1、Designation: A 833 84 (Reapproved 2001)Standard Practice forIndentation Hardness of Metallic Materials by ComparisonHardness Testers1This standard is issued under the fixed designation A 833; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 practice covers the determination of indentationhardness of metallic materials using compar
3、ison hardnesstesters.1.2 This practice applies only to those comparison hardnesstesters, normally portable, that use standardized test blocks inaccordance with Test Method E 10 as a basis for comparison.1.3 Calibration of comparative test bars (rods), used forcomparison to determine hardness numbers
4、, is also covered bythis practice.1.4 The indenting force used during comparison hardnesstesting is normally an impact load applied by striking ahammer at the appropriate areas as outlined in the manufac-turers instructions. Final indentation diameter in both thecomparative test bar and material tes
5、ted shall be within therange of the comparator used for the instrument.1.5 This standard does not purport to address all of thesafety problems, 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 th
6、e applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:A 370 Test Methods and Definitions for Mechanical Testingof Steel Products2E 10 Test Method for Brinell Hardness of Metallic Materi-als33. Apparatus3.1 Comparison hardness testers are used principally f
7、ortesting articles that are too large or unwieldy to be tested in theusual types of testing machines, for testing parts of fixedstructures, or for testing under any conditions that require thatthe indenting force be applied in a direction other than vertical.3.1.1 Required equipment includes an appa
8、ratus that con-tains the Brinell ball and a slot or spacing to insert thecalibration bar, the bar and an impacting tool, normally ahammer. This apparatus is designed to allow a ball impressionto be produced on the standard rod simultaneously with oneproduced on the piece to be tested. Calibration ta
9、bles (sliderule) are used to compare impression diameters and thehardness of the calibration bar to determine the hardness of thepiece.3.1.2 This apparatus is designed with a surface directlyabove the Brinell ball where impact is to occur. The apparatusmay also be designed to include an extension fo
10、r stabilization.3.2 Measuring MicroscopeThe divisions of the microme-ter scale on the microscope, or other measuring devices usedfor the measurement of the diameter of the impression, shallpermit the direct measuring of the diameter to 0.1 mm and theestimation of the diameter to 0.02 mm. This requir
11、ementapplies to the construction of the microscope only and is not arequirement for measurement of the impression.4. Test Parts4.1 Parts tested by this hardness testing practice vary greatlyin form since it is frequently desirable to make the impressionupon a part to be used in the finished product
12、rather than upona sample test specimen.4.1.1 DimensionsThe thickness of the tested part shall besuch that no bulge or other marking showing the effect of theload appears on the side of the piece opposite the impression.In any event, the thickness of the part shall be at least ten timesthe depth of t
13、he indentation. The minimum width shall be atleast two and one half times the diameter of the indentation.4.1.2 FinishWhen necessary, the surface on which theimpression is to be made shall be filed, ground, machined, orpolished with abrasive material so that the edge of theimpression shall be define
14、d clearly enough to permit themeasurement of the diameter to the specified accuracy. Takecare to avoid overheating or cold working the surface. Suffi-cient metal shall be removed to eliminate decarburized metal.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel,
15、and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Oct. 4, 1984. Published December 1984.2Annual Book of ASTM Standards, Vol 01.03.3Annual Book of ASTM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Dr
16、ive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 SupportAll parts to be tested shall be adequatelysupported to prevent any movement or deflection duringapplication of the impact load.5. Verification of Apparatus and Calibration ofComparative Bars5.1 VerificationThe hardness-test
17、ing apparatus and testbars shall be calibrated in accordance with Test Method E 10prior to use when new, upon replacement of the ball indentor,and periodically during usage as deemed necessary.5.2 Comparative BarsHardness of comparative bars(rods) shall be determined by the manufacturer on at least
18、oneface at approximately the mid-length of the bar. The ends of thebar shall be permanently marked with the hardness number bythe manufacturer prior to shipment. The user shall check thehardness on each additional face to be used prior to testing inaccordance with Test Method E 10. If the hardness o
19、f a face isnot within 62 % of the marked hardness number, the face shallnot be used for part testing.6. Procedure6.1 Assemble the comparative bar into the apparatus mak-ing sure a minimum distance of no less than 5 mm will existbetween diameter of the impression to be made and any otherindentations
20、on the face. Minimum distance of the indentationdiameter from the edge of the part tested shall be 12.5 mm. Ifthe apparatus is equipped with a presetting bar stop, ensure thefixture is properly in place. Place the apparatus on the surfaceof the component to be tested and apply the impact load. It is
21、essential to apply a well guided, short blow in order to avoid arebound and thus a double blow that may produce an erroneousresult by damaging the sharp edge of the ball impression.6.2 Impression DiameterThe diameter of the impressionproduced on the comparative bar should not exceed 4.2 mm. Ifa larg
22、er impression is produced, the comparative bar may giveway laterally and the test result may be in error.6.3 MeasurementsMeasurement of the impression diam-eters shall be in accordance with Test Methods and DefinitionsA 370.6.4 Determination of Part HardnessEmploying the cali-bration device supplied
23、 by the manufacturer for the apparatus,determine the hardness of the part by comparing both impres-sion diameters and the hardness of the comparative bar.Accuracy can be improved by using a comparative bar with ahardness number within thirty Brinell (HB) numbers of the parttested.6.4.1 Analytical Ha
24、rdness DeterminationAnalytically, thehardness of the part being tested may be determined from thefollowing equation:B15 B210 =100 D12!/10 =100 D22!B1= indentation hardness of the part being tested,B2= Brinell hardness of the comparative bar,D12= diameter of impression in the comparative bar,D22= dia
25、meter of impression in the part being tested.7. Report7.1 The report shall include the following information:7.1.1 Indentation hardness number of the component andthe Brinell hardness number of the comparative bar,7.1.2 Identification of the manufacturers equipment, and7.1.3 Diameters of the indenta
26、tions in the component andcomparative bar.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and t
27、he riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision
28、of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shoul
29、dmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 833 84 (2001)2
