热带海洋大气环境中钢腐蚀异常原因研究

重庆大学硕士学位论文热带海洋大气环境中钢腐蚀异常原因研究姓名：王成章申请学位级别：硕士专业：环境工程指导教师：马利;汪学华20060501I50%,ntAD•=(D—μmt—A—n1)An1(,)1.97“”Q235Cor-TenA,SEMX,Cl—Cl—Cl—“”,Cl—IIABSTRACTThecorrosiveproblemspreadsovertheeachrealmofnationaleconomydeve-lopments,afloodofthepieceofcomponents,facilities&establishmentsinvalidationbecauseofcorrosionbringaboutenormouseconomylossforthenation.Atmospherecorrosionofmetalsisthemostwidespreadandseriousamongallofcorrosion,the50%economylosesresultinvariouscorrosionareaccountedforinvitedmetalsatmospherecorrosion.Therefore,studythemetalscorrosionintheatmosphereenvironment,under-standitscorrosionregulationandcharacteristicinthedifferentenvironment,Ithaveverymuchimportanttheoriesmeaningandextensiveapplicationvalueforreasonablechoosematerialtouse,providehomologousprotectionmeasure,controlcorrosionrateintheatmosphere,extensiontheservicelifeoftheequipmentsandmaterial,reduceeconomylosethatcorrosionresultin,andsoon.Carbonsteelandlowalloysteelisthemostincommonusemetalsmaterialforeverykindofthepieceofcomponents,equipmentandengineeringfacilities,itlong-termatmospherecorrosionregulationinourcountrytypicalregionenvironmentaresatisfiesthedynamicsequationntAD•=(D—corrosiondepth,μm;t—exposurestime,year,A—constant,equaltocorrosiondepthofthefirstyearandhavesomethingtodowithenvironmentandmaterial;ntokenthedevelopmenttrendofcorrosiondepth,changingwiththesteelsandtheenvironmentisverybig,butgenerallyandnotonlymostover1).ItIndicatethatcorrosionrateofcarbonsteelandlowalloysteelgraduallydescendwiththehoraryextensionandtendinsteadybutdonottherisinginthemajoritytheregionofourcountry.ButthevalueofAissmallerinthetropicaloceanatmosphereenvironment.Thevalueofnislargerthan1(suchaswanninganqionghai),indeedgetto1.97thatpredicatethecorrosionproductsarenon-protectiveintheseregions,thecorrosionratehastherisingtrendcontinuously,thatisso-calledabnormalityphenomenon.TheauthorofthistextadoptsthatthesteelsofQ235andCor-TenAwasexposedatwanningsitelocatedinhainanprovinceofChina.Samplesweretestedwithdifferentorientation,surfacestate,time,periodsanddistancetothesea.ThecorrosionproductswereanalyzedwithSEMandX-raydiffraction.ThesimilarexperimentintheseasideofQingdaowasbeendonethatcontrastwithwanning.TemperatureandhumidityandconcentrationofCl—intestdistrictwerecontinuousexaminationandanalysisandIIIresearch.Theresearchesindicatethattheeffectsofhotandhumidmarineatmospherictocorrosionofsteelswerecomplicatedprocessandhadduplexcharacteristic.Thesteelsurfaceissmoothduringinitialstages,althoughitisdifficultforsteeltoformstable,compactandprotectiverustlayer,therustlayerwasslightlyprotectiveininitialstageandresultinthecorrosionratetodecrease.Buthighhotandhumidweatherhaveveryhighcausticity,ifhighhotandhumidsuperaddedtohighCl—concentration,protectiverustlayerwasbeendestroy,madethecorrosionratereverse,steelscorrosionraterisingveryrapidly.Thetimeofreversionvarieswiththekinds,thequalityandsurfacestateofsteelandenvironmentalcondition.ThemainfactorsdeterminetheatmosphericcorrosionofsteelwerehotandhumidweatherandCl—concentrationintheenvironmentofhotandhumidmarineatmosphere.Theabnormalityofsteelscorrosioninwanningsitewasactuallythereflectionofcharacteristicofcorrosioninhotandhumidmarineatmosphere.Itisreasonthattherustlayerbecomeaccelerativetocorrosionundersynthesisreflectedofhighhotanddamp,highsunshine,highradiateandhighCl—concentrationfunctionnext.Keywords:tropicseashoreatmospheric,atmosphericcorrosion,steel,lowalloysteel1111.11/4—l/324%19821260(NACEInternational)[1]300011002002[2]228850005%50050%[3]70%0.5351999101.85121.2()100%100%131.31.3.11021.3.2SCN1-1SO2SO21981[4]SO244.413.43.714SO2SO2SO21100[4]Cl—1.1Table1.1MaincompositionsoftheairpollutantsSO2SO3H2SCl2HClCl—NaClCaCO3NONO2NH3ZnOCOCO2O3(C1-C5)1.41.4.1O2+2H2O+4e→4OH—(1.1)()O2+4H++4e→2H2O(1.2)151.4.2M+XH2O→Mn+·XH2O+ne—(1.3)MMn+nMn+·XH2O100%1.4.3()1.4.4Fe3O4FeOOHα-OOHγ-FeOOHEvans/Fe3O4Fe→Fe2++2e(1.4)Fe3O4/FeOOH6FeOOH+2e→2Fe3O4+2H2O+2OH—(1.5)161.51.5.120ISO(ASTM)1906Larrabee[5-7]Kucera[8]Shastry[9]19551980[10][11-12][13]l7ntAD•=(1.6)17D—μmt—aAn—AnA304060nn0.30.40.51.97nlw.Hou[14]“”SO20.09%P0.4%CuSPCu0.035%P0.07%Cu4S0.02%0.01%Cor-TenBCor-TenA[15-26]SO2Cl—[27-29][30][31-33]18a.3—5b.c.d.1)NaCl(NSS)(ASS)(CASS)32)3)(CORR)4)(EC)——5)[31]6)PourbaixSO2SO219a.b.c.d.SvenssonJohnansson[34-40]50[41]TomashovSereda[42]Mansfeld[43-45][46-48]“”(CellFacterCF)meacalmCFµ∆=(1.7)∆μcalmmeaMansfeld1976(AtmosphericCorrosionMonitor(ACM))[43]ACMACMACMACMACMACMTafelStratmannCoxFiaudIR110LeygrafLinderIRStratmannKelvinKelvinStratmannKelvin[49-53]2—3mmAuACACACKelvinKelvinEGGUBMMesstechnikGmbhHOKUODENKOKelvin[54]“Kelvin”KelvinKelvinKelvin1111.5.2Atmmmv321∆+−=(1.8)vgmZh1mg3mg3m∆8Am2thAtmmv12−=(1.9)vgm2h1mg2mg112Am2thDunbar[55]Haynie[56]R(μm/year)RH(%)S02(ppb)SO2()[]248.481092.3SORHR−×=−(1.10)SO2RHRHSO2BenarieLipfert[57]bwttAM=(1.11)twtAb()−++=ClSORRA253.08.4(1.12)pHb142.055.1−=(1.13)2SOR−ClRSO2Cl—pH(1)()(QuartzCrystalMicrobalance)[58-70]3)(QuartzCrystalMicrobalance)(QCM)—(10-9g)(AuPt)(fHz)(mAng/cm2)[71]()()µρnAfmf202∆−=∆(1.14)113f0(Hz)n(1)μ(2.947×1011g