ASTM_B_633-98.pdf

46B633APPENDIXES(Nonmandatory Information)X1.SERVICE LIFE OF ZINCX1.I The service life of zinc coating is a function of itsvalues are only relative,since individual studies in variousthickness and the type of environment to which it is exposed.parts of the world have resulted in figures which vary widelyWhile the conditions of exposure and uses of electroplatedfrom these averages.metal are so varied that it is not definitely possible to predictAtmosphereMean Corrosion Ratethe exact life of articles protected by a coating of a giventhickness,those using zinc coatings can draw on the wealth ofIndustrial5.6 um/yearUrban nonindustrial or marine1.5 um/yearpractical experience at hand,supplemented by results ofSuburban1.3 um/yearcorrosion tests carried out over the years.As a result ofRural0.8 um/yearlarge-scale and long-range tests conducted by ASTM and otherIndoorsconsiderably less than 0.5 um/yearorganizations,there is excellent information on the corrosionNorE X1.1-The mean corrosion rate given pertains to zinc only andbehavior of zinc and zinc coatings.The following data,baseddoes not include a corrosion rate when zinc is passivated or in contact withon worldwide testing,may be used to compare the behavior ofother materials.electrodeposited coatings of zinc in various atmospheres.TheX2.EXAMPLES OF APPROPRIATE SERVICE CONDITIONS AND DESCRIPTION OF SERVICE CONDITIONSX2.1 SC 4-Very Severe-Exposure to harsh conditions,orX2.3 SC 2-Moderate-Exposure mostly to dry indoorsubject to frequent exposure to moisture,cleaners,and salineatmospheres but subject to occasional condensation,wear.orsolutions,plus likely damage by denting,scratching,or abra-abrasion.Examples are:tools,zippers,pull shelves,machinesive wear.Examples are:plumbing fixtures,pole line hard-partsware.X2.2 SC 3-Severe-Exposure to condensation,perspira-X2.4 SC/-Mild-Exposure to indoor atmospheres withtion,infrequent wetting by rain,and cleaners.Examples arerare condensation and subject to minimum wear or abrasion.tubular furniture,insect screens,window fittings,buildersExamples are:buttons,wire goods,fasteners.hardware,military hardware,washing machine parts,bicycleparts.The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard.Users of this standard are expressly advised that determination of the validity of any suchpatent rights,and the risk of infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards,at the address shown below.This standard is copyrighted by ASTM,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at610-832-9585(phone),610-832-9555(fax),or serviceastm.org(e-mail);or through the ASTM website(www.astm.org).e with ASTMUcensce-SEOUL NATL UNI9986257001No roproduction or notworking permitled without liconso from IHSNot for Rotale.08/13/2006 08:31:11 MDT