1、Designation: D6138 16D6138 18Standard Test Method forDetermination of Corrosion-Preventive Properties ofLubricating Greases Under Dynamic Wet Conditions (EmcorTest)1This standard is issued under the fixed designation D6138; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case of revision, the year of last revision. A number 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 covers the determination of corrosion- preventi
3、ve corrosion-preventive properties of greases usinggrease-lubricated ball bearings under dynamic wet conditions.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safet
4、y concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in a
5、ccordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 AST
6、M Standards:2D217 Test Methods for Cone Penetration of Lubricating GreaseD665 Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of WaterD1193 Specification for Reagent Water2.2 ISO Standards:3ISO 15 Rolling BearingsRadial BearingsBoundary DimensionsGeneral Plan
7、bearingsRadial bearingsBoundarydimensionsGeneral planISO 3696 Water for Analytical Laboratory UseSpecifications and Test Methodsanalytical laboratory useSpecifications andtest methodsISO 7120 Petroleum Productsproducts and LubricantsPetroleum Oils and Other FluidsDetermination of Rust-preventingChar
8、acteristics in the Presence of WaterlubricantsPetroleum oils and other fluidsDetermination of rust-preventingcharacteristics in the presence of water2.3 EI Standards:4IP 530 Determination of the density of greaseDensity cup method3. Terminology3.1 Definitions:3.1.1 lubricating grease, na semifluid t
9、o solid product of a thickener in a liquid lubricant.3.1.1.1 Discussion1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.G0.06 on Functional Tests - Contamination.Current edition a
10、pproved April 1, 2016April 1, 2018. Published May 2016April 2018. Originally approved in 1997. Last previous edition approved in 20132016 asD6138 13.D6138 16. DOI: 10.1520/D6138-16.10.1520/D6138-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service a
11、t serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from Energy Institute,
12、 61 New Cavendish St., London, W1G 7AR, U.K., http:/www.energyinst.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depi
13、ct all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM Internation
14、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface tension and otherphysical forces. Other ingredients are commonly included to impart special properties. D21
15、73.1.2 thickener, nin lubricating grease, a substance composed of finely-divided particles dispersed in a liquid lubricant to formthe products structure.3.1.2.1 DiscussionThe thickeners can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickener), which ar
16、einsoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that the solid particles beextremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the liquid lubricant. D2173.2 Definitions of Terms Specific to
17、 This Standard:3.2.1 corrosion, nreddish rust or black spots on the race.3.2.1.1 DiscussionAny stain through which the underlying metal surface is still visible shall be ignored.4. Summary of Test Method4.1 New, cleaned, and lubricated bearings are tested partially immersed in water (distilled, synt
18、hetic sea water, or sodiumchloride solution) under no applied load at a speed of 83 rmin 6 5 rmin in a predetermined sequence of running and stoppingfor a period of approximately one week. After cleaning, the bearing rings are examined and rated according to the degree ofcorrosion.5. Significance an
19、d Use5.1 This test method is used to assess the ability of grease to prevent corrosion in rolling bearings operated in the presence ofdistilled water, sodium chloride solution, or synthetic sea water. It is used for development and specification purposes.6. Apparatus6.1 Test BearingsUse a double row
