1、Designation: E18 14aE18 15 An American National StandardStandard Test Methods forRockwell Hardness of Metallic Materials1,2This standard is issued under the fixed designation E18; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the
2、 year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () 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. Scope*1.1 These test methods cover t
3、he determination of the Rockwell hardness and the Rockwell superficial hardness of metallicmaterials by the Rockwell indentation hardness principle.This standard provides the requirements for Rockwell hardness machinesand the procedures for performing Rockwell hardness tests.1.2 This standard includ
4、es additional requirements in annexes:Verification of Rockwell Hardness Testing Machines Annex A1Rockwell Hardness Standardizing Machines Annex A2Standardization of Rockwell Indenters Annex A3Standardization of Rockwell Hardness Test Blocks Annex A4Guidelines for Determining the Minimum Thickness of
5、 aTest PieceAnnex A5Hardness Value Corrections When Testing on ConvexCylindrical SurfacesAnnex A61.3 This standard includes nonmandatory information in appendixes which relates to the Rockwell hardness test.List of ASTM Standards Giving Hardness ValuesCorrespondingto Tensile StrengthAppendix X1Examp
6、les of Procedures for Determining RockwellHardness UncertaintyAppendix X21.4 UnitsAt the time the Rockwell hardness test was developed, the force levels were specified in units of kilograms-force(kgf) and the indenter ball diameters were specified in units of inches (in.). This standard specifies th
7、e units of force and lengthin the International System of Units (SI); that is, force in Newtons (N) and length in millimeters (mm). However, because of thehistorical precedent and continued common usage, force values in kgf units and ball diameters in inch units are provided forinformation and much
8、of the discussion in this standard refers to these units.1.5 The test principles, testing procedures, and verification procedures are essentially identical for both the Rockwell andRockwell superficial hardness tests. The significant differences between the two tests are that the test forces are sma
9、ller for theRockwell superficial test than for the Rockwell test. The same type and size indenters may be used for either test, depending onthe scale being employed. Accordingly, throughout this standard, the term Rockwell will imply both Rockwell and Rockwellsuperficial unless stated otherwise.1.6
10、This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documen
11、ts2.1 ASTM Standards:3A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA623 Specification for Tin Mill Products, General Requirements1 These test methods are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee
12、E28.06 on IndentationHardness Testing.Current edition approved Oct. 1, 2014Feb. 1, 2015. Published November 2014March 2015. Originally approved in 1932. Last previous edition approved in 2014 asE18 14.E18 14a. DOI: 10.1520/E0018-14A.10.1520/E0018-15.2 In this test method, the term Rockwell refers to
13、 an internationally recognized type of indentation hardness test as defined in Section 3, and not to the hardness testingequipment of a particular manufacturer.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of
14、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 provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically
15、 possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standa
16、rdCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1A623M Specification for Tin Mill Products, General Requirements MetricB19 Specification for Cartridge Brass Sheet, Strip, Plate, Bar, and DisksB36/B36M Specification for Brass Plate, S
17、heet, Strip, And Rolled BarB96/B96M Specification for Copper-SiliconAlloy Plate, Sheet, Strip, and Rolled Bar for General Purposes and Pressure VesselsB103/B103M Specification for Phosphor Bronze Plate, Sheet, Strip, and Rolled BarB121/B121M Specification for Leaded Brass Plate, Sheet, Strip, and Ro
18、lled BarB122/B122M Specification for Copper-Nickel-Tin Alloy, Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-Nickel AlloyPlate, Sheet, Strip, and Rolled BarB130 Specification for Commercial Bronze Strip for Bullet JacketsB134/B134M Specification for Brass WireB152/B152M Specification for Coppe
19、r Sheet, Strip, Plate, and Rolled BarB370 Specification for Copper Sheet and Strip for Building ConstructionE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE92 Test Method for Vickers Hardness of Metallic Materials (Withdrawn 2010)4E140 Hardness Con
