ASTM_B_322_-_99_2014.pdf

Designation:B32299(Reapproved 2014)Endorsed by AmericanElectroplaters SocietyEndorsed by NationalAssociation of Metal FinishersStandard Guide forCleaning Metals Prior to Electroplating1This standard is issued under the fixed designation B322;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.INTRODUCTIONThis guide is intended to illustrate general principles of cleaning prior to electroplating.It is notmeant to apply to every specific application.In specific cases,cleaning practice may depart from thegeneral principles given in this guide.1.Scope1.1 This guide describes the procedure for cleaning metalsurfaces to obtain good adhesion of electrodeposited metals.The degree of cleanliness required for metals to be electro-plated is greater than for most other finishes.Methods ofremoval of heat-treat or mill scale are not included in thesemethods,because they are covered in practices referring tospecific metals.It should also be understood that while theseprocedures are broadly applicable,particular substrates mayrequire certain specific cleaning procedures.1.2 Adequate cleaning requires a proper combination ofcleaning procedures.The choice of these procedures must bebased on a knowledge of the metals to be cleaned and of thesoils to be removed.Because most experience and knowledgein cleaning have been obtained by suppliers of proprietaryprocesses and formulations,these sources should be consultedbefore setting up a cleaning process.1.3 Atreatment to remove tarnish,light rust,fingerprints,oroxides is usually provided before immersion of the piece in theelectroplating tank.This treatment activates the metal and isusually accomplished in acid baths which also serve toneutralize the residual alkaline film from alkaline cleaning.Alkaline chelated derusting and cleaning solutions,alone orwith sodium cyanide,used as a soak or electrocleaner,are oftenpreferred before electroplating on ferrous alloys.1.4 Invariably several stages are necessary to provide ad-equate cleaning.These stages are discussed in three parts:Part IPrecleaning(use of a solvent,emulsion,or alkalinespray)to remove the bulk of the soil.Part IIIntermediate(alkaline)cleaning.Part IIIFinal electrocleaning,to remove trace solids andespecially adherent impurities.Part IVTrouble shooting.Often,depending largely on the amount and type of soil onthe workpieces as received,one or more of these stages may beeliminated or modified.Usually,even with light soils,it isadvisable to retain multistage cleaning,thereby increasing thelife and efficiency of the cleaning solutions.1.5 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.(For more specificsafety precautionary statements see Sections 11 and 16.)2.Significance and Use2.1 The performance and quality of electroplated articlesdepend upon the surface cleanliness and condition.Variousmetals are electroplated for decorative or engineering finishes.The common electroplates applied are usually copper,nickel,and chromium for decorative and functional uses.Electro-plated articles are used in many industries such as the marine,automotive,plumbing fixtures,and appliance industries.3.Nature of the Soil3.1 Some of the soils commonly encountered in electroplat-ing are:3.1.1 Solid buffing compounds containing waxes,fattyacids,and abrasives.3.1.2 Liquid buffing compounds.3.1.3 Drawing and stamping compounds including thosecontaining fillers(pigments).1This guide is under the jurisdiction of ASTM Committee B08 on Metallic andInorganic Coatings and is the direct responsibility of Subcommittee B08.02 on PreTreatment.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 1958.Last previous edition approved in 2009 as B322 99(2009).DOI:10.1520/B0322-99R14.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.4 Machining oils.3.1.5 Rust-preventive slushing oils or greases.3.1.6 Electroplaters stop-off residues.3.1.7 Fingerprints.3.1.8 Dry dirt from storage or dry pickling smut formedduring derusting by pickling.3.1.9 Rust or oxide scales,especially admixed with oil,including heat-treat scales after oil quenching.3.1.10 Phosphate coating with or without lubricant.3.1.11 Smut resulting from improper vapor degreasing ofheavily buffed work.3.1.12 Smut resulting from annealing parts without pre-cleaning between drawing operations.3.1.13 Heat-treating salts,with or without quenching oils.3.2 Consideration sho