20、 self-aligning ball bearing (30 mm by 72 mm by 19 mm), conforming to 1306 K of ISO 15,with a steel cage.5 In cases of dispute, the SKF bearing specified in Footnote 5 shall be used as the referee bearing.6.2 SKF TMG/Emcor Test Machine, see Annex A1 for description.6.3 Dentists Mirror, non-magnifying
21、.6.4 Graduated Pipette or Syringe, capable of measuring 20 mL 6 1 mL water.6.5 Oven, capable of maintaining 90 C 6 2 C.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications
22、of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.6 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.7.2 Purit
23、y of WaterUnless otherwise indicated, references to water shall be understood to mean freshly boiled double distilledwater, water conforming to Specification D1193 Type II, or reagent water as defined by Grade 2 of ISO 3696.7.3 Synthetic Sea WaterIf required, as specified in Specification D665, and
24、ISO 7120.7.4 Sodium Chloride Solutiona 0.5 molL solution of sodium chloride prepared using freshly boiled double distilled water,water conforming to Specification D1193 Type II, or water conforming to Grade 2 of ISO 3696, at a pH of 8.0 to 8.2 adjusted bytitration with sodium hydroxide solution.NOTE
25、 1Other water types, such as that specified in Specification D1193, Type III, or other salt solutions and salt concentrations can be used in thistest method, although the precision when using other water types and salt solutions has not been determined. It is recommended that the pH of the otherwate
26、r types is determined before use.5 1306 K steel caged bearing manufactured by NTN and DKF may be used; however, precision had only been evaluated using SKF 1306 K/236 725 bearings.6 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestion
27、s on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeil Convention, Inc. (USPC), Rockville, MD.D6138 1827.5 Isopropyl Alcohol(War
28、ningFlammable. Poison. Causes burns. Vapor extremely irritating. May be fatal if swallowed.Harmful if inhaled.)7.6 Ammonium Hydroxide(WarningFlammable. Poison. Causes burns. Vapor extremely irritating. May be fatal ifswallowed. Harmful if inhaled.)7.7 Solvent Rinse Solution, of the following composi
29、tion by volume:7.7.1 90 % Isopropyl alcohol.7.7.2 9 % Distilled water.7.7.3 1 % Ammonium hydroxide, 3.2 molL concentration. (WarningFlammable. Poison. Causes burns. Vapor extremelyirritating. May be fatal if swallowed. Harmful if inhaled.)7.8 Mineral Spirit, also known as Stoddard Solvent, reagent g
30、rade. (WarningCombustible. Vapor Harmful.)8. Preparation of Bearings8.1 Examine the test bearings carefully and select only bearings that have outer rings and balls entirely free of corrosion. Duringthe bearing preparation, handle the bearings with tongs or protective gloves. Do not touch the bearin
31、gs with bare fingers at anytime. Use two new bearings for each grease being tested.8.2 Number bearings on the outside diameter of the outer ring, but do not use chemical etching. One method to number thebearings is with an electric pen, which should be grounded on the outer ring surface being marked
32、.8.3 Wash the selected bearings thoroughly in hot (50 C to 65 C) mineral spirits (Warningsee 7.8) to remove the rustpreventive.To ensure complete removal, subject the bearing to a second wash in fresh hot mineral spirits. (WarningThe washingtemperatures specified are considerably above the flash poi
33、nt of the solvent. Accordingly, the washing operation should be carriedout in a well-ventilated hood where no ignition source is present.)NOTE 2The purpose of the two washes with hot mineral spirits in 8.3 is to completely remove the rust preventative applied to the bearings for storage.The duration
34、 of the washes required to remove this preventative will be dependent on the equipment used by the lab and the type and amount of rustpreventative applied by the bearing manufacturer. It is recommended to visually inspect each bearing to assure the rust preventative is removed beforeproceeding to 8.
