ASTM_E_18-02.pdf

NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.4E18-02(Manganese Brass)Sheet and Strip*Rockwell hardness number of 72 on the Rockwell B scaleB 370 Specification for Copper Sheet and Strip for Buildingmeasured using a tungsten carbide ball indenter.Construction3.1.3 Rockwell hardness test-an indentation hardness testE4 Practices for Force Verification of Testing Machines6using a verified machine to force a diamond spheroconicalE29 Practice for Using Significant Digits in Test Data toindenter(diamond indenter).or a ball indenter(steel orDetermine Conformance with Specificationstungsten carbide)under specified conditions,into the surface ofE 140 Hardness Conversion Tables for Metals6the material under test in two operations,and to measure thedifference in depth of the indentation under the specified3.Terminologyconditions of preliminary and total test forces(minor and major3.1 Definitions:loads,respectively).3.1.1 calibration-determination of the values of the sig-3.1.4 Rockwell superficial hardness test-same as the Rock-nificant parameters by comparison with values indicated by awell hardness test except that smaller preliminary and total testreference instrument or by a set of reference standards.forces are used.3.1.2 Rockwell hardness number,HR-a number derivedfrom the net increase in the depth of indentation as the force on3.1.5 verification-checking or testing to assure conform-ance with the specification.an indenter is increased from a specified preliminary test forceto a specified total test force and then returned to the prelimi-4.Significance and Usenary test force.3.1.2.1 Discussion-Indenters-Indenters for the Rockwell4.1 The Rockwell hardness test is an empirical indentationhardness test include a diamond spheroconical indenter andhardness test.Rockwell hardness tests provide useful informa-ball indenters(steel or tungsten carbide)of several specifiedtion about metallic materials.This information may correlate todiameters.tensile strength,wear resistance,ductility,and other physical3.1.2.2 Discussion-Rockwell hardness numbers are al-characteristics of metallic materials,and may be useful inways quoted with a scale symbol representing the indenter andquality control and selection of materials.forces used.The hardness number is followed by the symbol4.2 Rockwell hardness testing at a specific location on a partHR and the scale designation.When a ball indenter is used,themay not represent the physical characteristics of the whole partscale designation is followed by the letterSto indicate theor end product.use of a steel ball or the letter Wto indicate the use of a4.3 Rockwell hardness tests are considered satisfactory fortungsten carbide ball.acceptance testing of commercial shipments,and have been3.1.2.3 Examples-64 HRC Rockwell hardness numberused extensively in industry for this purpose.of 64 on Rockwell C scale.81 HR30N Rockwell superficialhardness number of 81 on Rockwell 30N scale.72 HRBW4.4 Performance verifications of Rockwell hardness indent-ers and hardness machines shall be made using test blockscalibrated traceable to the Rockwell standards maintained by6 Annual Book of ASTM Standards,Vol 03.01.NIST when primary reference test blocks are available fromAnnual Book of A.STM Standards,Vol 14.02.NIST for the specific Rockwell scale.A.GENERAL DESCRIPTION AND TEST PROCEDURE FOR ROCKWELL HARDNESS AND ROCKWELLSUPERFICIAL HARDNESS TESTS5.Principles of Test and Apparatus。5.1 General Principles-The general principles of theRockwell hardness test are illustrated in Fig.I(diamondindenter)and Fig.2(ball indenters)and the accompanyingTable 1 and Table 2.In the case of the Rockwell superficial testthe general principles are illustrated in Fig.3(diamondindenter)and Fig.4(ball indenter)and the accompanyingTable 3 and Table 4.Detam line5.1.1 See Equipment Manufacturers Instruction Manualfor a description of the machines characteristics,limitationsand respective operating procedures.Typical applications ofthe various hardness scales are shown in Tables 5 and 6.Rockwell hardness values are usually determined and reportedFIG.1 Rockwell Hardness Test with Diamond Indenterin accordance with one of these standard scales.An indenter is(Rockwell C Example)(Table 1)forced into the surface of a test piece in two steps underspecified conditions(see Section 7)and the difference in depth5.1.2 The unit measurement for e is 0.002 mm and 0.001of indentation is measured as e.mm