1、Designation: D4170 10Standard Test Method forFretting Wear Protection by Lubricating Greases1This standard is issued under the fixed designation D4170; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method evaluates the fretting wear protectionprovided by lubricating greases.1.2 The values stated in SI units are to be regar
3、ded as thestandard. Other units are for information only.1.3 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-bili
4、ty of regulatory limitations prior to use. For specificwarning statements, see 7.2 and 9.2.2. Referenced Documents2.1 ASTM Standards:2Test Methods for Rating Motor, Diesel, andAviation Fuels;Motor Fuels (Section I), Reference Materials and BlendingAccessories (Annex 2), Reference Fuels (A2.7.3.3), a
5、ndTable 32 (Specification for n-Heptane Motor Fuel)2.2 Military Standard:3MIL-S-22473D Sealing, Locking and Retaining Com-pounds, Single-Component3. Terminology3.1 Definitions:3.1.1 fretting wear, na form of attritive wear caused byvibratory or oscillatory motion of limited amplitude character-ized
6、by the removal of finely-divided particles from therubbing surfaces.43.1.1.1 DiscussionAir can cause immediate local oxida-tion of the wear particles produced by fretting wear. Inaddition, environmental moisture or humidity can hydrate theoxidation product. In the case of ferrous metals, the oxidize
7、dwear debris is abrasive iron oxide (Fe2O3) having the appear-ance of rust, which gives rise to the nearly synonymous terms,fretting corrosion and friction oxidation. A related, but some-what different phenomenon often accompanies fretting wear.False brinelling is localized fretting wear that occurs
8、 when therolling elements of a bearing vibrate or oscillate with smallamplitude while pressed against the bearing race. The mecha-nism proceeds in stages: (1) asperities weld, are torn apart, andform wear debris that is subsequently oxidized; (2) due to thesmall-amplitude motion, the oxidized detrit
9、us cannot readilyescape, and being abrasive, the oxidized wear debris acceler-ates the wear. As a result, wear depressions are formed in thebearing race. These depressions appear similar to the Brinelldepressions obtained with static overloading. Although falsebrinelling can occur in this test, it i
10、s not characterized as such,and instead, it is included in the determination of fretting wear.4. Summary of Test Method4.1 The tester is operated with two ball thrust bearings,lubricated with the test grease, oscillated through an arc of 0.21rad (12), at a frequency of 30.0 Hz (1800 cpm), under a lo
11、adof 2450 N (550 lbf), for 22 h at room temperature (Note 1).Fretting wear is determined by measuring the mass loss of thebearing races.NOTE 1Arc, frequency, and load are factory-set operating conditionsand should not be altered. The load spring constant may change over anextended time period. Sprin
12、g calibration should be checked periodicallyand, if necessary, a suitable shim should be fabricated to obtain therequired load (63 %) at the assembled length of the spring.5. Significance and Use5.1 This test method is used to evaluate the property oflubricating greases to protect oscillating bearin
13、gs from frettingwear. This method, used for specification purposes, differenti-ates among greases allowing low, medium, and high amountsof fretting wear under the prescribed test conditions. The testhas been used to predict the fretting performance of greases inwheel bearings of passenger cars shipp
14、ed long distances.5Testresults do not necessarily correlate with results from other1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.G0.04 on Functional Tests - Tribology.Current edition approved
15、May 1, 2010. Published June 2010. Originallyapproved in 1982. Last previous edition approved in 2002 as D417097(2002)1.DOI: 10.1520/D4170-10.2See 1998 Annual Book of ASTM Standards, Vol 05.04.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelp
16、hia, PA 19111-5098.4NLGI Lubricating Grease Guide, 3rd edition.5Verdura, T. M., “Development of a Standard Test to Evaluate FrettingProtection Quality of Lubricating Grease,” NLGI Spokesman, Vol XLVII, No. 5,August 1983, pp. 15767.1*A Summary of Changes section appears at the end of this standard.Co
17、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.types of service. It is the responsibility of the user to determinewhether test results correlate with other types of service.6. Apparatus6.1 Falex Fretting Wear Tester, Model F-1581,6,7as
18、 pur-chased and illustrated in Figs. 1 and 2.6.2 Spring Guide, conforming to description in Fig. 3,ifnotsupplied with tester.6.3 Test Bearings,7,8of the ball thrust type having an insidediameter of 16.00 6 0.025 mm (0.630 6 0.001 in.), an outsidediameter of 35.69 6 0.025 mm (1.405 + 0.001 in.), anda
19、ssembled height of 15.75 6 0.25 mm (0.620 6 0.010 in.) andequipped with nine 7.142-mm (0.2812-in.) diameter balls in apressed steel retainer; all surfaces (except retainer) to beground. Different surface finishes are provided on commercialbearings. Bearings with ground surfaces are lustrous; tumbled
20、bearings appear slightly dulled or grayish. Bearings withground races, as specified in 6.3 are required to obtain correctresults. Tumbled bearings with reground races are satisfactory.Magnification should be used to inspect the races to verify thatthey have been ground. Part-number bearings7,8are pr
21、ovidedwith ground races. A drawing of the test bearing, givingcomplete, detailed dimensions and specifications is available inRR:D02-1159.96.4 Vibration Mount,7,10upon which the tester is placed.6.5 Time Switch, (optional) shown in Fig. 1 and described indetail in Fig. 4, or a commercial equivalent.
