1、Designation: D 4048 02An American National StandardStandard Test Method forDetection of Copper Corrosion from Lubricating Grease1This standard is issued under the fixed designation D 4048; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method c
3、overs the detection of the corrosive-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
4、use. It is theresponsibility 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 hazardstatements, see Sections 7, 8, and 10.2. Referenced Documents2.1 ASTM Standards:D97 Test Method for P
5、our Point of Petroleum Oils2D 130 Test Method for Detection of Copper Corrosion fromPetroleum Products by the Copper Strip Tarnish Test2D 2500 Test Method for Cloud Point of Petroleum Prod-ucts22.2 ASTM Adjuncts:Copper Strip Corrosion Standard33. Terminology3.1 There are no terms in this test method
6、 that require newor other than dictionary definitions.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 6 1C (212 6 2F) for 24 h 6
7、 5 min.At theend of this heating period, the strip is removed, washed, andcompared 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
8、possible chemical attack onlubricated 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 measur
9、e either the ability of thelubricant to inhibit copper corrosion caused by factors otherthan the lubricant itself nor does it measure the stability of thegrease in the presence of copper.6. Apparatus6.1 Test JarsCloud and pour jars, cylindrical jars of clearglass with flat bottoms, 30 mm to 33.5-mm
10、(1316 in. to 1516 in.)inside diameter, and 115 mm to 125 mm (412 in. to 5 in.) inheight as described in Test Methods D 97 and D 2500.6.2 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 gl
11、azed 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 of the inside of the jars to foreign vapors present inthe oven will also be satisfactory.6.3 Oven
12、A 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 firmlywithout marring the edges while polishing. Any convenienttype of holder (see Appendix X1 of Test
13、Method D 130) maybe used, provided that the strip is held tightly and that thesurface of the strip being polished is supported above thesurface of the holder.6.5 Viewing Test TubesFlat glass test tubes may be used toprotect corroded strips for close inspection or storage. (See theAppendix X1 of Test
14、 Method D 130.)1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.G on Lubricating Grease.Current edition approved April 10, 2002. Published July 2002. Originallypublished as D 404881. Last previou
15、s edition D 404897.2Annual Book of ASTM Standards, Vol 05.01.3Available from ASTM International Headquarters. Order Adjunct No.ADJD0130.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.6 Copper Strip Corrosion Standardconsists of re
16、pro-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 light to avoid the possibility offading. Inspect for fading b
17、y 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 evidence of fading is observed,particularly at the left end of the p
18、laque, 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 purchased. At intervals, remove theopaque strip and observe. If t
19、here 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 encased in plastic for protection.Directions for their use ar
20、e 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 is suitable. (WarningExtremely flammable. Harm-ful if inhaled.
21、 Vapors may cause flash fires.)7.2 Copper StripsUse strips 12.5 6 2mm(12 6116 in.)wide, 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 of Test M
22、ethod D 130.) 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 fineness, including 65-m (240-grit) paper orcloth, also a supply of 105-m (150-mesh) silicon carbide grainand a
23、bsorbent cotton (cotton wool).7.4 Wash SolventVolatile, sulfur-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 suita
24、ble solvents.Because of possible toxic effects, the use of 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 acc
25、omplish the desiredresults efficiently. Finish with 65-m (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 i
26、n which it can bestored for future use.8.1.1.1 As a practical 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
27、 impervious gloves (see Note 1). Alternatively,the surface of the strip may be prepared by use of motor-drivenmachines using appropriate grades of dry paper or cloth.NOTE 1Disposable polyethylene is one type of glove that has beenfound to be satisfactory. However, any type of glove that is imperviou
28、s tothe reagents and materials used in this test method, while 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 w
29、ith the 105-m(150-mesh) silicon carbide grains picked up from 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 1) or with stainless s
30、teel forceps;do not touch with naked fingers. Clamp the strip 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 dus
31、t from the strip beforereversing the direction. Clean all 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 re
32、sults.)8.1.2.1 It is important to polish the whole surface of the stripuniformly to obtain a uniformly 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
33、(about 50 to 70 g, depending on itsspecific gravity) 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.
34、9.2 To prevent touching the strip with fingers, wear imper-vious gloves (see Note 1) 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) l
35、oosely 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 temperature for a specified periodof time. Commonly used conditions are 100 6
36、1C (212 62F) for 24 h 6 5 min.D40480229.5 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 Note 1), or usingstainless steel forceps, remove the strip from the grease, an
37、dcarefully 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 and not by wiping, andinspect for evidence of tarnishing or corrosion by compa
38、risonwith the Copper Strip Corrosion Standard. Hold both the teststrip and the standard strip plaque in such a manner that lightreflected from them at an angle of approximately 45 will beobserved.NOTE 2It has been suggested that a very light grease may be blottedoff the strip with filter paper or a
39、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 disturbthe tarnish or corrosion on the strip.9.6.2 In handling the test strip during the inspection andcomparison, the
40、danger of marking or staining can be avoidedif it is inserted in a flat tube (see Appendix X1 of Test MethodD 130), which can be stoppered with absorbent cotton.10. Interpretation10.1 Interpret the corrosiveness of the sample according tohow the appearance of the test strip agrees with one of thestr
41、ips 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 ob
42、served 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 overtone. To d
43、istinguish between them, immerse thestrip in acetone (Warningsee 7.1). a strip will appear as a 1bstrip, 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 four to six
44、 minutes using a hotplate. Adjust the temperature by observing an ASTM hightemperature distillation thermometer inserted in a second testtube lying on the hot plate. c strip will assume the color of a 2dstrip and successive stages of tarnish, while a 3b strip will takeon the appearance of a 4a strip
45、.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 are observed.10.1.5 Repeat the test also if the sharp edges along the flatfaces of the strip appear to be in a classification hi
46、gher than thegreater portion of the strip; in this case, it is likely that theedges were burnished during polishing.11. Report11.1 Report the corrosiveness in accordance with one of theclassifications and descriptions in Table 1. State the duration ofthe test and the test temperature.12. Precision a
47、nd Bias12.1 Due to the nature of the results, the precision of thistest method was not obtained in accordance with RR: D02-1007.412.1.1 Repeatabilitycan be judged by the fact that 96 %of duplicate results obtained in the normal simultaneousprocedure by twelve laboratories with six samples were inagr
48、eement (see Note 3).12.1.2 Reproducibilitymay be judged by the fact thattwelve laboratories matched consensus within a numericalclassification (1, 2, 3, 4) 92 % of the time and within anumerical and descriptive classification (a, b, c, d) 69 % of thetime with five samples showing good or poor protec
49、tion againstcopper corrosion. A sample (Grease F) with somewhat mar-ginal corrosion protection properties found agreement betweenlaboratories only 50 % of the time by either numerical ornumerical and descriptive classification.NOTE 3Actual data on which this precision statement is based can befound in Appendix X1. Test conditions were 100C, 24 h.12.2 BiasThe procedure in Test Method D 4048 has nobias because the rating of copper corrosion is defined only interms of this test method.13. Keywords13.1 copper corrosion; copper strip; copper
