ISO 10289-1999 Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates - Rating of test specimens and manufactured article.pdf

1、A Referencenumbe r ISO10289:1999 (E) INTERNATIONAL STANDARD ISO 10289 Firstedition 19991015 Methodsforcorrosiontestingofmetallic andotherinorganiccoatingsonmetallic substratesRatingoftestspecimensand manufacturedarticlessubjectedto corrosiontests Mthodesdessaidecorrosiondesrevtementsmtalliqueset ino

2、rganiquessursubstratsmtalliquesCotationdesprouvettesetdes articlesmanufacturssoumisauxessaisdecorrosionISO10289:1999(E) ISO1999 Allrightsreserved.Unlessotherwisespecified,nopartofthispublicationmaybereproducedorutilizedinanyformorbyan ymeans,electronic ormechanical,includingphotocopyingandmicrofilm,

3、withoutpermissioninwritingfromthepublisher. InternationalOrganizationforStandardization Casepostale56 CH1211Genve20 Switzerland Internet isoiso.ch PrintedinSwitzerland ii Contents Page 1Scope 1 2Termsanddefinitions .1 3Principle 2 4Typesofdefect .2 5Methodofinspection. 3 6Assignmentofratings .3 7Tes

4、treport 5 AnnexA (informative) Dotchartsandcolourphotographsforcoatingscathodictothebasemetal7 AnnexB (informative) Dotchartsforcoatingsanodictothebasemetal17 Bibliography22ISO ISO10289:1999(E) iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsb

5、odies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in li

6、aisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommi

7、tteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. InternationalStandardISO10289waspreparedbyTechnicalCommitteeISO/TC107, Metallicandotherinorganic coatings,SubcommitteeSC7, Corrosiontests . Thisfirsteditioncan

8、celsandreplacesISO1462:1973,ISO4540:1980andISO8403:1991. AnnexesAandBofthisInternationalStandardareforinformationonly.ISO10289:1999(E) ISO iv Introduction TheratingmethoddescribedinthisInternationalStandardrecognizesthatdecorativeandprotectivemetallicand inorganiccoatingsonmetallicsubstratescanbeeit

9、heranodicorcathodictothesubstrate.Inratingthesecoatings fortheeffectsofcorrosion,twoevaluationsshallbemade: theabilityofthecoatingtoprotectthesubstratefromcorrosionandthuspreventdegradationofthebasemetal; theabilityofthecoatingtoretainitsintegrityandthusmaintainasatisfactoryappearance. Althoughthese

10、functionsoverlap,theycanbeevaluatedseparatelyintermsof: aprotectionrating( R p )relatingtothecorrosionofthebasemetal; anappearancerating( R A )relatingtothedeteriorationofthecoating. Theprotectionrating( R p )assignsanumberrepresentingtheabilityofthecoatingtoprotectthebasemetalfrom corrosion. Theapp

11、earancerating( R A )assignsasequenceoflettersandnumberstotheoverallappearanceofthespecimen whichincludesalldeteriorationcausedbythecorrosiontestorenvironment. NOTE1 Imperfectionsonapanelorarticlebeforeexposuretestingshouldbenotedandgivendueconsiderationwhen evaluatingtheresultsoftheexamination.Delib

12、erateimperfectionsmayalsobeintroducedaspartofatestprogramme. Thecoatingsystemhastobeknownandreportedifthisratingsystemisapplied.Itisespeciallyimportanttoknow, ifpossible,whetherthecoatingisanodicorcathodictothebasemetal. NOTE 2 Determinationoftheanodicandcathodiccorrosivemechanismscanbeextremelydiff

13、icultinsomecases (chromatedzinconsteelormultiplecoatings).Forthepurposesofthisdocumentknowledgeofthesemechanismsisnot necessary.INTERNATIONALSTANDARD ISO ISO10289:1999(E) 1 Methodsforcorrosiontestingofmetallicandotherinorganic coatingsonmetallicsubstratesRatingoftestspecimensand manufacturedarticles

14、subjectedtocorrosiontests 1Scope ThisInternationalStandardgivesamethodofevaluatingtheconditionofdecorativeandprotectivemetallicand inorganiccoatedpanelsorarticleswhichhavebeenexposedtocorrosiveenvironmentsfortestorforother purposes. Itisapplicabletotestpanelsorcomponentsexposedtonaturalatmospheres,i

15、nmobileorstaticconditions,or subjectedtoacceleratedtests. NOTE1 ExamplesofsuchtestsaregivenintheBibliography. ThisInternationalStandardrecognizesthattheprotectionratingcanbeassessedobjectivelyinaccordancewith clause6.However,theassessmentofappearancedependsonmanysubjectivefactors(see6.2). NOTE2 Thee

16、dgesoftestpanelsorcomponentsmaybeprotected,e.g.bytapeorwax(paraffin),ifthisisanagreedpartof thetestandisrecordedinthetestreport.Thisisessentialifthespecimensarecutfromlargerpiecesandhaveexposed uncoatededges. 2 Termsanddefinitions 2.1 protectionrating R p ratingnumber(seeTable1)assignedtotheabilityo