22、6.6 Ultrasonic Cleaner.7,116.7 Analytical Balance having a capacity of about 100 gand with a minimum sensitivity of 0.1 mg.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to th
23、e specifications of the Commit-tee on Analytical Reagents of the American Chemical Society6Falex Fretting Wear Tester, formerly known as the Fafnir Friction OxidationTester, is available from Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554.7The sole source of supply of the apparatus known to th
24、e committee at this timeis listed. If you are aware of alternative suppliers, please provide this information toASTM Headquarters.Your comments will receive careful consideration at a meetingof the responsible technical committee,1which you may attend.8Andrews (Part No. 06X65) have been found to be
25、satisfactory. Preparedbearings (part number F-1581-50 (formerly FL-1081), that is, with set screw flat(see 8.1), are available from Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554.9Supporting data (the results of the cooperative test program, from which thesevalues have been derived) have been
26、filed at ASTM International Headquarters andmay be obtained by requesting Research Report RR:D02-1159.10Isomode Vibration control Pad No. 3451801 has been found satisfactory andis available from rubber products suppliers.11A Bransonic 2200 cleaner (Branson Ultrasonics Co., Danbury, CT 06813)having a
27、 capacity of about 3 L (34 gal) operating at a frequency of about 55 kHz,with a power input of about 125 W, has been found satisfactory.FIG. 1 Fafnir Friction Oxidation Tester and Time SwitchFIG. 2 Chuck and Housing AssemblyD4170 102where such specifications are available.12Other grades may beused,
28、provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 n-heptane, reagent grade or ASTM Motor Fuel Grade 3.(WarningFlammable. Health hazard.)NOTE 2This test method was originally developed using chlorof
29、orm,which was subsequently replaced by 1,1,1-trichloroethane because of itslower toxicity. Since then, 1,1,1-trichloroethane was declared an OzoneDepleting Substance by the U.S. Environmental ProtectionAgency (EPA).Federal regulations ban the production of this material after December 31,1995, but e
30、xisting stocks may continue to be used. Currently there are noEPA restrictions on the use of chloroform, but the user should be aware ofits health hazards if it is used as a functionally equivalent solvent. Noother solvent intended as a substitute for 1.1.1-trichloroethane in this testmethod has bee
31、n cooperatively evaluated. However, it is the experience ofthe Grease Subcommittee that elimination of the cleaning step using1,1,1trichloroethane does not affect the reported results from this test.8. Bearing Preparation8.1 Grind a suitable set screw flat (approximate dimensions;8 by 4 by 0.5 mm) o
32、n the periphery of each bearing race;8flatmust be square with face to prevent cocking of races when setscrews are tightened.NOTE 3It is extremely difficult to grind the flat square with the facewhen using a hand or bench grinder. Good results have been obtained byracking a number of bearing races in
33、 a V-block and using a surfacegrinder.8.2 Scribe suitable identification marks on the outer lands ofbearing races to distinguish races of upper bearing from racesof lower bearing. Identification marks should not be scribed onback or periphery of the bearing race.8.3 Fill tank of ultrasonic cleaner w
34、ith distilled water to adepth of 30 to 40 mm. Place two bearing sets in a 250-mLbeaker containing about 125-mL of n-heptane. Cover beakerand place in ultrasonic bath. After cleaning for 10 to 15 min,transfer bearing parts to second beaker containing 125 mL ofn-heptane (see 7.2). Clean for 8 to 10 mi
35、n, then repeatoperation for two additional 4 to 5-min washes, using newn-heptane and clean beakers each time.8.4 Place bearing parts onto freshly cleaned, glass Petridishes or aluminum moisture dishes to air dry. Bearings shouldbe propped against rim of dish to permit air circulation. Cleanbearings
