ASTM G174-2004 Standard Test Method for Measuring Abrasion Resistance of Materials by Abrasive Loop Contact《磨擦环接触法测量材料耐磨性的标准试验方法》.pdf

1、Designation: G 174 04Standard Test Method forMeasuring Abrasion Resistance of Materials by AbrasiveLoop Contact1This standard is issued under the fixed designation G 174; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of

2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers ranking rigid engineering ma-terials for abrasion resistance in rubbing against a 30-maluminu

3、m oxide abrasive finishing tape. Though most solidscan be tested, this test method addresses its use for metals, andcoatings applied to metals.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purpo

4、rt 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 prior to use.2. Referenced Documents2.1 ASTM Standards:2E 17

5、7 Practice for Use of the Terms Precision andAccuracyas Applied to Measurement of a Property of a MaterialE 178 Practice for Dealing with Outlying ObservationsE 691 Practice for Conducting an Inter-laboratory Study toDetermine the Precision of a Test MethodG40 Terminology Relating to Erosion and Wea

6、rG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from Inter-laboratory Wear andErosion TestsG 132 Test Method for Pin Abrasion Testing3. Terminology3.1 Definitions:3.1.1 abrasive wear, nwear due to hard particles or hardprotuberances forced against, and moving along, a solid

7、surface.3.2 Definitions of Terms Specific to This Standard:3.2.1 abrasion, nthe process of abrasive wear.3.2.1.1 DiscussionTerminology G40 does not defineabrasion.3.2.2 abrasion resistance, nin tribology, the ability of amaterial to resist damage or attrition by abrasion.3.2.3 fixed abrasive tape, n

8、hard particles or grains bonded(fixed) to one side of a flexible web with a resin or similarbinder. the particles can be of any hard material and vary insize. (This abrasive medium is also known as “finishing tape,”“microfinishing tape,” “microfinishing film,” or “finishingfilm.”)3.2.4 flexible web,

9、 nplastic, paper, rubber, or other mate-rial that is thin enough to conform to a 180 wrap around a16-mm diameter cylinder under a tension of less than 1.8kg/cm width.4. Summary of Test Method4.1 This test involves rubbing an abrasive tape loop initiallyin line-contact with a solid surface. The tape

10、abrasion producesa groove in the test surface, and the volume of materialremoved in a designated amount of abrasive rubbing ismeasured by mass loss or by calculation from the groovegeometry. The continuous loop of abrasive is used for theduration of the test and then discarded. A fresh loop is used

11、foreach one-hour test.4.2 The wear volume produced in this test provides ameasure of the ability of a surface to resist wear damage fromabrasive substances. The smaller the wear volume in this test,the better the abrasion resistance.4.3 The test was developed using 30 m-mean diameteraluminum oxide a

12、brasive on a 127 m-thick polyester support,but other commercially available abrasive tapes could be used.The test has also been used with webs such as paper that areinherently abrasive to many materials.5. Significance and Use5.1 This test is useful for screening materials for use in toolsthat are s

13、ubjected to abrasion from the material that is beingmachined, worked, or formed. It has been used to screen toolsteels for punch press dies, hardfacings for earth-movingmachinery, and wear coatings. This test utilizes a test that is1This test method is under the jurisdiction of ASTM Committee G02 on

14、 Wearand Erosion and is the direct responsibility of Subcommittee G02.30 on AbrasiveWear.Current edition approved Nov. 1, 2004. Published November 2004. Originallyapproved in 2003. Last previous edition approve din 2003 as G 174 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org

15、, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.simpler to bui

16、ld and use than those used in the Test MethodG 132 abrasion test which, like this test, uses a fixed abrasivecounterface to abrade a test material.5.2 The one-hour test is intended for metals and materialsthat are softer than hardened steel (67 HRC), but may beapplied to harder materials (see 7.1.7)

17、.6. Apparatus6.1 The test apparatus used in inter-laboratory tests isillustrated in Fig. 1. A 132-cm long by 25.4-mm wide abrasivetape is made into a continuous loop with a pressure sensitiveadhesive (PSA) butt splice (Fig. 2). The web is tensioned toform a triangle with the 16-mm diameter drive spi

18、ndle at theapex. The idler rolls can be of any diameter, but a convenientsize is about 50 mm radius with flanges to prevent lateralmovement of the tape. The test sample shall have the dimen-sions shown in Fig. 3. It is clamped or attached to thecounterbalanced loading arm with PSA foam. The loading

19、armis pivoted on rolling element bearings. A 200 g loading mass isattached to the pivot arm and centered directly over the linecontact between the specimen and drive spindle.6.2 One idler roller must be adjustable to produce tapetension sufficient to drive the tape with spindle-to-tape slippageof le

