简介:MobarakehsteelCompanyproduces3milliontonsofsteelannuallywitheight180tonsEBTfurnaces.Differenttypesofmagnesia-carbonrefractorieshavebeenemployedatslaglineduringlast5years.InthepresentstudythewearandcorrosionofMgO-Crefractoriesofthesefurnaceshavebeenstudiedviapost-mortemanalysisofusedbricksandtheobservationofoperationaleffects.Laboratorycorrosiontestswerealsoarrangedtoinvestigatetheeffectofslagchemistryandthemechanismofchemicalcorrosion.Characterizationofdifferentmagnesia-carbonbricksclarifiedthatthecrystalsize,typeandchemistryofmagnesiaaswellasgraphitestructurehavethemaininfluenceoncorrosionresistance.TheCaO:SiO2ratioinslagalsoplaysavitalroleinthewearofslaglinerefractories.Theironoxidecontentofslagalsohasamajorroleingraphiteoxidation.Ofmetallurgicalparameters,theelectricpowerinputandthecontacttimehavegreatinfluenceonrefractorieslife.TheresultswillbediscussedwithemphasisonparticularoperationalfactorsinMobarakehsteelplant.
简介:ThepaperdescribestheeffectofadditivesAl,Si,SiCandB4ContheexpansionofMgO-ZrO2-Cmaterialafterbeingcoked.TheresultsindicatethatAlandSicannotincreaseitshotandcoldstrength.AlandSiwereoxidizedtoformAl2O3andSiO2respectively,andthenreactedwithCaZrO3orstabilizerinc-ZrO2toformcalciumaluminate,spinel(MA),dicalciumsilicate(C2S)andforsterite(M2S).Meanwhile,α-C2Swastransformedtoγ-C2Sandc-ZrO2tom-ZrO2whentemperaturechanged.AlltheabovereactionsresultedinthedecreaseoftheamountofAl4C3andSiCandtheincreaseinbulkvolume,whichcausedthestructureofMgO-ZrO2-Cmaterialdestroyed.Hence,contrarytotheMgO-Cmaterial,whenaddingAl.andSi,theMgO-ZrO2-Cmaterialwouldbestructurallydeterioratedafterheat-treatmentanditsstrengthandcorrosionresistancedecreased.
简介:ThefracturetoughnessofMgOpartiallystabilizedzirconia(MgO-PSZ)hasbeenmea-suredbythehardnessindentationmethod.TheinfluencesofheattreatmentonthefracturetoughnessK1cofMgO-PSZwerestudied,ItwasfoundthatthefracturetoughnessofMgO-PSZcanbegreatlychangedbydifferentheattreatmentprofile.Thefracturetoughnesswasimprovedbytheheattreatmentat1100℃afteragingat1400℃,TherewasthegreatestK1cvalue(11.30MPa.m^1/2)ofthesamplesagedat1400℃for2hfollowedbyasubse-quentannealat1100℃for10h.ThechangesinthemicrostructureofMgO-PSZceramicsagedwithdifferentthermaltreatmentwerestudieddbyuseoftransmissionelectronmicroscopy.