20、version Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness,Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb HardnessE384 Test Method for Knoop and Vickers Hardness of MaterialsE691 Practice for Conducting an Interlaboratory Study to Determi
21、ne the Precision of a Test Method2.2 American Bearings Manufacturer Association Standard:ABMA 10-1989 Metal Balls52.3 ISO Standards:ISO 6508-1 Metallic MaterialsRockwell Hardness TestPart 1: Test Method (scales A, B, C, D, E, F, G, H, K, N, T)6ISO/IEC 17011 Conformity AssessmentGeneral Requirements
22、for Accreditation Bodies Accrediting Conformity AssessmentBodies6ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories62.4 Society of Automotive Engineers (SAE) Standard:SAE J417 Hardness Tests and Hardness Number Conversions73. Terminology and Equations3.1 De
23、finitions:3.1.1 calibrationdetermination of the values of the significant parameters by comparison with values indicated by a referenceinstrument or by a set of reference standards.3.1.2 verificationchecking or testing to assure conformance with the specification.3.1.3 standardizationto bring in con
24、formance to a known standard through verification or calibration.3.1.4 Rockwell hardness testan indentation hardness test using a verified machine to force a diamond spheroconical indenteror tungsten carbide (or steel) ball indenter, under specified conditions, into the surface of the material under
25、 test, and to measurethe difference in depth of the indentation as the force on the indenter is increased from a specified preliminary test force to aspecified total test force and then returned to the preliminary test force.3.1.5 Rockwell superficial hardness testsame as the Rockwell hardness test
26、except that smaller preliminary and total testforces are used with a shorter depth scale.3.1.6 Rockwell hardness numbera number derived from the net increase in the depth of indentation as the force on an indenteris increased from a specified preliminary test force to a specified total test force an
27、d then returned to the preliminary test force.3.1.7 Rockwell hardness machinea machine capable of performing a Rockwell hardness test and/or a Rockwell superficialhardness test and displaying the resulting Rockwell hardness number.3.1.7.1 Rockwell hardness testing machinea Rockwell hardness machine
28、used for general testing purposes.3.1.7.2 Rockwell hardness standardizing machinea Rockwell hardness machine used for the standardization of Rockwellhardness indenters, and for the standardization of Rockwell hardness test blocks. The standardizing machine differs from a regularRockwell hardness tes
29、ting machine by having tighter tolerances on certain parameters.3.2 Equations:3.2.1 The averageH of a set of n hardness measurements H1, H2, , Hn is calculated as:4 The last approved version of this historical standard is referenced on www.astm.org.5 Available from American Bearing Manufacturers Ass
30、ociation (ABMA), 2025 M Street, NW, Suite 800, Washington, DC 20036.6 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.7 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001
31、, http:/www.sae.org.E18 152H5H11H211Hnn (1)3.2.2 The error E in the performance of a Rockwell hardness machine at each hardness level, relative to a standardized scale,is determined as:E 5H2HSTD (2)where:H = average of n hardness measurements H1, H2, , Hn made on a standardized test block as part of
32、 a performanceverification, andHSTD = certified average hardness value of the standardized test block.3.2.3 The repeatability R in the performance of a Rockwell hardness machine at each hardness level, under the particularverification conditions, is estimated by the range of n hardness measurements
33、made on a standardized test block as part of aperformance verification, defined as:R 5Hmax2Hmin (3)where:Hmax = highest hardness value, andHmin = lowest hardness value.4. Significance and Use4.1 The Rockwell hardness test is an empirical indentation hardness test that can provide useful information
34、about metallicmaterials. This information may correlate to tensile strength, wear resistance, ductility, and other physical characteristics ofmetallic materials, and may be useful in quality control and selection of materials.4.2 Rockwell hardness tests are considered satisfactory for acceptance tes
35、ting of commercial shipments, and have been usedextensively in industry for this purpose.4.3 Rockwell hardness testing at a specific location on a part may not represent the physical characteristics of the whole partor end product.4.4 Adherence to this standard test method provides traceability to n
