1、Designation: D 4340 96 (Reapproved 2007)Standard Test Method forCorrosion of Cast Aluminum Alloys in Engine CoolantsUnder Heat-Rejecting Conditions1This standard is issued under the fixed designation D 4340; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, 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.1. Scope1.1 This test method covers a laboratory screening proce-dure for evaluating the eff
3、ectiveness of engine coolants incombating corrosion of aluminum casting alloys under heat-transfer conditions that may be present in aluminum cylinderhead engines.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
4、user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Sections 11 and 12.2. Referenced Documents2.1 ASTM Standards:2D 1176 Practice for Sampling and Preparin
5、g Aqueous So-lutions of Engine Coolants or Antirusts for Testing Pur-poses3. Summary of Test Method3.1 In this test method, a heat flux is established through acast aluminum alloy typical of that used for engine cylinderheads while exposed to an engine coolant under a pressure of193 kPa (28 psi). Th
6、e temperature of the aluminum specimenis maintained at 135C (275F) and the test is continued for 1week (168 h). The effectiveness of the coolant for preventingcorrosion of the aluminum under heat-transfer conditions(hereafter referred to as heat-transfer corrosion) is evaluated onthe basis of the we
7、ight change of the test specimen.4. Significance and Use4.1 It is essential that engine coolants prevent heat-transfercorrosion of aluminum cylinder heads during engine operation.Any corrosion products formed may deposit on interior radia-tor surfaces, reducing heat-transfer efficiency of the radiat
8、or.Overheating and boil-over of the cooling system may thenoccur.4.2 This test method provides a means for selectivelyscreening unused engine coolants and will readily distinguishthose coolants that are unsuitable for use with aluminumcylinder head engines. However, satisfactory performance of acool
9、ant in this test method does not ensure adequate long-termservice performance. Additional, more comprehensive evalua-tions with simulated service, dynamometer, and vehicle testsshould be used to establish the long-term effectiveness of thecoolant.5. Apparatus5.1 Heat-Transfer Corrosion CellThe assem
10、bled corro-sion cell is shown schematically in Fig. 1. It is assembled fromcomponents, some of which require glass blowing or machin-ing. The glass O-ring cell shall be constructed from two glassO-ring joints3joined to an additional middle section of glasstubing4of the same diameter to make a total
11、length of 53 cm(21 in.). Heat-resistant O-rings5shall be used. Internal pressureshall be monitored using a suitable pressure gage,6and apressure-relief valve7shall be installed to protect againstbursting.5.1.1 The top assembly plate (shown in Fig. 2) shall beconstructed of stainless steel, and the h
12、eat-transfer bar andbottom assembly plate (also illustrated in Fig. 2) shall prefer-ably be constructed of stainless steel. Mild steel may be usedfor the heat-transfer bar and bottom assembly plate.1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and is the direct
13、responsibility of Subcommittee D15.06 on GlasswarePerformance Tests.Current edition approved April 1, 2007. Published May 2007. Last previousedition approved in 2001 as D 4340 96(2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
14、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Corning 6780, No. 40 Pyrex Brand O-ring joints have been found satisfactory.Equivalent O-ring joints with a low coefficient of expansion may be used.4Pyrex Brand Glass, a trad
15、emark of Corning Glass Works, with a standard wallthickness of 2.0 mm has been found satisfactory. Equivalent high-strength glass witha low coefficient of expansion may be used.5Viton, a trademark of E.I. duPont de Nemours and Co., Inc. has been foundsatisfactory. Silicone O-rings may also be satisf
16、actory. Polytetrafluoroethylene is notsuitable due to a high creep rate at the test temperature.6Ametek, U.S. Gauge Division, Model E-82 has been found satisfactory. Anequivalent pressure gage may be used.7Nupro, Catalog No. SS-4CPA2-3 has been found satisfactory. An equivalentpressure relief valve
17、may be used.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Temperature Controller,8with high-temperature alarmoption and temperature control range up to at least 150C(302F). Use Type J thermocouple. A heavy-duty electricalpower
18、relay or SCR solid-state contactor is connected to thetemperature controller to carry the current load to the bandheaters.5.3 Electrical Relay,930-amp rating. The relay is changedafter about every 50 000 cycles to prevent contact welding.8Athena, Model 2500T-B-16 F/C used with an electrical power re
