简介：Intheproductionofhotextrusionpipes,thebilletwillbeheatedinaninductionfurnace,beforepiercingorextrusion,toacertaintemperature.Theinductionheatingtemperaturefieldprofileinthebilletwillexertaninfluenceonthedeformationprocesses.ThestudyhasdevelopedandataconversionprogramtoconvertthetemperaturedatafrominductionheatingbyANSYStodeformationsimulationsoftwareDEFORM;therefore,notonlytherelativelyaccuratetemperaturefieldcanbemadeavailable,comparedwiththeusuallyassumeduniformtemperaturefield,butalsotheconnectionbetweeninductionheatinganddeformationcanbeestablished,whichisessentialtoevaluatetheprocessingparameters.Numericalsimulationofthepiercingprocessesofdifferenttemperaturefieldsbyinductionheatingwascarriedout,andtheresultshaveshownthatthedifferentinitialtemperaturefieldsinthebilletcanleadtodifferentdeformationcurves,whichindicatesthattheconversionprogramisnecessarytostudytheproductionprocessofhotextrusionpipes.

简介：Temperatureevolutionofaworkingpieceduringhotrollinghasasignificantinfluenceonthemicrostructureandfinalmechanicalpropertiesofthematerial.Asthemeasurementtechnologiesimprove,on-linemeasurementofthetemperatureacrossthestripwidthhasbecomeaccessible,andthusmonitoringandcontrolofthetransversaltemperaturedistributionduringhotrollingcanberealized.Thescanningofthetemperatureacrossthestripwidthcanhelpustounderstandthestateofthetemperaturevariationatthestripedgesandasaresulthelpusimprovethetemperaturehomogeneityofthestrip.Inthispaper,reaearchontemperaturedistributionalongthestripwidthisreviewedfirst,andthenthemechanismofthescanningmeasuringdevicesisintroduced.Withthetemperaturescanningmeasurementdatatakenfromthefinishingmillentrypointandthedowncoilerentrypoint,thetemperaturedistributionatthestripedgesisanalyzed.Itispointedoutthattheroughingprocessisthemaincontributortothetemperatureinhomogeneity.Furthermore,thecontributionoftheedgerheatertothetemperaturehomogeneityisinvestigated.

简介：Toimprovetheprecisionofthecoilingtemperatureandtheperformanceofthefeedbackcontrolsystemwithlongpuretimedelayonhotstripmills,weanalyzedthedesignprocessoftheDahlinalgorithmindetail.ThecoilingtemperaturecurvescontrolledbythePIDalgorithmandDahlinalgorithmweresimulatedandcompared,whichshowedthatthecontrolprecisionwiththeDahlinalgorithmwashigherthanthatwiththePIDalgorithm.Thatwasfurtherverifiedbytheproductionpractice.

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简介：High-temperatureperformancetestsofchromium-containingstuffingsandforasteelladlewithdifferentratioswereperformed.Ahigh-temperaturesimulationtestfurnacewasusedtoanalyzetheinfluenceofthecompositionratioofladlefillersandandsinteringtimeonthehigh-temperaturecompressionresistanceofchromium-containingstuffingsandinthetemperaturerangeof1500-1600℃.Theresultsshowthattherefractorinessofladlefillersandwasthelowest(only1610℃)whenthecompositionratioofchromitesandandsilicasandwas6∶4.Moreover,thehigh-temperaturecompressionresistancewashighwhenthecontentofchromitesandwasat70%;theresistanceincreasedwithincreasingsinteringtime.Whenthesinteringtimewasextendedatatemperatureof1600℃,thehigh-temperaturecompressionresistanceofladlefillersandfirstincreasedandthendecreasedafterbeingoverburnt.