17、fthecoatingtoprotectthebasemetalfromcorrosion 2.2 protectiondefect defectusedtoassesstheprotectionrating,includingcratercorrosion,pinholecorrosion,corrosionstaindueto corrosionfromthesubstrate,blistersandotherdefectsthatinvolvebasemetalcorrosion NOTE Blistersonelectroplatedaluminiumandzincalloydieca

18、stingsusuallysignifybasemetalcorrosion,butthe inspectorsjudgementmayberequiredtodecidewhetherablisterdoesordoesnotariseatthesubstratecoatinginterface. 2.3 appearancerating R A ratingnumberandsymbols(seeTable2)assignedtodescribetheoverallappearanceofthespecimen,includingall defectscausedbyexposure 2.

19、4 appearancedefect defectthatdetractsfromtheappearanceofthespecimen(seeTable2)ISO10289:1999(E) ISO 2 2.5 performancerating combinationoftheprotectionratingnumber(R p )followedbyaslashmarkfollowedbytheappearancerating number( R A ),i.e. R p /R A 2.6 coatingsystem particularseriesofdepositsincludingth

20、ethicknessandtypeoflayersinmultilayerdepositsandtreatmentswhich havebeenappliedtothebasemetal 2.7 significantsurface partofthesurfacewhichisessentialintheappearanceorserviceabilityofthearticleandwhichistobecoveredor iscoveredbythecoating(seeclause5) 3Principle ThisInternationalStandardestablishesara

21、tingsystemforevaluatingthedeteriorationofthecoatingandthebase metalduetocorrosion.TheratingmethoddescribedinthisInternationalStandardisappliedtoevaluatethe appearanceofthecoating,aswelltheextentofthecorrosionontestpanelsorthesignificantsurfacesof componentswhichhavebeensubjectedtoperformancetests. T

22、heresultofinspectingasurface,calledtheperformancerating,isrecordedastwoseparateratings,theprotection rating( R p )andtheappearancerating( R A ). Whenrecordingtheratingofasurface,thetype(s)andseverityofdefect(s)contributingtotheratingshallbenoted ifthisinformationisrequired.Thisinformationisrecordedu

23、singagreedsymbolsforthedefectsandtheextentof thesedefects. Whenonlytheprotectionrating( R p )isrequired,itispermittedtoomittheappearancerating( R A ).However,insuch acase,awrittendashshouldfollowtheprotectionratinginordertoindicatedeliberateomissionoftheappearance rating. 4 Typesofdefect Itispossibl

24、efordefectstoaffectboththeprotectionrating( R p )andtheappearancerating( R A ).Inthisrating system,theprotectionratingisasimplenumericalratingwhiletheappearanceratingispermittedtoincludespecific defectsalongwithanumericalratingdesignatingtheintensity. AlistofdefectsisgiveninTable2.Additionsmayalsobe

25、madetothelist,asappropriate,whenrecordingspecific defects. Defectsincludecratercorrosion,pinholecorrosion,generalcorrosionofthecoating,corrosionproducts,blisters, andanyotherdefectthatinvolvesthecoating.Somedefects,suchasblisters,canbeassociatedwiththecoating, thebasemetal,theinterfacebetweenthecoat

26、ingandthebasemetal,orbetweenlayersinthecoating. Otherdefectscanhaveasmallcorrosioncontentbutanappreciableaffectontheappearance,e.g.,staining, tarnishing,cracks,etc. Defectsonthesurfaceofthebasismetalsuchasscratches,porosity,nonconductinginclusions,rollanddiemarks, coldshutsandcrackscanadverselyaffec

27、ttheperformanceofcoatingsappliedthereto,despitetheobservanceof thebestfinishingpractices.Suchdefectsshallbereportedandratedseparately. Ensurethatthecoatingsystemisreported,becausethesignificanceofcertaindefectscanbedependenton whetherthecoatingisanodicorcathodictothebasemetal. Notedefectsthatdevelop

28、onexposure,e.g.peelingorspallingofthecoating,sincethisindicatespossibleimproper preparationofthebasemetalorimproperapplicationofthecoating.ISO ISO10289:1999(E) 3 5 Methodofinspection Usedrawingsorsuitablymarkedsamplestoindicatethesignificantsurface. Itmaysometimesbenecessaryorappropriatetoexposemate

29、rialwhichisdefectiveincertainrespectsbefore carryingoutenvironmentaltesting.Insuchcases,makeaninspectionandrecordthefindingsbeforethespecimens aretested. Ifdeliberatedamageisappliedtoasurface,recordthedamagebeforethespecimensaretestedandsoreported.If thespecimenispurposelydeformed,ratethedeformedare

30、asseparately. Materialmaybeinspectedeitherontheexposureracksorinamoresuitablelocation.Ensurethatlightingduring inspectionisasuniformaspossible;avoiddirectreflectionfromsunorclouds,andusevariousanglesofinspection toensurethatalldefectsarerevealed. Attheconclusionofthetest,iftheconditionofthespecimens

