7/24/2019 ASTM B733 Electroless Nickel Plating
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Standard Specification for
Autocatalytic (Electroless) Nickel-Phosphorus Coatings on
Metal '
Thrs s tandard
is
l rsued u n d e r
h e
fired
deri mrionB
733:
the
n u m b c r irnmcdialcly f o l i o r i n ~
he
d r r i ~ ma t i o n
ndica~es
he
ycnr of
original adoption or, in
the case
ofrevision,
the
year
of larl
revlson.
A
number in
parentheses
indicales
the year af larl
reapproval.
A
superscript
cpri lo~l
E)
ind~cvtes
n edilorial chanee
since
Ule l a s ~evision
or
reapproval.
Tlii s o rdord hm
bee
,~,~rol.i.dor sc
hl .
ogn~cicr /ihc Dcpornneni o/Defeme
1
Scope
1. I This specification
covers requirements for autocatalytic
(electroless) nickel-phosphorus coat ings applied from aqueous
solutions to metallic products for engineering (functional) uses.
1.2 The coatings are alloys of nickel and phosphorus pro-
-duced by autocatalytic chemical reduction with hypophosphite.
Because the deposited nickel alloy is a catalyst for the reaction,
tlie process is self-sustaining. The chemical and physical
properties of the deposit vary primarily with its phosphorus
content and subseque~it eat treatment. The chemical makeup
of the plating solution and the use of the solution can affect tlie
porosity and col ~os ion esista~iceof the deposit. For more
details, see S T M STP 265 (1) and Refs 2)
3)
(4) and 5 )
also refer to Figs. XI. 1, Figs. X1.2, and Figs. XI.: in the
Appendix of Guide
B
656.
1.3 The coatings are generally deposited from acidic solu-
tions operating at elevated temperatures.
1.4 The process produces coatings of uniform thickness on
il~egular ly haped parts, provided tlie plating solution circu-
lates freely over tlieir surfaces.
1.5 The coatings have multifunctional properties, such as
hardness, heat hardenability, abrasion, wear and col~osion
resistance. magnetics, electrical conductivity p~ ov id e iffusion
barrier, and solderability. They are also used for the salvage of
.om or mismachined parts.
1.6 The low phosphorus (2 to I
P) coatings are microc-
rystalline and possess high as-plated hardness (620 to 750
HK
100). These coatings are used in applications requiring abra-
sion and wear resistance.
1.7 Lower phosphorus deposits in the range between 1 atid
phosphorus are also microcrystalline. These coatings axe
used in electronic applications providing solderability, bond-
ability, increased electrical conductivity, and resistance to
strong alkali solutions.
This
ipec~fica lion
s under the jurisdiction
of
AST M
Commillce
8-08 on Melal
Pordcrr and
Mesa1
Powder
Produca
and is
the
direct
rcipo~ir~blllry
f Subcom-
millee
B06.08.01 on Englneenng Coat ings
C u nm , cdition approved
July
10. 1997.
Published October 1997. Oiiginally
published as
B
713 81 Last prevlour edit ion
B
733
90 (19941.
'The
boldfac,
numbrrr in
rercr lo a
lis1 of references 0
,hr
end of rhe ex, .
l .8 The medium phosphorous coatings (5 to
9
P) are most
widely used to meet the general purpose requirements of wear
and corrosion resistance.
1.9 The high phosphorous (more than 10 P) coatings
have superior salt-spray and acid resistance in a wide range of
applications. They are used on beryllium and titanium parts for
low stress properties. Coatings with phosphorus contents
greater than 11.2 P are not considered to be ferromagnetic.
1.10 The values stated in S1 units are to be regarded as
standard.
1.11 The following precautionary statement pertains only to
the test method ponion, Section 9, of this specification. T11is
s m ~ ~ d a r does norpurp or~o nddress al l o/r he sq/erv concerns.
i/ar??, associo~edwi ih ils use. IS rhe responsibilip o/lhe user
of lhis sla~ldnrd
1
eslnblish appropriare sa/e(v and Ircnlfh
pracrices and delern~inehe applicabil i~y /regula~oo; intira-
rio17s p,- ior lo use.
2
Referenced Documents
2.1
ASTM Sra~~dards:
B 368 Test Method for Copper-Accelerated Acetic Acid-
Salt Spray ( Fog) Testing (CASS Testing)'
B
374 Terminology Relating to Electroplating3
B 380 Test Method of Corrosion by the Corrodkote Proce-
dure3
B 487 Test Method for Measurement of Metal and Oxide
Coating Thicknesses by Microscopical Examination of a
Cross Section'
B 199
Test Method for Measurement of Coating Thick-
nesses by the Magnetic Method: Nonmagnetic Coatings on
Magnetic Basis Metals3
B 504 Test Method for Measurement of Thickness of Me-
tallic Coatings by the
Coulometric Method3
B 537 Practice for Rating of Electroplated Panels Subjected
to Atmospheric Exposure'
B 567 Method for Measurement of Coating Thickness by
the Beta Dackscatter ~ e t h o d ~
B 568 Method for Measurement of Coating Thickness by
X-Ray Spectrometry3
'.l a>i,oI ook o j l S T A 4 Yundords, Vol 020S
Copyrlghl
OASTM
International 100 Ban Harbor Dive. PO Box C100 Wart CmnrhMosXen PA
19428-2959,
United Slales
7/24/2019 ASTM B733 Electroless Nickel Plating
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B 571 Test Methods for Adhesion of Metal lic Coatings3
TABLE Deposit Alloy Types
78 Test Metho d for M icrohardne ss of Electroplated Type P h o ~ p h o w ~
~t
Coatings3
Nil
Requi remen1
for
Phosphorus
B 602 Test Method for Attribute Sampling of Metallic and
I I
I 1 0 3
Inorganic Coating"
2
io
4
IV 5 to 9
B 656 Guide for Autocatalytic Nickel-Phosphorus Deposi-
v
10 and
above
tion on Metals for Eneineerine Use3
B
667 Practice for Cot%uctio; and Use o f a Probe for
Measuring Electrical Contact Resistance"
TABLE
2 Service Conditions
B 678 Test Method for Solderability of Metallic-Coated
Coating Thickness Requirements
Products'
Mtn8mum
Coaling
B 697 Guide for Select ion o f Sampling Plans for Inspection
C o n d l l o n Thickness ~ r m in ( m m )
SpeciScauon
of Electrodeposited Metallic and lnorganic Coatings"
SCO Minlrnun Thickness
0.1
0.000004
(
B 762 Method for Variable Samplin g of Metallic and Inor- S C I
Light
Service 5 0.0002
(
ganic Coating?
