ASTM E18-2018a Standard Test Methods for Rockwell Hardness of Metallic Materials.pdf

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1、Designation: E18 18a 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 year

2、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 the det

3、ermination of theRockwell hardness and the Rockwell superficial hardness ofmetallic materials by the Rockwell indentation hardness prin-ciple. This standard provides the requirements for Rockwellhardness machines and the procedures for performing Rock-well hardness tests.1.2 This test method include

4、s requirements for the use ofportable Rockwell hardness testing machines that measureRockwell hardness by the Rockwell hardness test principle andcan meet all the requirements of this test method, including thedirect and indirect verifications of the testing machine. PortableRockwell hardness testin

5、g machines that cannot meet the directverification requirements and can only be verified by indirectverification requirements are covered in Test Method E110.1.3 This standard includes additional requirements in thefollowing annexes:Verification of Rockwell Hardness Testing Machines Annex A1Rockwell

6、 Hardness Standardizing Machines Annex A2Standardization of Rockwell Indenters Annex A3Standardization of Rockwell Hardness Test Blocks Annex A4Guidelines for Determining the Minimum Thickness of aTest PieceAnnex A5Hardness Value Corrections When Testing on ConvexCylindrical SurfacesAnnex A61.4 This

7、 standard includes nonmandatory information in thefollowing appendixes that relates to the Rockwell hardnesstest.List of ASTM Standards Giving Hardness ValuesCorrespondingto Tensile StrengthAppendix X1Examples of Procedures for Determining RockwellHardness UncertaintyAppendix X21.5 UnitsAt the time

8、the Rockwell hardness test wasdeveloped, the force levels were specified in units ofkilograms-force (kgf) and the indenter ball diameters werespecified in units of inches (in.). This standard specifies theunits of force and length in the International System of Units(SI); that is, force in Newtons (

9、N) and length in millimeters(mm). However, because of the historical precedent andcontinued common usage, force values in kgf units and balldiameters in inch units are provided for information and muchof the discussion in this standard refers to these units.1.6 The test principles, testing procedure

10、s, and verificationprocedures are essentially identical for both the Rockwell andRockwell superficial hardness tests. The significant differencesbetween the two tests are that the test forces are smaller for theRockwell superficial test than for the Rockwell test. The sametype and size indenters may

11、 be used for either test, dependingon the scale being employed. Accordingly, throughout thisstandard, the term Rockwell will imply both Rockwell andRockwell superficial unless stated otherwise.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I

12、t is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on

13、 standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3A370 Test Methods and Definitions for Me

14、chanical Testingof Steel ProductsA623 Specification for Tin Mill Products, General Require-mentsA623M Specification for Tin Mill Products, General Re-quirements Metric1These test methods are under the jurisdiction of ASTM Committee E28 onMechanical Testing and are the direct responsibility of Subcom

15、mittee E28.06 onIndentation Hardness Testing.Current edition approved Oct. 1, 2018. Published October 2018. Originallyapproved in 1932. Last previous edition approved in 2018 as E18 18. DOI:10.1520/E0018-18A2In this test method, the term Rockwell refers to an internationally recognizedtype of indent

16、ation hardness test as defined in Section 3, and not to the hardnesstesting equipment of a particular manufacturer.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to t

17、he standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with interna

18、tionally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1A883 Test Method for Ferrimagnetic Resonance Linew

19、idthand Gyromagnetic Ratio of Nonmetallic Magnetic Mate-rialsA956 Test Method for Leeb Hardness Testing of SteelProductsA1038 Test Method for Portable Hardness Testing by theUltrasonic Contact Impedance MethodB19 Specification for Cartridge Brass Sheet, Strip, Plate,Bar, and DisksB36/B36M Specificat

20、ion for Brass Plate, Sheet, Strip, AndRolled BarB96/B96M Specification for Copper-Silicon Alloy Plate,Sheet, Strip, and Rolled Bar for General Purposes andPressure VesselsB103/B103M Specification for Phosphor Bronze Plate,Sheet, Strip, and Rolled BarB121/B121M Specification for Leaded Brass Plate, S

