1、Designation: G99 17Standard Test Method forWear Testing with a Pin-on-Disk Apparatus1This standard is issued under the fixed designation G99; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in pare
2、ntheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a laboratory procedure fordetermining the wear of materials during sliding using apin-on-disk apparatus. Materials are tested i
3、n pairs undernominally non-abrasive conditions. The principal areas ofexperimental attention in using this type of apparatus tomeasure wear are described. The coefficient of friction mayalso be determined.1.2 This test method standard uses a specific set of testparameters (load, sliding speed, mater
4、ials, etc.) that were thenused in an interlaboratory study (ILS), the results of which aregiven here (Tables 1 and 2). (This satisfies the ASTM form inthat “The directions for performing the test should include allof the essential details as to apparatus, test specimen,procedure, and calculations ne
5、eded to achieve satisfactoryprecision and bias.”) Any user should report that they “fol-lowed the requirements of ASTM G99,” where that is true.1.3 Now it is often found in practice that users may followall instructions given here, but choose other test parameters,such as load, speed, materials, env
6、ironment, etc., and therebyobtain different test results. Such a use of this standard isencouraged as a means to improve wear testing methodology.However, it must be clearly stated in any report that, while thedirections and protocol in Test Method G99 were followed (iftrue), the choices of test par
7、ameters were different from TestMethod G99 values, and the test results were therefore alsodifferent from the Test Method G99 results. This use should bedescribed as having “followed the procedure of ASTM G99.”All test parameters that were used in such case must be stated.1.4 The values stated in SI
8、 units are to be regarded asstandard. No other units of measurement are included in thisstandard.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
9、practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E178 Practice for Dealing With Outlying ObservationsG40 Terminology Relating to Wear and ErosionG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from I
10、nterlaboratory Wear or Ero-sion Tests (Withdrawn 2016)32.2 DIN Standard:4DIN 50324 Testing of Friction and Wear3. Summary of Test Method3.1 For the pin-on-disk wear test, two specimens are re-quired. One, a pin with a radiused tip, is positioned perpen-dicular to the other, usually a flat circular d
11、isk. A ball, rigidlyheld, is often used as the pin specimen. The test machinecauses either the disk specimen or the pin specimen to revolveabout the disk center. In either case, the sliding path is a circleon the disk surface. The plane of the disk may be orientedeither horizontally or vertically.NO
12、TE 1Wear results may differ for different orientations.3.1.1 The pin specimen is pressed against the disk at aspecified load usually by means of an arm or lever and attachedweights. Other loading methods have been used, such ashydraulic or pneumatic.NOTE 2Wear results may differ for different loadin
13、g methods.3.2 Wear results are reported as volume loss in cubicmillimetres for the pin and the disk separately. When twodifferent materials are tested, it is recommended that eachmaterial be tested in both the pin and disk positions.3.3 The amount of wear is determined by measuring appro-priate line
14、ar dimensions of both specimens before and after the1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.40 on Non-Abrasive Wear.Current edition approved Jan. 1, 2017. Published January 2017. Originallyapproved in 1
15、990. Last previous edition approved in 2016 as G99 05 (2016). DOI:10.1520/G0099-17.2For 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 the standards Document Summary pa
16、ge onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Beuth Verlag GmbH (DIN- DIN Deutsches Institut furNormung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/www.en.din.de.Copyright ASTM International, 100 Barr Harbor Dr
17、ive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations i
18、ssued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1test, or by weighing both specimens before and after the test. Iflinear measures of wear are used, the length change or shapechange of the pin, and the depth or shape change of the diskwear track (in millimetres) are
19、determined by any suitablemetrological technique, such as electronic distance gaging orstylus profiling. Linear measures of wear are converted to wearvolume (in cubic millimetres) by using appropriate geometricrelations. Linear measures of wear are used frequently inpractice since mass loss is often