SC2 Mild Service
13 0.0005
( )
B 849 Specification for Pre-Treatment of Iron or Steel for
sc3 Moderate Service 25 0.001 [ )
SC4
Severe Service 75 0003 (
)
Reducing the Risk of Hydrogen Embrinlement3
B 850 Specification for Post-Coating Treatments of lron or
Steel fi r Reducing the Risk of Hydrogen Em brittlement3
MIL-S-13 165 Shot Peening o f Metal PartsI3
B 85 1 Specification for Autom ated C ontrolled Sho t Peening
MIL-STD-105 Sampling Procedures and Tables for lnspec-
of M etallic Articles Plior to Nickel, Autocatalytic Nickel.
tion by AttributeI3
Chromium. or As A Final Finish3
2.3
IS0
Standards:
D 1193 Specification for Reagellt Wale9
1SO 4527 Autocata lytic Nickel-P hosphoru s Coatings-
D2 67 0 Method for Measur ing Wear Propert ies of Fluid
Specification and Test Methods"
Luhricants (Falex Methodi6
~~
~~ ~ ,
D 2714 Method for Calibration and Operation of an Alplia
LFW-I Fr ict ion and Wear Testing Machine6
D 1951 Practice for Commercial Packaging'
D 4060 Test Method for Abrasion Resistance of Organic
Coat ings by tl ie Taber ~ b ra se r '
E
60 Practice for Photometric h4ethods for Chem ical Analy-
sis of Metals9
E
156 Test Metliod for Det erm inati o~i of Phosphorus in
Higll-Phosphorus Brazing Alloys (Photometric Met11od)'~
E 352 Test Methods for Chemical Analysis of Tool Steels
and Other Similar Medium-and High-Alloy Steel9
F 519 Test Method for Mechan ical H ydrogen Embrinle-
m en t l l
G 5 Practice for Standard Reference Metho d for Making
Pote~itiostatic and Potentiodynamic Anodic Polar izat ion
Measurements"
G
3 1 Practice for Laboratory l~ nn ~e rs io norrosion Testing
of Metals"
G 59 Pract ice for Conducting Potentiodynamic Polar izat io~i
R es ~s t an ceMeasurements"
G 85 Practice for Modified Salt Spray (Fog) Testing"
2.2 144ilira1,~ ta17 dar.d~:
MIL-R-81841 Rotary Flap Peening of Metal PartsI3
.4nri?rol Book o/ASTM Slundords. Vol 0J.04.
4 i??
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include requirements for diffusion barrier, undercoat, electrical
4.3.6 Class 6-Heat treatment at 300 to 320C for at least 1
co~~ductivitynd wear and corrosion protection in specialized
h to improve coating adhesion for titanium alloys.
environments.
NOT -Heal-treatable aluminum alloys such as Type
7075 can
4.2.3 SCl Light Ser?'ice, wpThiss
a
undergo
micrortructu~vl
changes
and
lose strength
=,hen licarcd ro o v e r
minimum coating thickness of 5 pm for extending the life of
130-c
the part. Typical environments include light-load lubricated
wear, indoor corrosion protection to prevent rusting, and for 5. Ordering Information
soldering
and mild abrasive wear.
5.1 Tlie following informati011 shall be supplied by The
4.2.4 SC2 ~ i l dervice, 13 W-This is defined by mild
purchaser in either the purchase order or on the engineering
corrosion and wear environments. It is characterized by indus-
drawing of the pan to be plated:
trial atmosphere exposure on steel substrates in d~ or oiled
5.11 T ~ ~ ~ ~ , A S T Mesignation number, and year ofis sue of
environments.
4.2.5 SC3 Moderare Service, 25 pm-This is defined by
moderate environments such as non marine outdoor exposure,
alkali salts at elevated temperature, and moderate wear.
4.2 .6 SC4 Severe Se n~ ice, 5 pm-This is defined by a very
aggressive enviro~lment.Typical environments would include
acid solutions, elevated temperature and pressure, hydrogen
ulfide and carbon dioxide oil service, liigll-temperature chlo-
ride systems, very severe wear, and marine immersion.
NOTE
?-The
performance
af the autacatalytic nickel coating depends
ra a
large
errent on r be surface finish
of t h e
article to be plated and
lrow
t was prelreated. Rough, non uniform
surfaces
require thicker coutinxs
than smootll surfaces to achieve maximum corrosion res is tance and
minimum porosiry
4.3 Posr Hear Pear1ne111 Class-The nickel-phosphorus
coatings shall be classified by heat treamient after plating to
increase coating adhesion and or hardness (see Table 3).
4.: l Class I-As-deposited, no heat treannent.
4.3.2 Class 2-Heat treatment at 260 to 400C to produce a
minimum hardness of 850 HK100.
4.3.3 C1as.r 3-Heat treatment at
180
to 200C for 2 to 4 11
to improve coating adhesion on steel and to provide for
hydrogen embrittlement relief (see section 6.6).
4.3.4 Class 4-Heat treatment at 120 to 130DC or at least
h to increase adhesion of heat-treatable (age-hardened) alumi-
nun) alloys aud carburized steel (see Note 3).
4.3.5 Class 5-Heat treatment at 110 to 150C for at least I
i to improve coating adhesion for aluminum, non age-
hardened aluminum alloys, copper, copper alloys and beryl-
liutn.
TABLE Classification
of
Post eat
Treatment
LRSS
Oe~cription
Temperature xme hl
iCl
1 No HealTrealment A s Plated
2
Heal Treatment for Maximum Hardness
TYPE
260
285
320
nn
TYPE
I
TYPE I l l
TYPE
IV
TYPF
V
3 Hydmgen
Embriniemenl
and 180 o 200
Adhesion
on
Sleel
4
Adhesion.
Carburized
Steel and 12010 130
this specification.
5.1.2 Classification of the deposit by type, service condi-
tion, class, (see 4.1, 4.2 and 4.3)
51.3 Specify maximum dimension and tolerance require-
meuts, if any.
5.1 4 Peening, if required (see 6.5).
5.1.5 Stress relief heat treatment before plating, (see 6.3).
5.1.6 Hydrogen Embrittlernent Relief after plating, (see
6.6).
5.1.7 Significant surfaces and surfaces not to be plated must
be indicated on drawings or sample.
51.8 Suppletnental or Special Government Requirements
such as, specific phosphorus content, abrasion wear or corro-
sion resistance of tlie coating, solderability, contact resistance
and packaging selected from Supplemental Requirements.
5.1.9 Requirement for a vacuum, inert or reducing atmo-
sphere for heat treatment above 260C to prevent surface
oxidation of the coating (see S3).
51 .10 Test methods for coating adhesion, composition,
thickness, porosity, wear and corrosion resistance, if required,
selected from those found in Section 9 and Supplemental
Requirements.
5.1.11 Requirements for sampling (see Section 8).
NOT &The
pnrchaser
should
furnish separate
lesl specimens or
coupons of rhe basis metal
for
lest purposes to be plated coneunentiy with
the artieles la be plated
see 8.4 .
6 Materials and Manufacture
6.1 S~~bslrare-Defects in the surface of the basis metal
such as scratches, porosity, pits, inclusions, roll and die marks,
laps, cracks, burrs, cold shuts, and roughness may adversely
affect the appearance
and performance of tlie deposit. despite
the obser\.ance of the best plating practice. Any such defects on
significant surfaces shall be brought to the attention of the
purchaser before plating. The producer shall not be responsible
for coatings defects resulting from surface conditions of the
metal, if these conditions have been brought to the attention of
the purchaser.
6.2 P,.er~eamte~il- -Pans o be autocatalytic nickel plated
may be pretreated in accordance with Guide B 656. A suitable
method shall activate tlie surface and remove oxide and foreign
materials, which may cause poor adhesion and coating poros-
ity.
Age Hardened Aluminum
NOT
-Heat
treatment of the base material may effecr its metallur-
5 Adherlo
on
Beryllium and 140 o 150 to 2
Aluminum
eical properties. An example
is l eaded
steel
which
may exhib i t
l iquid or
6 Adhesion on Xlan ium 30C~320 1 4 solid ernbrittlemen1
afrer
heal
treatment.
Careful selection of the
pre
and
past heal treatments are recommended.
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6.3 Su-ess
elief
6.3. l Prerr-ealnienl offron andSleel/or~Reduci iighe Risk of
Hydrogen En~brirllemenl-Parts that are made of steel with
ultimate tensile strength of greater than 1000 Mpa (hardness of
31 HRC or
greater ,
that have been machined, ground, cold
formed, or cold straightened subsequent to heat treatment, shall
require stress relief hear treatment when specified by the
purchaser the tensile srrength to be supplied by the purchascr,
Specification B 849 may be consulted for a list of pre-
treatments that are widely used.
6.3.2 Peening-Peening prior to plating may be required on
liigh-strength steel pans to induce residual conipressive
stresses in the surface, which can reduce loss of fatigue
strength and improve stress corrosion resistalice after plating.
(See Supplementary Requirements).
6.3.3 Steel parts which are designed for unlimited life under
dynamic loads shall be shot peened or rotary flap peened.
Nors Contolled shotpeening
is
the preferred method because rhere
- - a r e
georneoy's where rotary flap peening is not effective.See S11.2.
6.3.3.1 Unless otl icwisc specified, tlie shut peclling shall be
accomplished on all surfaces for which the coating is required
and all immediate adjacent surfaces when they contain notches,
fillets, or other abrupt changes of section size where strcsscs
will be concentrated.
6.4 Racking-Parts should be positioned so as to minimize
trapping of hydrogen gas in cavities and holes, allowing free
circulation of solution over all surfaces to obtain uniforni
coating thickness. The location of rack or wire marks in the
coating shall be agreed upon between the producer and
purchaser.
6.5 Plarirtg Process:
6.5.1 To obtain consistent coating properties, the bath niust
be monttored periodically for pH, tcmperature, nickel and
liypopliosphite. Replenislments to the plating solutioli should
be as fiequent as required to maintain tlie concentration of :lie
nickel and l~ypopl~osphireetween 90 and 100 of set point.
'he use of a statistical regimen to establish tlie control limits
-nd frequency of analysis may be employed to ensure quality
deposits are produced.
6.5.2 Mechanical movement of parts and agitation of tlie
bath is recommended to increase coating smoothness and
uniformity and prevent pitting or streaking due to hydropcn
bubbles.
6.6 Posr Cooririg T,rarn~erif,forrorr arid Sleel/or Redt,cirig
the Risk of HI^-ogen Ei7ibrir/ler1re1ir Partn that are made of
steel with ultimate tensile strengths of 1000 Mpa (hardness of
31 H R C or greater), as well as surface hardened parts, shall
require post coating hydrogen embrittlement relief baking
when specified by the purchaser, the tensile strength to be
supplied by the purchaser. Specification
B
850 may be con-
sulted for a list of post treatments that are widely used.
6.6.1 Heat treatment shall be perfomied prefetably within 1
I1 but not Inore than 3 li of plating on plated afier plating of
steel palis to reduce tlie i s k of hydrogen enibrittlement. In all
cases, the duration of thc hcat trcatment shall cornmetice from
the rime at which the wl~o le f each part attains the specified
temperature.
6.6.2 Higli-strength steel pans with acrual tensile strengths
greater than 1000 MPa (corresponding hardness values 300
HV10,303 HB or 3 HRC) slid surface hardened parts shall be
processed after coating in accordance with Specification B 850.
6.7 Hear Trennnenl Afler- Platir rg ro Intpwve Adhesiort-To
improve the adhesion of the coating to various substrates, the
heat treatments in Table 3 should be perfonned as soon as
practical after plating (see 4.3 .
6.8 Heal T,-ealmenl 4per Pla ti ,~g o Irrcreose Har-drress:
6.8.1 To increase the hardness of the coating a heat treat-
ment of over 2h03C is required. Table 3 describes thc heat
treatment for maximum hardness.
