20钢锅炉钢管的断裂及腐蚀穿孔失效

3(a)470,25V,1h(b)470,15V,1h(c)470,25V,30min3(1),451152021470,,(2),,,,(3),,,,:[1],.[M].[2]Hermann.C.starck.TechnicalBulletin.20,(,310027):20,,CaMgAl,,,:;;;:TG157;TG172.3+2:A:025426051(2000)0520029204FractureandCorrosionFailureoftheBoilerTube20SteelWUJin2ming,LIZhi2zhang(Dept.ofMaterialsScience&Engineering,ZhejiangUniversity,ZhejiangHangzhou310027,China)Abstract:Inthispaper,thetwotypicalfailureways,i.e.,fractureandcorrosioninducedpenetration,ofthebolilertube20steelwasin2vestigated.TheimmediatecauseofthehightemperaturecreepruptureofthetubeisfoundtobethethicklayerofionsofCa,Mg,Al9220005etc.depositedintheinnerofthetube.Spherizationofthecarbideinthepearliteinthesteelacceleratesthecreepruptureprocess.How2ever,themeltingsaltdevelopedduringcombustionofthesulphur2richcoalacceleratestheoxidativecorrosionoftheironmatrixandhenceresultsinpenetrationofthetube.Inaddition,erosionoftheparticlefromsmokealsocontributestothepenetrationprocess.Keywords:failureanalysis;boilertube;fracture;corrosion120,,,450,,,[1],2,,1/3,,1,10mm,3mm,,219mm0117mm,15mm,,015mm,,,,012013mm112,,(2a),,(2b),2a,(3),44a,:(1972),,,,,20Tel:[phone]Fax:[phone]E2mail:[e-mail]:19992112242(a)500(b)10003500,,(4),,(4bc)5,6,0320005456737FeSClSiAlMgNaX,Fe2O3FeSO4H2O6CaO4SiO23H2OFeCl3Na2S2O35H2O,FeSSCaAlMg(,8),FeCa,ClSiAlMg(9)8X11Fe2O3212CaO4SiO2H2O31FeSO4H2O41FeCl351Na2S2O3H2O94411,,(4),2,,,,,,,(Ac11320005,470480),300[2],,012013mmCaSiMg,300,,,,[1],412,015mm,,(5)(7)X(8),Fe2O3FeSFeSO4H2O6CaO4SiO23H2OFeCl3Na2S2O35H2O(6)(3),SClO()()(1)2Fe+3Cl22FeCl3,4Fe+3O22Fe2O3,Fe+SFeSFe+SO3+H2OFeSO4+H2,SClSO3()(2)[2]FeS2FeSSO2SO3,:4FeS2+11O28SO2+2Fe2O34FeS+7O24SO2+2Fe2O32SO2+O22SO3SO3Na2O:SO3+Na2ONa2SO4Na2SO4+SO3Na2S2O3+2O2Na2S2O3(MS2O3)(400),(M=Na):3Na2S2O3+Fe2O32Na3Fe(SO4)32Na3Fe(SO4)3+11Fe3Na2SO4+4Fe2O3+3FeS,5(1)CaMgAl,,(470480,Ac1),,,(2)SS,,,:[1].[M].:,1987.[2].[M].:,1984.451,2(11,221008;21031100):4524h,,,:;;:TG157;:A:025426051(2000)0520032202FailureAnalysisfortheEarlyFatigueFractureofMajorAxleofSlurryPumpSUNZhi1,QIANYong2kang2(11CollegeofMechtronicEngineering,ChinaUniversityofMining&Technology,JiangsuXuzhou221008,China;21ShanxiPingyaoReducerMachineryFactory,031100,China)Abstract:Themajoraxlemadeof45steelfracturedafterrunningfewerthan24h.Theprocessandreasonoffracturewereanalysisinthepaper.Theresultsshowthatthefractureofaxleresultsfromtherotarybendfatiguefracture.Thefatiguecracksextendedfromthemicrofracturesformedinworkingprocessonthesurfaceofaxle.Therefore,thecoarsepearliteandWit.microsructurespeeduptheex2tensionofcracks.Keywords:fatiguefracture;surfacedefect;microstructure124h:(1963),,,,40:051623885979E2mail:[e-mail]:19992112222320005