ASTM_B_296_-_03_2014.pdf

Designation:B29603(Reapproved 2014)Standard Practice forTemper Designations of Magnesium Alloys,Cast andWrought1This standard is issued under the fixed designation B296;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.1.Scope1.1 This practice covers a system for designating the tem-pers of magnesium alloys,cast and wrought.The designationsused in ASTM specifications under the jurisdiction of Com-mittee B07 for magnesium alloy castings and wrought productsconform to this practice.22.Basis of Codification2.1 The designations for temper are used for all forms ofmagnesium and magnesium-alloy products except ingots andare based on the sequence of basic treatments used to producethe various tempers.2.2 The temper designation follows the alloy designation,the two being separated by a dash.2.3 Basic temper designations consist of letters.Subdivi-sions of the basic tempers,where required,are indicated by adigit or digits following the letter.These designate specificsequences of basic treatments,but only operations recognizedas significantly influencing the characteristics of the productare indicated.Should some other variation of the same se-quence of basic operations be applied to the same alloy,resulting in different characteristics,then additional digits areadded to the designation.NOTE1In material specifications containing reference to two or moretempers of the same alloy which result in identical mechanical properties,the distinction between the tempers should be covered in suitableexplanatory notes.2.4 The temper designations and the subdivisions are fullydefined and explained in Table 1.A brief outline for quickreference is given in Table 2.1This practice is under the jurisdiction of the ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.04 onMagnesium Alloy Cast and Wrought Products.Current edition approved May 1,2014.Published June 2014.Originallyapproved in 1954.Last previous edition approved in 2008 as B296 03(2008).DOI:10.1520/B0296-03R14.2The designations used in ASTM Committee B07 specifications for aluminum-alloy wrought and cast products conform to the American National StandardH 35.1/H 35.1(M).Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 TABLE 1 Temper DesignationsFAs Fabricated Applies to products that acquire some temper from shaping processes not having special control over the amount of strain hardeningor thermal treatment.OAnnealed,RecrystallizedApplies to the softest temper of wrought products.HStrain Hardened(Wrought Products Only)Applies to products that have their strength increased by strain hardening with or without supplementarythermal treatments to produce partial softening.Two or more digits always follow the H.Subdivisions of the 9H9 Temper:H1Strain Hardened OnlyApplies to products that are strain hardened to obtain the desired mechanical properties without supplementary thermaltreatment.The number following this designation indicates the final degree of strain hardening.H2Strain Hardened and Then Partially AnnealedApplies to products that are strain hardened more than the desired final amount and then reduced instrength to the desired final amount by partial annealing.The number following this designation indicates the final degree of strain hardening remaining after the product has been partially annealed.H3Strain Hardened and Then StabilizedApplies to products that are strain hardened and then stabilized by a low temperature heating to slightly lowertheir strength and increase ductility.This designation applies only to alloys which,unless stabilized,gradually age soften at room temperature.The number following this designation indicates the degree of strain hardening remaining after the product has been strain hardened a specificamount and then stabilized.Subdivisions of the 9H1,9 9H2,9 and 9H39 Tempers:The digit following the designations 9H1,9 9H2,9 and 9H39 indicates the final degree of strain hardening.Tempers between 0(annealed)and 8(full hard)are designated by numerals 1 through 7.Material having a strength about midway between that of the 0 temper and that of the 8 temper is designated by thenumeral 4(half hard);between 0 and 4 by the numeral 2(quarter hard);between 4 and 8 by the numeral 6(three-quarter hard);and so forth.The third digit,when used,indicates a variation of a two-digit H temper.It is used when the degree of control of temper or the mechanical propertiesare different from but close to those for the two-digit H temper to which it is added.Numerals 1 through 9 may be arbitrarily assigned for an alloy and productto indicate a spec