31、allows,inspectthemintheuncleanedcondition.Ifdirt, saltdeposits,etc.,maskthedefectsandcreatedifficultieswithinspection,thesurfacemaybespongedwithamild soapsolutionandthenrinsedwithwater.However,exertnopressureduringsuchcleaninginordertoavoid accidentallyupgradingtheratingby,forexample,cleaningoffthec

32、orrosionproducts.Cleaningsolutionsshouldbe compatiblewiththecoatingsandnotcauseanydegradationofthecoating.Inthecaseofintermediate,periodic inspectionsdonotcleanorotherwisedisturbthespecimens. Allowsurfacestodrybeforetheyareinspected. Defectstobenotedandtakenintoaccountwhenratingsurfacesincludeonlyth

33、osewhichcanbeseenbynormalor correctedvision. NOTE1 Opticalaidsmaybeusedsubsequentlytocharacterizedefects,afterinitialdetection. Edgedefects,occurringwithin5mmoftheedgeofaspecimenortape/wax,maybenotedinthereport,butshould notnormallyinfluencethenumericalrating.Similarly,disregardcontactandrackmarks,m

34、ountingholes,etc. NOTE2 Edgedefectsmaybedifficulttoassessondeeplyworkedmanufacturedspecimens,suchasthreads,boresetc.In thesecasesitmaybenecessarytoobtainagreementbetweenpurchaserandsupplierregardingtheexactdefectiveareatobe reported. Whenthecoatingisanodictothebasemetal,whitecorrosionproductdevelope

35、dfromtheedgesofthespecimen shallnotconstitutefailure. Rubbing,polishing,chemicalcleaning,etc.,ofthesurfaceofthespecimenmaybeusedtofacilitatestudyofthe surfacebutconfineittotheminimumpracticablearea,preferablynotmorethan100 mm 2 onasurfaceof 100mm 3150mm.Notethisareaforsubsequentratings. 6 Assignment

36、ofratings 6.1 Assignmentofprotectionrating( R p ) Thenumericalratingsystemisbasedontheareaofthesubstratethatexhibitscorrosion,bythefollowingformula: RA p =- 32 (l o g) (1) whereAisthepercentageofthetotalareawhichshowsbasemetalcorrosion. R p isroundedofftothenearest wholenumber,leadingtothetabulation

37、giveninTable1. NOTE1 Insomecases,calculatingtheexactareamaybedifficult,especiallyondeeplyworkedspecimenssuchasthread, bores,etc.Inthesecases,itmaybenecessaryfortheinspectortoestimatetheareaascloselyaspossible. Strictapplicationofequation(1)wouldleadtoratingsgreaterthan10forspecimenswithextremelysmal

38、ldefective areas.Therefore,equation(1)isonlydefinedforareaswhere A .0,046416%.Aratingof10,accordingly,is arbitrarilyassignedtoasurfaceshowingnocorrosionofthebasemetal.ISO10289:1999(E) ISO 4 Ifdesired,fractionalratingsmaybeassignedbetweentheratingslistedinTable1. NOTE2 Whencoatingsystemsanodictotheba

39、semetalareused,itmaybeimpossibletoassessalegitimateprotection ratingnumberduetotheextremevoluminouscorrosionproductsformedbythecoating.Becauseofthehighlyabsorbable natureofthesecorrosionproducts,theywouldtendtoobliteratethetrueareaofsubstratecorrosion.Anexamplewouldbea zinccoatingonsteelexposedinasa

40、lineatmosphere.AlthoughthisInternationalStandardmaybeusedtoratethe performanceofzinconsteel,itmaybedifficultinsomeenvironmentstodefinetheprotectionrating. Ifthedefectsareverylocalized,standardsintheformofdotchartsorphotographs,suchasthosegiveninannexes AandB,maybeused.Flexiblegraticuleshaving1mm,2mm

41、,or5mmsquarescouldalsobeusedtoassessthe corrodedarea. Ifalargegroupofspecimensisbeinginspectedatonetime,itisrecommendedthattheybeassessedindividually byuseofequation(1).Whentheentiregrouphasbeenrated,theindividualratingsshouldthenbereviewedto ensurethateachoftheratingsassignedactuallyreflectstheexte

42、ntofthedefectsrelatingtothoseoftheother specimens.Thereviewactsasacheckonindividualratingsandhelpstoensurethattheinspectorsjudgementor frameofreferencehasnotchangedduringthecourseoftheinspectionbecauseofsuchfactorsaschangesin lightingconditionsorfatigue. Inspectionisimprovedby: a) removingindividualitemsfromtheirracksandgroupingthenwithotherspecimensforcomparison; b) arrangingallofthespecimensinorderofmerit. Table1Protection( R p )andappearance( R A )ratings Areaofdefects Rating A (%) R p or R A Nodefects 10 0 , A 0,1 9 0,1