21、heet,Strip, and Rolled BarB122/B122M Specification for Copper-Nickel-Tin Alloy,Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-Nickel Alloy Plate, Sheet, Strip, and Rolled BarB130 Specification for Commercial Bronze Strip for BulletJacketsB134/B134M Specification for Brass WireB152/B152M Specif

22、ication for Copper Sheet, Strip, Plate,and Rolled BarB370 Specification for Copper Sheet and Strip for BuildingConstructionB647 Test Method for Indentation Hardness of AluminumAlloys by Means of a Webster Hardness GageE29 Practice for Using Significant Digits in Test Data toDetermine Conformance wit

23、h SpecificationsE92 Test Methods for Vickers Hardness and Knoop Hard-ness of Metallic MaterialsE110 Test Method for Rockwell and Brinell Hardness ofMetallic Materials by Portable Hardness TestersE140 Hardness Conversion Tables for Metals RelationshipAmong Brinell Hardness, Vickers Hardness, Rockwell

24、Hardness, Superficial Hardness, Knoop Hardness, Sclero-scope Hardness, and Leeb HardnessE384 Test Method for Microindentation Hardness of Mate-rialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 American Bearings Manufacturer Association Stan-dard

25、: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 Require-ments for Accreditation Bodies Accrediting ConformityAssessment Bodies5ISO/IEC 17025 General R

26、equirements for the Competenceof Testing and Calibration Laboratories52.4 Society of Automotive Engineers (SAE) Standard:SAE J417 Hardness Tests and Hardness Number Conver-sions63. Terminology and Equations3.1 Definitions:3.1.1 calibrationdetermination of the values of the sig-nificant parameters by

27、 comparison with values indicated by areference instrument or by a set of reference standards.3.1.2 standardizationto bring in conformance to a knownstandard through verification or calibration.3.1.3 verificationchecking or testing to assure confor-mance with the specification.3.1.4 Rockwell hardnes

28、s testan indentation hardness testusing a verified machine to force a diamond spheroconicalindenter or tungsten carbide (or steel) ball indenter, underspecified conditions, into the surface of the material under test,and to measure the difference in depth of the indentation as theforce on the indent

29、er is increased from a specified preliminarytest force to a specified total test force and then returned to thepreliminary test force.3.1.5 Rockwell superficial hardness testsame as the Rock-well hardness test except that smaller preliminary and total testforces are used with a shorter depth scale.3

30、.1.6 Rockwell hardness numbera number derived fromthe net increase in the depth of indentation as the force on anindenter is increased from a specified preliminary test force toa specified total test force and then returned to the preliminarytest force.3.1.7 Rockwell hardness machinea machine capabl

31、e ofperforming a Rockwell hardness test and/or a Rockwell super-ficial hardness test and displaying the resulting Rockwellhardness number.3.1.7.1 Rockwell hardness testing machinea Rockwellhardness machine used for general testing purposes.3.1.7.2 Rockwell hardness standardizing machinea Rock-well h

32、ardness machine used for the standardization of Rock-well hardness indenters, and for the standardization of Rock-well hardness test blocks. The standardizing machine differsfrom a regular Rockwell hardness testing machine by havingtighter tolerances on certain parameters.3.1.7.3 portable Rockwell h

33、ardness testing machineaRockwell hardness testing machine that is designed to betransported, carried, set up, and operated by the users, and thatmeasures Rockwell hardness by the Rockwell indentationhardness test principle.3.1.7.4 movable Rockwell hardness testing machineaRockwell hardness testing m

34、achine that is designed to bemoved to different locations on a moveable frame, table orsimilar support that is integral to the testing machine (forexample, securely fixed to a rolling table), or a Rockwell4Available from American Bearing Manufacturers Association (ABMA), 2025M Street, NW, Suite 800,

35、 Washington, DC 20036.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.6Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.E18 18a2hardness testing machi

