1、Designation: E10 14 American Association State Highwayand Transportation Officials StandardAASHTO No.: T7086Standard Test Method forBrinell Hardness of Metallic Materials1This standard is issued under the fixed designation E10; the number immediately following the designation indicates the year of o
2、riginaladoption or, in the case of revision, the 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
3、 Defense.1. Scope*1.1 This test method covers the determination of the Brinellhardness of metallic materials by the Brinell indentationhardness principle. This standard provides the requirements fora Brinell testing machine and the procedures for performingBrinell hardness tests.1.2 This standard in
4、cludes additional requirements in fourannexes:Verification of Brinell Hardness Testing Machines Annex A1Brinell Hardness Standardizing Machines Annex A2Standardization of Brinell Hardness Indenters Annex A3Standardization of Brinell Hardness Test Blocks Annex A41.3 This standard includes nonmandator
5、y information in anappendix which relates to the Brinell hardness test:Table of Brinell Hardness Numbers Appendix X1Examples of Procedures for DeterminingBrinell Hardness UncertaintyAppendix X21.4 At the time the Brinell hardness test was developed, theforce levels were specified in units of kilogra
6、ms-force (kgf).Although this standard specifies the unit of force in theInternational System of Units (SI) as the Newton (N), becauseof the historical precedent and continued common usage of kgfunits, force values in kgf units are provided for information andmuch of the discussion in this standard r
7、efers to forces in kgfunits.1.5 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 the applica-bility of regulatory limitations
8、prior to use.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing MachinesE140 Hardness Conversion Tables fo
9、r Metals RelationshipAmong Brinell Hardness, Vickers Hardness, RockwellHardness, Superficial Hardness, Knoop Hardness, Sclero-scope Hardness, and Leeb HardnessE384 Test Method for Knoop and Vickers Hardness ofMaterials2.2 American Bearings Manufacturer Association Stan-dard:ABMA 10-1989 Metal Balls3
10、2.3 ISO Standards:ISO/IEC 17011 Conformity AssessmentGeneral Require-ments for Accreditation Bodies Accrediting ConformityAssessment Bodies4ISO/IEC 17025 General Requirements for the Competenceof Calibration and Testing43. Terminology and Equations3.1 Definitions:3.1.1 calibrationdetermination of th
11、e values of the sig-nificant parameters by comparison with values indicated by areference instrument or by a set of reference standards.3.1.2 verificationchecking or testing to assure confor-mance with the specification.1This test method is under the jurisdiction of ASTM Committee E28 onMechanical T
12、esting and is the direct responsibility of Subcommittee E28.06 onIndentation Hardness Testing.Current edition approved May 1, 2014. Published August 2014. Originallyapproved in 1924. Last previous edition approved in 2012 as E10 12. DOI:10.1520/E0010-14.2For referenced ASTM standards, visit the ASTM
13、 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.3Available from American Bearing Manufacturers Association (ABMA), 2025M Street, NW, Suite 800,Washington,
14、DC 20036, http:/www.americanbearings.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
15、est Conshohocken, PA 19428-2959. United States13.1.3 standardizationto bring in conformance with aknown standard through verification or calibration.3.1.4 Brinell hardness testan indentation hardness testusing a verified machine to force an indenter (tungsten carbideball with diameter D), under spec
16、ified conditions, into thesurface of the material under test. The diameter of the resultingindentation d is measured after removal of the force.3.1.5 Brinell hardness numbera number, which is propor-tional to the quotient obtained by dividing the test force by thecurved surface area of the indentati
17、on which is assumed to bespherical and of the diameter of the ball.3.1.6 Brinell hardness scalea designation that identifiesthe specific combination of ball diameter and applied forceused to perform the Brinell hardness test.3.1.7 Brinell hardness testing machinea Brinell hardnessmachine used for ge