6.8.2 See Appendixes 3 and 4 and Guide B 656; Figs. X1.2
and Figs. X1.3.
6.8.3 A heat treatment at 260C for greater than 20 h should
be used to reduce rhe loss of surface hardness and strength of
some ferrous basis metals. Avoid rapid heating and cooling of
plated parts. Suficient time must be allowed for large parts to
reach oven temperature.
NOTE 7-The length of time to reach maximum hardness vanes with
the phosphorus content of
the deposit.
High phosphorus deposits may
require longer time or
a
higher rempcrarure, or both.
Individual
alloys
should e tested for rnaxinum hardness attainable, especially for condi-
t ons o f lower temperarures an d longer timcs.
NOTE 8-Inerr or rcducing atmosphere or Wacuum rufficienro prevent
oxidation is recamrnendzd for hear treatment above 260C. a not usegas
containing
hydrogen
u,ith
high-srrength steel
parts.
7. Requirements
7.1 Process-The coating shall be produced froni an aque-
ous solution through chemical reduction reaction.
7.2 Acceprarice Requir-ernenrs-These requirements are
placed on each lot or batch and can be evaluated by tesling the
plated part.
7.2.1 ilppear-aiice:
7.2.1.1 The coating surface shall have a uniform, metallic
appearance without visible defects such as blisters, pits,
pimples, and cracks (see 9.2 .
7.2.1.2 Imperfections that arise froni surface conditions of
the substrate which the producer is unable lo remove using
conventional pretl-eatmcnt tcchniques and that persist in the
coating shall not be cause for rejection (see 6.1 . Also,
discoloration due to heat treatment shall not be cause for
rejection unless special heat treatment atmosphere is spccificd
(see section 5.1.9).
7.2.2 Tliicbiess-The thickness of the coating shall exceed
the niiliimuni requirements in Table 2 as specified hy the
service condition agreed to prior to plating (see 9.3). After
coating and if specified, the part shall not exceed maximu111
dimension on sig~i ificant urface (sce section 5.1.3).
UOIE 9-The thickness
of
the caatms canno1be canrrolled
in
blind or
small
diameter dcep holes or where salution circulat~ans rcsrricted.
7.2.3 Adl~esion-The coating shall have sufficient adhesion
to the basis metal to pass the specified adhesion test (see 9.4
and Test Methods
B
571).
7.2.4 Porosi+The coatings sliall be essentially pore free
when tested according to one of the methods of 9.6. Tie test
method. the duration of the test, and number of allowable spots
per unit area shall be specified (see section 5. 11 0 and 9.6).
7/24/2019 ASTM B733 Electroless Nickel Plating
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7.3 Qual~ficaiionRequirentenrs-These requiremetits are 8.3 All specimens used in the sampling plan for acceptance
placed on the deposit and process and are performed on
tests shall be ma de of the sam e basis material and in tlie same
specimens to qualify the deposit and plating process. Tlie tests
metallurgical condition
as
articles being plated to this specifi-
for these qualifica tion requiremelits shall be perform ed cation.
monthly or more frequently. 8.4 All specimens shall be provided by the purchaser unless
7.3.1 Compositiot~-Type 11 111, IV, V deposits shall be
ot he nr ise agreed to by the producer.
analyzed for alloy composition by testins for
P ~ ~ ~ P ~ ~ ~ ~
see
N~~~
1 1 -~ l , ~ au to cawly r ic n ick e l p raccs r i s d mamic an d
a
daily
9.1). The w'e~ghtpercent of pl i os pl lo ~ s hal l be in the range
is recommended.
For
Coatings requiring alloy analysis and
designated by type classification (see 4.1).
corrosion tes t ing w eekly sampling sho uld be considered a s
an
opuon.
7.3.2 Micioho~-dness-The microhardness of Class 2 depos-
its shall be determined by Test Method
B
578 (Knoop). For
Class
coatings, the microhardness sliall equal or exceed a
minimum of 850 (HKLOO (or equivalent Vickers) (see 4.3 and
9.5). Tlie conversion of Vickers to h o o p using Tables
E
140
is not recommetided.
7.3 .3 M ~d ro ge rl E1tibrirrieme17r-TI1e proces s used to de-
posit a coating onto high shength steels shall be evaluated for
'lydrogen embrittlement by Test Method
F
519.
8.
Sampl ing
8.1 The purchaser and producer are urged to employ statis-
tical process control in the coating process. Properly perfomled
this will ensure coated produ cts of satisfactory quality and will
reduce the amount of acceptance inspection.
8.1.1 Sampling plans can only screcn out unsatisfactory
products without assurance that non e of them will be accepted.
7 )
8.2 The samp ling plan used for the inspectioti of a quantity
of coated parts (lot) shall be Test Method B 602 unless
otherwise specified by purchaser in the purchase order or
contract (see section 5.1.11 and S.Il.1).
NO TE 10-Usually. %.hen
a
collect ion of coated parts ( the
inspection
lot
E.21 is examined for compliance with the requirements placed
a n the parts
a
relatively small number of parrr, the sample, is selected
at
random and
inspected . T he inspection lor is l i~ en classif ied as complying or
no
9
Test Methods
9.1 Deposil An ahs is /or Phosp horus:
9 . 1 . 1 Ph o s p h o r r~s Dererniinarion Determine mass %
phosphorus content according to Practice
E
60, Test Methods
E
352, or Test Method
E
156 on known weight of deposit
dissolved in warm concentrated nitric acid.
9.1.2 Composition can be determined by atomic absorption,
emission or X-ray fluorescence spectrometry.
N O T E
12-inductively
coupled plasma techniques can determine the
.
alloy to with in 0 .5 %.T he fo l lowing analysis wavelength l ines have been
used with min imu m inteiference to determine the alloy.
Ni 216 10
rn
Cd 214 44nrn Fe 238 20 nrn
215 40 nrn O 238 34
nm Pb
283 30nm
213 62
nrn
Cr 284 32 nm Sn 198 94nm
l 202 55
nrn
u 324 75 nnr Zn 206 20
nrn
9.2 Appenrance-Examine the coating visually for compli-
ance with the requirements of 7.2.1.
9.3 Tltickf~ess:
NOTE
13--Eddy-current type insrruments give erraric meas urem ents
d u e to variarions in conductivit y of the coalings with chang es in
phaspharur content .
