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【英文标准名称】:StandardPracticeforDetectionofHexavalentChromiumOnZincandZinc/AluminumAlloyCoatedSteel
【原文标准名称】:锌及锌/铝合金涂覆钢上六价铬检测的标准实施规程
【标准号】:ASTMD6492-1999(2003)
【标准状态】:现行
【国别】:
【发布日期】:1999
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D01.53
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:钝化;钝化;薄板;锌;锌/铝;二苯基烃;六价铬
【英文主题词】:diphenylcarbohydrazide;hexavalentchromium;passivate;passivation;steel;zinc;zinc/aluminum
【摘要】:1.1Thispracticecanbeusedtodetectthepresenceofhexavalentchromiumongalvanizedandzinc/aluminumalloycoatedsteelsurfaces.Hexavalentchromium-bearingtreatments(passivates)canbeappliedtocoatedsteelstopreventstoragestain.Whilepassivated55%aluminum-zincalloycoatedsteeliscommonlypainted,passivatedgalvanizedsteelisnot.Chromepassivationmayinterferewiththesuccessfulpretreatmentofgalvanizedsteel,aswellascontaminatecleaningandpretreatmentbathsonacoilcoatingline.1.2Theamountofhexavalentchromiumthatwillcausetheindicatortoproduceadiscerniblepinkcolorisintherangeof0.5partspermilliondissolvedintheindicatorsolution.Itispossiblethatacoatedsteelsurfacethatproducesanegativeresultdoeshavechromiumonthesurface.Ifamaterialthatyieldsanegativeresultissuspectedofhavingchromiumonthesurface,instrumentalmethodsshouldbeused.Chromedepositsof1mg/ft2canbeeasilymissedbyanalyticalinstrumentssuchasthescanningelectronmicroscopewithenergydispersivex-rayanalysis(EDXA)capability.Augerelectronspectroscopy(AES)orelectronspectroscopyforchemicalanalysis(ESCA)canidentifychemicalspeciespresentinthelevelsrequiredforadequatedetection.Strippingthemetalliccoatingandanalyzingforchromebyatomicabsorptionorinductivelycoupledplasmacanalsogivereliableresultsindetectingthepresenceofchrome.1.3Thispracticeisdesignedtobeaqualitativemeansofscreeningchromepassivatedcoilsfromthosewhicharenotchromepassivated.1.4Somechromium-freepassivatesarebeingusedcommercially.Althoughtheseproductswilltestnegativeforhexavalentchromium,theymayinterferewithcleaningandpretreating.Chromiumbearingpassivatesthatcontainfilmformingconstituentssuchasacrylicresinsarealsobeingcommerciallyapplied.Thereactionoftheseproductstothespottestwillvary.Abradingthesurfacewithemerypaperwillimprovethelikelihoodofreliabledetection.Thistechniqueisnotrecommendedforacrylicresincontainingpassivationtreatments.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A29
【国际标准分类号】:25_220_40
【页数】:2P.;A4
【正文语种】: