ASTM_G_85_-_11.pdf

Designation:G8511Standard Practice forModified Salt Spray(Fog)Testing1This standard is issued under the fixed designation G85;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This practice covers and sets forth conditions for fivemodifications in salt spray(fog)testing for specificationpurposes.These are in chronological order of their develop-ment:1.1.1 Annex A1,acetic acid-salt spray test,continuous.1.1.2 Annex A2,cyclic acidified salt spray test.1.1.3 Annex A3,seawater acidified test,cyclic(SWAAT).1.1.4 Annex A4,SO2salt spray test,cyclic.1.1.5 Annex A5,dilute electrolyte cyclic fog dry test.1.2 Thispracticedoesnotprescribethetypeofmodification,test specimen or exposure periods to be used fora specific product,nor the interpretation to be given to theresults.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 ExceptionFahrenheit temperature values are givenfor information only throughout this practice.1.4 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 consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2B117 Practice for Operating Salt Spray(Fog)ApparatusD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint,Varnish,Conversion Coatings,andRelated Coating ProductsD1141 Practice for the Preparation of Substitute OceanWaterD1193 Specification for Reagent WaterD1654 Test Method for Evaluation of Painted or CoatedSpecimens Subjected to Corrosive EnvironmentsE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3.Significance and Use3.1 This practice is applicable to ferrous and nonferrousmetals;also organic and inorganic coatings.The variationsdescribed herein are useful when a different or more corrosiveenvironment than the salt fog described in Practice B117 isdesired.4.Apparatus4.1 Cabinet:4.1.1 The apparatus required for salt spray(fog)testingconsists of a fog chamber,a salt solution reservoir,a supply ofsuitably conditioned compressed air,one or more atomizingnozzles,specimen supports,provision for heating the chamber,and necessary means of control.The size and detailed con-struction of the cabinet are optional,provided the conditionsobtained meet the requirements of this practice.The material ofconstruction shall be such that it will not affect the corrosive-ness of the fog.Suitable apparatus that may be used to obtainthese conditions is described in Appendix X1 of Practice B117with necessary modifications described in each annex of thispractice.4.1.2 Design the cabinet so that drops of solution thataccumulate on the ceiling or cover of the chamber do not fallon the specimens being tested.Do not return drops of solutionthat fall from the specimens to the solution reservoir forrespraying.4.1.3 Equip the cabinet with one or more timing devices toprovide for intermittent spraying or periodic introduction of agas,or both.4.2 Air Supply:4.2.1 Make sure the compressed air supply to the nozzle ornozzles for atomizing the salt solution is free of oil and dirt andmaintain the air supply between 69 and 172 kPa(10 and 25psi).1This practice is under the jurisdiction of ASTM Committee G01 on Corrosionof Metals and is the direct responsibility of Subcommittee G01.05 on LaboratoryCorrosion Tests.Current edition approved May 1,2011.Published August 2011.Originallyapproved in 1985.Last previous edition approved in 2009 as G8509.DOI:10.1520/G0085-11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE1The air supply may be freed of oil and dirt by passing itthrough a water scrubber or at least 610 mm(2 ft)of suitable cleaningmaterial such as asbestos,sheeps wool,or activated alumina.4.2.2 Temperature in the saturator tower(bubble tower)varies depending on the test method used.4.3 Conditions in Salt-Spray Chamber:4.3.1 TemperatureThe temperature in the exposure zonevaries with the test method used.For recommended exposurezone temperatures for the various methods,see the annexes inthis practice.Each set point and its tolerance represents anoperational control point for equilibrium conditions at a singlelocation in the cabinet which may not necessarily represent theunif