19、lay or Model2500S-B-16 F/C used with an SCR solid-state contractor has been found satisfac-tory. An equivalent temperature controller may be used.9Dayton 5X850A, SPST-NO-DM, 120 V, 30 amp has been found satisfactory.An equivalent mechanical, solid-state, or mercury-wetted relay may be used.FIG. 1 He
20、at-Transfer Corrosion Test AssemblyMetric Equivalentsin.141258 114 22116 2916 412 514mm 6.35 12.7 15.88 31.75 50.8 52.39 65.09 114.3 133.35FIG. 2 Heat-Transfer Corrosion Test ComponentsD 4340 96 (2007)25.4 Band Heaters,10at least 950 W, 120-V ac, 5.1-cm(2-in.) inside diameter, 12.7-cm (5-in.) length
21、.5.5 Ultrasonic Cleaner,11about 50 W, for cleaning alumi-num test samples.5.6 Vacuum Oven,12with temperature range up to about150C (302F) for thoroughly drying cast aluminum samples.5.7 Vacuum Pump,13for use with vacuum oven.5.8 Thermal Cutoff,14for over-temperature protection, lo-cated 1.3 cm (12 i
22、n.) from the heat-transfer bar.5.9 Compressed Air, for pressurizing test cell.5.10 Clear Plastic Safety Shield, for protection againstbursting.6. Sampling6.1 The engine coolant concentrate shall be sampled inaccordance with Test Method D 1176.7. Metal Test Specimen7.1 Cast Aluminum, conforming to UN
23、S A0319015is used.Specimen size is 6.5 cm (2.6 in.) in diameter, 1.3 cm (0.5 in.)thick. Fig. 2 illustrates location of the thermocouple holes.8. Test Solution8.1 Dissolve 165 mg of reagent grade sodium chloride in750 mL of distilled or deionized water, and then add 250 mLof the test coolant. This is
24、 sufficient solution for two tests.9. Test Conditions9.1 The aluminum heat-transfer specimen temperature ismaintained at 135 6 1C (275 6 2F) throughout the test bymeans of a thermocouple connected to the temperature con-troller. The thermocouple is inserted into one of the thermo-couple holes in the
25、 test specimen. The other thermocouple holeis used for occasional precise temperature measurements.9.2 The test is run continuously for 1 week (168 h).9.3 Duplicate tests are required.10. Preparation of Test Specimen10.1 The following steps are necessary in the preparation ofthe aluminum test specim
26、en for maximum repeatability andreproducibility:10.2 Polish the test specimen progressively with coarse-,medium-, and fine-grit emery cloth or paper, and finally with600-grit paper.10.3 Wash the test specimen with warm tap water, then rinsewith distilled or deionized water, and finally with acetone.
27、Make sure thermocouple holes are free of metal chips andpolishing debris. Flush the holes with acetone and removeexcess liquid with a glass capillary pipet or other suitablemeans.10.4 Dry the test specimen in a vacuum oven for a minimumof4hat65to90C (149 to 194F) to remove residual liquidthat may be
28、 retained in a porous casting. From this point, usethin cotton gloves, or equivalent, to handle the specimen toavoid weighing errors.10.5 Remove the specimen from the oven and allow it tocool to room temperature in a desiccator.10.6 Weigh the specimen to 0.1 mg using an analyticalbalance. The test s
29、ample may be reused if desired, but shall beprepared in accordance with 10.1-10.6.11. Procedure11.1 AssemblyAssemble the cell in accordance with Fig.1. Use new O-rings between the aluminum test specimen andglass cell for each test. To help ensure that the O-rings areproperly seated, apply a small am
30、ount of the test solution to theglass O-ring groove for lubrication. Avoid overtightening ofthe threaded rod nuts.11.2 Starting the TestTransfer 500 mL of test coolantsolution into the test cell, screw the plug in the hole, andtighten. Place the safety shield around the cell, (see Warning)pressurize
31、 the cell to 138 kPa (20 psi) with compressed air, andturn the band heater on. Provision must be made for a pressurerise with increase in temperature.Adjust the pressure graduallyso that when the temperature reaches the proper value, the finalpressure is 193 kPa (28 psi). (WarningDespite the presenc
32、eof a safety relief valve, test cells have burst under pressure. Useof a safety shield is absolutely necessary. A clear plasticenclosure, having allowance for adequate circulation of air yetcompletely surrounding the test apparatus has been success-fully used for this purpose.)11.3 Conducting the Te
33、stAdjust the temperature to 135 61C (275 6 2F) with the temperature controller. Monitor thetemperature at the auxiliary thermocouple hole at periodicintervals with a precision potentiometer. Operate the cellcontinuously at this temperature for 1 week (168 h).11.4 Terminating the TestAt the end of th
