1、Designation: E18 15E18 16 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 th
3、e 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 include
4、s 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 X1Exampl
6、es 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 the
7、 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 o
8、f 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 smal
9、ler 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 T
10、his 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 Document
11、s2.1 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 E
12、28.06 on IndentationHardness Testing.Current edition approved Feb. 1, 2015May 1, 2016. Published March 2015May 2016. Originally approved in 1932. Last previous edition approved in 20142015 asE18 14a.E18 15. DOI: 10.1520/E0018-15.10.1520/E0018-162 In this test method, the term Rockwell refers to an i
13、nternationally 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 ASTM
14、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 poss
15、ible 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 standardCop
16、yright 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, Sheet,
17、 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 Rolled
18、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 Copper She
19、et, 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 Methods for Vickers Hardness and Knoop Hardness of Metallic MaterialsE140 Hardness Conver
20、sion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness,Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb HardnessE384 Test Method for Microindentation Hardness of MaterialsE691 Practice for Conducting an Interlaboratory Study to Determine t
21、he Precision of a Test Method2.2 American Bearings Manufacturer Association Standard:ABMA 10-1989 Metal Balls42.3 ISO Standards:ISO 6508-1 Metallic MaterialsRockwell Hardness TestPart 1: Test Method (scales A, B, C, D, E, F, G, H, K, N, T)5ISO/IEC 17011 Conformity AssessmentGeneral Requirements for
22、Accreditation Bodies Accrediting Conformity AssessmentBodies5ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories52.4 Society of Automotive Engineers (SAE) Standard:SAE J417 Hardness Tests and Hardness Number Conversions63. Terminology and Equations3.1 Defini
23、tions: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 conform
24、ance 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 tes
25、t, 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 exce
26、pt 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 and th
27、en 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 used
28、 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 testing
29、 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 Available from American Bearing Manufacturers Association (ABMA), 2025 M Street, NW, Suite 800, Washington, DC 20036.5 Available from Ameri
30、can National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.6 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http:/www.sae.org.E18 162H5H11H211Hnn (1)3.2.2 The error E in the performance of a Rockw
31、ell 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 a performanceverification, andHSTD = certified average hardness value of the standardized
32、 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 made on a standardized test block as part of aperformance verification, defined as:R 5Hmax
33、2Hmin (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 about metallicmaterials. This information may correlate to tensile strength, wear resistan
34、ce, 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 testing of commercial shipments, and have been usedextensively in industry for this purpose.4
35、.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 national Rockwell hardness standards except as statedotherwise.5. Principles of Test and Ap
36、paratus5.1 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 1The indenter is brought into contact with the test specimen, and the preliminary test force
37、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 additional test force F1 to achieve the total test forceF. The total test force is held for a spec
38、ified 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 measured. The Rockwell hardness value is derived from the differenceh in the final and baseline
39、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 1635.1.1 There are two general classifications of the Rockwell test: the Rockwell hardness te
40、st 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 kgf (98 N) and the total test forces are 60 kgf (589 N), 100 kgf (981 N), and 150kgf (147
41、1 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 hardness test include a diamond spheroconical indenter and tungsten carbide ball indenters ofs
42、pecified 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.Testing of this product may give significantly differing results usinga tungsten carbide ball a
43、s 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 considered the standard type of Rockwell indenter ball. The use of tungsten carbide balls provid
44、e 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 hardnesstests comparing the use of steel and tungsten carbide balls have been shown to give different
45、 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 steel ball indenter is used.5.1.3 The Rockwell hardness scales are defined by the combinat
46、ions 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 reported in accordance with one of these standard scales.5.2 Calculation of the Rockwell Hardnes
47、s 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 indentationdepth measurements, while under the preliminary test force, is measured as h (see Fig. 1).5
48、.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 Tables 1 and 2):Rockwell Hardness51002 h0.002 (4)Rockwell Superficial Hardness51002 h0.001
49、(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.TABLE 1 Rockwell Hardness ScalesScaleSymbol IndenterTotal TestForce, kgfDialFigures Typical Applications of ScalesB 116-in. (1.588-mm) ball 100 red Copper alloys, soft steels, aluminum alloys, malleable iron, etc.C diamond 150 black Steel, hard cast irons, pearlitic malleable iron, titanium, deep case hardened steel, and othermaterials harder than B100.A diamond 60 black C
