ASTM_G_110_-_92_2015.pdf

Designation:G11092(Reapproved 2015)Standard Practice forEvaluating Intergranular Corrosion Resistance of HeatTreatable Aluminum Alloys by Immersion in SodiumChloride+Hydrogen Peroxide Solution1This standard is issued under the fixed designation G110;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.1.Scope1.1 This practice covers the procedures for immersion testsin sodium chloride+hydrogen peroxide solution.It is primar-ily for tests of wrought heat treatable aluminum alloys(2XXXand 7XXX)but may be used for other aluminum alloys,including castings.It sets forth the specimen preparationprocedures and the environmental conditions of the test and themeans for controlling them.1.2 This practice is intended for evaluations during alloydevelopment and for evaluating production where it may serveas a control test on the quality of successive lots of the samematerial(see MIL-H-6088 and U.S.Federal Test Method Std.151b).Therefore strict test conditions are stipulated for maxi-mum assurance that variations in results are attributable tolot-to-lot differences in the material being tested.NOTE1This practice does not address sampling or interpretation orsignificance of results.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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:2D1193 Specification for Reagent WaterE3 Guide for Preparation of Metallographic SpecimensE407 Practice for Microetching Metals and AlloysG1 Practice for Preparing,Cleaning,and Evaluating Corro-sion Test SpecimensG15 Terminology Relating to Corrosion and Corrosion Test-ing(Withdrawn 2010)3G67 Test Method for Determining the Susceptibility toIntergranular Corrosion of 5XXX Series Aluminum Al-loys by Mass LossAfter Exposure to NitricAcid(NAMLTTest)G69 Test Method for Measurement of Corrosion Potentialsof Aluminum Alloys2.2 Other Documents:U.S.Military Specification MIL-H-6088 Heat Treatment ofAluminum Alloys4U.S.Federal Test Method,Std.No.151b Method 822.1,Intergranular Corrosion Test for Aluminum Alloys43.Summary of Practice3.1 This practice consists of immersing etched test speci-mens in a sodium chloride+hydrogen peroxide solution for 6or more hours.After immersion,metallographic sections areexamined to determine the extent of intergranular corrosion(see Terminology G15).4.Significance and Use4.1 This practice is especially useful for evaluating theadequacy of quenching when performed on material in theas-quenched condition.The practice may also be used to studythe effect of subsequent thermal processes(for example,paintor bonding cures)or of actual precipitation treatments on theinherent type of corrosion.Intergranular corrosion resistance ofheat treatable aluminum alloys is often directly related to thequenching conditions applied after solution heat treatment andto the subsequent aging treatment.51This practice is under the jurisdiction of ASTM Committee G01 on Corrosionof Metals and is the direct responsibility of Subcommittee G01.05 on LaboratoryCorrosion Tests.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 1992.Last previous edition approved in 2009 as G11092(2009).DOI:10.1520/G0110-92R15.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Standardization Documents Order Desk,Building 4,Section D,700 Robbins Avenue,Philadelphia,PA 19111-5094.5Lifka,B.W.,and Sprowls,D.O.,“Significance of Intergranular Corrosion ofHigh Strength Aluminum Alloy Products,”Localized Corrosion Cause of MetalFailure,ASTM STP 516,1972,pp.120144.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.2 This practice is not well suited for non-heat treatablework hardening aluminum alloys,such as the 1XXX,3XXX,and 5XXX series(see Test Method G67).4.3 This practice does not deal with the interpretation ofresulting intergranular corrosion.The significance of the extentand depth of any intergranular corrosion resulting from this testis to be agreed upon between producer and user.5.Reagents5.1 Reagent grade chemicals sodium chloride(NaCl),70%nitric acid(HNO3),48%hydrofluoric acid(HF),37%hydro-chloric acid(HCl),and 30%hydrogen pero