1、Designation: A967/A967M 13A967/A967M 17Standard Specification forChemical Passivation Treatments for Stainless Steel Parts1This standard is issued under the fixed designation A967/A967M; the number immediately following the designation indicates the yearof original adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last 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. Scope*1.1 This specificat
3、ion covers several different types of chemical passivation treatments for stainless steel parts. It includesrecommendations and precautions for descaling, cleaning, and passivation of stainless steel parts. It includes several alternativetests, with acceptance criteria, for confirmation of effective
4、ness of such treatments for stainless steel parts.1.2 Practices for the mechanical and chemical treatments of stainless steel surfaces are discussed more thoroughly in PracticeA380A380/A380M.1.3 Several alternative chemical treatments are defined for passivation of stainless steel parts. Appendix X1
5、Appendix X1 andAppendix X2 givesgive some nonmandatory information and provides some general guidelines regarding the selection ofpassivation treatmenttreatments appropriate to particular grades of stainless steel. It This specification makes no recommendationsregarding the suitability of any grade,
6、 treatment, or acceptance criteria for any particular application or class of applications.1.4 The tests in this specification are intended to confirm the effectiveness of passivation, particularly with regard to the removalof free iron and other exogenous matter. These tests include the following p
7、ractices:1.4.1 Practice AWater Immersion Test,1.4.2 Practice BHigh Humidity Test,1.4.3 Practice CSalt Spray Test,1.4.4 Practice DCopper Sulfate Test,1.4.5 Practice EPotassium FerricyanideNitricFerricyanide-Nitric Acid Test, and1.4.6 Practice FDamp Cloth Test, and1.4.7 Practice FGDamp Cloth Boiling W
8、ater Immersion Test.NOTE 1Free iron denotes iron present on the surface of the parts, including but not limited to iron contamination, iron-tool marks, residual-iron saltsfrom pickling solutions, iron dust, atmospheric exposure, iron deposits in welds, embedded iron, and iron oxide.1.5 The values st
9、ated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1
10、.6 The following precautionary caveat pertains only to the test method portions, Section 14 of this specification:This standarddoes not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety
11、 and health practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standar
12、ds, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A380A380/A380M Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and SystemsB117 Practice for Operating Sal
13、t Spray (Fog) Apparatus1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.14on Methods of Corrosion Testing.Current edition approved Feb. 15, 2013July 1, 2017. Published March 2013July 2
14、017. Originally approved in 1996. Last previous edition approved in 20052013 asA967 05A967/A967M 13.2. DOI: 10.1520/A0967-13.10.1520/A0967-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolu
15、me information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequ
16、ately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM I
17、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1B254 Practice for Preparation of and Electroplating on Stainless SteelB600 Guide for Descaling and Cleaning Titanium and Titanium Alloy SurfacesB912 Specification for Passivation of Stainless Steels Usi
18、ng Electropolishing2.2 Federal Specification:3QQ-P-35C Passivation Treatments for Corrosion-Resistant Steels43. Terminology3.1 Definition of Term Specific to This StandardIt is necessary to define which of the several commonly used definitions ofthe term passivation will be used in this specificatio
19、n. (See Discussion.)3.1.1 DiscussionStainless steels are autopassivating in the sense that the protective passive metal oxide film is formedspontaneously on exposure to air or moisture. The presence of exogenous surface contamination, including dirt, grease, free ironfrom contact with steel tooling,
20、 and so forth, may interfere with the formation of the passive metal oxide film. The cleaning of thesecontaminants from the stainless steel surface will facilitate the spontaneous passivation by allowing the oxygen uniform access tothe surface. The passive metal oxide film may be augmented by chemic
21、al treatments that provide an oxidizing environment forthe stainless steel surface.3.1.1.1 In this specification, passivation, unless otherwise specified, is defined as the chemical treatment of a stainless steel witha mild oxidant, such as a nitric acid solution, for the purpose of the removal of f
22、ree iron or other foreign matter, but which isgenerally not effective in removal of heat tint or oxide scale on stainless steel. In the case of stainless steels with additions of sulfurfor the purpose of improved machinability, passivation may also include the removal of sulfides from the surface of
23、 the metal forthe purpose of maximizing corrosion resistance.3.1.1.2 The formation of the protective passive metal oxide film on a stainless steel, also called passivation in a more generalcontext, will occur spontaneously in air or other oxygen-containing environment when the stainless steel surfac
24、e is free of oxidescale and exogenous matter.3.1.1.3 Chemical treatments, such as sodium dichromate solutions, may facilitate the more rapid formation of the passive filmon a stainless steel surface already free of scale or foreign matter. Such treatments, also sometimes called passivation in common
25、usage, are designated as post-cleaning treatments in this specification in order to distinguish them from chemical treatmentscapable of removing free iron from stainless steels.3.1.1.4 The chemical treatments capable of removing heat tint or oxide scale from stainless steel and capable of dissolving
26、 thestainless steel itself, typically called pickling, are substantially more aggressive than treatments used for passivation, as defined in3.1.1.1. The surface of stainless steel that has been pickled is free of scale, free iron, and exogenous foreign matter, and does notrequire a separate treatmen
27、t for passivation as defined in 3.1.1.1. The passivation process defined in 3.1.1.2 will occur withoutfurther chemical treatment but may be augmented and improved by the post-cleaning treatments defined in 3.1.1.3.3.1.1.5 Electrochemical treatments, including electropickling and electropolishing cap
28、able of removing heat tint or oxide scalefrom stainless steel and capable of dissolving the stainless steel itself, are substantially more aggressive than treatments used forpassivation, as defined in 3.1.1.1. The surface of stainless steel resulting from these treatments is free of scale, free iron