for the Rockwell hardness test and Rockwell superficial2NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.E18-028号01004FIG.3 Rockwell Superficial Hardness Test with Diamond Indenter(Rockwell 30N Example)(Table 3)FIG.2 Rockwell Hardness Test with Ball Indenter(Rockwell BExample)(Table 2)!8回TABLE 1 Symbols and Designations Associated with Fig.3Number SymbolDesignation1Angle at the top of the diamond indenter(120)2Radius of curvature at the tip of the cone(0.200mm)39Preliminary Test Force 10 kgf(98 N)4PAdditional Force=140 kgf(1373 N)Total Test Force Po+P 10+140 150 kgf(1471NDo.m nrDepth of penetration under preliminary test forcebefore application of additional forceIncrease in depth of penetration under additionalforce8Permanent increase in depth of penetration underpreliminary test force after removal of additionalforce,the increase being expressed in units ofFIG.4 Rockwell Superficial Hardness Test with Ball Indenter0.002mm(Rockwell 30T Example)(Table 4)9xx HRCRockwell C hardness 100-eTABLE 3 Symbols and Designations Associated with Fig.3TABLE 2 Symbols and Designations Associated with Fig.2Number SymbolDesignation1Angle at the tip of the diamond indenter(120)Number SymbolDesignation2Radius of curvature at the tip of the cone(0.200DDiameter of ball=s in.(1.588 mm)mm)3Preliminary Test Force=10 kgf(98 N)3PoPreliminary Test Force-3 kgf(29 N)4PAdditional force 90 kgf(883 N)BAdditional force 27 kgf(265 N)Total Test Force=P+P=10+90=100 kgf(9815Total Test ForceP。+P,=3+27=30kgf(294NN6Depth of penetration under preliminary test force6Depth of penetration under preliminary test forcebefore application of additional forcebefore application of additional force7Increase in depth of penetration under additionalIncrease in depth of penetration under additionalforceforce8Permanent increase in depth of penetration under8ePermanent increase in depth of penetration underpreliminary test force after removal of additionalpreliminary test force after removal of the additionalforce,the increase being expressed in units offorce,the increase being expressed in units of0.001mm0.002mm9xx HR30NRockwell 30N hardness 100-e9xx HRBRockwell B hardness 130-e5.2.1 There are two general classifications of the Rockwellhardness test,respectively.From the value of e,a numbertest:the Rockwell hardness test and the Rockwell superficialknown as the Rockwell hardness is derived.There is nohardness test.Rockwell hardness value designated by a number alone be-5.2.2 In the Rockwell hardness test the preliminary testcause it is necessary to indicate which indenter and force haveforce is 10 kgf(98 N).Total test forces are 60 kgf(589 N).100been employed in making the test(see Table 5 and Table 6).kgf(981 N)and 150 kgf(1471 N).In the Rockwell superficial5.2 Description of Machine and Method of Test-The testerhardness test the preliminary test force is 3 kgf(29 N)and totalfor making Rockwell hardness determinations is a machine thattest forces are 15 kgf(147 N),30 kgf(294 N),and 45 kgf(441measures hardness by determining the difference in penetrationN).The indenter for either test shall be of a spheroconical ordepths of an indenter under two specified forces,calledspherical configuration.Scales vary by a combination of totalpreliminary and total test forces.test force and type of indenter.3NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.E18-02TABLE 4 Symbols and Designations Associated with Fig.4of the anvil by the indenter.If the anvil is damaged from anyNumber SymbolDesignationcause,it shall be replaced.Anvils showing the least visible dent1DDiameter of ball=e in.(1.588 mm)will give inaccurate results on thin material.3PoPreliminary Test Force=3 kgf(29 N)5.4.1 Cylindrical pieces shall be tested with a V-grooved4PAdditional force=27 kgf(265 N)5PTotal Test Force=Po+P1=3+27=30 kgf(294 N)anvil that will support the specimen with the axis of the6Depth of penetration under preliminary test forceV-groove directly under the indenter or on hard,parallel,twinbefore application of additional forcecylinders properly positioned and clamped in their base.7Increase in depth of penetration under additionalforce5.4.2 Flat pieces shall be tested on a flat anvil that has a8ePermanent increase in depth of penetration undersmooth,flat bearing surface whose plane is perpendicular topreliminary test force after removal of the additionalthe axis of the indenter.force,the increase being expressed in units of 0.001mm5.4.3 For thin materials or specimens that are not perfectly9XXHR30TRockwell 30T hardness=100-eflat,an anvil having an elevated,flat spot about 14 in.