315paperT23高压锅炉管的研制English

ThedevelopmentofASMESA－213T23highpressureboilertubeWangQijiang1ZouFengming2ZhangKe3（1.BaosteelTechnologyCent,R&Ddept.ofSteelPipeShanghai,201900）（2.BaosteelTube,Shanghai,201900）（3.ServiceCenterofPowerEquipmentTheMinistryofMachineryIndustry,Beijing,100823）Abstract:ThedevelopmentofASMESA－213T23inBaosteel,whichisusedforhighpressureboilertube,isdescribedinthepaper,coveringdetailsoftheelevatedtemperaturetensilestrength,creeprupturestrengthandanti-oxidationability,etc.TestsshowthesepropertiesarestableandsatisfiedwiththerequirementsofASMESA-213standard.Therefore,thiskindoftubesissuitableforpowerstationboiler.KeyWords:T23highpressureboilertube;Property;Standard;Powerstationboiler1.IntroductionASMESA213T23(simplifiedasT23)steelisbasedonT22(2.25Cr-1Mo)steel,substitutingWforapartofMoandaddingmicro-alloyingelementssuchasV,Nb,B.Duetothesolidsolutionstrengtheningandtheprecipitationstrengthening,theallowablestressofT23steelistwicehigherthanASMESA213-T22steelinthecreepregionfrom550℃to625℃.ThecreeprupturestrengthofT23steelisapproximately1.4timeshigherthan12Cr1MoVsteelat580℃andapproachesthatof12Cr2MoWVTiB（R102）steeldevelopedbyourcountry.Besides,theimpacttoughnessofT23steelishigh,andtheweld-abilityisimprovedsogreatlythatitcanbeusedinas-weldedconditionwithoutpreheatingandpost-weldheattreatment.Insteadof10CrMo910,T22,12Cr1MoVand12Cr2MoWVTiB,itcanbeusedtomanufacturethesuperheaterandreheaterinpowergenerationboilerswithhighcapacity.Withthequickdevelopmentofpowergenerationboilersinourcountrytowardshighcapacityandhighparameter,moreandmoreT23steeltubeswillbeusedtomanufacturethesub-criticalorsuper-criticalboilerswithhighcapacityandhighparameterintheindustryofboiler.However,alltheT23steelhadtobeimportedsinceT23steelcouldnotbeproducedinChinabeforethisresearchwasdone.Therefore,theindustryofboileriseagertohopethatBaosteelcandevelopandproduceT23steelinplaceofimport.Inordertoimprovethemanufacturecapabilityofhigh-capacitysteampowerplantsandsatisfytherequirementtomanufacturesub-criticalorsuper-criticalpowerstationboilersinChina,BaosteelbegantodevelopT23steelinApril2001.Afterexperiencingthestagesofsteeltrialproduction,tubetrialrolling,propertyevaluationandmassproduction,Baosteelhasthecapabilityofmassproductionandsupply.ThemainpurposeofthisstudyistodiscussthetechnicalprocessduringthedevelopmentofT23,theproductpropertiesandtheapplicationofT23steelproducedbyBaosteel.2.TheDevelopmentofT23steel2.1ChemicalcompositionsTable1givesthechemicalcompositionsofT23steelaccordingtotheASMEstandardofSA-213.Themechanicalpropertydependsonthechemicalcomposition.However,arelativelywiderangeofeveryelementisgiveninthestandard.Inordertoobtaintheoptimumcomprehensivepropertyitisnecessarytooptimizeandcontrolthechemicalcomposition.Toimprovetheweld-ability,highcreeprupturestrengthandductilityofT23steel,itisextremelyimportanttostrictlycontroltheelementsofC,P,S,Alandsoon,forinstance,P0.015%andS0.005%.Table1Chemicalcompositions%2.2TheproductionprocessofT23steeltubeThemainproductionprocessisasfollows:steelmakinginconverter→ladlerefiningfurnace→ingot→blooming→mandrelmill→tubeheattreatment→tubestraightening→ET&UTinspection→finalinspecting→packingandenteringwarehouse.Amongalltheprocesses,steelmakingandtubeproducingarequiteimportant.Besides,inordertoobtaingoodprocessingproperty,heat-treatmentisalsoimportant.SpecialtechnologieshavebeenmasteredbyBaosteel.standardCMnPSSiCrMoVWNbBNAlASMESA-2130.04~0.100.10~0.60≤0.030≤0.010≤0.501.90~2.600.05~0.300.20~0.301.45~1.750.02~0.080.0005~0.006≤0.030≤0.0302.3HeattreatmentofT23steelInthestandardsofASMEA213andASMEcodecase,theheattreatmentofT23steelshouldinclude:normalizing≥1040℃andtempering≥730℃.AccordingtothestandardofASMESA–213,T23steelshouldhavetheproperties:yieldstrength≥400MPa,tensilestrength≥510MPa,elongation≥20%andhardness≤220HB.However,aftermanytimesofresearchondifferentnormalizingtemperaturesandtemperingtemperatures,theheattreatmentwasdeterminedtobenormalized1050℃formorethan20minutesandtempered760℃formorethan60minutes.Theas-suppliedmicrostructureofT23steelistemperedbainiteafterheattreatment,seefigure1.Figure1.OpticalmicrostructureofT23steeltubes3.ThepropertiesofT23steel3.1TensilepropertyatelevatedtemperaturesAccordingtoGB/T4338-1995standard(Metallicmaterials-Tensiletestingatelevatedtemperature),thespecimensweremachinedfromtheT23steeltubeinarcproportion,andusedfortensiletestatelevatedtemperatures.Figure2comparestheelevatedtemperaturetensilepropertyofT23steeltubewiththeASMEstandard.ItisseenthattheelevatedtemperaturetensilepropertyofT23steeltubeproducedbyBaosteelissatisfiedwiththerequirementofstandardcompletely.100300500700100250400550700试验温度(℃)抗拉强度(MPa)ASME允许值两组试验值100300500700100250400550700试验温度(℃)屈服强度(MPa)ASME允许值两组试验值(a)ElevatedtemperaturetensilestrengthofT23tube(b)ElevatedtemperatureyieldstrengthofT23tubeFigure2.ElevatedtemperaturetensilepropertyofT23tube3.2CreeprupturestrengthAccordingtoGB/T2039-1997standard“Metallicmaterials-Tensilecreeptestingandcreeprupturetestingatelevatedtemperature”,thecreeprupturetestwascarriedoutat550℃,600℃and