9.3.1 Mio.os copica 1 Merhod-M easure tlie coating thick-
ness of a cross section according to rest Method
B
487.
NOTE
L T o protect the edger , e lccrroplare the specimens with
a
minimum of f n ickel
or
capper prior to roir sectioning.
com ply ing u.ir11
rbe requirements
bared
on
the results of the inspection
sample,
Ti e
the
sample
and the cr i ter ia of
9.3.2 Mogiiefic Inducfion I~ ~ sl ru i i ~e nfethod-Test Method
.
etermined by the applicat ion of s ta t is t ics . ~h~ ~m c ed u re s known as
B
499 is applicable to magnetic substrates ~I a t e d ith auto-
samolinc insoecrion. Three
standards
Test Method B 602. Guide B 697.
catalvtic nickel deoosits. thar contain more than 11 mass
%
- .
and Test Method B 762 conlain rampling p lans
rhat are
designed
far thc
phosphorus (not ferrom agnetic) and that have not been heat-
sampling inspection of coatings.
treated. The instrument shall be calibrated with deposits plated
Tesr
Method B 602 conrains four sampling p lans, three fa r
use
with tests
in the same under the
same
on magnetic
thal are nondestructive and
one
for use w th tes ts hat
are
destructive. The
.--..
purchaser and produccr may agree an the plan(s) to be used. lf rhe y do not.
Terr Merhod
B
602 identifier th e plan to be used.
9.3.3 Be ta Bac krcalte t, Meihod-Test Method 567 is only
Guide B 6 9 7
a l ye
n u mb er o fp lan s an d piv s guidance to
coatings On magnesium,
an
he selecrion
of a dan. When
Guide
697 is rDccihed, rhc purcl aser
and titan~um. he instrument must be calibrated with standards
and producer need
to a g e e on
the plan to be used.
havitlg the same compositioti as the coating.
Test Method B 762 can be used only for coating requirements that have
15-The density
varier
u , i rh t s
mass
%
a
numerical limir, such as coating th icknerr .
The
last must yield
a
ms
content
See
Appendix X2).
numcncal value and certa in swrirr ica l reauiremeers
must
bc met. Terr
Merhod B 762 contains several p lans and a lso g ives instmclionr for
9.3.4 Micrvtnerer Melhod-M easure the vart, rest coupon,
.
. . .
calculating
plans
to
meet
speeia l needs. The purchaser and producer may
or pin ill a specif ic spot before and after plating using a suitable
n
the to b e
If do
Test 762
micrometer Make sure that the sutiace s measured are smooth,
identifies the plan ro
be
used.
clean, and dry.
An inspection lat shall be defined
as a
collection of coated parts which
are
of the same kind, that Ihave becn produced to th e samc rp ec i f i ca t~o n ,
9.3.5 Weigh, Pia re. Weigh Method-Using a similar sub-
that have been coated by
a
s ingle producer a t one rime
ar
approximately
strate
surface area, weigh the nearest
the same time undcr essentially identical conditions, and thar
are
submit-
milligram before an d after plating making sure that the Part or
ted
for
scceprance
or re ject~on
n
a
group.
coupon is dry and at room ternperamre f i r each measurement.
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Calculate the thickness from the increase in weight, specific
gravity, and area as follows:
where:
It
=
weight gain in milligrams,
1
=
total surface area in squarc centimetres, and
= gram s per cubic centimetres (see Appendix X2 ).
9.3.6 Coulo~aerricMethod-Measure the coating thickness
in accordance with Test Method B 504. The solution to be used
shall be in accordance with manufacturcr's recommendations.
Tlie surface of the coating shall be clea ned prior to testing (see
Note 14).
9.3.6.1 Calibrate standard thickness specimens with depos-
its plated in the same solution under the same conditions.
9 . 3 . 7 X - R a y S p e o r o r n e r ~ ~ M e a s u r ehe coating thickness
in accordance with Test Method B 568. Tlie instrument must be
alibrated with standards having the same composition as the
-coat ing.
NOT l&Ti>is method is only recommended for depasjts in
the
as-plared condition The phosphorus c o n te n t o f t h e coating must
b e
known
to calculare t he
thickness
of the deposit. Mahix effect
d u e
to the
dismbutian
of
phosphoms in layers af t he coating
also
effect the
measurement
accuracy
and
require
t h a ~ a l ib r at io n svrndards be made
under the same conditions as
the
produclion process
9.4 Adhesion:
9.1.1 Be nd Tesl (Test Me tliods 571)-A sam ple specim en
is bent 180 over a mandrel diameter 4X the thickness (10
mm
minimum) of the specimen and examined at 4X power
magnification for flaking or separation at tlie interface. Fine
cracks in tlie coating on the tension side of the bend are not an
indication of poor adhesion. Insertion of a sharp probe at the
tnterface of the coating and basis metal to d ete m~ ine he
.,
,
derennination is permissible.
9.6 POI-osih,-There is no universally acce pted test for
porosity. When required, one o ft he following tests can be used
on the plated part or specimen.
9.6.1 Ferroxj~lTest for h a n Base Sr~bslrates-Prepare the
test solution by dissolving 25 g of potassium ferricyanide and
15
g
of sodium chloride in 1 L of distilled water. After
cleaning, immerse the part for 30
s
in the test solution at 25C.
After rinsing and air drying, examine the pan for blue spots,
which form at pore sites.
9.6.2 Boiling Walei- Test fo r Iron-B ase Substrares-
Completely immerse the pan to be treated in a vessel filled
with aerated water at room temperature. Apply heat to the
beaker at such a rate that the water begins to boil in not less
than 15 min, nor m ore than 20 min after tlie initial application
of heat. Continue to boil the water for 30 min. Then rem ove the
pa n, air dry, and exa mine for rust spots, wliich indicate pores.
NOTE 19-Aerated
water
is prepared by bubbling clean compressed
air
rhrough disrilled
ujater
by means
of
a glass
diffusion
disk at
room
tempemrum for 12 h. Th e pH of the aerated water should h e 6.7 0.5.
9.6. 3 A er nl ed N'aler Test fo r Iro n- Ba se Su bsrt-ares-
Immerse the part for 4 h in vigorously aera tedT ype 1V or better
water (see Specification D 1193) at 25 C temperature and
then examine the part for rust spots.
