1、Designation:B 724 00(Reapproved 2006)Standard Test Method forIndentation Hardness of Aluminum Alloys by Means of aNewage,Portable,Non-Caliper-Type Instrument1This standard is issued under the fixed designation B 724;the number immediately following the designation indicates the year oforiginal adopt
2、ion or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers indentation hardness testing ofaluminum alloys using a
3、Newage,portable,non-caliper-type,hardness instrument which provides readout values numeri-cally equivalent to Rockwell B-scale as determined by TestMethods E 18.NOTE1This is a comparative Rockwell B test and does not providean actual Rockwell B test value.HRBN,the values obtained from theNewage inst
4、rument,are numerically equivalent to Rockwell B values,butdo not represent an actual Rockwell B test in accordance with TestMethods E 18.1.2 This test method measures indentation hardness ofheat-treatable aluminum alloys having a hardness from 30 to100 HRBN,a thickness greater than 1.50 mm(0.060 in.
5、),andpieces too large to be tested by a caliper type instrument.NOTE2This test method covers two instruments(one analog and onedigital)which operate differently.Refer to the manufacturers instructionfor proper operation.1.3 The flat surface size of the area being tested must becompatible with the in
6、strument support area and the materialmust not deflect during the test.1.4 The values stated in SI units are the standard.The valuesgiven in parentheses are for information only.2.Referenced Documents2.1 ASTM Standards:2B 648 Test Method for Indentation Hardness of AluminumAlloys by Means of a Barco
7、l ImpressorE 18 Test Methods for Rockwell Hardness and RockwellSuperficial Hardness of Metallic MaterialsE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definit
8、ions:3.1.1 Definitions of terms relating to hardness testing ap-pearing in Test Methods E 18 shall apply to terms used in thistest method.3.1.2 HRBNThe suffix“N,”added to the HRB scaledesignation,indicates hardness numbers derived using this testmethod which can be related to,but are not necessarily
9、identical to,Rockwell-B(HRB)values obtained in accordancewith Test Methods E 18.When reporting results derived usingthis test method,this designation should follow the numericvalue.4.Summary of Test Method4.1 A portable hand-held and hand-operated instrumentrests firmly upon an aluminum alloy surfac
10、e.The manualdownward movement of the tester in a steady,even andsynchronous manner toward the surface moves a penetratorinto the surface.Depth of penetration between preload and fullload as reflected on the display of the unit,(dial or digital)is anindication of the hardness value.4.1.1 The indicato
11、r of dial read-out units is read while thetester is in the fully depressed position,while the digitaldisplay of digital read-out units is read when the tester is in thefully released position,since the reading is automaticallylocked in at the preload position as the unit is being released.NOTE3Anoth
12、er portable non-caliper-type instrument is employed inTest Method B 648.One hand is used to operate the instrument.Hardnessnumbers are given as Barcol Impressor readings.5.Significance and Use5.1 The instrument may be used on a variety of geometriesof aluminum alloy test pieces,providing the surface
13、 beingtested has proper support for the instrument.1This test method is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.05 onTesting.Current edition approved Sept.1,2006.Published September 2006.Originallyapproved in 1983.La
14、st previous edition approved in 2000 as B 724 00.2For 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.1Copyright ASTM I
15、nternational,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.Copyright by ASTM Intl(all rights reserved);Thu Apr 16 06:48:36 EDT 2009Downloaded/printed byLaurentian University pursuant to License Agreement.No further reproductions authorized.5.2 This test method is in
16、tended for quality assurance andproduction control purposes.This test method is not intendedto be an independent material-acceptance test.5.3 The thickness of the test piece shall be such that a markor bulge is not produced on the reverse side of the test pieceand the test piece does not deflect during the test.5.4 Calibration of the instrument through the use of refer-ence blocks is required for true comparative hardness values.6.Apparatus6.1 Newage,Portable,NonCaliperType Instrument,con-tainin
