简介:ThisstudyresearchestheeffectsoftherefiningtreatmentonthemicrostructureandthemechanicalpropertiesofH13mandrelsteelandcomparestheseeffectswiththoseoftheconventionaltreatment.Theresultsindicatethatbothcarbideparticlesandgrainswererefined,carbideparticleswereuniformlydistributedbytherefiningtreatment,andtherefore,thestrengthandtoughnessofH13mandrelsteelwereimproved.Rapidcoolingafterthesolutiontreatmentmayinhibitintra-granularprecipitationofcarbideparticles,whichisfavorabletoenhancingtoughness.Consequently,high-performanceH13mandrelsteelcanbeproducedbyproperrefiningtreatment.
简介:Opticalmicroscope,stereomicroscope,scanningelectronicmicroscope(SEM)andmechanicalpropertytestingwereusedtoresearchtheeffectsofdifferentquenchingtemperaturesonthemicrostructureandmechanicalpropertiesoftheH13mandrelsteel.Theresultsindicatethatfollowinganincreaseinthequenching,thedegreeofalloyingisenhancedduetothecarbidesdissolvinggraduallyinaustenite,whichimprovesthehardenabilityofthespecimens,aswellastheirroomandhigh-temperaturestrength.Atthesametime,thefracturetoughnessincreasesduetotheincrementofthemartensitenumberandtheinterparticledistanceofthecarbides.However,extremelycoarsegrainandmartensitecandecreasetheimpacttoughness.Optimalperformancecanbeobtainedafterquenchingat1060℃anddoubletemperingat620℃.Consequently,theservicelifeoftheH13mandrelsteelisextendedsignificantly.
简介:ThemicrostructuralchangesofFe83Si4B13amorphousmotheralloyduringtheheatingprocesswereinvestigatedbyLaserScanningConfocalMicroscopy(LSCM),andthephasetransformationwasdeterminedbytheThermo-Calccalculations.ThedifferencesinthemeltingpointsmeasuredbyDifferentialScanningCalorimetry(DSC)andLSCM,andthoseobtainedbyThermo-Calccalculationswerealsodiscussed.ItisfoundthatthemeltingpointsmeasuredbyDSCandLSCMarerelativelysimilar,whereastheonsetandendofthemeltingtemperaturescalculatedbyThermo-CalcsoftwarearehigherthanthosemeasuredbyDSCandobservedbyLSCM.
简介:Themechanicalandcorrosivepropertiesof00Cr13Ni4Mo(S13-4N)weretestedandcomparedwiththoseof00Cr13Ni6Mo(S13-6).Theeffectsofnitrogenonthepropertiesofthesteelswereanalyzed.Theresultsofthetensileandcorrosiontestsshowthestrength,theductility,andthepittingcorrosionresistanceofS13-4Narehigher,lowerandpoorerthanthoseofS13-6respectively,whentemperedatatemperaturebelow550℃andviceversawhenthetemperingtemperatureishigherthan550℃.TheresultsoftheX-raydiffraction(XRD)andtheelectronbackscattereddiffraction(EBSD)analysesrevealthatinversedausteniteappearsat550℃andtheamountofitpeaksat600℃withthebestductility.AndthetotalamountoftheinversedausteniteinS13-6ismorethanthatinS13-4Nindifferentforms.Nitrogenperformsbetterintermsofstabilizinginversedaustenitewhilenickelismorefavorableforforminginversedaustenite,theamountandstabilityofwhichaffecttheductilityremarkably.ThereasonfortheembrittlementofS13-4Nat450℃canbetheresultofcarbideandnitrideprecipitatingatgrainboundaries.
简介:将95%Mg+3%Ni+2%MnO2混合粉末在行星式高能球磨机中充氢反应球磨100h,利用X射线衍射(XRD)和扫描电镜(SEM)对球磨后的粉体进行表征,并研究其与水反应的动力学性能。结果表明,充氢球磨能对Mg-3Ni-2MnO2进行充分的氢化,Mg全部形成MgH2。制备的氢化态Mg-3Ni-2MnO2复合粉末的颗粒尺寸为0.1~5gm,晶粒尺寸在1~40nm之间。复合物在二次去离子水中水解时,随温度升高,放氢量增加,当温度为343K时,在20min内放出的氢气达到理论放氢量的91-3%,有望成为1种新的安全高效氢源技术。Avrami指数的数值变化表明,氢化态Mg-3Ni-2MnO2复合粉体的水解过程中,不同阶段其水解机理有所不同。
简介:Throughout30yearsofimportation,adoptionandinnovation,theColdRollingPlantofBaosteelhasadheredtoamarket-orientedstrategy,andgraduallyexpandeditsoutputandraiseditstechnicallevelthroughtheexpansionofproductionscale,theoptimizationofproductionlines,thedevelopmentofhighaddedvalueproducts,theimprovementofproductquality,environmentallyfriendlymanufacturingandtechnologicalinnovation.Inthisway,theplanthasdevelopedintoaworldclasscoldrollingplantthatproducescutting-edgeeconomicandtechnicalindices.
简介:世界领先的高科技产品——氢燃料电池已在宜兴投入生产,国家级氢燃料电池基地将在宜兴落户。2005年元月,市委书记史祖能带领市经贸、国土、科技、建设和宜城镇等有关部门和单位主要负责人,来到位于诸桥工业集中区的四通家电企业现场办公,就建设国家级氢燃料电池基地的有关问题进行了协调。确保氢燃料电池基地在宜“生根开花”,结出丰硕果实。