1、Designation: D4048 16Standard Test Method forDetection of Copper Corrosion from Lubricating Grease1This standard is issued under the fixed designation D4048; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the detection of the
3、 corrosive-ness to copper of lubricating grease.1.2 The values stated in SI units are to be regarded as thestandard.1.2.1 ExceptionThe values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is t
4、heresponsibility of the user of this standard to establish appro-priate safety and heal practices and determine the applicabilityof regulatory limitations prior to use.For specific warningstatements, see Sections 7, 8, and 10.2. Referenced Documents2.1 ASTM Standards:2D97 Test Method for Pour Point
5、of Petroleum ProductsD130 Test Method for Corrosiveness to Copper from Petro-leum Products by Copper Strip TestD2500 Test Method for Cloud Point of Petroleum Productsand Liquid FuelsD4175 Terminology Relating to Petroleum Products, LiquidFuels, and Lubricants2.2 ASTM Adjuncts:Copper Strip Corrosion
6、Standard33. Terminology3.1 DefinitionsSee Terminology D4175.3.2 copper corrosion, neffect of a chemical attack oncopper metal by a lubricant causing various levels of tarnishingand change in appearance.3.2.1 DiscussionAcidic and other aggressive species, of-ten sulfur-based, in a lubricant can attac
7、k copper or copperalloys present in bearings or other lubricated surfaces. Thepresence of this antagonistic interaction is often apparent in awell-defined series of color changes.3.3 lubricant, nany material interposed between two sur-faces that reduces the friction or wear between them.3.4 lubricat
8、ing grease, na semi-fluid to solid product of adispersion of a thickener in a liquid lubricant.3.4.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredients arecommonly included to impart sp
9、ecial properties.4. Summary of Test Method4.1 A prepared copper strip is totally immersed in a sampleof grease and heated in an oven or liquid bath at a specifiedtemperature for a definite period of time. Commonly usedconditions are 100 C 6 1 C (212 F 6 2 F) for 24 h 65 min. At the end of this heati
10、ng period, the strip is removed,washed, and compared with the Copper Strip Corrosion Stan-dard.5. Significance and Use5.1 This test method measures the tendency of lubricatinggrease to corrode copper under specific static conditions. Itmay be of some value in predicting possible chemical attack onlu
11、bricated parts, such as bearings that contain copper or copperalloys. Such corrosion, for example, can cause prematurebearing failures. However, no correlations with actual fieldservice, most of which are under dynamic conditions, havebeen established. It does not measure either the ability of thelu
12、bricant to inhibit copper corrosion caused by factors otherthan the lubricant itself nor does it measure the stability of thegrease in the presence of copper.NOTE 1Because this test method requires the ability to determinesubtle differences in color of copper strips, persons with certain types ofcol
13、or blindness may find it difficult to accurately compare a test strip to theCopper Strip Corrosion Standard.6. Apparatus6.1 Test JarsCloud and pour jars, cylindrical jars of clearglass with flat bottoms, 30 mm to 33.5 mm (1316 in. to 1516 in.)1This test method is under the jurisdiction of ASTM Commi
14、ttee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.G0.01 on Chemical and General Laboratory Tests.Current edition approved Dec. 1, 2016. Published January 2017. Originallypublished in 1981. Last previous edition approved in 2010 as D4048 1
15、0. DOI:10.1520/D4048-16.2For 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 page onthe ASTM website.3Available from ASTM International He
16、adquarters. Order Adjunct No.ADJD0130. Originally produced in 1973.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance
17、 with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1inside diameter, and 115 mm to 125 mm
18、 (412 in. to 5 in.) inheight as described in Test Methods D97 and D2500.6.2 Test Jar CoversBeakers, 50 mL; borosilicate glass,approximately 40 mm (1.6 in.) by 50 mm (2.0 in.) suitable forcovering individual test jars. Small porcelain or glazed silicacrucibles or crucible covers or watch glasses or v
19、ented corksthat lightly cover the test jars, allowing pressure equalizationbetween the inside and outside of the jars, yet minimizingexposure of the inside of the jars to foreign vapors present inthe oven will also be satisfactory.6.3 OvenA circulating air oven or liquid bath capable ofmaintaining a
20、 temperature of 100 C 6 1 C (212 F 6 2 F)or other desired temperatures with the same precision.6.4 Polishing ViseFor holding the copper strip firmlywithout marring the edges while polishing. Any convenienttype of holder (see Appendix X1 on Optional Useful Equip-ment in Test Method D130) may be used,
21、 provided that thestrip is held tightly and that the surface of the strip beingpolished is supported above the surface of the holder.6.5 Viewing Test TubesFlat glass test tubes may be used toprotect corroded strips for close inspection or storage. (SeeAppendix X1 on Optional Useful Equipment in Test
22、 MethodD130.)6.6 Copper Strip Corrosion Standardconsists of repro-ductions in color of typical strips representing degrees oftarnish and corrosion, the reproductions being encased inplastic in the form of a plaque.6.6.1 Keep the plastic-encased printed Copper Strip Corro-sion Standard protected from
23、 light to avoid the possibility offading. Inspect for fading by comparing two different plaques,one of which has been carefully protected from light (new).Observe both sets in diffused daylight (or equivalent), firstfrom a point directly above and then from an angle ofapproximately 45. If any eviden
24、ce of fading is observed,particularly at the left end of the plaque, it is suggested that theone that is the more faded with respect to the other bediscarded.6.6.1.1 Alternatively, place a 20 mm (34 in.) opaque strip(masking tape) across the top of the colored portion of theplaque when initially pur
25、chased. At intervals, remove theopaque strip and observe. If there is any evidence of fading ofthe exposed portion, it is suggested that the standard bereplaced.6.6.1.2 These plaques are full-color productions of typicalstrips. They have been printed on aluminum sheets by afour-color process and are
26、 encased in plastic for protection.Directions for their use are given on the reverse side of eachplaque.6.6.2 If the surface of the plastic cover shows excessivescratching, it is suggested that the plaque be replaced.7. Reagents and Materials7.1 AcetoneAmerican Chemical Society Reagent Gradeacetone
27、is suitable. (WarningExtremely flammable. Harm-ful if inhaled. Vapors may cause flash fires.)7.2 Copper StripsUse strips 12.5 mm 6 2mm(12 in. 6116 in.) wide, 1.5 mm to 3.0 mm (116 in. to18 in.) thick, cut75 mm 6 5mm(3in.614 in.) long from smooth-surfaced,hard-temper, cold-finished copper of 99.9 + %
28、 purity; electri-cal bus bar stock is generally suitable. (See Appendix X1 onOptional Useful Equipment in Test Method D130.) The stripsmay be used repeatedly but should be discarded when thesurfaces become deformed on handling.7.3 Polishing MaterialsSilicon carbide grit paper of vary-ing degrees of
29、fineness, including 65 m (220 grit CAMI-gradeor P220 FEPA-grade) paper or cloth, also a supply of 105 m(120 grit to 150 grit CAMI-grade or P120 to P150 FEPA-grade) silicon carbide grain and absorbent cotton (cottonwool).7.4 Wash SolventVolatile, sulfur-free hydrocarbon solventmay be used provided th
30、at it shows no tarnish at all when testedat 50 C 6 1 C (or 122 F 6 2 F). Knock test-gradeisooctane (Warningsee 8.1.2) or American Chemical Soci-ety Reagent Grade n-heptane (Warningsee 7.1) are suitablesolvents. Because of possible toxic effects, the use of benzeneshould be avoided.8. Preparation of
31、Strip8.1 Mechanical Cleaning of Strips:8.1.1 Surface PreparationRemove all surface blemishesfrom all six sides of the strip with silicon carbide paper of suchdegrees of fineness as are needed to accomplish the desiredresults efficiently. Finish with 65 m (240 grit) silicon carbidepaper or cloth, rem
32、oving all marks that may have been made byother grades of paper used previously. Immerse the strip inwash solvent (Warningsee 7.1.) from which it can bewithdrawn immediately for final polishing or in which it can bestored for future use.8.1.1.1 As a practical manual procedure for surfacepreparation,
33、 place a sheet of the paper on a flat surface, moistenit with wash solvent, and rub the strip against the paper with arotary motion, protecting the strip from contact with the fingersor by wearing impervious gloves (see Note 2). Alternatively,the surface of the strip may be prepared by use of motor-
34、drivenmachines using appropriate grades of dry paper or cloth.NOTE 2Disposable polyethylene is one type of glove that has beenfound to be satisfactory. However, any type of glove that is impervious tothe reagents and materials used in this test method, while preventingfingers from contacting the str