36、ational Rockwell hardness standards except as statedotherwise.5. Principles of Test and Apparatus5.1 Rockwell Hardness Test PrincipleThe general principle of the Rockwell indentation hardness test is illustrated in Fig. 1.The test is divided into three steps of force application and removal.Step 1Th
37、e indenter is brought into contact with the test specimen, and the preliminary test force F0 is applied. After holdingthe preliminary test force for a specified dwell time, the baseline depth of indentation is measured.Step 2The force on the indenter is increased at a controlled rate by the addition
38、al test force F1 to achieve the total test forceF. The total test force is held for a specified dwell time.Step 3The additional test force is removed, returning to the preliminary test force. After holding the preliminary test forcefor a specified dwell time, the final depth of indentation is measur
39、ed. The Rockwell hardness value is derived from the differenceh in the final and baseline indentation depths while under the preliminary test force. The preliminary test force is removed and theindenter is removed from the test specimen.FIG. 1 Rockwell Hardness Test Method (Schematic Diagram)E18 153
40、5.1.1 There are two general classifications of the Rockwell test: the Rockwell hardness test and the Rockwell superficialhardness test. The significant difference between the two test classifications is in the test forces that are used. For the Rockwellhardness test, the preliminary test force is 10
41、 kgf (98 N) and the total test forces are 60 kgf (589 N), 100 kgf (981 N), and 150kgf (1471 N). For the Rockwell superficial hardness test, the preliminary test force is 3 kgf (29 N) and the total test forces are 15kgf (147 N), 30 kgf (294 N), and 45 kgf (441 N).5.1.2 Indenters for the Rockwell hard
42、ness test include a diamond spheroconical indenter and tungsten carbide ball indenters ofspecified diameters.5.1.2.1 Steel indenter balls may be used only for testing thin sheet tin mill products specified in Specifications A623 and A623Musing the HR15Tand HR30Tscales with a diamond spot anvil.Testi
43、ng of this product may give significantly differing results usinga tungsten carbide ball as compared to historical test data using a steel ball.NOTE 1Previous editions of this standard have stated that the steel ball was the standard type of Rockwell indenter ball. The tungsten carbide ballis consid
44、ered the standard type of Rockwell indenter ball. The use of tungsten carbide balls provide an improvement to the Rockwell hardness test becauseof the tendency of steel balls to flatten with use, which results in an erroneously elevated hardness value. The user is cautioned that Rockwell hardnesstes
45、ts comparing the use of steel and tungsten carbide balls have been shown to give different results. For example, depending on the material tested andits hardness level, Rockwell B scale tests using a tungsten carbide ball indenter have given results approximately one Rockwell point lower than whena
46、steel ball indenter is used.5.1.3 The Rockwell hardness scales are defined by the combinations of indenter and test forces that may be used. The standardRockwell hardness scales and typical applications of the scales are given in Tables 1 and 2. Rockwell hardness values shall bedetermined and report
47、ed in accordance with one of these standard scales.5.2 Calculation of the Rockwell Hardness NumberDuring a Rockwell test, the force on the indenter is increased from apreliminary test force to a total test force, and then returned to the preliminary test force. The difference in the two indentationd
48、epth measurements, while under the preliminary test force, is measured as h (see Fig. 1).5.2.1 The unit measurement for h is mm. From the value of h, the Rockwell hardness number is derived. The Rockwell hardnessnumber is calculated as:5.2.1.1 For scales using a diamond spheroconical indenter (see T
49、ables 1 and 2):Rockwell Hardness51002 h0.002 (4)Rockwell Superficial Hardness51002 h0.001 (5)where h is in mm.5.2.1.2 For scales using a ball indenter (see Tables 1 and 2):Rockwell Hardness51302 h0.002 (6)Rockwell Superficial Hardness51002 h0.001 (7)where h is in mm.5.2.2 The Rockwell hardness number is an arbitrary number, which, by method of calculation, results in a higher number forharder material.TABLE 1 Rockwell Hardness ScalesScaleSymbol IndenterTotal TestForce, kgfDialFigures Typical Applications of ScalesB 116-in. (1.588-mm) ball 100 red
