简介：镁碳砖诞生于70年代的日本，80年代开始在我国生产、应用和发展，进入90年代以来，我国镁碳砖有了空前的发展，形成了较大的生产能力，年生产能力由15年前的4-5万t增加到现在的40万t。镁碳砖以其独特的耐火性能、良好的热震稳定性和很强的抗渣性而被广泛地应用于转炉炉衬、

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简介：Thedevelopmentofefficientbondingagentsisoneaspectoftheadvancementofrefractories.Basedonanewlydevelopedbindersystem,anewgenerationoftar-resinbondedmagnesiacarbonproductswithhighperformancehasbeendeveloped.Furthermore,thebindersystemcharacterizedbyhighcarbonyieldaftercarbonizationresultsinforminganextremelystrongcarbonbonding.Itcanimproverefractoriespropertiestogetnewproductwithmoreadvantagesthanoldrefractories:moreeconomic,lowercostandlowtoxicity.Tar-resinisnotonlyusedinshapedrefractories,butalsoinmorerefractoriestypes,suchasmonolithicrefractories.ImmersionexperimentsofMgO-Cmonolithicrefractoriessamplesinliquidsteelat1600℃havebeencarriedoutforsteelmakingindustry.TheseexperimentsshowedtheformationofadenseandcontinuousMgOrichlayer,ontheinterfacebetweenrefractoryandsteel,andthepossibleformationofinclusionsaslargeclustersprotrudingfromtherefractorysurface.Forthemechanicalproperties,thepowderwasheatedupto1400℃inairtoremovecarbon,andwassubsequentlyformedintobrickshape.StandardASTMwasusedtodeterminetheMOR,porosityanddensity.Itisfoundthatantioxidantmaterialsplayanimportantroleinimprovingthemechanicalproperties.

简介：MobarakehsteelCompanyproduces3milliontonsofsteelannuallywitheight180tonsEBTfurnaces.Differenttypesofmagnesia-carbonrefractorieshavebeenemployedatslaglineduringlast5years.InthepresentstudythewearandcorrosionofMgO-Crefractoriesofthesefurnaceshavebeenstudiedviapost-mortemanalysisofusedbricksandtheobservationofoperationaleffects.Laboratorycorrosiontestswerealsoarrangedtoinvestigatetheeffectofslagchemistryandthemechanismofchemicalcorrosion.Characterizationofdifferentmagnesia-carbonbricksclarifiedthatthecrystalsize,typeandchemistryofmagnesiaaswellasgraphitestructurehavethemaininfluenceoncorrosionresistance.TheCaO:SiO2ratioinslagalsoplaysavitalroleinthewearofslaglinerefractories.Theironoxidecontentofslagalsohasamajorroleingraphiteoxidation.Ofmetallurgicalparameters,theelectricpowerinputandthecontacttimehavegreatinfluenceonrefractorieslife.TheresultswillbediscussedwithemphasisonparticularoperationalfactorsinMobarakehsteelplant.

简介：EffectsofAl—Siadditiononhotmodulusofrupture（HMOR）,thermalshockresistanceC3andAlN:SireactswithCtoformSiC.Ultimately,in-situformednonoxidesincreaseappreciablywithtemperaturerisingandarewellinterlacedinpericlaseskeletonstructureat1300-1400℃.whichisbeneficialtothermomechanicalproperties.

简介：近年来，我国MgO-C砖有了空前的发展，年生产能力已达到40万吨，并已广泛应用于转炉炉衬，电炉炉墙、钢包渣线和一些精炼炉，转炉炉衬使用寿命达3000——5000炉。目前，有些钢厂同时采用溅渣护炉技术，使炉衬寿命提高到了8000炉以上，武钢将MgO-C砖使用在90吨转炉衬寿命达到15000炉以上，并且使底吹供气元件与炉龄同步，取得了在溅渣护炉条件下，转炉炉役全程复吹国际领先水平成果。

