1、Designation:A25510(Reapproved 2014)Standard Test Methods forDetermining Hardenability of Steel1This standard is issued under the fixed designation A255;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numbe
2、r 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 These test methods cover the identification and descrip-tio
3、n of test methods for determining the hardenability of steels.The two test methods include the quantitative end-quench orJominy Test and a method for calculating the hardenability ofsteel from the chemical composition based on the original workby M.A.Grossman.1.2 The selection of the test method to
4、be used for deter-mining the hardenability of a given steel shall be agreed uponbetween the supplier and user.The Certified Material TestReport shall state the method of hardenability determination.1.3 The calculation method described in these test methodsis applicable only to the range of chemical
5、compositions thatfollow:ElementRange,%Carbon0.100.70Manganese0.501.65Silicon0.150.60Nickel1.50 maxChromium1.35 maxMolybdenum0.55 maxCopper0.35 maxVanadium0.20 max1.4 Hardenability is a measure of the depth to which steelwill harden when quenched from its austenitizing temperature(Table 1).It is meas
6、ured quantitatively,usually by noting theextent or depth of hardening of a standard size and shape of testspecimen in a standardized quench.In the end-quench test thedepth of hardening is the distance along the specimen from thequenched end which correlates to a given hardness level.1.5 The values s
7、tated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use
8、.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:2E18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE112 Test Methods
9、 for Determining Average Grain Size2.2 ASTM Adjuncts:ASTM Hardenability Chart3END-QUENCH OR JOMINY TEST3.Description3.1 This test method covers the procedure for determiningthe hardenability of steel by the end-quench or Jominy test.Thetest consists of water quenching one end of a cylindrical testsp
10、ecimen 1.0 in.in diameter and measuring the hardeningresponse as a function of the distance from the quenched end.4.Apparatus4.1 Support for Test SpecimenA fixture for supporting thetest specimen vertically so that the lower end of the specimenis a distance of 0.5 in.(12.7 mm)above the orifice of th
11、ewater-quenching device.A satisfactory type of support for thestandard 1.0-in.(25.4-mm)specimen is shown in Fig.1.NOTE1A suitable support for other sizes and shapes of specimens isshown in Fig.X1.1.4.2 Water-Quenching DeviceAwater-quenching device ofsuitable capacity to provide a vertical stream of
12、water that canbe controlled to a height of 2.5 in.(63.5 mm)when passingthrough an orifice 0.5 in.(12.7 mm)in diameter.A tank of1These test methods are under the jurisdiction of ASTM Committee A01 onSteel,Stainless Steel and Related Alloys and are the direct responsibility ofSubcommittee A01.15 on Ba
13、rs.Current edition approved Oct.1,2014.Published October 2014.Originallyapproved in 1942.Last previous edition approved in 2010 as A255 10.DOI:10.1520/A0255-10R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of
14、ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Standard ASTM Hardenability Charts(812by 11 in.pads of 50 charts)areavailable from ASTM International Headquarters.Order Adjunct No.ADJA0255.Original adjunct produced in 1945.*A Summary of Changes secti
15、on appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 sufficient capacity to maintain the water temperature require-ments of 6.3 with a small pump and control valves will befound satisfactory.The water-supp
16、ly line shall also be providedwith a quick opening valve.5.Test Specimens5.1 Wrought SpecimensEnd-quench specimens shall beprepared from rolled or forged stock and shall represent the fullcross section of the product.If negotiated between the supplierand the user,the end-quench specimen may be prepared froma given location in a forged or rolled product or from acontinuous cast billet.The test specimen shall be 1.0 in.(25.4mm)in diameter by 4.0 in.(101.6 mm)in length,with meansfor hanging it in a