9.6.4 Alimriri Tesr for Al rdi ~~ i~~ ur nllo~,s- Wioe the nlated
part or specime~iwith 10 mass o sodium hydroxide solution.
After 3 min contact, rinse, and apply a solution of alizarin
sulfonate prepared by dissolving 1.5 g of methyl cellulose in 90
mL of boiling water to which, after cooling. 0.1 g sodium
alizarin sulfonate, dissolved in 5 mL of ethanol is added. After
4 min contact, apply gl ac ~a l cetic acid until the violet color
disappears. Any red spots remaining indicate pores.
9.6.5 Po ro si h Tesr for Coppe r Subslrares-Wipe the plated
aoneslon 1s suggesrea.
pa n or specimen with glacial acetic acid After 3 min, apply a
ari 17-Appropnare rest specimens
are strips approximately
5 ta 50
mln wide,
200
lo 300
mm
long
and
3 to 6 mrn illick
9.4.2 In ~p nc t Tesl-A spring-loaded ce nter punch with a
\-point having 2 to
3
radius is used to test adhesion of the
coating on nansignificant suifa ces of the plated pa n. Make
three closely spaced tndentations and examine under IOX
~iiagn ificatlon or flaking or blistering o f the coating, w hich is
cause for rejection.
9.4.3 Tl7er-mnlS11ock-The coate d p a n is heated to 200C in
an oven and then que ~ic hed n room temperature w ater. The
coating is examined for blistering or other evidence of poor
adhesion at 4X magnification.
9.5 M~c~ahard,?ess-The microhardness of the coating can
be measured by Test Method B 578 using Knoop indenter and
is reponed in Knoop Hardness Number (HK). It will v a ~ y
depending on loads, type of indenter, and operator. A100 g load
is r ecom m en ded. l l ~ ehombic Knoop indenter gives higher
hardness readings than tlie square-hase pyramidal Vickers
diamond ~n denter or 100 to 300 g loads, see Ref 6). For
~na rim urn ccuracy, a minimum coating thickness of 75 p n is
recommended. Conversions of Vickers or K~ioophardness
number to Rockwell C is not recommended.
Nore 1 8 4 n
hick
(75 pm+)
coatings
on steel a
surface
microhardness
solution of potassium ferrocyanide prepared by dissolving 1 g
of potassium ferrocyanide and 1.5 methyl cellulose in 90 mL
of boiling distilled \x8atcr.The appearance of brown spots after
2 min indicate pores.
9.7 Ot he r Tesl Methods-Test meth ods whic h have been
developed that are equal to or better than these may be
substituted. The precision and bias requiremetits will vary for
each type of test. If an alternate test is specified it shall be
agreed upon between the producer and the purchaser.
10 Rejection and Rehear ing
10.1 Part(s) that fail to conform to the requuements of this
standard may be rejected. Rejection shall be reponed to tlie
producer promptly in writing. In the case of dissatisfaction
occurs with tlie results of a test, the producer may make a claim
for a hearing Coatings that show imperfections may be
rejected.
11. Cert i f icat ion
11.1 When specified in the purchase order or contract, the
purchaser shall be furnished certification that tlie samples
representing each lot have been processed, tested and inspected
as directed in this specification and the requirem ents have been
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met. When specified in the purchase order or contract, a report
of the test results shall be funislied.
12.1 autocatalytic; chemical nickel; coatings; conductive;
comosion resistance; electroless; functional; nickel: nickel
phosphorus; wear resistance
S U P P L E M E N T A R Y R E Q U I R E M E N T S
The following supplementary requirements shall apply only when specified by the purchaser in tlie
contract or order.
S1 .l Shot Peening-W hen specified by the purchaser in the
ordering information, the part(s) shall be shot peened prior to
plating in accordance with Specification
B
851 or MIL-S-
'3165.
S1.2 Con~po sifion-When specified by tlie purchaser in the
orderiny information the phosplioms content shall be main-
tained in the deposit to within 1
.
Use the test methods
described in 9.1.
S l .3 1rrer.fArmosphere-When spec ified by the purch aser in
the orderiny information, the coating shall be heat treated in a
vacuum, inert, or reducing am ~os plie re o prevent surface
oxidation of tlie coating.
S1.4 Hy drog en Embi-itrlemerzr-When spec ified by the pur-
chaser in the ordering informatinn tlie plating process shall be
evaluated at the time of processing pans for hydrogen em-
brittlement using Test Metho d
F
5 19.
S1 Abr-orice Wear-When speci fied by tlic purch aser in
the ordering information, the coating shall be tested for
abrasion wear resistance using the method in Appendix XI of
this specification. Thc coating sh all tuect a maxim um wear rate
which is specified by the purchaser and agreed to by the
producer.
1 .6 Adhrs i~ ,eWeor-When spec ified by tlie purc haser in
ordering information, the coating shall be tested for
hd lie siv e wear resistance usine T est Method D 2714 or Test
S1.7 Coi7tacr Resisrance-W hen speci fied by the purch aser
in the ordering information. the coating shall be tested for
contact resistance using Test Method
B
667.
S1.8 Solderabili1)-When specified by the purchaser in the
ordering information, thc unaged coating shall pass Test
Method B 678 on solderability.
S1.9 Corrusiori ResisfanceWhen specif ied by the pur-
chaser in the ordering information the coating shall pass any
special corrosion tests agreed to by the producer The corrosion
resistance of tlie coating to a specific liquid medium can be
determined by means of immersion tests (see Practice
G
3 I ) or
electrochemical test (see Practices G 5 and G 59).
S1.10 irling Col.,nsiorl Resbrance-Use Method
G
85
(acetic acid-salt spray test), Method B 368 (copper-accelerated
acetic acid-salt spray, CASS), or Method B 380 (Corrodkote)
lo evaluate the corrosion resistance of the coating to pitting.
S 1. l S pe cioi Go ve n ~ ~ n e n teqlrirernents:
S 1.11.1 Sonipling-Part(s) plated for the US Govcrnrnent
and Militaly use shall us e MIL -STD-105 as tlie sampling plan.
