ASTM_D_6675_-_01_2015.pdf

Designation:D667501(Reapproved 2015)Standard Practice forSalt-Accelerated Outdoor Cosmetic Corrosion Testing ofOrganic Coatings on Automotive Sheet Steel1This standard is issued under the fixed designation D6675;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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.INTRODUCTIONCorrosion of painted sheet steel of auto bodies is classified according to the initial location anddirection of the corrosive attack.When the corrosion starts on the visible exterior surface,mostly atnicks and scratches in the paint,it is called“cosmetic”or“outside in”corrosion.Corrosion initiatedat an interior surface or within a closed or semi-closed part is called“perforation”or“inside out”corrosion.1.Scope1.1 This practice is designed to assist procedures to befollowed when conducting outdoor exposures to evaluatecosmetic corrosion that might occur in steel panels coveredwith an organic coating that has been damaged.The outdoorexposures described are based on Practice G7 and includeperiodic wetting of the test specimens with a salt solution.1.2 The methods of preparing test specimens and the par-ticular exposure requirements of materials are beyond thescope of this practice.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 establish appro-priate safety and health practices and determine the applica-bility 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 ProductsD610 Practice for Evaluating Degree of Rusting on PaintedSteel SurfacesD823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1014 Practice for Conducting Exterior Exposure Tests ofPaints and Coatings on Metal SubstratesD1654 Test Method for Evaluation of Painted or CoatedSpecimens Subjected to Corrosive EnvironmentsD1730 PracticesforPreparationof AluminumandAluminum-Alloy Surfaces for PaintingD2201 Practice for Preparation of Zinc-Coated and Zinc-Alloy-Coated Steel Panels for Testing Paint and RelatedCoating ProductsD3170 Test Method for Chipping Resistance of CoatingsG7 Practice for Atmospheric Environmental Exposure Test-ing of Nonmetallic MaterialsG50 Practice for Conducting Atmospheric Corrosion Testson MetalsG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from Interlaboratory Wear or Ero-sion Tests3.Significance and Use3.1 Tests of the type described in this practice may be usedto evaluate the corrosion resistance of organic coatings onmetal products exposed to highly salty environments,such asareas subjected to deicing salts or coastal areas.Exposureconditions are complex and changeable.Important factorsinclude climate,time of year,presence of pollution,and soforth.Generally it is difficult,if not impossible,to define ormeasure precisely all the factors that influence degradation.Repeated exposure testing during different seasons and over aperiod of at least two years is required to obtain resultsrepresentative of any given location.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 2001.Last previous edition approved in 2011 as D6675 01(2011).DOI:10.1520/D6675-01R15.2For 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 3.2 Control specimens must always be used because this isa comparative test.4.Test Site4.1 LocationThe preferred location for the racks is acleared,grass covered area.Other conditions can be agreedupon between the parties involved.4.2 Rack Position and Type45 open rack facing theequator,direct weathering unless other conditions are agreedupon between the buyer and seller.NOTE1Information on location,rack construction,and position aregiven in Practices D1014,G7,and G50.5.Test Specimens5.1 Methods for the preparation of test panels and substratesare given in Practices D609,D1730 and D2201.Practice D823covers techniques for producing uniformly coated test panels.6.Preparation of Test Specimens6.1 Prior to