1、Designation: A833 08a (Reapproved 2014)A833 17Standard Practice Test Method forIndentation Hardness of Metallic Materials by ComparisonHardness Testers1This standard is issued under the fixed designation A833; the number immediately following the designation indicates the year oforiginal adoption or
2、, 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.1. Scope1.1 This practice covers the determination of indentation hardness of metallic mate
3、rials using comparison hardness testers.1.2 This practice applies only to those comparison hardness testers, normally portable, that use comparative test bars that havebeen standardized according to Test Method E10 as a basis for comparison.1.3 Calibration of comparative test bars (rods), used for c
4、omparison to determine hardness numbers, is also covered by thispractice.1.4 The impression force used during comparison hardness testing is normally an impact load applied by striking a hammer onthe appropriate areas as outlined in the manufacturers instructions.1.5 The values stated in SI units ar
5、e to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practic
6、es and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsE10 Test Method for Brinell Hardness of Metallic Materials3. Significance and Use3.1 The comparative hardness
7、test is an empirical dynamic indentation hardness test. Comparative hardness tests provide usefulinformation about metallic materials. This information may correlate to tensile strength, wear resistance, ductility, heat treatmentcondition, or other physical characteristics of metallic materials, and
8、 may be useful in quality control and selection of materials.3.2 Comparative hardness testing at a specific location on a part may not represent the physical characteristics of the whole partor end product.4. Apparatus4.1 Comparison hardness testers are used principally for testing articles that are
9、 too large or unwieldy to be tested in the usualtypes of testing machines, for testing parts of fixed structures, or for testing under any conditions that require that the indentingforce be applied in a direction other than vertical.4.1.1 Required equipment includes an apparatus that contains the im
10、pression ball and a slot or spacing to insert the comparativetest bar (rod), the comparative test bar, a structure to apply the impact (anvil), and an impacting tool, normally a hammer. Thisapparatus is designed to allow a ball impression to be produced on the standard rod simultaneously with one pr
11、oduced on the pieceto be tested. Comparison of the impression diameters together with the hardness of the comparative bar (rod) is used to determinehardness of the part.1 This practice test method is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the d
12、irect responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Oct. 1, 2014Nov. 1, 2017. Published October 2014December 2017. Originally approved in 1984. Last previous edition approved in 20082014as A833 08a(2014). DOI: 10.1520/A0833-08AR1410.1520/A0833-17.2 For r
13、eferencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provid
14、e the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the st
15、andard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.2 The structure to convey the impact to the test bar, impression ball, and part being tested is designed with th
16、e strikingsurface for the impacting tool centered directly above the location of the impression ball.4.1.3 The apparatus may also be designed to include an extension for stabilization.4.1.4 The Brinell hardness of the comparison test bar (rod) used should be within 615% of the anticipated Brinell ha
17、rdness ofthe part being tested, and of the same general type of material.4.1.5 Impression Ball:4.1.5.1 The diameter of the impression ball shall be 10 6 0.01 mm.4.1.5.2 The ball shall be made from steel hardened within the range of 60 to 67 HRC and shall be capable of being used in areasonable numbe
18、r of tests without incurring damage that could affect the results. Use of a tungsten carbide ball may result infracture or spalling of the ball.4.1.5.3 The ball shall be inspected regularly according to the equipment manufacturers recommendations to ensure accuracy.4.2 Measuring MicroscopeThe divisi
19、ons of the micrometer scale of the microscope, or other measuring devices used formeasuring the impression diameter, shall be such as to permit the direct measuring of the diameter to 0.1 mm and the estimationof the diameter to 0.05 mm.5. Test Parts5.1 Parts tested by this hardness testing practice
20、vary greatly in form since it is frequently desirable to make the impression upona part to be used in the finished product rather than upon a sample test specimen.5.1.1 DimensionsThe thickness of the tested part shall be such that no bulge or other marking showing the effect of the loadappears on th
21、e side of the piece opposite the impression. In any event, the thickness of the part shall be at least ten times the depthof the indentation. The minimum width shall be at least two and one half times the diameter of the indentation.5.1.2 FinishWhen necessary, the surface on which the impression is
22、to be made shall be filed, ground, machined, or polishedwith abrasive material so that the edge of the impression shall be defined clearly enough to permit the measurement of the diameterto the specified accuracy.Take care to avoid overheating or cold working the surface. Sufficient metal shall be r
23、emoved to eliminatedecarburized metal.5.2 SupportAll parts to be tested shall be adequately supported to prevent any movement or deflection during application ofthe impact load.6. Verification of Apparatus and Calibration of Test Bars6.1 Verification of ApparatusThe hardness-testing apparatus (inclu
24、ding test bars) shall be verified by performing tests onBrinell blocks that have been standardized according to the requirements of Test Method E10.6.1.1 Full verification of the apparatus shall be performed prior to use when new, and upon replacement of the impression ball.The full verification sha
25、ll include testing at least one Brinell test block 3 times. The average of the three measurements shall bewithin 65 % of the Brinell value of the test block.6.1.2 Periodic verifications are recommended at the beginning of each day the comparative tester is used, or during usage asdeemed necessary. P
26、eriodic verifications should be performed using Brinell test blocks within 615 % of the expected Brinellhardness of the parts being tested. One measurement is satisfactory for periodic testing. The result of the periodic test measurementshould be within 65 % of the Brinell value of the test block to
27、 be considered to be in compliance with this practice.6.2 Calibration of Comparative BarsThe Brinell hardness of the comparative test bars shall be determined by the test barmanufacturer using a 10 mm diameter ball and a 3000 kg load according to Test Method E10 on each of the four faces of the test
28、bar at approximately the mid-length of the bar. If the test bar is too soft to permit the use of a 3000 kg load, then a 1500 kg loadshall be used. The hardness values obtained shall not vary from each other by more than 62 %. The ends of the bar shall bepermanently marked with the average hardness v
29、alue, as well as the applied load if the 1500 kg load was used by the manufacturerprior to shipment.7. Procedure7.1 Assemble the comparative test bar into the apparatus making sure a minimum distance of no less than 5 mm will existbetween diameter of the impression to be made and any other indentati
30、ons on the face. Minimum distance of the indentationdiameter from the edge of the part tested shall be 12.5 mm. If the apparatus is equipped with a presetting bar stop, ensure the fixtureis properly in place. Place the apparatus on the surface of the component to be tested and apply the impact load
31、using a 1 to 214kg hammer. It is essential to apply a well guided, short blow in order to avoid a rebound and thus a double blow that may producean erroneous result by damaging the sharp edge of the ball impression.NOTE 1A hammer weight of 2 to 5 lb may be used instead of the kilogram rating.7.2 Imp
32、ression DiameterThe diameter of the impression produced on the comparative test bar should not exceed 4.2 mm. Ifa larger impression is produced, the comparative bar may give way laterally and the test result may be in error. In this case theuse of the 1500-kg load should be considered (see 6.2).A833
33、 1727.3 MeasurementsTwo diameters of each impression at right angles to each other shall be measured to within 0.05 mm andtheir mean value used as the basis for subsequent calculations.7.3.1 If the two diameter measurements differ by more than 0.1 mm, the readings shall be discarded in accordance wi
34、th TestMethods and Definitions A370, and the test repeated.7.4 Determination of Part HardnessEmploying the calibration device or mathematical equation supplied by the manufacturerfor the apparatus, determine the hardness of the part by using both (test bar and part) impression diameters and the hard
35、ness ofthe comparative bar in accordance with the equipment manufacturers instructions. AnnexA1 gives details of typical formulae usedin calculating the comparison hardness.8. Report8.1 The report shall include the following information:8.1.1 Indentation hardness number of the part or component as c
36、alculated in 7.4 with the designation HBC and the Brinellhardness number of the comparative test bar,8.1.1.1 The result shall be written as shown in the following example:232HBC/240 where 232 is the hardness determined as defined in 7.4 and 240 is the Brinell hardness of the comparative test bar.8.1
37、.2 Identification of the manufacturers equipment, and8.1.3 Diameters of the impressions in the part or component and comparative test bar.A833 1739. Keywords9.1 Brinell hardness; comparative hardness; comparative hardness testers; metallicANNEXA1. ANALYTICAL HARDNESS DETERMINATIONA1.1 As an example,
38、 the hardness of the part being tested may be determined from the following equation, based on the use ofa 10 mm diameter ball. However the manufacturer of the actual apparatus used may use another formula for obtaining thecomparison hardness value as stated in 7.4.B15B2102=1002D12!/102=1002D22!wher
39、e:B1 = comparison hardness of the part being tested,B2 = Brinell hardness of the comparative bar,D12 = diameter of impression in the comparative bar,D22 = diameter of impression in the part being tested.ASTM International takes no position respecting the validity of any patent rights asserted in con
40、nection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the respon
41、sible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful c
42、onsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 10
43、0 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 w
44、ebsite(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ Scope*1.1 This test method covers the determination of indentation hardness of metallic materials using compari
45、son hardness testers.1.2 This test method applies only to those portable comparison hardness testers that use test bars that have been standardizedaccording to Test Method E10 as a basis for comparison.1.3 Calibration of test bars, used for comparison to determine hardness numbers, is also covered b
46、y this test method.1.4 The impression force used during comparison hardness testing is normally an impact load applied by striking a hammer onthe appropriate areas as outlined in the manufacturers instructions.1.5 The values stated in SI units are to be regarded as standard. No other units of measur
47、ement are included in this standard.1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofr
48、egulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Or
49、ganization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsE10 Test Method for Brinell Hardness of Metallic MaterialsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 Definitions:A833 1743.1.1 test bar, nthat part of the testing apparatus which is used to determine a comparable hardness us
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1