S l .I I. 2 Sl ~o t eening--High strength steel palt(s) pro-
cessed Tor US Government and Mililaty use shall be shot
peened in accordance u.ith M IL-S-13 165 or rotary flap peened
in accordance with MIL-R-81841. (see Note
6).
Method
D
2670. Ih e wea r rite shall be specified by the
S I . 11.3 Packaging--Parts shall be packaged in accord ance
purchaser and agreed to by the producer.
with Practice D 3951.
A P P E N D I X E S
(Nonrnandator Inlormation)
XI
T AHE HAB RAS E R W E AR TEST M E T HOD
Xl . 1
cope
the laboratory and [he storage
conditions o
[he CS-10
WIIPP IP
are
X1.1.1 This test method will evalu ate the resistance of the
be conrrol lhe
J u m i d i v bewee
tests
coating to abrasive wear. The test is performed by rotating a
X1.1.2 The results are variable between tests and therefore
plated panel under rotatins rubber wheels and weighing the
three plated test specimens should be tested to 6000 cycles
panel after each 100 0 cycles for weigh t loss. Duration of the
each. The results should b e averaged w itl~ ou t he first 1000
test is 6000 cycles and it can be extended to 25 000 cycles for
cycles and abrasion wear resistance is reported as the
more complete resnlts.
wetght loss in rngIlOO0 cycles (Taber Wear Index).
NOT ll-Variation in results ha\w been atrributed la the humidiry i n
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X1.Z pparatus X1.3.2 Wear test the specimens. For each of the three
X1.2.1 Taber Abi-asei. 14ear- Tes ting Unit-The un it mu st be
specimens complete the foilowing steps:
capable of loading u itll 1000 g load and operating w ith a
X1.3.2.1 Run the CS-I0 wheels on the coating for 1000
cycles to remove any surface roughness. The wheels shall be
vacuum.
loaded with 100 0 with a vacuum on high for the entire test.
X1.2.2 A~I-asior?Wlzeels- Use CS-10 (resilie nt rubb er)
X1.3.2.2 c o o l weigh (he specimen to the nearest 0.1
Taber wheels. To reface the whe els use
CS-I1
discs from Taber
,-
The hardness of CS-I0 wheels can change with time and call
X1.3.2.3 Dress the CS -I0 w heels with a CS-11 disc for 50
effect the reproducibility o f results (see Test Metho d D 4060 ).
cycles
X1.2.3 k t Specimeiu- Test specimen s shall be made
from 20 gage CR steel 4 by in. (100 by 100 by 1.3 m m) with
a 0.250 (6.35 mm) hole in the center. Test specimens are
available from Taher.
X1.2.4 Ana/lrrcal Balance-Scale which is capable of mea -
suring lo 150 g 0.1 mg .
X1.3 Procedure
X1.3.1 Plate three specimens with 0.001 in. (25 pm) of
-nickel phosphorus coaling.
X1.3.2.4 Abrasion test the coating with 1000 g load for
1000 cycles.
X1.3.2.5 Repeat X1.3.2.2, X1.3.2.3 and Xl.3.2.4 until a
total of 6000 cycles have been accomplished for each specl-
men.
X1.4 Reporting
XI .4.1 Determine the average weight loss in milligrams for
each sp ecimen per 100 0 cycles Taber Wear Index and the mean
weight loss per 1000 cycles for all specimens. Report the mean
and stand ard deviation fo r the coating.
7/24/2019 ASTM B733 Electroless Nickel Plating
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XZ
DENSITY O F UTOC T LYTIC NICKEL DEPOSITS
ensity
of
Electroless
Nickel
Deposits
A
R ei de l, Wd fgan g , E l e i t r o l e r r N i ck e l P l a tmg . ASH 1n :er nal l ona l. H e r a l r Pa r k .
OH
1991, p92 DIN 5096 6
+ IS0
52:
Annex
Vendor . E ln l r , unpubl l rhed
Ratam,
C S
ajam r t a 1 M e t a i
Flo\ rh \og.
V o l 88 No 11
119401
N I S T . F ~ e l d ~ n ggburn e l a\ . P:at lnq an d Sur face F lntsh lng, V a l 68, No 3 l I '18 l l
K a n q e n , AS T M S I P
No
265 . i l e r t r o l e s s N l c k e l P l a t ~ n g 959
Oak
Rldse
D Smith, Thermal Condurr iv8ty
o f
E l ec t r a l e r r N l i k e l - Phos phor us A I l c y P l a l lng . N ahana l
Sr lente Foundahon, 1'163
Garbunova. K
M
lorbunova and A A N l k t o roua . Phy s ~ r a c he m~ i a l
Pr lnr lp les a f N i c k e l PIa t8ng. N a t~ a na l oenc e Founda i l an '963
endor S i he rl ng . u i l pub l ~ s hed na l y t~ c a l es u l t s . S r he r mg KG, Be r l ~ n 982
M a ll or y. G l e x Ha: la ry t al , s tudies nd P r o p e r t i e s o f Very H ar d E l ec t r o l es s
Nickel
D e p a i c t r
EN'95. ( lardner Management. Cinclnn at. OH 1995
FIG X2 1
Density
of
Autocatalytic Nickel Phosphorus Alloy Summaw of Reported Values
7/24/2019 ASTM B733 Electroless Nickel Plating
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X3
H RDNESS VERSUS HE T TRE TMENT
HARDNESS
OF
ELECTROLESSICKEL
v
TEMPERATURE
TYPE
OO
I ' 1
1 2 3 OO 5
TEMPERATUREC) I HOUR
FIG. X3 1 Hardness of Autocatalytic Nickel Phosphorus Versus Heat Treatment Versus Phosphorus
X4
L L OY T Y P E S
NOTE
X?