35、ip directly, may also be used.8.1.2 Final PolishingRemove strip from the wash solvent.Holding it in the fingers protected with the ashless filter paper,polish first the ends and then the sides with the 105 m(150 mesh) silicon carbide grains picked up from a clean glassplate with a pad of cotton (cot
36、ton wool) moistened with a dropof wash solvent. Wipe vigorously with fresh pads of cotton(cotton wool) and subsequently handle only when wearingimpervious gloves (see Note 2) or with stainless steel forceps;do not touch with naked fingers. Clamp the strip in a vise, andpolish the main surfaces with
37、silicon-carbide grains on absor-bent cotton. Rub in the direction of the long axis of the strip,carrying the stroke beyond the end of the strip before reversingthe direction. Clean all metal dust from the strip beforereversing the direction. Clean all metal dust from the strip byrubbing vigorously w
38、ith clean pads of absorbent cotton until aD4048 162fresh pad remains unsoiled. When the strip is clean, immedi-ately immerse it in the prepared sample. (WarningForcepscan scratch copper, affecting the results.)8.1.2.1 It is important to polish the whole surface of the stripuniformly to obtain a unif
39、ormly stained strip. If the edges showwear (surface elliptical), they will likely show more corrosionthan the center. The use of a vise will facilitate uniformpolishing.9. Procedure9.1 Place about 60 mL (about 50 g to 70 g, depending on itsspecific gravity) of grease sample into the bottom of a clea
40、ntest jar (see 6.1). Bring the depth of the grease to about 80 mm(3.2 in.). Tap the grease down into the jar carefully. Smooth thetop to give a relatively flat surface. Wipe excess grease off thejar walls.NOTE 3The use of a syringe to prepare a grease sample with minimalentrained air and then to tra
41、nsfer it to the test jar has been found to behelpful in reducing the amount of air trapped in the sample during filling.A syringe with a wide nozzle and a diameter just less than that of the testjar may be most helpful in this regard. This may reduce the potential riskof breaking the somewhat fragil
42、e test jar during the action of tapping it toremove air from the grease sample.9.2 To prevent touching the strip with fingers, wear imper-vious gloves (see Note 2) or use stainless steel forceps; andinsert cleaned copper strip into the grease until it touches thebottom of the tube and is completely
43、immersed and covered byat least 5 mm (0.2 in.) of grease.9.3 Cover the jar(s) loosely with a beaker, crucible, watchglass, or vented cork (see 6.2).9.4 Place the jar(s) in an oven or liquid bath so that they aresupported approximately vertical. Regulate the oven or liquidbath to maintain a specified
44、 temperature for a specified periodof time. Commonly used conditions are 100 C 6 1 C (212 F6 2 F) for 24 h 6 5 min.9.5 At the end of the test period, remove the jar(s) from theoven or liquid bath and allow them to cool to room tempera-ture.9.6 Strip Examination:9.6.1 Wearing impervious gloves (see N
45、ote 2), or usingstainless steel forceps, remove the strip from the grease, andcarefully remove excess grease clinging to the strip. Take carenot to disturb the tarnish on the strip, and immediately immerseit in wash solvent. Withdraw the strip at once, dry withquantitative filter paper by blotting a
46、nd not by wiping, andinspect, in diffused daylight (or equivalent), for evidence oftarnishing or corrosion by comparison with the Copper StripCorrosion Standard. Hold both the test strip and the standardstrip plaque in such a manner that light reflected from them atan angle of approximately 45 will
47、be observed.NOTE 4It has been suggested that a very light grease may be blottedoff the strip with filter paper or a laboratory wiper. Heavier greases mayrequire wiping or removal with a plastic, rubber, or stainless steel spatula.However the grease is removed from the strip, exercise care not to dis
48、turbthe tarnish or corrosion on the strip.9.6.2 In handling the test strip during the inspection andcomparison, the danger of marking or staining can be avoidedif it is inserted in a flat tube (see Appendix X1 on OptionalUseful Equipment in Test Method D130), which can bestoppered with absorbent cot
49、ton.10. Interpretation10.1 Interpret the corrosiveness of the sample according tohow the appearance of the test strip agrees with one of thestrips of the Copper Strip Corrosion Standard.10.1.1 When a strip is in the obvious transition statebetween that indicated by any two adjacent standard strips,judge the sample by the more tarnished standard strip. Shoulda strip appear to have a darker orange color than standard strip1b, consider the observed strip as still belonging in thisClassification 1b; however, if any evidence of r