20、ss than 20 m in a one-hour test time. The drive spindleshall be 16 mm in diameter and have a total indicated run-outof less than 20 m at a rotational speed of 300 rpm.7. Test Procedure7.1 Standard Test for Metals Softer than 67 HRC:7.1.1 Specimen PreparationThe test surfaces (7.6 by 32mm) should hav

21、e a ground or lapped finish with a roughnessless than 0.2 m Ra. The surface lay shall be aligned with thelong axis of the test specimen. When testing molded surfaces orspecific finishes, the test samples should have the finish ofinterest on the test faces.7.1.2 CleaningCleaning is not needed if the

22、test surfacesare untouched after the sample preparation and no lubricants,and so forth, were used in fabrication. If the surfaces arecontaminated, clean in a solvent that will not leave a surfacefilm or degrade the properties of the test surface (acetone issuitable for most metals).7.1.3 WeighingIf

23、mass change is going to be used as thetest metric, weigh the test specimen to the nearest tenth of amilligram and record this as the initial weight.7.1.4 Sample AttachmentAffix the test sample to loadingarm and the 200 g-loading mass over the line where thespecimen has tangential contact with the ta

24、pe.7.1.5 Belt TensioningTension the abrasive belt over thedrive spindle and idler rollers by moving idler rollers. Checkthe loop for slip with a mark on the tape and spindle. Loops areused only once for one hour.7.1.6 Check Systems AlignmentTapered scars will result ifthe sample is not parallel to t

25、he drive spindle. Check alignmentby putting pressure sensing media on the spindle and bring thespecimen in contact with the spindle. The pressure-sensingmedium must show line contact across the sample width. Thinfoils (less than 25 m) can also be used to make sure that bothedges of the test sample a

26、re contacting the spindles. Put the foilbetween the spindle and the edge of the sample and pull the foilout. Repeat on the other side. Equal pull force on both sidesshows good alignment, and can be measured with a forcemeasuring device. Lock the aligned sample arm in place. Putthe loop on and tensio

27、n it as in 7.1.5. Turn the tester on for 5to 10 s and lift the sample arm and check for a uniform wearscar across the sample width.7.1.7 TestingSet the spindle rotational speed to 300 rpmand turn the tester on. Start timing or set a time on the machinepower to shut off after one hour.NOTE 1Some ceme

28、nted carbides and other hard materials mayrequire a longer time to develop a measurable wear scar. Sometimes thesematerials require several one-hour test cycles with the tape changed eachhour. This is a non-standard test and is not covered by this method.7.1.8 Scar MeasurementClean wear debris from

29、thespecimen with an acetone or alcohol wipe or other suitabletechnique. Measure the scar width in at least three places(edge-center-edge) to within 0.1 to 0.25 mm. Calculate sampleFIG. 1 Schematic of Test RigG174042wear volume using the following equation or other model forcalculating a segment of a

30、 cylinder (see Fig. 4).7.1.9 Measurement of Mass ChangeIf gravimetric mea-surement is used as the test metric, weigh the sample to 611018 mil-thick microfinishing film was used in inter-laboratory tests. It was purchased at:3M CorporationImperial Lapping Film 262LGrade 30 MIC, Mineral A/OBacking 5 m

31、il Size 1 by 150 by 3 in.2Scotch Magic Tape (3M Corp.) was used in inter-laboratory tests33M Corp.3M Center, Building 251-2A-08St. Paul, MN 551441000 USANOTESome tapes may have a release agent on the back that must be removed by abrasion followed by solvent wipe.FIG. 2 Loop Splicing DetailNOTE0.1 to

32、 0.2 m Ra surface roughness on test surface.FIG. 3 Loop Abrasion Test SampleG174043mg and subtract this mass from the initial mass. Take the masschange and convert it into wear volume by dividing by thedensity for the test material.NOTE 2Mass loss is usually not used on tool steels and similar hardm

33、aterials. Scar measurement is usually more accurate.7.2 Test option for thin (50 m) hard coatings and surfacetreatments:7.2.1 TestingSet the spindle rotational speed to 300 rpm,installa3maluminum oxide loop and a 100 g loading mass,and jog the machine to produce about 400 mm of loop abrasionon the s

34、pecimen. Check to ensure uniform contact across thewidth of the specimen. Adjust the specimen arm if necessaryand initial the test in a new spot on the specimen. Repeat thisuntil uniform marking is accomplished within 400 mm ofabrasion.7.2.2 When uniform contact is established, test the coatingor tr

35、eatment until penetration just starts and terminate the test.Decade testing (1 loop pas, 10 loop passes, 100 loop passes,and 1000 loop passes) is recommended as a way to assess whenthe coating or treatment may abrade through. If it is intact at 10loop passes, but well penetrated at 100 loop passes,

