1、Designation: D4048 10Standard 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 Department of Defense.1. Scope1.1 This test method covers the detection of the corro
3、sive-ness to copper of lubricating grease.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 purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
4、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 of Petroleum Product
5、sD130 Test Method for Corrosiveness to Copper from Pe-troleum Products by Copper Strip TestD2500 Test Method for Cloud Point of Petroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and Lubricants2.2 ASTM Adjuncts:Copper Strip Corrosion Standard33. Terminology3.1 DefinitionsS
6、ee 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 attack copper or copperalloys present in bea
7、rings 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 lubricating grease, na semi-fluid to solid prod
8、uct 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 special properties.4. Summary of Test Met
9、hod4.1 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 6 1C (212 6 2F) for 24 h 6 5 min.At theend of this heating period, the strip is removed, washed, andco
10、mpared with the Copper Strip Corrosion Standard.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 onlubricated parts, such as bearings that contain c
11、opper 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 thelubricant to inhibit copper corrosion caused by f
12、actors 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 ofcolor blindness may find it difficult to accuratel
13、y comparre a test strip tothe Copper 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.)inside diameter, and 115 mm to 125 mm (412 in. to 5 in.) inheight as described in Test Methods D97 and
14、D2500.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.G0.01 on Chemical and General Laboratory Tests.Current edition approved May 1, 2010. Published July 2010. Originallypublished in 1981. Last
15、previous edition approved in 2008 as D404802(2008).DOI: 10.1520/D4048-10.2For 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 A
16、STM website.3Available from ASTM International Headquarters. Order Adjunct No.ADJD0130. Originally produced in 1973.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Test Jar CoversBeakers, 50-mL; borosilicate glass,approximately 4
17、0 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 vented corksthat lightly cover the test jars, allowing pressure equalizationbetween the inside and outside of the jars, yet minimizingexposure
18、 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 temperature of 100 6 1C (212 6 2F) or otherdesired temperatures with the same precision.6.4 Polishing ViseFor holding the copper strip firml
19、ywithout marring the edges while polishing. Any convenienttype of holder (see Appendix X1 on Optional Useful Equip-ment in Test Method D130) may be used, 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 Te
20、st TubesFlat glass test tubes may be used toprotect corroded strips for close inspection or storage. (SeeAppendix X1 on Optional Useful Equipment in Test MethodD130.)6.6 Copper Strip Corrosion Standardconsists of repro-ductions in color of typical strips representing degrees oftarnish and corrosion,
21、 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 light to avoid the possibility offading. Inspect for fading by comparing two different plaques,one of which has been carefully protected from ligh
22、t (new).Observe both sets in diffused daylight (or equivalent), firstfrom a point directly above and then from an angle ofapproximately 45. If any evidence 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 b
23、ediscarded.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 purchased. At intervals, remove theopaque strip and observe. If there is any evidence of fading ofthe exposed portion, it is suggested that the standa
24、rd 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 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 s
25、hows excessivescratching, it is suggested that the plaque be replaced.7. Reagents and Materials7.1 AcetoneAmerican Chemical Society Reagent Gradeacetone is suitable. (WarningExtremely flammable. Harm-ful if inhaled. Vapors may cause flash fires.)7.2 Copper StripsUse strips 12.5 6 2mm(12 6116 in.)wid
26、e, 1.5 to 3.0 mm (116 to18 in.) thick, cut 75 6 5mm(3614 in.) long from smooth-surfaced, hard-temper, cold-finishedcopper of 99.9 + % purity; electrical bus bar stock is generallysuitable. (See Appendix X1 on Optional Useful Equipment inTest Method D130.) The strips may be used repeatedly butshould
27、be discarded when the surfaces become deformed onhandling.7.3 Polishing MaterialsSilicon carbide grit paper of vary-ing degrees of fineness, including 65-m (240-grit) paper orcloth, also a supply of 105-m (150-mesh) silicon carbide grainand absorbent cotton (cotton wool).7.4 Wash SolventVolatile, su
28、lfur-free hydrocarbon solventmay be used provided that it shows no tarnish at all when testedat 50 6 1C (or 122 6 2F). Knock test-grade isooctane(Warningsee 8.1.2) or American Chemical Society ReagentGrade n-heptane (Warningsee 7.1) are suitable solvents.Because of possible toxic effects, the use of
29、 benzene should beavoided.8. Preparation of 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 (
30、240-grit) silicon carbidepaper or cloth, removing 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 practi
31、cal manual procedure for surface prepa-ration, place a sheet of the paper on a flat surface, moisten itwith 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
32、 of the strip may be prepared by use of motor-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, w
33、hile preventingfingers from contacting the strip directly, may also be used.8.1.2 Final PolishingRemove strip from the wash sol-vent. Holding it in the fingers protected with the ashless filterpaper, polish first the ends and then the sides with the 105-m(150-mesh) silicon carbide grains picked up f
34、rom a clean glassplate with a pad of cotton (cotton 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 st
35、rip in a vise, andpolish the main surfaces with 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
36、metal dust from the strip byrubbing vigorously with clean pads of absorbent cotton until afresh 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
37、 of the stripuniformly to obtain a uniformly stained strip. If the edges showD4048 102wear (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 to 70 g, depending on itsspecific gravi
38、ty) of grease sample into the bottom of a cleantest 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.9.2 To prevent touching the strip with fingers, w
39、ear 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 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 ve
40、nted 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 temperature for a specified periodof time. Commonly used conditions are 100 6 1C (212 62F) for 24 h 6 5 min.9.5 At the end of t
41、he 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 Note 2), or usingstainless steel forceps, remove the strip from the grease, andcarefully remove excess grease clinging to the strip. Ta
42、ke 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 and not by wiping, andinspect, in diffused daylight (or equivalent), for evidence oftarnishing or corrosion by comparison with the Copp
43、er 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 be observed.NOTE 3It has been suggested that a very light grease may be blottedoff the strip with filter paper or a laboratory wiper.
44、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 disturbthe tarnish or corrosion on the strip.9.6.2 In handling the test strip during the inspection andcomparison, the danger of marking
45、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 cotton.10. Interpretation10.1 Interpret the corrosiveness of the sample according tohow the appearance of the test strip agrees with one
46、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, consid
47、er the observed strip as still belonging in thisClassification 1b; however, if any evidence of red color isnoticed, the observed strip belongs in Classification 2.10.1.2 A claret red 2a strip can be mistaken for a 3a strip, ifthe brassy underlay of the 3a strip is completely masked by amagenta overt
48、one. To distinguish between them, immerse thestrip in acetone (Warningsee 7.1). A 2a strip will appear asa 1b strip, while a 3a strip will not change.10.1.3 To distinguish a 2c strip from a 3b strip, place it in a20-mm by 150-mm test tube, and bring it to a temperature of315 to 370C (600 to 700F) in
49、 four to six minutes using a hotplate. Adjust the temperature by observing an ASTM hightemperature distillation thermometer inserted in a second testtube lying on the hot plate. A 2c strip will assume the color ofa 2d strip and successive stages of tarnish, while a 3b strip willtake on the appearance of a 4a strip.10.1.4 Repeat the test if blemishes due to fingerprints or dueto spots from any water droplets or entrained air that may havetouched the test strip during the test period or from otherunknown causes are observed. If blemis
