1、Designation: D6547 16Standard Test Method forCorrosiveness of Lubricating Fluid to Bimetallic Couple1This standard is issued under the fixed designation D6547; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 corrosiveness of hydraulicand lubricating fluids to a bimetallic galvanic couple.NOTE 1This test met
3、hod replicates Fed-Std No. 791, Method 5322.2.It utilizes the same apparatus, test conditions, and evaluation criteria, butit describes test procedures more explicitly.1.2 The values stated in SI units are to be regarded asstandard.1.2.1 ExceptionThe values given in parentheses are forinformation on
4、ly.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-bility of regulatory limitations prior to use.2. Reference
5、d Documents2.1 ASTM Standards:2A322 Specification for Steel Bars, Alloy, Standard Grades2.2 Federal Standards:FED-STD-791, Method 5322.2 Corrosiveness of Oil on aBimetallic Couple33. Summary of Test Method3.1 This test method consists of fitting a brass clip to thefluid-coated surface of a steel dis
6、k, storing the assembly atapproximately 50 % relative humidity for ten days, and visu-ally inspecting the assembly for evidence of galvanic corro-sion.4. Significance and Use4.1 Corrosiveness of a fluid to a bimetallic couple is one ofthe properties used to evaluate hydraulic or lubricating fluids.I
7、t is an indicator of the compatibility of a fluid with a brass onsteel galvanic couple at ambient temperature and 50 % relativehumidity.5. Apparatus5.1 Desiccating Jars, two.5.2 Magnifier, 10 power.5.3 Glass Stirring Rod.5.4 Abrasive Papers, silicon-carbide or aluminum oxide(150, 240, 400, 600 grit,
8、 one sheet per disk).5.5 Cloth, lint-free, clean, dry.5.6 Chromium Alloy Steel Disks, three for each test sample.45.7 Brass Clips, three for each test sample.46. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended
9、thatall reagents conform to the Committee on Analytical Reagentsof the American Chemical Society where such specificationsare available.56.2 Etching Solution, consisting of distilled water, 450 mL;nitric acid, concentrated, 225 mL; sulfuric acid, concentrated,300 mL; and hydrochloric acid, concentra
10、ted, 8 mL.6.2.1 To avoid hazardous reactions when preparing theetching solution, place the distilled water (450 mL) in a 1.5 L,or larger, glass beaker set in a container of ice and water. Stirwith a glass mechanical stirrer or plastic coated magnetic spinbar while slowly adding concentrated sulfuric
11、 acid (300 mL).Add more ice to the cooling bath as needed. When acidaddition is complete, continue stirring until the solution hascooled to room temperature, and then start slow addition of the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and L
12、ubricants and is the direct responsibility ofSubcommittee D02.N0 on Hydraulic Fluids.Current edition approved Jan. 1, 2016. Published February 2016. Originallyapproved in 2000. Last previous edition approved in 2010 as D6547 00 (2010).DOI: 10.1520/D6547-16.2For referenced ASTM standards, visit the A
13、STM 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 online at ASSIST Quicksearch (http:/quicksearch.dla.mil).4The sole source of supply of the ap
14、paratus known to the committee at this timeis Metaspec, 790 W. Mayfield Rd., San Antonio, TX 78211. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical c
15、ommittee,1which you may attend.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., a
16、nd the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.*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 States1concent
17、rated nitric acid (225 mL). Continue stirring after acidaddition until the solution has cooled to room temperature, andthen add concentrated hydrochloric acid (8 mL). Allow themixture to equilibrate to room temperature before use.(WarningNitric, hydrochloric, and sulfuric acids are verycorrosive. Ni
18、tric acid and sulfuric acid are also oxidizing acids.The analyst should prepare the etching solution in a well-ventilated hood and wear appropriate gloves, apron, and faceshield.)6.3 Acetone, technical grade. (WarningFlammable.Health hazard.)6.4 Distilled Water.NOTE 2Both distilled and deionized wat
19、er were used in the roundrobin with no apparent impact on test outcome.6.5 Saturated Aqueous Solution , in contact with excesscalcium nitrate tetrahydrate.NOTE 3A saturated aqueous solution in contact with an excess ofCa(NO3)24H2O will produce 51 % relative humidity within a closedspace at 25 C. To
20、prepare the saturated solution, dissolve 660 g ofCa(NO3)24H2O in 100 cc of water at 30 C.66.6 Low-Erucic Rapeseed Oil, commercial grade.NOTE 4Low-erucic rapeseed oil may be used at the operatorsdiscretion as a failing reference fluid to monitor test severity.7. Test Specimen7.1 Gather reagents and m
21、aterials before beginning speci-men preparation. The specimens must be prepared and as-sembled for testing on the same day to reduce formation ofpassivating oxide films on the surface of the bimetallic couple.For each test fluid, prepare three steel disks. These steel disksmay either be new or from
22、a previous test.7.1.1 The steel disks shall consist of a chromium alloy steelin accordance with Specification A322 (E52100 or G52986),heat treated to Rockwell C-62. When new, the steel disks shallbe 25.4 mm (1.00 in.) in diameter by 13 mm to 25 mm (0.5 in.to 1.0 in.) thick. Prior to initial use, the
23、 steel disk shall beground on one side to a 0.51 m (20 in.) rms. This treatmentneed not be repeated prior to reuse.7.1.2 Polish the surface of the ground side using 150, 240,400, and 600-grit silicon carbide or aluminum oxide paper insuccession. Use one sheet of each per disk. Perform eachpolishing
24、operation at right angles to the previous one, andcontinue until all the cross scratches from the previous opera-tion are removed.NOTE 5Hand polishing techniques were used exclusively in the roundrobin evaluation of this test method. Mechanical polishing was notevaluated and may not yield equivalent
25、 results.7.1.3 Clean the disks by wiping with a clean, dry, lint-freecloth, being careful not to touch the polished surfaces with barehands.7.1.4 Examine with a 10 power magnifier fordiscoloration, etching, pitting, or other signs of corrosion.Discard disks with any signs of corrosion.7.1.5 Store th
26、e disks in a desiccator containing desiccantuntil time of use.7.2 For each test fluid, prepare three brass clips. These brassclips may either be new or from a previous test.7.2.1 The clips shall consist of a QQ-B-613, composition 2brass, spring temper, fabricated to the dimensions shown inFig. 1.7.2
27、.2 Place 150 mL of etching solution in a 250 mL beaker.Immerse the brass clips in etching solution for 20 s. Removethe clip from the etching solution and immediately washsuccessively in cold running water, distilled water, and acetone.If a visible stain remains on the clip in the area that will be i
28、ncontact with the disk, repeat the etching process for anadditional 20 s with fresh etching solution. Change etchingsolution and acetone every six clips. Allow the clip to air dryand store it in the desiccator until ready for use. Be careful notto touch the surface that will be in contact with the s
29、teel diskswith bare hands.8. Procedure8.1 Remove the disks from the desiccator, being careful notto touch the finished surface.8.2 Using the stirring rod, place two drops of the test fluidalong a diameter in a line on the polished surface of each ofthree disks.8.3 Remove the brass clips from the des
30、iccator, beingcareful not to touch the area to be in contact with the steeldisks.8.4 Place the clips on the disks as indicated in Fig. 1 so thatthe center of the clip is in full contact with the wetted area ofthe disk.8.5 Place the assemblies in a covered desiccating jar con-taining the saturated aq
31、ueous Ca(NO3)24H2O solution for tendays (relative humidity approximately 50 %).6CRC Handbook of Chemistry and Physics, CRC Press, Inc., Boca Raton, FL,1993.NOTE 1Dimensions in millimetres.NOTE 2Tolerance 60.8 mm.FIG. 1 Brass Clip DimensionsD6547 1628.6 Remove the assemblies from the desiccating jar
32、after tendays. Absorb excess fluid from the assemblies with a lint-freecloth. Using a sharp pencil, mark an outline of the clips wherethey are in contact with the polished surface of the disks.Remove the clips and wipe the disks clean with a lint-freecloth.8.7 Using the 10 power magnifier, examine t
33、he marked-offarea for discoloration, etching, pitting, or other signs ofcorrosion. Fig. 2 depicts galvanic corrosion stains typical oftests using low-erucic rapeseed oil as the failing referencefluid.9. Report9.1 Report the following information:9.1.1 Report the fluid as failing the test if the test
34、 areas ofmore than one disk show signs of corrosion, pitting, or otherattack. Also report the fluid as failing if two disks are free ofcorrosion, but the third shows more than three affected spots.9.1.1.1 Wipe the dish with a lint-free cloth. Rate thespecimen as passing if no discoloration or pittin
35、g is visible.9.1.2 Report the fluid as passing if the condition of the disksis other than these.10. Precision and Bias10.1 PrecisionIt is not practical to specify the precision ofthe procedure in this test method because the results of this testmethod are only intended to give a pass/fail rating to
36、the fluidbeing tested.10.2 BiasThe procedure in this test method has no biasbecause the value of corrosion-preventing characteristics isdefined only in terms of this test method.11. Keywords11.1 copper corrosion; corrosion; galvanic corrosion; hy-draulic fluidsSUMMARY OF CHANGESSubcommittee D02.N0 h
37、as identified the location of selected changes to this standard since the last issue(D6547 00 (2010) that may impact the use of this standard. (Approved Jan. 1, 2016.)(1) SI unit formatting was revised throughout.ASTM International takes no position respecting the validity of any patent rights asser
38、ted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by
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40、e careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Intern
41、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 2 Appearance of Disks After Performing Testwith Low-erucic Rapeseed OilD6547 163