18、neral testing purposes.3.1.8 Brinell hardness standardizing machinea Brinellhardness machine used for the standardization of Brinellhardness test blocks. The standardizing machine differs from aregular Brinell hardness testing machine by having tightertolerances on certain parameters.3.1.9 force-dia
19、meter ratioa number calculated as the ratioof the test force in kgf to the square of the indenter balldiameter in mm (see Table 1).3.2 Equations:3.2.1 The Brinell hardness number is calculated as:HBW 52FkgfDD 2 =D22 d2!(1)where:Fkgf= test force in kgf,D = diameter of the indenter ball in mm, andd =
20、measured mean diameter of the indentation in mm(see Table 1).3.2.2 The repeatability R in the performance of a Brinellhardness machine at each hardness level, under the particularverification conditions, is estimated by the range of diametermeasurements of n indentations made on a standardized testb
21、lock as part of a performance verification, defined as:R 5 dmax2 dmin(2)where:dmax= mean diameter of the largest measured indentation,anddmin= mean diameter of the smallest measured indentation.3.2.3 The averageHof a set of n Brinell hardness measurementvalues H1, H2, ., Hnis calculated as:H5H11H211
22、Hnn(3)3.2.4 The error E in the performance of a Brinell hardnessmachine at each hardness level is determined as:E 5 H2 HSTD(4)where:H(Eq3)= average of n hardness tests H1, H2, ., Hnmade ona standardized test block as part of a performanceverification, andHSTD= certified average hardness value of the
23、 standard-ized test block.3.2.5 The mean diameter of an indentationd is calculated as:d 5d11d211dnn(5)Where:d1,d2, ., dn= measured indentation diameters in mm, andn = the number of diameter measurements.3.2.6 The average mean diameter dof a set of indentationsis calculated as:d5d11d211dNN(6)where:d1
24、,d2, . dN = mean indentation diameters in mm, andN = number of indentations (see Annex A4).4. Significance and Use4.1 The Brinell hardness test is an indentation hardness testthat can provide useful information about metallic materials.This information may correlate to tensile strength, wearTABLE 1
25、Symbols and DesignationsSymbol DesignationD Diameter of the ball, mmF Test force, NFkgfTest force, kgfFkgf51gn3Fwhere gnis the acceleration due to gravity.gn= 9.80665 kgf/Nd Mean diameter of the indentation, mmd 5d11d211dnnwhere d1+ d2+ . + dnare the measured indentationdiameters in mm, and n is the
26、 number of diameter mea-surements.h Depth of the indentation, mmh 5D 2D22 d22Force-Diameterratio5FkgfD2HBW Brinell hardness5Test ForceSurface area of indentation52Fkgf D sD 2D22 d2dE10142resistance, ductility, or other physical characteristics of metal-lic materials, and may be useful in quality con
27、trol and selectionof materials.4.2 Brinell hardness tests are considered satisfactory foracceptance testing of commercial shipments, and have beenused extensively in industry for this purpose.4.3 Brinell hardness testing at a specific location on a partmay not represent the physical characteristics
28、of the whole partor end product.5. Principles of Test and Apparatus5.1 Brinell Hardness Test PrincipleThe general principleof the Brinell indentation hardness test consists of two steps(see Fig. 1).5.1.1 Step 1The indenter is brought into contact with thetest specimen in a direction perpendicular to
29、 the surface, andthe test force F is applied. The test force is held for a specifieddwell time and then removed.5.1.2 Step 2The diameter of the indentation is measuredin at least two directions perpendicular to each other. TheBrinell hardness value is derived from the mean of the diametermeasurement
30、s.5.2 Brinell Testing MachineEquipment for Brinell hard-ness testing usually consists of a testing machine, whichsupports the test specimen and applies an indenting force to aball in contact with the specimen, and a system for measuringthe mean diameter of the indentation in accordance with theBrine
31、ll hardness test principle. The design of the testingmachine shall be such that no rocking or lateral movement ofthe indenter or specimen occurs while the force is beingapplied. The design of the testing machine shall ensure that theforce to the indenter is applied smoothly and without impactforces.
