
establish
ish satisfa
satisfactory
ctory proce
procedures
dures..
A2.5 NitricNitric-hydro
hydrofluori
fluoricc acid soluti
solutions
ons may inter
intergranu
granularly
larly
corrode certain alloys if they have been sensitized by improper
heat treatment or by welding. Crevices resulting from intergranul
gra
nular
ar atta
attack
ck can col
collect
lect and con
concen
centrat
tratee hal
haloge
ogens
ns und
under
er
service conditions or during cleaning or subsequent processing;
these halogens can cause stress-corrosion cracking. Such alloys
should not be cleaned with nitric-hydrofluoric acid solutions
while
whi
le in the sen
sensiti
sitized
zed con
condit
dition
ion.. Con
Consid
sidera
eration
tion sho
should
uld be
given to use of stabilized or low-carbon alloys if this kind of
cleaning after welding is unavoidable.
A2.6 Sever
Severee pitting may resul
resultt from prolonged exposure
exposure to
cert
ce
rtai
ain
n ac
acid
idss if th
thee so
solu
luti
tion
on be
beco
come
mess de
depl
plet
eted
ed or if th
thee
concentration of metallic salts becomes too high as a result of
prolonged
prolo
nged use of the soluti
solution;
on; the concen
concentration
tration of iron shoul
should
d
not exceed 2 weight %; take care to avoid overexposure.
A2.2 The hig
A2.2
high-c
h-carb
arbon
on and fre
free-m
e-mach
achini
ining
ng allo
alloys
ys may be
subjectt to etching or discol
subjec
discoloratio
oration
n in nitric acid. This tendency
can be minimized by the use of high acid concentrations with
inhibitors such as Na2Cr2O7·2H2O or CuSO4·5H2O. Oxidizing
action increases with increasing concentration of nitric acid;
additional oxidizing action is provided by Na 2Cr2O7·2H2 O.
Avoid acid cleaning when possible; use mechanical cleaning
follow
fol
lowed
ed by scr
scrubb
ubbing
ing with hot wat
water
er and dete
deterg
rgent
ent,, fina
finall
thorough water rinsing and drying.
A2.7 Nitric acid solutions are effective
effective for remov
removing
ing free
iron
iro
n and oth
other
er met
metalli
allicc con
contam
taminat
ination
ion,, but are not ef
effec
fective
tive
agains
aga
instt sca
scale,
le, hea
heavy
vy dep
deposi
osits
ts of cor
corros
rosion
ion pro
produc
ducts,
ts, tem
temper
per
films, or greasy or oily contaminants. Refer to Annex A1 for
recommended practices where scale, heavy deposits of corro-
A2.3 Inh
A2.3
Inhibi
ibitor
torss may not alw
always
ays be req
requir
uired
ed to main
maintain
tain
brig
br
ight
ht fin
finis
ishe
hess on 20
200
0 an
and
d 30
300
0 Se
Seri
ries
es,, ma
mara
ragi
ging
ng,, an
and
d
precipitation-hardening alloys.
sion
products, or heat-temper
discoloration
must be
Use conventional
degreasing methods
for removal
of removed.
greasy or
oil contaminants before any acid treatment.
A2.4 Harden
Hardenable
able 400 Series
Series,, maragi
maraging,
ng, and precip
precipitation
itation-harden
har
dening
ing allo
alloys
ys in the har
harden
dened
ed con
condit
dition
ion are sub
subject
ject to
hydrogen embrittlement or intergranular attack when exposed
to acids that can cause the generation of hydrogen on the item
being
bein
g clea
cleaned
ned.. Clea
Cleanin
ning
g by mech
mechanic
anical
al meth
methods
ods or oth
other
er
chemic
che
mical
al met
metho
hods
ds is re
reco
comme
mmend
nded
ed.. If aci
acid
d tre
treatm
atmen
entt is
unavoidable, parts should be heated at 120 to 150°C [250 to
300°F] for 24 h immediately following acid cleaning to drive
off hydrogen and reduce susceptibility to embrittlement. The
cleaning methods described in Parts II and III of Table A2.1
will not lead to the generation of hydrogen on hardenable 400
Series,
Ser
ies, mar
maragi
aging,
ng, and pre
precip
cipitat
itation
ion-ha
-harde
rdenin
ning
g allo
alloys
ys in the
A2.8
A2.
8 The citr
citric
ic acid
acid-so
-sodiu
dium
m nit
nitrate
rate treatment
treatment is the lea
least
st
hazardous for remov
hazardous
removal
al of free iron and other metallic contaminatio
na
tion
n and lig
light
ht su
surf
rface
ace con
contam
tamina
inatio
tion.
n. Sp
Spray
rayin
ing
g of the
solution, as compared to immersion, tends to reduce cleaning
time.
hardened condition. Therefore, the post-cleaning thermal treatment is not required when these solutions are used for cleaning.
accelerate or improve the overall cleaning action but it may
also increase the risk of surface staining or damage.
