1、Designation: B 647 84 (Reapproved 2006)Standard Test Method forIndentation Hardness of Aluminum Alloys by Means of aWebster Hardness Gage1This standard is issued under the fixed designation B 647; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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 the determination of indentationhardness of aluminum alloys with a
3、Webster hardness gage,Model B.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.NOTE 1Two other models, A and B-75, are in use, but are not coveredin this test method. Model A does not provide numerical values ofhardness and
4、Model B-75 covers only a part of the range of interest foraluminum alloys.1.3 This standard does not purport to address all of thesafety concerns, 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
5、 the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E6 Terminology Relating to Methods of Mechanical Test-ingE10 Test Method for Brinell Hardness of Metallic Materi-alsE18 Test Methods for Rockwell Hardness and RockwellSuperficial Hardness of Metalli
6、c Materials3. Terminology3.1 DefinitionsThe definitions of terms relating to hard-ness testing appearing in Terminology E6shall be consideredas applying to the terms used in this test method.4. Significance and Use4.1 The Webster hardness gage is portable and thereforeuseful for in situ determinatio
7、n of the hardness of fabricatedparts and individual test specimens for production controlpurposes. It is not as sensitive as Rockwell or Brinell hardnessmachines; see 10.2.4.2 This test method should be used only as cited inapplicable material specifications.5. Apparatus ( Fig. 1)5.1 The Webster har
8、dness gage, Model B, consists of threemain parts: the frame, operating handle, and penetrator housingassembly. The penetrator housing assembly includes the prin-cipal working parts, including the penetrator, loading spring,adjusting nut, penetrator housing, housing key, return spring,and dial indica
9、tor.5.2 The indentor is a hardened steel truncated cone.5.3 The dial indicator is graduated from 1 to 20, and isactuated by the penetrator so that the higher the reading, thehigher is the hardness of the test material.5.4 The configuration of the Webster hardness gage is suchthat it is operated like
10、 a pair of pliers.5.5 The clearance between the penetrator and the anvil isabout 6 mm (14 in.), limiting the thickness of sample that canbe tested.6. Test Parts or Specimens6.1 Any part or piece of material greater than 1 mm (0.04in.) in thickness and equal to or less than 6 mm (14 in.) inthickness
11、and with a clear flat area at an edge approximately 25by 25 mm (1 by 1 in.) in size is suitable for test.6.2 The surfaces shall be essentially parallel, smooth, clean,and free of mechanical damage. The test surface may be lightlypolished to eliminate scratches or die lines.6.3 The clear, flat area s
12、hall be such that there will be a cleardistance of at least 3 mm (18 in.) from the edge of the part orspecimen.6.4 Parts or specimens with a slight taper or curvature mayalso be tested if a round anvil is used, as described in 8.1.1 andFig. 2.1This test method is under the jurisdiction of ASTM Commi
13、ttee 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 1984. Last previous edition approved in 2000 as B 647 84 (2000).2For referenced ASTM standards, visit the ASTM
14、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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
15、States.7. Calibration7.1 Zero Adjustment:7.1.1 Operate the instrument against the bare anvil and notewhether or not the indicator gives the zero (full-scale) reading.7.1.2 A correction in zero reading is normally not neededexcept for one of the reasons listed below:7.1.2.1 A new penetrator has been
16、installed,7.1.2.2 The dial indicator is changed from one instrument toanother, or7.1.2.3 Excessive wear has taken place.7.1.3 If an adjustment in zero is needed, turn the zeroadjustment screw below the indicator dial slowly (Fig. 3),while operating the tester against the bare anvil and maintain-ing
17、handle pressure, until the hand of the dial indicator rests onthe zero line (which is located at the full-scale reading of 20).7.1.4 The zero adjustment should never be used to make theindicator read correctly on a standard sample.7.2 Load Spring Adjustment:7.2.1 Measure the hardness of a standard s
18、ample of mediumto low hardness, either one furnished with the tester or onedeveloped from reference stock; the dial should show thereading indicated for the standard within 60.5.7.2.2 If the readings on the standard or the bare anvil, orboth, do not indicate the proper values, adjust the load spring
19、with the special wrench provided until agreement is reached(Fig. 4).8. Procedure8.1 Place the test part or specimen between the penetratorand the anvil, and apply pressure to the handle.8.1.1 If the test part or specimen has a slight taper orcurvature, use a round anvil and apply the gage in such a
20、waythat the penetrator is applied normal to the test surface and theanvil bears along a line that is parallel to the surface in contactwith the penetrator, as illustrated in Fig. 2.FIG. 1 Webster Hardness Gage, Model BFIG. 2 Making the TestFIG. 3 Zero Adjustment Screw, A (indicated by arrow)B 647 84
21、 (2006)28.2 Apply sufficient pressure to cause the flat face of thepenetrator housing to come in contact with the surface of thetest part or specimen.NOTE 2Excess pressure on the handle is not harmful and does notaffect the reading, but neither is it necessary, as the hardness reading isdetermined s
22、olely by the spring deflection.8.3 Read the hardness from the dial indicator. Report thereading to the nearest 0.5.NOTE 3For relatively soft materials, the dial may indicate some drifttoward lower numbers with time, after the initial pressure. It is recom-mended that readings be made quickly and tha
23、t the highest observed valuebe used.9. Report9.1 The report shall include the following:9.1.1 Identification of material tested,9.1.2 Model and serial number of hardness gage,9.1.3 Number of readings taken,9.1.4 Average of hardness values, rounded to the nearesthalf division, and9.1.5 Date of test.1
24、0. Precision and Bias10.1 The Webster hardness gage, Model B, is useful forhardness measurements of material in the range from 3003-0 to7075-T6 representing a range in Rockwell hardness from about5 HRE to 110 HRE.10.2 The application of portable impressors, such as theWebster, will produce greater v
25、ariation in hardness readingsthan standard fixed frame procedures, such as Test MethodsE10andE18. Further, since the scale of the Webster hardnessgage, Model B, has 20 divisions compared to 110 for theRockwell E scale, it is also less sensitive than the Rockwellscale.10.3 The variation in readings t
26、hat results from the applica-tion of the Webster hardness impressor has not yet beenestablished.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 determin
27、ation 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 responsible technical committee and must be reviewed every five years andif not revised, either reapproved or wit
28、hdrawn. 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 consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that yo
29、ur 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, 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).FIG. 4 Adjusting Load on Load SpringB 647 84 (2006)3