32、 Precautions shall be taken to prevent a momentary hightest force caused by the inertia of the system, hydraulic systemovershoot, etc.5.2.1 See the Equipment Manufacturers Instruction Manualfor a description of the machines characteristics, limitations,and respective operating procedures.5.2.2 Anvil
33、sAn anvil, or specimen support, should be usedthat is suitable for the specimen to be tested. The seating andsupporting surfaces of all anvils should be clean and free offoreign material. Typically, anvils need only be replaced if theyfail to support the test surface perpendicular to the indenter, o
34、rthey are deemed unsafe.5.2.3 IndentersIndenters for the Brinell hardness test shallbe tungsten carbide balls of four allowed diameters (1, 2.5, 5and 10 mm). Indenters shall meet the requirements defined inAnnex A3.5.2.4 Oil, dirt, or other foreign materials shall not beallowed to accumulate on the
35、indenter, as this will affect thetest results.5.2.5 Measurement DeviceThe measurement device usedfor the measurement of the diameter of Brinell indentationsmay be an integral part of the hardness machine or a separatestand-alone instrument. The allowable measurement devicesare classified into two ty
36、pes. The Type A device includesmicroscopes having movable measuring lines with some typeof indicator or computerized measuring system, or an imageanalysis system. The Type B device is a hand-held microscope(usually 20 or 40) with fixed measuring lines.5.2.5.1 Type A DeviceThe acceptable minimum reso
37、lutionfor a Type A device shall be as given in Table 2.5.2.5.2 Type B DeviceThe acceptable maximum spacingbetween the graduated lines ofType B devices shall be as givenin Table 2. Type B devices shall not be used for measuringindentations made with 2.5 mm and 1 mm ball indenters.5.3 VerificationBrin
38、ell testing machines and indentationmeasurement devices shall be verified periodically in accor-dance with Annex A1.5.4 Test BlocksTest blocks meeting the requirements ofAnnex A4 shall be used to verify the testing machine inaccordance with Annex A1.5.5 Brinell Hardness ScalesThe combinations of ind
39、ent-ers and test forces define the Brinell hardness scales. Thestandard Brinell hardness scales and test forces are given inTable 3, corresponding to force-diameter ratios (see Table 1)of1, 1.25, 2.5, 5, 10 and 30. Brinell hardness values should bedetermined and reported in accordance with one of th
40、esestandard scales. Other scales using non-standard test forcesmay be used by special agreement. Examples of other scalesand the corresponding force-diameter ratio (in parentheses) areHBW 10/750 (7.5), HBW 10/2000 (20), HBW 10/2500 (25),HBW 5/187.5 (7.5), and HBW 5/500 (20).5.6 Calculation of the Br
41、inell Hardness NumberTheBrinell hardness number shall be calculated from the meandiameter d of the indentation using Eq 1 or from the valuesgiven in Appendix X1.5.6.1 Brinell hardness values shall not be designated by anumber alone because it is necessary to indicate which indenterand which force ha
42、s been employed in making the test (seeFIG. 1 Principle of TestTABLE 2 Resolution and Graduation Spacing of IndentationMeasuring DevicesType A Type BBall DiametermmMinimumIndicator ResolutionmmMaximumGraduation Spacingmm10 0.0100 0.1005 0.0050 0.0502.5 0.0025 1 0.0010 E10143Table 3). Brinell hardnes
43、s numbers shall be followed by thesymbol HBW, and be supplemented by an index indicating thetest conditions in the following order:5.6.1.1 Diameter of the ball, mm,5.6.1.2 Avalue representing the test force, kgf, (see Table 3)and,5.6.1.3 The applied force dwell time, s, if other than 10 s to15 s.5.6
44、.2 The only exception to the above requirement is for theHBW 10/3000 scale when a 10 s to 15 s dwell time is used.Only in the case of this one Brinell hardness scale may thedesignation be reported simply as HBW.5.6.3 Examples:220 HBW = Brinell hardness of 220 determined with a ball of 10 mm diameter
45、and with a test force of 29.42 kN (3000 kgf) applied for 10 s to 15 s350 HBW 5/750 = Brinell hardness of 350 determined with a ball of 5 mmdiameter and with a test force of 7.355 kN (750 kgf) applied for 10 s to 15 s600 HBW 1/30/20 = Brinell hardness of 600 determined with a ball of 1 mmdiameter and
46、 with a test force of 294.2 N (30 kgf) applied for 20 s6. Test Piece6.1 There is no standard shape or size for a Brinell testspecimen. The test piece on which the indentation is madeshould conform to the following:6.1.1 ThicknessThe thickness of the specimen tested shallbe such that no bulge or othe
47、r marking showing the effect ofthe test force appears on the side of the piece opposite theindentation. The thickness of the material under test should beat least ten times the depth of the indentation h (see Table 4).Table 4 can also be used as a guideline for the minimum depthof a layer of a mater
48、ial, such as a coating.NOTE 1Brinell hardness testing can use high test forces. Under certainconditions of testing a relatively thin material or coating on a material withhigh hardness, there is a potential for the test material to break or shatterunder load resulting in serious personal injury or d
49、amage to equipment.Users are strongly cautioned to exercise extreme care when testing amaterial that could potentially fail under load. If there is a concern ordoubt, do not test the material.6.1.2 WidthThe minimum width shall conform to therequirements for indentation spacing.6.1.3 FinishWhen necessary, the surface on which theindentation is to be made should be filed, ground, machined orpolished flat with abrasive material so that the edge of theindentation can be clearly defined to permit the measurementof the diameter to the spe