36、ne that is designed to move into testingposition prior to a test, (for example, securely fixed to a movingsupport arm), and has been previously verified to ensure thatsuch a move will not affect the hardness result.3.2 Equations:3.2.1 The average Hof a set of n hardness measurementsH1, H2, , Hnis ca

37、lculated as:H5H11H211Hnn(1)3.2.2 The error E in the performance of a Rockwell hard-ness machine at each hardness level, relative to a standardizedscale, is determined as:E 5 H2 HSTD(2)where:H= average of n hardness measurements H1, H2, , Hnmade on a standardized test block as part of aperformance ve

38、rification, andHSTD= certified average hardness value of the standardizedtest block.3.2.3 The repeatability R in the performance of a Rockwellhardness machine at each hardness level, under the particularverification conditions, is estimated by the range of n hardnessmeasurements made on a standardiz

39、ed test block as part of aperformance verification, defined as:R 5 Hmax2 Hmin(3)where:Hmax= highest hardness value, andHmin= lowest hardness value.4. Significance and Use4.1 The Rockwell hardness test is an empirical indentationhardness test that can provide useful information about metallicmaterial

40、s. This information may correlate to tensile strength,wear resistance, ductility, and other physical characteristics ofmetallic materials, and may be useful in quality control andselection of materials.4.2 Rockwell hardness tests are considered satisfactory foracceptance testing of commercial shipme

41、nts, and have beenused extensively in industry for this purpose.4.3 Rockwell hardness testing at a specific location on a partmay not represent the physical characteristics of the whole partor end product.4.4 Adherence to this standard test method provides trace-ability to national Rockwell hardness

42、 standards except as statedotherwise.5. Principles of Test and Apparatus5.1 Rockwell Hardness Test PrincipleThe general prin-ciple of the Rockwell indentation hardness test is illustrated inFig. 1. The test is divided into three steps of force applicationand removal.Step 1The indenter is brought int

43、o contact with the testspecimen, and the preliminary test force F0is applied. Afterholding the preliminary test force for a specified dwell time,the baseline depth of indentation is measured.Step 2The force on the indenter is increased at acontrolled rate by the additional test force F1to achieve th

44、etotal test force F. The total test force is held for a specifieddwell time.Step 3The additional test force is removed, returning tothe preliminary test force. After holding the preliminary testforce for a specified dwell time, the final depth of indentationis measured. The Rockwell hardness value i

45、s derived from thedifference h in the final and baseline indentation depths whileunder the preliminary test force. The preliminary test force isremoved and the indenter is removed from the test specimen.5.1.1 There are two general classifications of the Rockwelltest: the Rockwell hardness test and t

46、he Rockwell superficialhardness test. The significant difference between the two testclassifications is in the test forces that are used. For theRockwell hardness test, the preliminary test force is 10 kgf (98N) and the total test forces are 60 kgf (589 N), 100 kgf (981 N),and 150 kgf (1471 N). For

47、the Rockwell superficial hardnesstest, the preliminary test force is 3 kgf (29 N) and the total testforces are 15 kgf (147 N), 30 kgf (294 N), and 45 kgf (441 N).5.1.2 Indenters for the Rockwell hardness test include adiamond spheroconical indenter and tungsten carbide ballindenters of specified dia

48、meters.5.1.2.1 Steel indenter balls may be used only for testing thinsheet tin mill products specified in Specifications A623 andA623M using the HR15T and HR30T scales with a diamondspot anvil. Testing of this product may give significantlydiffering results using a tungsten carbide ball as compared

49、tohistorical test data using a steel ball.NOTE 1Previous editions of this standard have stated that the steelball was the standard type of Rockwell indenter ball. The tungsten carbideball is considered the standard type of Rockwell indenter ball. The use oftungsten carbide balls provide an improvement to the Rockwell hardnesstest because of the tendency of steel balls to flatten with use, which resultsin an erroneously elevated hardness value. The user is cautioned thatRockwell hardness tests comparing the use of steel and tungsten carbideballs have be