35、4. If rust preventative is still present after two washes, the bearings should be washed again in the hot mineral spirits until the bearingsare clean and free of residue.8.4 Transfer bearings to the solvent rinse solution (Warningsee 7.7.3) to remove any mineral spirits which may be present.Rinse ea
36、ch bearing and slowly rotate one ring relative to the other ring in fresh hot (65 C 65 C) solvent rinse solution. Freshrinse solution is used to avoid the selective evaporation of the components at the rinse temperature.NOTE 3Care must be taken when handling bearings in the hot rinse solution to avo
37、id burns. Tongs and heat resistant gloves are recommended.8.5 Remove each bearing from the solvent rinse solution and place on filter paper to drain. After draining, dry the bearing inan oven at 90 C 6 2 C for 15 min to 30 min.8.6 Permit the bearing to cool to room temperature and reexamine the surf
38、aces to ensure that corrosion-free bearings have beenselected. (Exercise care when handling the bearing to avoid rotating one ring relative to the other ring after cleaning and drying.)8.6.1 Inspect the outer ring tracks. (Fig. 1 illustrates the area to be inspected.) If etch spots or corrosion are
39、evident, reject thebearing. A dentists mirror can be helpful for inspection purposes.9. Procedure9.1 Prepare the apparatus by removing all traces of grease from the previous tests by wiping the plummer blocks. Wash theplummer blocks with the solvent rinse solution followed by water. Dry thoroughly u
40、sing a lint-free cloth.9.2 Distribute 10 g 10.5 mL 6 0.1 g0.1 mL of the grease evenly in each test bearing using a spatula or bearing packer. TakeThe weight of grease that is equivalent to this volume is calculated by weight in grams = density (10.5 mL 6 0.1 mL), whereFIG. 1 Partial Outer Ring of Do
41、uble-Row Self-Aligning BearingD6138 183the density of the grease is in grams per milliliter. If the density of the grease is not known, it shall be determined either by usinga pycnometer method, as detailed in IP 530, or by using another suitable procedure to determine the density of grease. Whenpac
42、king the bearings, take care to avoid the inclusion of air bubbles. Rotate the outer ring slightly with a gloved hand to assistdistribution. Smear all the external surfaces of the bearing with additional grease.9.3 Prepare two bearings for each grease to be tested. Each pair of bearings is used for
43、one test.9.4 Place the adapter sleeves, bearings, and V-ring seals in position on the shaft and finger-tighten the sleeve nuts.9.5 Place the shaft complete with greased bearings in position in the test rig, taking care that the bearings are centered in theplummer blocks.9.6 Place the top halves of t
44、he plummer block in position and finger-tighten the locking screws.9.7 Press the V-ring seals up against the plummer blocks using the special tool supplied with the test machine.9.8 Run the test rig for 30 min 6 5 min at 83 rmin 6 5 rmin immediately after assembly to distribute the grease evenly.9.9
45、 Without delay, remove the top halves of the plummer blocks and introduce 10 mL of distilled water, synthetic sea water orsodium chloride solution into each side of each plummer block (a total of 20 mL 6 1 mL) using a pipette or syringe. Refit tophalves of plummer blocks and finger-tighten the locki
46、ng screws.NOTE 4Although the test can be run with other user-defined solutions, the precision limits described in Section 12 apply only to tests conducted withreagents described in Section 7.9.10 Without delay, operate the test rig according to the following schedule:9.10.1 Run 8 h 6 10 min, stop, a
47、llow to stand 16 h 6 10 min;9.10.2 Run 8 h 6 10 min, stop, allow to stand 16 h 6 10 min;9.10.3 Run 8 h 6 10 min, stop, allow to stand 108 h 6 2 h.9.11 Immediately following the time schedule (9.10), remove the top halves of the plummer blocks. Lift the shaft and bearingson to a suitable support on t
48、he work bench. Unscrew the sleeve nuts one or two revolutions. Tap the bearings lightly to free them,then pull bearings, sleeves, and seals off the shaft.9.12 Dismantle the bearings for inspection by prying balls out of the cage pockets until the outer ring can be removed.9.13 Wash the outer rings i
49、n the solvent rinse solution and dry, using a lint-free cloth. Examine immediately.10. Rating Procedure10.1 Visually examine the outer ring track area for rust or etch spots, without the aid of any optical adjuncts, and evaluate asdescribed in Table 1. Fig. 1 illustrates the area to be examined. Fig. 2 illustrates examples intended to assist in the assessment ofthe degree of corrosion. Ignore any staining through which the underlying metal surface is clearly visible.11. Report11.1 Report the degree of corrosion and the