(6 mm)in diameter shall be used.This spot shall be polished smoothand flat and shall have a Rockwell hardness of at least 60 HRC.5.2.3 The difference in depth is normally measured by anVery soft material should not be tested on the spot anvilbecause the applied force may cause the penetration of theelectronic device or by a dial indicator.The hardness value,asanvil into the under side of the specimen regardless of itsread from the instrument,is an arbitrary number which isthickness.related to the difference in the depths produced by the twoforces;and since the scales are reversed,the higher the number5.4.4 When testing thin sheet material with a ball indenter,the harder the material.it is recommended that a diamond spot anvil be used.5.2.4 In accordance with the operating procedures recom-NoTE 3-Caution:A diamond spot anvil should only be used with amended by the manufacturer of the hardness tester,the test issuperficial hardness tester and ball indenter.This recommendation shouldstarted by applying the preliminary test force causing an initialbe followed,except when directed otherwise by material specification.penetration of the specimen.Since measurement of the differ-5.5 Test Blocks-Test blocks meeting the requirements ofence in depth starts after the preliminary force has beenPart C shall be used to periodically verify the hardness tester.applied,the dial gage pointer is set to zero if the instrument isa dial indicator model.On a digital readout instrument,the zero6.Test Piecepoint is captured by the electronics automatically.The instru-ment shall be designed to eliminate the effect of impact in6.1 The test shall be carried out on a smooth,even surfaceapplying the preliminary test force.that is free from oxide scale,foreign matter,and,in particular,5.2.5 The additional force is applied for the required dwellcompletely free from lubricants.An exception is made fortime and then removed.The return to the preliminary test forcereactive metals,such as titanium,that may adhere to theposition holds the indenter at the point of deepest penetrationindenter.In such situations,a suitable lubricant such asyet allows elastic recovery to occur and the stretch of the framekerosene may be used.The use of a lubricant shall be reportedto be factored out.The test result is displayed by the testingon the test report.machine.6.2 Preparation shall be carried out in such a way that any5.3 Indenters:alteration of the surface hardness(for example,due to heat or5.3.1 The standard indenters are the diamond spheroconicalcold-working)is minimized.indenter and steel ball indenters having steel or tungsten6.3 The thickness of the test piece or of the layer under testcarbide balls,s,4,and in.(1.588,3.175,6.350,andshould be as dictated in Tables 7-9,and Table 10 and as12.70 mm)in diameter.presented graphically in Figs.5 and 6.These tables were5.3.2 The diamond indenter shall conform to the require-determined from studies on strips of carbon steel and givements prescribed in 13.1.2.1.reliable results.For all other materials it is recommended that5.3.3 Indenter balls can be either tungsten carbide or hard-the thickness exceed 10 times the depth of indentation with aened steel;however,tungsten carbide balls are recommendeddiamond indentor and 15 times the depth of indentation with ato reduce errors associated with the tendency of steel balls toball indentor.As a rule,no deformation should be visible on theflatten with use.Indenter balls shall conform to the require-back of the test piece after the test although not all suchments prescribed in 13.1.2.2.marking is indicative of a bad test.5.3.4 Dust,dirt,grease,and scale shall not be allowed to6.4 For tests on convex cylindrical surfaces the correctionsaccumulate on the indenter as this will affect the test results.given in Tables 11-13,and Table 14 shall be applied.Correc-5.4 Anvils-An anvil shall be used that is suitable for thetions for tests on spherical and concave surfaces should be thespecimen to be tested.The seating and supporting surfaces ofsubject of special agreement.When testing cylindrical speci-all anvils shall be clean and smooth and shall be free from pits,mens,the accuracy of the test will be seriously affected bydeep scratches,and foreign material.If the provisions of 6.3 onalignment of elevating screw,V-anvil,indenters,surface finish,thickness of the test piece are complied with,there will be noand the straightness of the cylinder.For diameters betweendanger of indenting the anvil,but,if it is so thin that thethose given in the tables,correction factors may be derived byimpression shows through on the under side,the anvil may belinear interpolation.Tests performed on diameters smaller thandamaged.Damage may also occur from accidental contactingthose given in Tables 11-14 are not acceptable.NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.4E18-02TABLE 5 Rockwell Hardness ScalesScaleIndenterTotal TestDialSymbolForce,kgtFiguresTypical Applications of Scales日h8-n.