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简介：TheeffectofTi(C,N)onpropertiesoflow-carbonMgO-Cbrickswasinvestigated.Thephasecompositionandthemicrostructureofthematrixoflow-carbonMgO-CbrickcontainingTi(C,N)werestudiedbyXRDandSEManalysistogetherwithEDS.TheresultsshowedthatTi(C,N)distributedinthematrixoflow-carbonMgO-Cbrickuniformlyafterbeingtreatedat1600℃for3hincokepowderbed,andTi(C,N)andMgOformedasolidsolution.Afterthetreatmentat1600℃for3hincokepowderbed,thebulkdensityandcoldcrushingstrengthoflow-carbonMgO-CbrickwithTi(C,N)decreased,andtheapparentporosityandlinearchangerateofspecimensincreased.Theoxidationresistanceoflow-carbonMgO-CbrickwithTi(C,N)wassuperiortothatoflow-carbonMgO-Cbrickwithnoadditives,butinferiortothatoflow-carbonMgO-CbrickwithAlpowder.TheslagresistanceofthespecimenwithTi(C,N)wasexcellentaswell.

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.

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简介：BycarbothermalreductionofMgOwithblackcarbonasreductionagentatahightemperature,MgOwasdepositedonthesurfaceofMgO-CaOclinker(ascoating)toimprovetheclinker'shydrationresistance.Inthepaper,effectofdepositiontemperatureandholdingtimeonthehydrationresistanceofthetreatedMgO-CaO,thedepositionmechanismandMgOcoatingkineticswereinvestigatedwithhydrationresistancetest,X-raydiffractometry(XRD)andscanningelectronicmicroscope(SEM).ResultsshowedMgOcoatinggrewina2DmodeonthesurfaceofMgO-CaOparticles;theMgOcoatingimprovedthehydrationresistanceofthecoatedMgO-CaOclinker,andthecoatedclinkerwouldbecomestrongerwhencoatedathigherdepositiontemperatureandlongerholdingtime.ThemeasurementsalsofoundthatMgOdepositionprocessvariedwiththedepositiontemperature:itwasmainlyachemical-controlledprocessattemperaturesbetween1400-1500℃,withanapparentactivationenergy(AAE)of97.8kJ·mol~(-1);itwouldchangeintoadiffusion-controlledprocesswhenthetemperaturerisingto1500-1600℃,withapparentactivationenergyof19.2kJ·mol~(-1).

简介：Thedependenceofperpendicularmagneticanisotropy(PMA)onthebarrierlayerMgOthicknessinMgO/CoFeB/Tamultilayersisinvestigated.TheresultsshowthatthestrongestPMAoccursinasmallwindowofabout2-4nmwiththeincreaseofMgOthicknessfroml-10nm.ThecrystallinedegreeofMgOandthechangeofinteratomicdistancealongtheout-of-planedirectionmaybethemainreasonsforthechangeofPMAinthesemultilayers.Moreover,theroughnessesof2-and4-nm-thickMgOsamplesare3.163and1.8nm,respectively,andboththesamplesshowPMA.TheseresultscouldbeusedtotunethemagneticcharacteristicoftheultrathinCoFeBfilmforfutureapplicationsinperpendicularmagneticdevices.

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简介：<正>棱角鲜方方正正结结实实铿锵有声原本是大地下的一层黏土一出世便展示出质朴的个性

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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.

简介：以聚乙烯醇(PVA)作为络合剂与醋酸镁反应制得前驱体,采用静电纺丝法制得聚乙烯醇(PVA)/醋酸镁复合纤维,经焙烧后得到分布均匀、具有较高比表面积和多孔结构的MgO纳米纤维.对所制得的纳米纤维的结晶度、纯度和表面形貌,分别采用X射线粉末衍射、差热-热重分析(TG-DTA)、红外光谱(IR)、扫描电镜(SEM)等分析测试手段进行了表征.结果表明,煅烧温度对纳米纤维的结晶度和形貌有很大影响.