1、Designation: D4340 10Standard Test Method forCorrosion of Cast Aluminum Alloys in Engine CoolantsUnder Heat-Rejecting Conditions1This standard is issued under the fixed designation D4340; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 effectiveness of engine
3、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 user of this standard
4、 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:2D1176 Practice for Sampling and Preparing Aqueous Solu-tions o
5、f Engine Coolants or Antirusts for Testing Purposes3. 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). The temperature of the al
6、uminum 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 weight change of the test
7、 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 radiator.Overheating and boil
8、-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 acoolant in this test method
9、 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 assembled corro-sion cell is
10、 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 length of 53 cm(21 in.)
11、. 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 heat-transfer bar andbot
12、tom 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 responsibility of Subco
13、mmittee D15.06 on GlasswarePerformance Tests.Current edition approved Dec. 1, 2010. Published January 2011. Last previousedition approved in 2007 as D4340 96(2007). DOI: 10.1520/D4340-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea
14、stm.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 tr
15、ademark 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 sati
16、sfactory. 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 valv
17、e 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 electricalpowe
18、r 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.5.4 Band Heaters,10at least 950 W, 120-V ac, 5.1-cm(2-in.) i
19、nside diameter, 12.7-cm (5-in.) length.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.8Athena, Model 2500T-B-16 F/C used with an electrical power relay or Model2500S-
20、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 or solid-state relay may be used.10Hotwatt, 950-W standard construction band
21、heater, standard tightening clamp,Type Lterminal has been found satisfactory.An equivalent band heater may be used.11Bransonic Model 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 ove
22、n maybe used.FIG. 1 Heat-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 ComponentsD4340 1025.7 Vacuum Pump,13for use with vacuum oven.5.8 Thermal Cutoff,14for over-temperature
23、 protection, lo-cated 1.3 cm (12 in.) 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 D1176.7. Metal Test Specimen7.
24、1 Cast Aluminum, conforming to UNS 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 2
25、50 mLof the test coolant. This is 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
26、of the thermo-couple holes in the 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 prepa
27、ration ofthe aluminum test specimen 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
28、 water, and finally with acetone.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
29、remove residual liquidthat may be 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
30、 an analyticalbalance. The test sample 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 are
31、properly seated, apply a small amount 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
32、the cell, (see Warning)pressurize 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
33、psi). (WarningDespite the presenceof 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 thi
34、s purpose.)11.3 Conducting the TestAdjust 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 Ter
35、minating the TestAt the end of the 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
36、drill motor, pumice powder,detergent, 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
37、polypropylene witha freshly sheared edge).12.2 In a fume hood, immerse the specimen for exactly 10min in an aqueous solution containing 4 parts concentratednitric acid (70 % by weight) plus one part water at 25C(77F). Occasionally brush the surface with a soft bristle brush.After 10 min, transfer th
38、e 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 notbreathe vapor.)12.3 Remove the specimen from the cleaning solution, flushwell with tap water
39、, then with distilled or deionized water, andfinally with acetone. Make sure thermocouple holes are flushed13Ace-Nelson Model 911 has been found satisfactory. An equivalent vacuumpump may be used.14Sylvania Model ELG 8218 has been found satisfactory. An equivalent thermalcutoff may be used.15Unified
40、 Numbering System for Metals and Alloys, SAE-ASTM, FourthEdition.16Alconox powder detergent has been found satisfactory. An equivalent cleanermay be used.D4340 103well and excess liquid is removed. Inspect the surface using amicroscope with a magnification range from 10 to 303.Ifanydeposits remain,
41、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 chromic acid, arecognized health haza
42、rd. The qualification of this cleaning method wascompleted by a D15.09 Task Group and is available as Research Report.1713. Determination of Blank Correction13.1 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
43、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 = corrosion 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 = hea
44、t-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 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 T
45、he appearance and final pH of test coolant.16. Precision and Bias16.1 PrecisionThe precision of the procedure in this testmethod for measuring corrosion of cast aluminum alloys inengine coolants under heat-rejected conditions is being deter-mined.16.2 BiasSince there is no accepted reference materia
46、lsuitable for determining the bias for the procedure in this testmethod, bias has not been determined.17. Keywords17.1 aluminum; cast aluminum alloys; cylinder head; en-gine coolant; heat transfer corrosionAPPENDIX(Nonmandatory Information)X1. INTERPRETATION OF RESULTSX1.1 Generally, unused coolants
47、 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 considered as candidates for further evaluation. Asindicated in 4.2, satisfactory performance of unused coolants inthis test method does not ensure adequ
48、ate long-term serviceperformance, which should be established in dynamometer andfield service tests.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that dete
49、rmination 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 should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical c
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