ASTM_D_7934_-_D_7934M_-_14.pdf

Designation:D7934/D7934M14Standard Test Method forCorrosion of Cast Aluminum Alloys in Non-Aqueous EngineCoolants Under Heat-Rejecting Conditions1This standard is issued under the fixed designation D7934/D7934M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript 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 non-aqueous enginecoolants in combating corrosion of aluminum casting alloysunder heat-transfer conditions that may be present in aluminumcylinder head engines.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.Some values have only SI units because theinch-pound equivalents are not used in practice.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.Some specifichazards statements are given in Sections 11 and 12.2.Referenced Documents2.1 ASTM Standards:2D1176 Practice for Sampling and Preparing Aqueous Solu-tions of Engine Coolants orAntirusts for Testing PurposesD4340 Test Method for Corrosion of Cast Aluminum Alloysin Engine Coolants Under Heat-Rejecting Conditions3.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 a non-aqueous engine coolant under apressure of 34.5 kPa 5 psig.The temperature of the aluminumspecimen is maintained at 149C 300F and the test iscontinued for 1 week(168 h).Effectiveness of the coolant forpreventing corrosion of the aluminum under heat-transferconditions(hereafter referred to as heat-transfer corrosion)isevaluated on the basis of the weight change of the testspecimen.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-over of the cooling system may thenoccur.4.2 This test method provides a means for selectivelyscreening unused non-aqueous engine coolants and will readilydistinguish those coolants that are unsuitable for use withaluminum cylinder head engines.However,satisfactory perfor-mance of a coolant in this test method does not ensure adequatelong-term service performance.Additional,more comprehen-sive evaluations with simulated service,dynamometer,andvehicle tests should be used to establish the long-term effec-tiveness of the coolant.5.Apparatus5.1 Heat-Transfer Corrosion CellThe assembled 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 length of 53 cm21 in.Heat-resistant O-rings5shall be used.Internal pressureshall be monitored using a suitable pressure gage,and apressure-relief valve shall 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 and1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and Related Fluids and is the direct responsibility of SubcommitteeD15.22 on Non-Aqueous Coolants.Current edition approved June 1,2014.Published September 2014.DOI:10.1520/D7934_D7934M142For 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 ASTM website.3O-ring joints with a low coefficient of expansion may be used.4High-strength glass with a low coefficient of expansion may be used.5Silicone O-rings may also be satisfactory.Polytetrafluoroethylene is notsuitable due to a high creep rate at the test temperature.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 bottom 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.5.2 Temperature Controller,with high-temperature alarmoption and temperature control range up to at least 177C350F.Use Type J thermocouple.A