ASTM_B_917_-_B_917M_-_12.pdf

Designation:B917/B917M12Standard Practice forHeat Treatment of Aluminum-Alloy Castings from AllProcesses1This standard is issued under the fixed designation B917/B917M;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.Scope*1.1 This practice covers,when specified by material speci-fication or purchase order,the heat treatment of aluminumalloy castings from all casting processes.1.1.1 The heat treatment of aluminum alloy castings used inspecific aerospace applications is covered in AMS 27712andspecific AMS2material specifications.1.1.2 The heat treatment of wrought aluminum alloys iscovered in Practice B918/B918M.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.2.1 SI UnitsThe SI units are shown in brackets or inseparate tables.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 The following documents of the issue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:3B26/B26M Specification for Aluminum-Alloy Sand Cast-ingsB108/B108M Specification for Aluminum-Alloy PermanentMold CastingsB275 Practice for Codification of Certain Zinc,Tin and LeadDie CastingsB557 Test Methods for Tension Testing Wrought and CastAluminum-and Magnesium-Alloy ProductsB557M Test Methods for Tension Testing Wrought and CastAluminum-and Magnesium-Alloy Products(Metric)B618/B618M Specification for Aluminum-Alloy InvestmentCastingsB686/B686M Specification for Aluminum Alloy Castings,High-StrengthB881 Terminology Relating to Aluminum-and Magnesium-Alloy ProductsB918/B918M Practice for Heat Treatment of Wrought Alu-minum AlloysB955/B955M Specification forAluminum-Alloy CentrifugalCastingsB969 Specification for Aluminum-Alloy Castings Producedby the Squeeze Casting,Thixocast and Rheocast Semi-Solid Casting ProcessesG110 Practice for Evaluating Intergranular Corrosion Resis-tance of Heat Treatable Aluminum Alloys by Immersionin Sodium Chloride+Hydrogen Peroxide Solution2.3 ANSI Standard:H35.1 Alloy and Temper Designation Systems for Alumi-num42.4 SAE Standard:AMS 2771 Heat Treatment of Aluminum Alloy Castings3.Terminology3.1 Definitions:3.1.1 Refer to Terminology B881 for terminology relating tothe heat treatment of castings.1This practice is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.01 onAluminum Alloy Ingots and Castings.Current edition approved May 1,2012.Published June 2012.Originallyapproved in 2001.Last previous edition approved in 2011 as B917/B917M 11.DOI:10.1520/B0917_B0917M-12.2Available from Society of Automotive Engineers(SAE),400 CommonwealthDr.,Warrendale,PA 15096-0001,http:/www.sae.org.3For 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.4Available from Aluminum Association,Inc.,1525 Wilson Blvd.,Suite 600,Arlington,VA 22209,http:/www.aluminum.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Equipment4.1 Heating MediaAluminum castings are typically heattreated in air chamber furnaces;however,lead baths,oil baths,fluidized beds,or even superheated steam may be used inspecific applications.The use of uncontrolled heating is notpermitted.Whichever heating means are employed,carefulevaluation is required to ensure that the casting respondsproperly to heat treatment and is not overheated or damaged bythe heat treatment environment.Salt baths are not recom-mended for the commercial heat treatment of aluminumcastings in volume.(WarningNitrate baths must not be usedin the heat treatment of 5xx.0 series castings because of theinherent explosion hazard.4.2 Air Chamber Furnacesmay be oil or gas-fired or maybe electrically heated.The atmosphere in air chamber furnacesmust be controlled to prevent porosity resulting from solutionheat treatment.Furnace components that are significantlyhotter than the metal should be suitably shielded for section