-lllese d~fferentlloy
TYPES are
produeed from processes point . These di5erences are produced by micro s t ructural
which are specifically formulared and controlled. Additional requirements
d i5 er en ce s b etw een ~i N i 3 p a nd ~ i 3 ph~~~ differences
f r internal mess purity and elong tion
may
be
necessary
for same
applicarions.
also effect non-destmcti\ e thickne ss resting by X-Ray and
magnet ic means . Careful a t tent ion to the select ion of TYPE
X4.1
The physical di fferences of these TYPE S provide for mill insure opt imu m pe rfo nn ai~ ce f the deposi t in the intended
a wide variation in perform ance in wire bonding contac t
application.
resistance machineability lubricity reactivation and melting
7/24/2019 ASTM B733 Electroless Nickel Plating
11/13
H RDNESS STRENGTH
M GNETICS TYPES
L O W HIGH O F R R O
MAGNETIC MAGNETIC
FIG
X4 1 Selected Properties of s Plated utocatalytic Nickel Phosphorus Coatings by Phosphorus Content
X5 SU MMA R Y PR O G R A M
4
X5.1 Results o 110 Mo17lh Exposrtrr
o f
Aulocatalylic
Nickel Deposits a/ Kurv Beach North Caiolina:
X5.1.1 Program 14 is part of an ongoing marine exposure
testing process at the 75 m site at LaQ ue Ceriter for Corrosion
echnology, Wrightsville, N C (Kure Beach). The program
called for the plating of both Type IV and Type V deposits on
standard smooth and ground steel Q Panels.
X5.1.2 There were nine different sources of deposits, each
providing five lots of five panels. Th e program involved plating
12.5, 25, and 75 pm thicknesses on smooth and ground surface
and one smo oth lot heat treated for hardn ess at 5 50 C for 2 11.
The heat treatment temperature was considerably higher than
typical processing and was chosento evaluate the formation of
diffusion products of iron, nickel and phosphorus.
X5.1.3 The following matrix of test panels were prepared
and exposed with subsequent analysis for alloy and thickness.
Panels were rated at Kure Beach each year by a team from
A ST M Committee using Practice B 537.
X5.1.4 Th e interpretation o f the results of these exp osure
test should be made on the basis of general performance of the
coating on panels. Base metal condition, undercoats, surface
preparation, arid post processing all have a significant effect on
the performance and should be given careful consideration
whe n designing the part and pretreatment processing sequence.
7/24/2019 ASTM B733 Electroless Nickel Plating
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TABLE X5.1 R e s u l t s o f 110 M o n t h E x p o s u r e
of
A u t oc a t a l y ti c (E l ec t ro l es s ) N i c k e l Depo s i t s a t Kure B eas h , No l t h Ca ro li naA
P ~ O S D ~ O R I Slloy
%wf
Ractice
Source Lot
Heal
Thickness, Thickness,
Deposit Type
B 537
Treatment
pm Target
pm
Actual
ICP
Ralings 110
E D M Months
1 Smoolh NO 12.5 3.6
1 3 0
Smooth
Smoolh
Smoolh
Ground
Smaath
Smooth
Smooth
Smooth
Ground
Smoolh
Smoolh
Smooth
Smooth
Ground
Smooth
Smooth
Smooth
Smooth
Ground
Smooth
Smooth
Smaath
Smooth
Ground
Smoolh
Smooth
Smooth
Smooth
Ground
Smoolh
Smooth
Smoolh
Smooth
Ground
Smoolh
Smooth
Smoath
Smooth
Ground
1 Smooth
No
12.5
2 Smooth
No
25
3 Smooth
No
75 80 7.1
4
Smooth Yea 25
5 Gro.nJ
ro
23 L O
Te ronr
.,on
'rum in s mar
r e
e x v o s ~ r c o g r m
l a. o w n
s.mmanzro
o)
Dr
George ) B a n
ol h :D
11 s
caper Mar :on05
o
i2etiormnn~r.1
C h :os.t nq
o r
Slce
F
r a Reporl
un
ASTM Fogr l - 14
ho
r h s DrcSPnleJ al i h r l
(:oo c.enre
P r o L r F
n s n
1.2
REFERENCES
(1) Symposium on Elecnolesr Nic ke l Plat ing, AS TM STP 265 ASTM,
12644 Research Parkway, Orlando,
FL
32826, 1986 Chapter 23.
1959.
(5)
M al l a r y
G.
and
Ha jd uI . Elecholess Plaling. . lESF 12644 Research
(2)
D ? ~ i ~ ~ r e r - i , i gl.oprr-lies q(E1ecnuless Nickei, Th e lntem arianal N ick el
Parkway. Orlando, F L 32826. 1990.
Ca.,
Inc.
Ncw York, N'i
(6)
Parker, K,~ ardness and ear Rerirra nce Tests
of
Elecrrolers N ickel
(3) Gawri lav , C. G. C l ~ e n ~ i c o lE lecnu lers ) N i d e l P lo ting , Pancu l l i s
Deposits, P lo r i ,? ~, ol 6 1 September 1971.
Press, London. 1974.
7 )
Parker,
K.,
Effects
of
Hea t Treatment on the Prapenier
of
Eiecrroiess
4)
Safranek,
W
H.. Tile P,-oper-ties
o
Elecnadeposired hf~:Iolr
orzd
Nl cke l Deposits.
Plorisg orzd B,r;/ cr
Fi,iishirrg. Vol 68, Decembe r
A/lr,~..
7/24/2019 ASTM B733 Electroless Nickel Plating
13/13
ASTM inleroa1,Onal lakes
no
position respecling lhe validity of any paten1 ghlr asserted n conneclion wih any rlem mentioned
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sfandaid are expressly adwsed lhal deleiminalion of ihe vaiidi ly of any su h palent rlqhls, and lhe nsk
of infnngemeol of such rights, are enl~rely heii own rerpoosibil,ly
This sleodard K subjecl to revision a1 any time by lhe iesponslbie lechnicai comminee and musl
t
eviewed eveiy five years and
if no1 revised, either reaowved r wrhdrawr~. our commenls re invited miher t rrevision oi his slandaid r for oidditiooal standards
and should be addressed lo ASTM lnlemal~onalHeadquarlers. Youimm menls Wli receive camfvl mosideiation a1
a
meeling of me
iesponsibie lecnnicai cornmillee, whrch you may anend if you feel ihal your mmmeotr have
ot
received
a
f ir heai~ng ou should
make your views known lo the ASTM Commitlee n Standards, a1 the address shown below
This slarldard is copyrighled by ASTM lnternaliononai. W an aao i Drive. PO
ox
C700, West Cooshohocken, PA 19428-2959,
Uoiled Slales. i,ldivrdual iepi;nls (singie
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muiupie copies)of lhrs standard may
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oblamed by coolacting ASTM a1 h e
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