(1.588-mmj100redCopper alloys,soft steels,aluminum alloys,malleable iron,etc.balldiamond150blackSteel,hard cast irons.pearlitic malleable iron,titanium,deep case hardened steel.and othermaterials harder than B100.Adiamond60blackCemented carbides,thin steel,and shallow case-hardened steeldiamond100blackThin steel and medium case hardened steel,and pearlitic malleable iron.E%-n.(3.175-mm)ball100redCast iron,aluminum and magnesium alloys,bearing metals.1hs-in.(1.588-mm)60redAnnealed copper alloys,thin soft sheet metals.ballG6-in.(1.588-mmj150redMalleable irons,copper-nickel-zinc and cupro-nickel alloys.Upper limit G92 to avoid possibleballflattening of ball.H%-in.(3.175-mm)bal60redAluminum,zinc,lead.K%-n.(3.175-mm)bal150redL4-in.(6.350-mm)ba60redM4-in.(6.350-mm)bal100redBearing metals and other very soft or thin materials.Use smallest ball and heaviest load that doesP14-in.(6.350-mm)ball150rednot give anvil effect.R1-in.(12.70-mm)ball60red1-in.(12.70-mm)ball100red-in.(12.70-mm)ball150redTABLE 6 Rockwell Superficial Hardness ScalesTotal Test ForceScale SymbolsN Scale.DiamondT Scale.is-in.W Scale.1-in.X Scale.4-in.Y Scale.%-in.kgf(N)Indenter(1.588-mm)Ball(3.175-mm)Bal(6.350-mm)Ball(12.70-mm)Bal15(147刀15W15T15W15X15Y30(29430N30T30W30X30Y45(44145N45T45W45X45YTABLE 7 A Minimum Thickness Guide for Selection of ScalesTABLE 8 A Minimum Thickness Guide for Selection of ScalesUsing the Diamond Indenter(see Fig.5)Using the 6-in.(1.588-mm)Diameter Ball Indenter(see Fig.6)NorE 1-For any given thickness,the indicated Rockwell hardness isNore 1-For any given thickness,the indicated Rockwell hardness isthe minimum value acceptable for testing.For a given hardness,materialthe minimum value acceptable for testing.For a given hardness,materialof any greater thickness than that corresponding to that hardness can beof any greater thickness than that corresponding to that hardness can betested on the indicated scale.tested on the indicated scale.Rockwell ScaleRockwell ScaleMinimum ThicknessMinimum ThicknessAFB么mmHardnessApproximate HardnessHardnessApproximateReadingC-ScaleDial ReadingmmHardnessHardnessReadingReading0.0140.36B-Scale0.0160.4186690.0220.560.0180.48650.0240.6172940.0200.51e61.50.0260.669160870.0220.56956690.0280.71800.0240.6150670.0300.76350.0260.6671650.0320.8169620.0280.716732620.0340.860.0300.766019570.0360.91400.0320.81520.0380.96280.0340.860.0401.020.0360.91370.0380.9628A These approximate hardness numbers are for use in selecting a suitable scale0.0401.0220and should not be used as hardness conversions.If necessary to convert testreadings to another scale refer to Hardness Conversion Tables E 140(Relation.A These approximate hardness numbers are for use in selecting a suitable scaleship Between Brinell Hardness,Vickers Hardness,Rockwell Hardness,Rockwelland should not be used as hardness conversions.If necessary to convert testSuperficial Hardness and Knoop Hardness).readings to another scale,refer to Hardness Conversion Tables E 140(Relation-ship Between Brinell Hardness,Vickers Hardness,Rockwell Hardness,RockwellSuperficial Hardness,and Knoop Hardness).than 3 s.When materials require the use of a dwell time greaterthan 3 s,this should be specified in the product specification.6.5 Precautions for materials having excessive,time-dependent plasticity(indentation creep):In the case of mate-7.Procedurerials exhibiting plastic flow after application of the total test7.1 As part of the test procedure,periodic checks shall beforce,the indenter will continue to move.The total test forceperformed.See Section 14 for recommendations.should be removed after the specified dwell time,and the time7.2 The test is normally carried out at ambient temperaturerecorded after the test results(that is,65 HRFW,4 s)if longerwithin the limits of 50 to 95F(10 to 35C).However,because