36、thepenetration can be determined by checking for penetration at20, 30, 40, and so forth, loop passes. Penetration is determinedoptically in most cases, but etching or similar techniques mightbe needed for some surface treatments.7.2.3 Measurement for Mass ChangeSame as 7.1.9.7.2.4 Measurement of Wea

37、r Volume form Scar SizeThescar width at penetration should be measured optically 6100m and wear volume is calculated from the equation in Fig. 4.For coatings with thickness less than a few micrometres, it isrecommended that wear volume be determined by profilometryof the scar depth at the point of p

38、enetration. Take several scardepth profiles; determine the average cross-sectional area ofthe scar and multiply the average area by the scar width toobtain a scar volume.7.2.5 Test MetricThe test metric for abrasion resistance ofcoating and surface treatments is wear volume in cubicmillimetres divid

39、ed by loop passes in metres (number of passesto penetrate multiplied by 1.32 m per pass), mm3/m.7.3 Other test options are summarized in Table X1.2.8. Report8.1 Report the following:8.1.1 Test material including all details on manufacture,treatment, and surface texture,8.1.2 Abrasive tape used, grit

40、 size, grit material, tapethickness, and width.8.1.3 Conditions: normal force, total abrasion distance, tapespeed, number of replicates, test temperature and relativehumidity, test metric (scar size or mass change), and8.1.4 Wear volume (average and standard deviation).9. Precision and Bias9.1 Preci

41、sionThe precision of an individual scar measure-ment can be checked by using mass change and different waysof measuring the scar by physical measurement. If all tech-niques produce the same wear volume, the measurement willbe precise. Physical measurements usually include optical orprofilometer meas

42、urement of scar width followed by calcula-tions to yield wear volume. Profilometer software is availablefor the calculation of wear from scar geometry.9.2 Repeatability and ReproducibilityThe repeatability ofthe test depends on the homogeneity of the test material, theFIG. 4 Scar MeasurementG174044u

43、niformity of the test abrasive sample/spindle alignment,tape/spindle slips and environmental conditions. All of thesefactors should be kept constant. The reproducibility of this teston hard and soft steels is shown in Appendix X1. Thewithin-lab coefficient of variation was 7.5 to 12.3 %; betweenlabs

44、 was 35.6 to 43.9 %. The COV is well below 10 % in labswhere this test is in continuous use. The inter-laboratory testincrease probably reflects operator differences. The reproduc-ibility would be better if more experienced operators wereused. This test was new to some inter-laboratory test collabo-

45、rators. A standard reference material can be periodically testedto check for lot-to-lot variability in abrasive, but this has notbeen a factor in the years that the test was in use beforestandardization. Interlaboratory test data were analyzed usingprocedures and methods outlined in ASTM standards o

46、ninterlaboratory tests: Practices E 177, E 178, E 691, and GuideG117.9.3 BiasSince there is no reference material for determin-ing the bias of a loop abrasion resistance for a material, thereis no basis upon which to determine bias.10. Keywords10.1 abrasion; abrasion resistance; abrasive wear; alumi

47、numoxide; finishing tape; fixed abrasive; tapeAPPENDIX(Nonmandatory Information)X1. HARD AND SOFT STEEL RESULTS USING THE STANDARD PROCEDURE ON A LOADING MASS OF 200 gX1.1 See Table X1.1 and Table X1.2.G174045TABLE X1.1 ASTM G02 Interlaboratory Test DataStatistical AnalysisAHardTestConditionsWithin-

48、Lab Repeatability Between-Lab ReproducibilityLab #Numberof ReplicatesAverage, mm3STD DEV, mm3k-Statistic DEV from AVG, mm3H-Statistic1 3 2.604 0.395 1.897 0.905 1.2482 3 1.170 0.099 0.475 -0.529 0.7293 3 1.006 0.069 0.331 -0.693 0.9554 3 2.015 0.053 0.255 0.316 0.4364Number3Average1.699Average0.208W

49、ithin-LabSTD DEV0.745Between-LabSTD DEV (PROV)C.O.V. (%) = 12.2 43.895% Limits = 0.58 2.09Use the larger of the 95% limits for the final value Within-Lab Between-Labk crit = 1.82 h crit = 1.49Any individual k and h values greater than k crit and h critsuggest that those data should be examined for “outliers”Recommended statement of precision: The average test value was 1.70 mm3with a 95% repeatability limit (within-lab) of 0.58 mm3and a 95% reproducibility limit (between-labs) of 2.09 mm3SoftTestConditionsWithin-Lab Repeatability Between-L