34、e test period,turn off the heater and allow the cell to cool to roomtemperature before disassembly. Release pressure, remove thefill plug, and pour or siphon out the test coolant.11.5 After disassembly, clean the cell with a large bristlebrush rotated by an electric drill motor, pumice powder,deterg
35、ent, and water.12. Cleaning of Aluminum Test Specimen12.1 Wash the specimen with a soft bristle brush using amild detergent.16Remove any O-ring residue by gentle scrap-ing with a material that is softer than the aluminum (forexample, a thick piece of polyethylene or polypropylene witha freshly shear
36、ed edge).12.2 In a fume hood, immerse the specimen for exactly 10min in an aqueous solution containing 4 parts concentrated10Hotwatt, 950-W standard construction band heater, standard tightening clamp,Type Lterminal has been found satisfactory.An equivalent band heater may be used.11Bransonic Model
37、12, 50 W, 1-qt capacity has been found satisfactory. Anequivalent ultrasonic cleaner may be used.12Thelco Model 10 has been found satisfactory.An equivalent vacuum oven maybe used.13Ace-Nelson Model 911 has been found satisfactory. An equivalent vacuumpump may be used.14Sylvania Model ELG 8218 has b
38、een found satisfactory. An equivalent thermalcutoff may be used.15Unified Numbering System for Metals and Alloys, SAE-ASTM, FourthEdition.16Alconox powder detergent has been found satisfactory. An equivalent cleanermay be used.D 4340 96 (2007)3nitric acid (70 % by weight) plus one part water at 25C(
39、77F). Occasionally brush the surface with a soft bristle brush.After 10 min, transfer the beaker containing the aluminumspecimen and cleaning solution to an ultrasonic cleaning unit.Apply power for 1 min. (WarningNitric acid is a strongoxidant. Avoid contact with skin, eyes, and clothing. Do notbrea
40、the vapor.)12.3 Remove the specimen from the cleaning solution, flushwell with tap water, then with distilled or deionized water, andfinally with acetone. Make sure thermocouple holes are flushedwell and excess liquid is removed. Inspect the surface using amicroscope with a magnification range from
41、10 to 303.Ifanydeposits remain, repeat 12.2 and 12.3.12.4 Dry the specimen in a vacuum oven using the sameprocedure and precautions in accordance with 10.4.12.5 Cool the specimen to room temperature in a desiccatorand weigh to the nearest 0.1 mg.NOTE 1This cleaning procedure replaces one using chrom
42、ic acid, arecognized health hazard. The qualification of this cleaning method wascompleted by a D15.09 Task Group and is available as Research ReportNo. D151017. Copies of this report may be purchased from ASTM, 100Barr Harbor Drive, West Conshohocken, PA. 19428-2959.13. Determination of Blank Corre
43、ction13.1 Clean and weigh at least 3 unused specimens inaccordance with 12.1-12.5.13.2 Use the average weight loss as the blank correction,provided the deviations are not significant.14. Calculation14.1 Calculate the heat-transfer corrosion rate (R) as fol-lows:R 5Wb2 Wa1 B! 3 1000A(1)where:R = corr
44、osion rate, mg/cm2/week,Wb= weight of test specimen before test, g,Wa= weight of test specimen after test, g,B = weight loss of blank, g, andA = heat-flux surface area inside O-ring, cm2.15. Report15.1 Report the following information:15.1.1 Report the heat-transfer corrosion rate to the nearest0.1
45、mg/cm2/week of each specimen.15.1.2 The appearance of each specimen, such as pitting,crevice attack, color, and residual corrosion products.15.1.3 The appearance and final pH of test coolant.16. Precision and Bias16.1 PrecisionThe precision of the procedure in this testmethod for measuring corrosion
46、 of cast aluminum alloys inengine coolants under heat-rejected conditions is being deter-mined.16.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod, bias has not been determined.17. Keywords17.1 aluminum; cast aluminum alloys; c
47、ylinder head; en-gine coolant; heat transfer corrosionAPPENDIX(Nonmandatory Information)X1. INTERPRETATION OF RESULTSX1.1 Generally, unused coolants that produce aluminumcorrosion rates greater than 1.0 mg/cm2/week should berejected, and coolants that produce less than 1.0 mg/cm2/weekshould be consi
48、dered as candidates for further evaluation. Asindicated in 4.2, satisfactory performance of unused coolants inthis test method does not ensure adequate long-term serviceperformance, which should be established in dynamometer andfield service tests.ASTM International takes no position respecting the
49、validity of any patent rights asserted 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 the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand
