Designation:D7474−17StandardPracticeforDeterminingResidualStressesinExtrudedorMoldedSulfonePlastic(SP)PartsbyImmersioninVariousChemicalReagents1ThisstandardisissuedunderthefixeddesignationD7474;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1ThispracticecoverstheevaluationofresidualstressesinextrudedprofileormoldedSPparts.Thepresenceandrelativemagnitudeofresidualstressesareindicatedbythecrazingofthespecimenpartuponimmersioninoneormoreofaseriesofchemicalreagents.ThespecifiedchemicalreagentswerepreviouslycalibratedbyuseofEnvironmentalStressCracking(ESC)techniquestocausecrazinginsulfoneplastics(SP)atspecifiedstresslevels.1.2Thispracticeappliesonlytounfilledinjectionmoldingandextrusiongradematerialsofhighmolecularweightasindicatedbythefollowingmeltflowrates:PSU9g/10min,max.,PESU30g/10m,max,andPPSU25g/10min,max.Lowermolecularweight(highermeltflow)materialswillcrazeatlowerstresslevelsthanindicatedinTables1-3.(SeeSpecificationD6394formeltflowrateconditions.)1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.NOTE1—ThereisnoknownISOequivalentforthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,healthandenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D543PracticesforEvaluatingtheResistanceofPlasticstoChemicalReagentsD618Pract...