A2.9
A2
.9 Some
Some la
lati
titu
tude
de is pe
perm
rmis
issi
sibl
blee in ad
adju
just
stin
ing
g ac
acid
id
concentrations, temperatures, and contact times; close control
over these variables is essential once proper values have been
established. Care shall be taken to prevent acid depletion and
buildup of metallic salt concentrations with prolonged use of
solutions. In general, increasing the treatment temperature may
11
A380/A380M − 17
Cleaning
g of Stainl
Stainless
ess Steel
TABLE A2.1 Acid Cleanin
Treatment
Alloy
Condition
Code
Co
de
A
Solu
So
luti
tion
on,, Vol
olum
ume
e%
Time,
MinutesB
Temperature °C [°F]
PART I—Cleaning with Nitric-Hydrofluoric Acid
Purpose—For use after descaling by mechanical or other chemical methods as a further treatment to remove residual particles of scale or products of chemical action
(that is, smut), and to produce a uniform “white pickled” finish.
200 and 300 Series, 400 Series containing Cr
16 % or more, duplex, and precip
precipitatio
itation-hard
n-hardening
ening
alloys (except free-machining alloys).
fully annealed only
D
HNO3, 6–25 % plus HF,
0.5–8 %C,D
20–60 [70–140]
as necessary
Free-machining alloys, maraging alloys, and 400
Series containing less than Cr 16 %.
fully annealed only
E
HNO3, 10 % plus HF,
0.5–1.5 %C,D
20 (up to 60 with caution)
[70–140]
1–2
PART II—Cleaning-Passivation with Nitric Acid Solution (see also Specification A967/A967M for additional passivation methods)
Purpose—For removal of solubl
soluble
e salts, corrosion
corrosion products, and free iron and other metall
metallic
ic contamination
contamination resulting from handli
handling,
ng, fabrication,
fabrication, or exposu
exposure
re to contam
contamiinated atmospheres (see 6.2.11
6.2.11)).
200 and 300 Series, 400 Series, duplex, precipitation hardening and maraging alloys containing Cr
16 % or more (except free-machining alloys). E
annealed, cold-rolled,
thermally-hardened, or
work-hardened, with
dull or non-reflective
surfaces
F
HNO3, 20–50 %D
50–70 [120–160]
20–40 [70–100]
10
30
SameE
annealed, cold-rolled,
thermally hardened, or
work-hardened with
bright-machined or polished surfaces
G
HNO3, 20–40 % plus
Na2Cr2O7·2H2O, 2–6
weight %D
50–70 [120–160]
20–40 [70–100]
10
30
400 Series, maraging and precipitation-hardening
alloys containing less than Cr 16 % high-carbonstraight Cr alloys (except free-machining alloys)E
annealed or hardened
with dull or non reflective surfaces
H
HNO3, 20–50 %
45–55 [110–130]
20–40 [70–100]
20
60
SameE
annealed or hardened
with bright
bright machin
machined
ed
or polished surfaces
I
HNO3, 20–25 % plus
Na2Cr2O7·2H2O, 2–6
weight %F
50–55 [120–130]
20–40 [70–100]
15
30
200, 300, and 400 Series free-machining alloys. E
annealed or hardened,
with bright
bright machin
machined
ed
or polished surfaces
J
HNO3, 20–50 % plus
Na2Cr2O7·2H2O, 2–6
weight %F,G
20–50 [70–120]
25
SameE
same
K
HNO3, 1–2 % plus
Na2Cr2O7·2H2O, 1–5
weight %
50–60 [120–140]
10H
SameE
same
L
HNO3, 12 % plus
CuSO4·5H2O, 4 weight %F
50–60 [120–140]
10
Special free-m
Special
free-machini
achining
ng 400 Series alloys with
more than Mn 1.25 % or more than S 0.40 %E
annealed or hardened
with bright
bright machin
machined
ed
or polished surfaces
M
HNO3, 40–60 % plus
Na2Cr2O7·2H2O, 2–6
weight %F
50–70 [120–160]
20
PART III—Cleaning with Other Chemical Solutions
Purpose—General cleaning.
200, 300, and 400 Series (except free-machining
alloys), duplex, precipitation hardening and maraging alloys
full
fu
lly
y an
anne
neal
aled
ed on
only
ly
N
citric
citr
ic ac
acid
id,, 1 we
weig
ight
ht % pl
plus
us
NaNO3, 1 weight %
20 [70]
60
Same
same
O
ammonium citrate, 5–10
weight %
50–70 [120–160]
10–60
P
inhibited solution of hydroxyacetic acid, 2 weight % and
formic acid, 1 weight %
95 [200]
6h
Assemblies of stainless and carbon steel (for
sensitized
example,
exampl
e, heat exchanger with stainl
stainless
ess steel tubes
and carbon steel shell)
12
A380/A380M − 17
TABLE
TAB
LE A2.1 Continued
Same
same
Q
inhibited ammonia
neutralized solution of EDTA
(ethylene-diamenetetraacetic acid) followed by
hot water rinse and dip in
solution of 10 ppm
ammonium hydroxide plus
100 ppm hydrazine
up to 120 [250]
6h
A
Solution prepared from reagen
Solution
reagents
ts of follow
following
ing weight %: HNO3, 67 %; HF, 70 %.
Minimum,
Minimu
m, unless range is indica
indicated
ted
C
For reasons of convenience and handling safety, commercial formulations containing fluoride salts may be found useful in place of HF for preparing nitrichydrofluoric
acid solutions.
D
After acid cleaning and water rising, a caustic permanganate solution containing NaOH, 10 weight %, and KMnO4, 4 weight %, 70 to 80°C [160 to 180°F], 5 to 60 min,
may be used as a final dip for removal of smut, followed by thorough water rinsing and drying.
E
The purchaser shall have the option of specifying in his purchase documents that all 400 Series ferritic or martensitic parts receive additional treatment as follows: Within
1 h after the water rinse following the specified passivation treatment, all parts shall be immersed in an aqueous solution containing 4 to 6 weight % Na 2Cr2O7 · 2H2O,
at 60 to 70°C [140 to 160°F], 30 min. This immersion shall be followed by thorough rinsing with clean water. The parts then shall be thoroughly dried.
F
See A2.2
A2.2..
G
If flash attack (clouding of stainless steel surface) occurs, a fresh (clean) passivating solution or a higher HNO 3 concentration will usually eliminate it.
H
Shorter times may be acceptable where established by test and agreed upon by the purchaser.
B
Materials
als shall be degreased before
before acid treatme
treatment,
nt,
A2.10 Materi
and
an
d sh
shall
all be th
thor
orou
ough
ghly
ly ri
rins
nsed
ed af
after
ter co
comp
mple
letio
tion
n of ac
acid
id
treatment; pH of final rinse water should be between 6 and 8
for most applications, or 6.5 to 7.5 for critical applications.
When applicable, materials may be vigorously brushed with
hot water and a bristle brush or with high-pressur
high-pressuree water jet on
completion of pickling; an initial low pressure rinse to minimize acid spl
splash
ashing
ing is per
permis
missib
sible.
le. To min
minimiz
imizee stai
stainin
ning,
g,
surfaces shall not be permitted to dry between successive steps
of the aci
acid
d clea
cleanin
ning
g or pas
passiv
sivatio
ation
n and rin
rinsin
sing
g pro
proced
cedure
ure..
Thorough drying should follow the final water rinse.
A2.11 Prope
A2.11
Properr perso
personnel
nnel protection,
protection, includ
including
ing face shields
shields,,
rubber
rub
ber glo
gloves
ves,, and rub
rubber
ber pro
protec
tective
tive clo
clothi
thing,
ng, mus
mustt be pro
pro-vided
vid
ed whe
when
n han
handli
dling
ng acid
acidss and oth
other
er cor
corros
rosive
ive che
chemica
micals.
ls.
Adequate
Adequ
ate ventil
ventilation
ation and strict personnel
personnel access controls must
be maintained where such chemicals are being used.
A2.12 Picklin
Pickling
g and cleanin
cleaning
g or passiv
passivating
ating solutions
solutions containing
taini
ng ni
nitr
tric
ic ac
acid
id wi
will
ll se
seve
vere
rely
ly att
attack
ack car
carbo
bon
n st
steel
eel ite
items
ms
including the carbon steel in stainless steel-clad assemblies.
SUMMARY OF CHANGES
Committ
Comm
ittee
ee A0
A01
1 ha
hass id
iden
entifi
tified
ed th
thee lo
loca
catio
tion
n of se
selec
lected
ted ch
chan
ange
gess to th
this
is st
stan
anda
dard
rd sin
since
ce th
thee la
last
st iss
issue
ue
(A380/A380M – 13) that may impact the use of this standard. (Approved Sept. 1, 2017/)
(1) Fed. Std 209E replaced by ISO 14644-1 and ISO 14644-2
(5) Removed contents of previous 7.2.5 and placed them in
due to its cancellation.
(2) 5.2.2 and 6.2.11 precleaning made a requirement in accordance with A1.5 and A2.10.
(3) Re
Revis
vised
ed 5.2
5.2.2
.2 and add
added
ed new 5.2
5.2.3.
.3. Ren
Renumb
umbere
ered
d sub
subsesequent sections accordingly.
(4) Revised 6.2.11 and added new 6.2.12.
new 7.2.1.1.
(6) Revised 7.2.5.1 and 7.2.5.3.
(7) Added duplex grades to Tables A1.1 and A2.1.
(8) Added low press
pressure
ure initial rinse option and reduc
reduced
ed scrubbing requirement in A1.5 and A2.10.
(9) Changed time spans to minimums in Table A2.1 Part II.
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validity
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ed in connec
connection
tion with any item mentio
mentioned
ned
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of infringement of such rights, are entirely their own responsibility.
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sible technical
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ed a fair hearing you should
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