29、, andexogenous foreign matter, and does not require a separate treatment for passivation as defined in 3.1.1.1. The passivation processdefined in 3.1.1.2 will occur without further chemical treatment, but may be augmented and improved by the post-cleaningtreatments defined in 3.1.1.3. Statements reg
30、arding chemical treatments, unless otherwise specified, are taken to includeelectrochemical treatments.4. Ordering Information4.1 This specification was written for the purpose of providing an alternative to United States Federal Specification QQ-P-35C.Determination of the suitability of this specif
31、ication for that purpose is the responsibility of the purchaser.4.2 Unless specified by the purchaser, the chemical treatment applied to the stainless steel parts shall be selected by thesellersupplier from among the listed passivation treatments. (See 5.1.)4.3 Unless specified by the purchaser, the
32、 test practice practice(s) and test frequency applied to the stainless steel parts shall beselected by the sellersupplier from among the listed test practices. (See Section 13.)4.4 The purchaser may also specify additional requirements, including the following:4.4.1 Post-cleaning treatments. (See Se
33、ction 10.)4.4.2 Availability of reports and records. (See 5.2.2 and Section 17.)5. Materials and Preparation for Passivation Treatments5.1 The passivation treatments shall be of one or more of the following types. The effectiveness of a particular treatment fora particular grade of stainless steel i
34、n a particular application is demonstrated by meeting the specified testing requirements:3 Available from Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.4 In accordance with QQ-P-35C Notice 3, September 11, 1998, Specification QQ-P-35C is cancelled and Specificati
35、on A967/A967M should be used in its place for DoDactivities other than aerospace applications.A967/A967M 1725.1.1 Treatments in nitric acid solutions (see Section 6),5.1.2 Treatments in citric acid solutions (see Section 7),5.1.3 Treatments in other chemical solutions, including electrochemical trea
36、tments (see Section 8),5.1.4 Rinsing and neutralization (see Section 9), and5.1.5 Post-cleaning treatments (see Section 10).5.2 Materials:5.2.1 The chemicals used for passivation treatments shall produce passivated surfaces that meet the requirements of one or moreof the tests of this specification.
37、 Attention shall be given to maintaining adequate volume, concentration, purity, and temperaturecontrol volume appropriate to the size and amount of stainless steel to be treated. treated, as well as concentration and temperaturecontrol appropriate to the selected treatment. (See Note 2.)NOTE 2Atten
38、tion should also be given to maintaining good cleanliness of the passivation solution to ensure the production of acceptable surfacesthat meet the requirements.5.2.2 The processorsupplier shall maintain a record with regard to concentration and temperature of the passivation solutionsufficient to de
39、monstrate that the specified passivation conditions were maintained for each lot of stainless steel parts processed.Such records shall be available for inspection when specified in the purchase order. The processorsupplier is not required by thisspecification to reveal the precise composition of pro
40、prietary chemical mixtures but shall maintain a unique identification of themixture that will ensure its accurate representation for subsequent use.5.2.3 The processorsupplier shall be responsible for the safe disposal of all material generated by this process.5.3 Preparation for Passivation Treatme
41、nts:5.3.1 TheAny pretreatment methods and procedures used prior to the passivation treatment, including mechanical and chemicalmethods, singly or in combination, for descaling and pickling, shall be in accordance with Practice A380A380/A380M. Whenelectrochemical cleaning is required, it shall be per
42、formed in accordance with Practice B254.5.3.2 The resulting pretreated surface shall be substantially free of oil, grease, rust, scale, and other foreign matter.5.3.3 When the final pretreatment of a part includes pickling of the entire surface of the part, no further passivation treatmentis require
43、d prior to testing of the surface unless specified by the purchaser.6. Treatments in Nitric Acid Solutions6.1 Passivation Treatment:6.1.1 Stainless steel parts shall be treated in one of the following aqueous solutions and maintained within the specifiedtemperature range for the specified time. Wher
44、e immersion is impractical, other methods of maintaining contact between thestainless steel surface and the solution within the specified temperature range for the specified time may be used.6.1.1.1 Nitric 1The solution shall contain 20 to 25 volume percent of nitric acid and 2.5 6 0.5 weight percen
45、t of sodiumdichromate. dichromate dihydrate. The parts shall be immersed for a minimum of 20 min at a temperature in the range from 50to 55C 120 to 130F.6.1.1.2 Nitric 2The solution shall contain 20 to 45 volume percent of nitric acid. The parts shall be immersed for a minimumof 30 min at a temperat
46、ure in the range from 20 to 30C 70 to 90F.6.1.1.3 Nitric 3The solution shall contain 20 to 25 volume percent of nitric acid. The parts shall be immersed for a minimumof 20 min at a temperature in the range from 50 to 60C 120 to 140F.6.1.1.4 Nitric 4The solution shall contain 45 to 55 volume percent
47、of nitric acid. The parts shall be immersed for a minimumof 30 min at a temperature in the range from 50 to 55C 120 to 130F.6.1.1.5 Nitric 5Other combinations of temperature, time, and concentration of nitric acid, with or without other chemicals,including accelerants, inhibitors, or proprietary sol
48、utions, capable of producing parts that pass the specified test requirements.6.2 Water RinseImmediately after removal from the passivating solution, the parts shall be thoroughly rinsed, using stagnant,countercurrent, or spray washes, singly or in combination, with or without a separate chemical tre
49、atment for neutralization of thepassivation media (see Section 9), with a final rinse being carried out using water with a maximum total solids content of 200 ppm.NOTE 3Each of the nitric acid solution treatments listed are recommended for different grades of stainless steel. See X1.3 or X2.1.7. Treatments in Citric Acid Solutions7.1 Passivation Treatment:7.1.1 Stainless steel parts shall be treated in one of the following aqueous solutions and maintained within the specifiedtemperature range for the specified time. Where immersion is impract
