ASTM_B_254_-_92_2014.pdf

Designation:B25492(Reapproved 2014)Endorsed by AmericanElectroplaters SocietyEndorsed by National Associa-tion of Metal FinishersStandard Practice forPreparation of and Electroplating on Stainless Steel1This standard is issued under the fixed designation B254;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript 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.Scope1.1 Various metals are electrodeposited on stainless steel forcolor matching,lubrication during cold heading,spring-coilingand wire-drawing operations,reduction of scaling at hightemperatures,improvement of wettability(as in fountain pens),improvement of heat and electrical conductance,prevention ofgalling,jewelry decoration,and prevention of superficialrusting.1.2 This practice is presented as an aid to electroplaters andfinishing engineers,confronted with problems inherent in theelectrodeposition of metals on stainless steel.It is not astandardized procedure but a guide to the production of smoothadherent electrodeposits on stainless steel.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A380 Practice for Cleaning,Descaling,and Passivation ofStainless Steel Parts,Equipment,and Systems3.Nature of Stainless Steel3.1 Because previous metal treatment may have a morepronounced effect on the final finish when stainless steel isbeing electroplated,the metal finisher should become ac-quainted with the fabrication procedure,grade,and mill finishof the stainless steel with which he is working before outlininghis electrodeposition procedure(see Appendix X1).3.2 Stainless steel surfaces are normally resistant to a widevariety of corrosive elements.This property is the result of athin transparent film of oxides present on the surface.Becausethis film rapidly reforms after it has been stripped off orpenetrated,it protects stainless steel against corrosion.Anadherent electrodeposit cannot be obtained over the oxide filmnormally present on stainless steel.However,once this film isremoved by surface activation and kept from reforming whilethe surface is covered with an electrodeposit,any of thecommonly electroplated metals may be electrodeposited suc-cessfully on stainless steel.3.3 Where the finished product is to be subjected to severeexposure,the deposit produced by the proposed electroplatingsequence should be tested under similar exposure conditionsbefore adoption,to determine whether the natural corrosionresistance of the stainless steel has been impaired by thepresence of the electrodeposit.4.Nature of Cleaning4.1 The preparation of stainless steel for electroplatinginvolves three basic steps in the following order:4.1.1 Removal of scale.If scale removal is necessary,one ofthe methods outlined in Appendix X2 may be used(Note 1).See also Practice A380.4.1.2 Removal of oil,grease,or other foreign material bycleaning,and4.1.3 Activation immediately before electroplating.4.2 PrecleaningRemoval of fabricating lubricants andfinishing compounds from the stainless steel may have to beundertaken immediately following the fabrication or finishingoperation(Note 2).4.3 ElectrocleaningAnodic cleaning is generally preferred(Note 3).4.4 Metal LubricantsMetal lubricants such as copper,lead,or cadmium,applied to stainless steel wire for coldheading,wire drawing,or spring forming are removed by1This practice is under the jurisdiction of ASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.02 onPre Treatment.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 1951.Last previous edition approved in 2009 as B25492(2009).DOI:10.1520/B0254-92R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 immersion in a solution of 200 mLof concentrated,67 mass%,nitric acid(density 1.40 g/mL)diluted to 1 Lat 50 to 60C.SeePractice A380.NOTE1Oil,grease or other fabricating lubricants should be removedby cleaning before heat treating.NOTE2Spray cleaning with a nozzle pressure of 200 to 400 kPa(30to 60 psi)in a power washer,using an alkaline or emulsion-type cleaner,is the generally preferred method,especially for the removal of heavydrawing,buffing,or polishing compounds.Soak cle