ASTM_A_428_-_A_428M_-_10_2014.pdf

Designation:A428/A428M10(Reapproved 2014)Standard Test Method forWeight Mass of Coating on Aluminum-Coated Iron or SteelArticles1This standard is issued under the fixed designation A428/A428M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,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.Scope1.1 This test method covers procedures for determining theweight mass of coating on aluminum-coated iron or steelsheets and wire,and on other aluminum-coated iron and steelarticles.1.2 The final results determined by this test method shall beexpressed in inch-pound units or SI units,depending on theunits used in the material specification to which the results areto be compared.Certain portions of the procedure involvingdetermination of specimen weight mass have traditionallybeen performed in SI units,and corresponding inch-poundunits are not included.1.3 For sheet products,the final results are expressed aseither coating weight mass total both sides,or coating weightmass separately on each side,depending on the specifiedrequirements.1.4This 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 a specificprecautionary statement,see Note 1.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 This test method provides a standard method of deter-mining the weight mass of coating for comparison withspecification requirements.A coating of aluminum on iron orsteel articles provides protection against corrosion by forminga relatively inert barrier.Specifications for aluminum-coatedarticles occasionally provide for different classes(weights)masses of coating so that the purchaser can select the coatingweight mass most suited to his needs.The heavier coatingwill provide greater protection against mechanical damagewhich may break the coating.4.Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4.2 Purity of WaterWater used in preparation of reagentsolutions shall conform to Specification D1193,Type IV orbetter.4.3 Antimony Trichloride SolutionDissolve 200 g of anti-mony trichloride(SbCl3)in 1000 mL of concentrated hydro-chloric acid(HCl,sp gr 1.18 to 1.19)without heating.4.4 Hydrochloric Acid(sp gr 1.18 to 1.19)Concentratedhydrochloric acid(HCl).1This test method is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.07 on Methods of Testing.Current edition approved Aug.1,2014.Published September 2014.Originallyapproved in 1958.Last previous edition approved in 2010 as A428/A428M 10.DOI:10.1520/A0428_A0428M-10R14.2For 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.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmaceutical Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.5 Sodium Hydroxide Solution(20%)Dissolve 20 partsby weight mass of sodium hydroxide(NaOH)in 80 parts ofwater.4.6 Stannous Chloride SolutionDissolve 100 g of stan-nous chloride(SnCl22H2O in 1000 mL of concentrated hydro-chloric acid(HCl,sp gr 1.18 to 1.19)without heating.Add afew granules of reagent grade tin.4.7 Hydrochloric Acid(1+1)Mix 500 mL of HCl(sp.gr.1.18 to 1.19)with 500 mL of reagent water and cool to roomtemperature.NOTE1Warning:Small amounts of the poisonous gas stibine(SbH3)may be evolved during the stripping