简介:TheinfluenceofrareearthoxideCeO2onmicrostructureandwearresistanceofM80S20thermalsprayandthermalsprayweldingcoatingsisstudiedusingopticalmicroscope,scanningelectronmicroscope,X-rayenergydispersionspectroscope,X-raydiffractometerandweartestingmachine.Theresultsshowthattheaddi-tionof8%CeO2canimprovethemicrostructure,microhardnessandwearresistanceofcoatingssignificantly.
简介:为提高涟钢薄板产品质量,2007年,公司决定对烧结原料进行分开配矿,杂质含量低,烧结性能好的原料进280m2烧结机,所有利废物全部进130m2烧结机和180m2烧结机(以下简称130+180m2),导致利废物由8%提高到18%;同时为了提高烧结矿品位,精粉比例从35%提高到45%。在此情况下,130+180m2烧结机烧结料透气性变差,利用系数下降,能耗升高,保矿压力增大。生产实践证明,提高烧结混合料温度,可以显著减少过湿层的发生,改善料层的透气性能,为实行厚料层烧结提供了有力保障,有效的降低了烧结固体燃料的消耗,提高了烧结生产率。涟钢130+180m2烧结机原在混合料仓安装了蒸汽预热,但预热效果达不到最佳状态。因此,为进一步运用余热回收蒸汽来预热混合料新技术,根据本车间现有的工艺状况,分别在130+180m2分料仓安装蒸汽喷头,通过对分料仓的改造,合理利用余热蒸汽,有效的提高了混合料的温度,取得了良好的经济效益。
简介:Baosteel'sNo.8airseparationunit(ASU)isthefirstdomestically-integrated60000m3/hASU.Thispaperdescribesthemechanicalequipment,thedesignandtheconfigurationcharacteristicsofthisunit.ThepotentialfailuremodesofthemechanicaldevicesarededucedviaanalysesonthefailurehistoryofsimilardevicesinotherASUs.Finally,thispaperalsobringsupsuggestionsondailymaintenance,overhaulandpurchasesofspareparts.
简介:Er~(3+)andLa~(3+)codopedY_2O_3nanocrystallinepowdersweresynthesizedbygelcombustionmethodandcharacterizedwiththermalanalysis,X-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),high-resolutionTEM(HRTEM)techniquesandfluorescencespectroscopy.Afterbeingcalcinedat1200oC,the(Y_(1–x)La_x)_2O_3:Er~(3+)powderswereconfirmedtobecubicY_2O_3phasewiththecrystallinegrainsizeintherangeof20–40nm.TheEr~(3+)emissionat1.53μmfromthe~4I_(13/2)→~4I_(15/2)transitionwasobserved,whichwasfoundtobeenhancedbyintroducingLa~(3+)ions.SuchenhancementcouldbeattributedtotheadjustmentofEr~(3+)ions'localenvironmentbythecodopingofLa~(3+)ions,leadingtotheincreasedgroundstateabsorptioncrosssectionofEr~(3+)ions.
简介:采用选择性激光熔覆法,在基板温度分别为100,150,和200℃条件下制备M2粉末高速钢合金,分析基板温度对合金组织结构与力学性能的影响。结果表明,基板温度升高有利于提高M2粉末高速钢的致密度和整体组织的均匀性。当基板温度为200℃时,高速钢组织均匀致密,各元素固溶程度高,且碳化物含量高,组织中柱状晶不再沿Z轴方向单一生长,同时合金的显微硬度(HV0.1)达到最高,HV0.1为1150,相比基板温度为100℃时的合金提高近40%。随基板温度从100℃升高到200℃,沿Z轴打印的M2高速钢室温抗拉强度从865.23MPa降低到443.85MPa,主要原因是合金中单一方向的柱状晶数量减少。
简介:AdetailedstudyofthefluorescenceemissionpropertiesandenergytransfermechanisminEr3+/Tm3+co-dopedleadsilicateglasseswasreported.Enhancednearinfrared1.8μmandvisibleup-conversionemissionswereinvestigatedunder808and980nmexcitations,respectively.TheenergytransfermechanismbetweenEr3+andTm3+wasanalyzedaccordingtotheabsorptionspectra,theemissionspectraandthelevelstructuresofEr3+andTm3+.TheenergytransferefficiencybetweenEr3+andTm3+reached68.1%intheEr3+/Tm3+co-dopedleadsilicateglasseswhenpumpedby808nmlaserdiode.Basedontheabsorptionspectra,theJudd-Ofeltparameters,spontaneousemissionprobability,absorptionandemissioncrosssections,gaincoefficientswerecalculatedandanalyzed.Itwasfoundthatthecalculatedemissioncrosssectionandthemaximumgaincoefficientaround1.8μmwere4.9×10–21cm2and1.12cm–1,respectively.TheseresultsindicatedthattheEr3+/Tm3+co-dopedlead-silicateglasseshadpotentialapplicationinnearinfraredlasers.