20、 too small to measure precisely.If loss of mass is measured, the mass loss value is converted tovolume loss (in cubic millimetres) using an appropriate valuefor the specimen density.3.4 Wear results are usually obtained by conducting a testfor a selected sliding distance and for selected values of l
21、oadand speed. One set of test conditions that was used in aninterlaboratory measurement series is given in Tables 1-3.Other test conditions may be selected depending on thepurpose of the test. In such cases, the user should report theirresults as “following the procedure of ASTM G99.”3.5 Wear result
22、s may in some cases be reported as plots ofwear volume versus sliding distance using different specimensfor different distances. Such plots may display non-linearrelationships between wear volume and distance over certainTABLE 1 Characteristics of the Interlaboratory Wear Test SpecimensNOTE 1See Not
23、e 4 for information.Composition (weight%) Microstructure Hardness (HV 10)RoughnessARz(mean) (m) Ra(mean) (m)Steel ball (100 Cr6) (AISI 52 100)BDiameter 10 mm1.35 to 1.65 Cr0.95 to 1.10 C0.15 to 0.35 Si0.25 to 0.45 Mnmartensitic with minor carbidesand austenite838 21 0.100 0.010Steel disc (100 Cr6) (
24、AISI 52 100)CDiameter 40 mm 0.030 P0.030 Smartensitic with minor carbidesand austenite852 14 0.952 0.113Alumina ball, diameter = 10 mmDAlumina disc, diameter = 40.6 mmD95 % Al2O3(with addi-tives of TiO2,MgO, and ZnO)equi-granular alpha aluminawith very minor secondaryphases1610 101 (HV 0.2)1599 144
25、(HV 0.2)1.3690.9680.1230.041AMeasured by stylus profilometry. Rzis maximum peak-to-valley roughness. Rais arithmetic average roughness.BStandard ball-bearing balls (SKF).CStandard spacers for thrust bearings (INA).DManufactured by Compagnie Industrielle des Ceramiques Electroniques, France.TABLE 2 R
26、esults of the Interlaboratory TestsANOTE 1See Note A for test conditions.NOTE 2Numbers in parentheses refer to all data received in the tests. In accordance with Practice E178, outlier data values were identified in somecases and discarded, resulting in the numbers without parentheses. The differenc
27、es are seen to be small.NOTE 3Values preceded by are one standard deviation.NOTE 4Data were provided by 28 laboratories.NOTE 5Calculated quantities (for example, wear volume) are given as mean values only.NOTE 6Values labeled “NM” were found to be smaller than the reproducible limit of measurement.N
28、OTE 7A similar compilation of test data is given in DIN 50324.Results (ball) (disk)Specimen PairsSteel-steel Alumina-steel Steel-alumina Alumina-aluminaBall wear scar diameter (mm) 2.11 0.27(2.11 0.27)NM 2.08 0.35(2.03 0.41)0.3 0.06(0.3 0.06)Ball wear volume (103mm3) 198(198). 186(169)0.08(0.08)Numb
29、er of values 102(102). 60(64)56(59)Disk wear scar width (mm) NM 0.64 0.12(0.64 0.12)NM NMDisk wear volume (103mm3) . 480(480). .Number of values . 60(60). .Friction coefficient 0.60 0.11 0.76 0.14 0.60 0.12 0.41 0.08Number of values 109 75 64 76ATest conditions: F =10N; v =0.1ms1, T = 23C; relative
30、humidity range 12 to 78 %; laboratory air; sliding distance 1000 m; wear track (nominal) diameter = 32 mm;materials: steel = AISI 52 100; and alumina = -Al2O3.G99172portions of the total sliding distance, and linear relationshipsover other portions. Causes for such differing relationshipsinclude ini
31、tial “break-in” processes, transitions between re-gions of different dominant wear mechanisms, and so forth.The extent of such non-linear periods depends on the details ofthe test system, materials, and test conditions.3.6 It is not recommended that continuous wear depth dataobtained from position-s
32、ensing gages be used because of thecomplicated effects of wear debris and transfer films present inthe contact gap, and interferences from thermal expansion orcontraction.4. Significance and Use4.1 The amount of wear in any system will, in general,depend upon the number of system factors such as the
33、 appliedload, machine characteristics, sliding speed, sliding distance,the environment, and the material properties. The value of anywear test method lies in predicting the relative ranking ofmaterial combinations. Since the pin-on-disk test method doesnot attempt to duplicate all the conditions tha
34、t may beexperienced in service (for example; lubrication, load,pressure, contact geometry, removal of wear debris, andpresence of corrosive environment), there is no insurance thatthe test will predict the wear rate of a given material underconditions differing from those in the test.4.2 The use of