36、must not be rotated or air blown. Do not placebearings on any surface other than freshly cleaned glass ormetal. Do not touch bearings with bare hands; use forceps ortongs, or wear surgeon gloves or finger cots.8.5 When bearings are dry, place dishes containing bearingsin a desiccator and let stand f
37、or a minimum of 30 min.8.6 Weigh the upper and lower bearing race pairs separatelyto the nearest 0.1 mg. (Each race pair consists of two races.)9. Procedure9.1 In a dust-free environment, install the test grease inunused, cleaned, weighed bearings.9.1.1 Fill the ball tracks of the bearing races with
38、 the testgrease. Use a suitable spatula to strike the grease level with thebearing lands. Bearing backs and bearing seats must be keptfree of grease and particulate matter. Clean with a lintfreecloth slightly moistened with n-heptane.9.1.2 Fill each ball retainer with test grease taking care to fill
39、all the cavities around the balls on both sides of the retainer.Remove excess grease from the bore and rim of the retainer,but leave an excess of grease on the cupped side. Adjust themass of the grease in each bearing to 1.0 6 0.05 g.9.2 Assemble the chuck. Use Fig. 5 as a guide to chuckassembly. Us
40、e minimal force when tightening set screws.Locate bearing set screw flats normal to set screws. Purpose ofset screws is to prevent rotation of races in seats. To precludeovertightening set screws, grasp hex-key (Allen wrench) byshank rather than by lever arm. If set screws tend to loosenduring the t
41、est, use a low-strength anaerobic sealant (MIL-S-22473D, Grade H or similar) on the threads rather than moreforce. Bearing races must bottom on bearing seats. Bottomingcan be verified by visual and tactile inspection. (WarningTight set screws, misalignment between set screws and flats, orset screw f
42、lats that are not square with the bearing face cancock the bearing upon tightening set screws, causing unevenwear. Loose set screws combined with oily or greasy bearingbacks and seats could allow a poor grease to give erroneous testresults because of race creep effects.)9.2.1 Install an upper bearin
43、g race in the chuck top andtighten the set screw, using minimal force.9.2.2 Invert the chuck top and secure in a bench vise.9.2.3 Place the retainer of the upper bearing on the race inthe chuck top (9.2). The cupped side must be positionedupward during assembly (downward during operation).9.2.4 Inst
44、all the other race of the upper bearing in theoscillating bearing seat. Using minimal force, tighten the setscrew. (With all bearing set screws oriented alike, permanentlymark the underside of the oscillating bearing seat crank arm.Thereafter, when using the same orientation for assembly thelower be
45、aring race will always be installed in the same seat.)9.2.5 Install a lower bearing race in the oscillating bearingseat. Using minimal force tighten the set screw.9.2.6 Assemble the oscillating bearing seat on the shaft suchthat the upper bearing components are properly mated.12Reagent Chemicals, Am
46、erican Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formula
47、ry, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 3 Spring GuideD4170 1039.2.7 Place the lower bearing retainer on the race in theoscillating bearing seat. Position the cupped side upward.9.2.8 Install the other lower bearing race in the chuck base.Using minimal force tighten the set
48、 screw.9.2.9 Place the chuck base on the shaft.9.2.10 Assemble the spring guide, spring, load shim (ifrequired), spacer, washer, and lock nut on the shaft. Whileholding the chuck base and oscillating bearing seat to preventrotation, tighten the lock nut until the spacer bottoms on theshaft shoulder.
49、NOTE 4Spring alignment may affect wear pattern. To ensure consis-tent spring alignment, paint a reference mark on the (cleaned) spring andthereafter, always install spring with mark aligned with the set screw in thechuck base.9.2.11 Remove chuck assembly from vise. Loosen all bear-ing race set screws. While holding chuck base in one hand,strike head of shaft with a 0.5-kg (1-lb) (approximate) soft-faced hammer to assist bearing seating. Lightly tighten all setscrews.9.2.12 Apply a film of grease to the surfaces of the chuckthat contact the housing.NOTE 5Use any low-f