35、this test method will fall in one of twocategories: (1) the test(s) will follow all particulars of thestandard, and the results will have been compared to the ILSdata (Table 2), or (2) the test(s) will have followed theprocedures/methodology of Test Method G99 but applied toother materials or using
36、other parameters such as load, speed,materials, etc., or both. In this latter case, the results cannot becompared to the ILS data (Table 2). Further, it must be clearlystated what choices of test parameters/materials were chosen.5. Apparatus5.1 General DescriptionFig. 1 shows a schematic draw-ing of
37、 a typical pin-on-disk wear test system.5One type oftypical system consists of a driven spindle and chuck forholding the revolving disk, a lever-arm device to hold the pin,and attachments to allow the pin specimen to be forced againstthe revolving disk specimen with a controlled load. Anothertype of
38、 system loads a pin revolving about the disk centeragainst a stationary disk. In any case the wear track on the diskis a circle, involving multiple wear passes on the same track.The system may have a friction force measuring system, forexample, a load cell, that allows the coefficient of friction to
39、 bedetermined.5.2 Motor DriveA variable speed motor, capable of main-taining constant speed (61 % of rated full load motor speed)under load is required. The motor should be mounted in sucha manner that its vibration does not affect the test. Rotatingspeeds are typically in the range 0.3 to 3 rad/s (
40、60 to 600r/min).5.3 Revolution CounterThe machine shall be equippedwith a revolution counter or its equivalent that will record thenumber of disk revolutions, and preferably have the ability toshut off the machine after a pre-selected number of revolutions.5.4 Pin Specimen Holder and Lever ArmIn one
41、 typicalsystem, the stationary specimen holder is attached to a leverarm that has a pivot.Adding weights, as one option of loading,produces a test force proportional to the mass of the weightsapplied. Ideally, the pivot of the arm should be located in theplane of the wearing contact to avoid extrane
42、ous loading forcesdue to the sliding friction. The pin holder and arm must be ofsubstantial construction to reduce vibrational motion during thetest.5.5 Wear Measuring SystemsInstruments to obtain linearmeasures of wear should have a sensitivity of 2.5 m or better.Any balance used to measure the mas
43、s loss of the test specimenshall have a sensitivity of 0.1 mg or better; in low wearsituations greater sensitivity may be needed.6. Test Specimens and Sample Preparation6.1 MaterialsThis test method may be applied to a varietyof materials.The only requirement is that specimens having thespecified di
44、mensions can be prepared and that they willwithstand the stresses imposed during the test without failureor excessive flexure. The materials being tested shall bedescribed by dimensions, surface finish, material type, form,composition, microstructure, processing treatments, and inden-tation hardness
45、 (if appropriate).5A number of other reported designs for pin-on-disk systems are given in “ACatalog of Friction and Wear Devices,” American Society of Lubrication Engineers(1973). Three commercially-built pin-on-disk machines were either involved in theinterlaboratory testing for this standard or s
46、ubmitted test data that comparedadequately to the interlaboratory test data. Further information on these machinescan be found in Research Report RR:G02-1008.TABLE 3 Test Parameters Used for Interlaboratory TestsNormal Force (N) 10Sliding Speed (m/s) 0.1Sliding Distance (m) 1000Pin-end Diameter, sph
47、erical (mm) 10Environment airTemperature, nominal (C) 23Humidity, (%RH) 1278Track Diameter (mm) 2535NOTE 1F is the normal force on the pin, d is the pin or ball diameter,D is the disk diameter, R is the wear track radius, and w is the rotationvelocity of the disk.FIG. 1 Schematic of Pin-on-Disk Wear
48、 Test SystemG991736.2 Test SpecimensThe typical pin specimen is cylindricalor spherical in shape. Typical cylindrical or spherical pinspecimen diameters range from 2 to 10 mm. The typical diskspecimen diameters range from 30 to 100 mm and have athickness in the range of 2 to 10 mm. Specimen dimensio
49、nsused in an interlaboratory test with pin-on-disk systems aregiven in Table 1.6.3 Surface FinishA ground surface roughness of 0.8 m(32 in.) arithmetic average or less is usually recommended.NOTE 3Rough surfaces make wear scar measurement difficult.6.3.1 Care must be taken in surface preparation to avoidsubsurface damage that alters the material significantly. Specialsurface preparation may be appropriate for some test programs.State the type of surface and surface preparation in the report.7. Test Parameters7.1