简介：Opticalmicroscope,stereomicroscope,scanningelectronicmicroscope(SEM)andmechanicalpropertytestingwereusedtoresearchtheeffectsofdifferentquenchingtemperaturesonthemicrostructureandmechanicalpropertiesoftheH13mandrelsteel.Theresultsindicatethatfollowinganincreaseinthequenching,thedegreeofalloyingisenhancedduetothecarbidesdissolvinggraduallyinaustenite,whichimprovesthehardenabilityofthespecimens,aswellastheirroomandhigh-temperaturestrength.Atthesametime,thefracturetoughnessincreasesduetotheincrementofthemartensitenumberandtheinterparticledistanceofthecarbides.However,extremelycoarsegrainandmartensitecandecreasetheimpacttoughness.Optimalperformancecanbeobtainedafterquenchingat1060℃anddoubletemperingat620℃.Consequently,theservicelifeoftheH13mandrelsteelisextendedsignificantly.

简介：Alloyingelements,suchassiliconandmanganese,haveamajorimpactonthephasetransformationpointofsteel.Specifically,manganeseisanelementfortheexpansionandstabilityoftheausteniteregion,whilesiliconcanexpandandstabilizetheferriteregion.Phasetransformationoccursduringthehotrollingprocessforthesteelwithcertainsiliconcontent,whichleadstogreatchangesofthedeformationresistance,therebyaffectingtherollingstability.Consequently,abetterunderstandingofphasetransformationintherollingprocesswillcontributetotheenhancementofproductquality.Inthispaper,theon-linerollingdatawereprocessedbymeansoftheinversecalculationmethod.Inthismethod,thesteeldeformationresistancewithvarioussiliconandmanganesecontentswasobtainedandanalyzedtodeterminethedeformationbehaviorofthesteel,whichcanhelpimprovetheon-linecontrolmodelandenhancethesteelquality.

简介：Expansionisanimportantoperationinthehotextrusionproductionlineofseamlesssteeltubes,whichistoproduceproperhollowbilletsforextrusion.Thebilletgoesthroughinductionheatingbeforeexpandedtoacquireapropertemperature.Inthisstudy,theeffectsofthreetypesofinhomogeneoustemperaturefieldson321stainlesstubesduringtheexpansionprocessweresimulated.Theresultshaveindicatedthatitwasanoptimumtemperaturefiledforexpansion,wherethetemperaturevariedlinearlyalongradialdirectionandthetemperaturewaslowerontheinnersurface.Thistemperaturefieldisbeneficialtoimprovingthestabilityofexpansionandensuringdimensionalaccuracyandincreasingtheutilizationrateoftubularbilletmaterial.

简介：Thisstudyaimstoinvestigatetheeffectofthe1-stepquenchingandpartitioning(Q&P)processonthemicrostructureandtheresultingVicker’shardnessof0.3C-1.5Si-1.5Mnsteelbyusingin-situdilatometry,opticalmicroscopy(OM),scanningelectronmicroscopy(SEM),X-raydiffractometry(XRD),andVicker’shardnessmeasurement.Systematicanalysesindicatethatthemicrostructureofthespecimensquenchedandpartitionedat150℃,200℃,250℃,and300℃mainlycompriseslathmartensiteandretainedaustenite.Thedilatometrycurveofthespecimenpartitionedat150℃ispresumablyascribedtotheformationofisothermalmartensite.Intheearlystagesofpartitioningat200℃,thenearlyunchangeddilatationcurveiscloselyrelatedtothesynergisticeffectofisothermalmartensiteformationandtransitionalepsiloncarbideprecipitation.Inthelaterstagesofpartitioningat200℃,theslightincreaseinthedilatationcurveisduetothecontinuousisothermalmartensiteformation.Withfurtherincreaseinpartitioningtemperatureto250℃,thedilatationincreasesgraduallyupto3600s,whichisrelatedtocarbonpartitioningandlowerbainiteformation.Partitioningatahighertemperatureof300℃causesarapidincreaseinthedilatationcurveduringtheinitialstages,whichsubsequentlylevelsoffuponprolongingthepartitioningtime.Thisismainlyattributedtotherapiddiffusionofcarbonfromathermalmartensitetoretainedausteniteandcontinuousformationoflowerbainite.

简介：Thehot-deformationbehaviorofFe-Mn-Ctwinninginducedplasticity(TWIP)steelwasinvestigatedbyconductinghotcompressiontestswithinarecommendedhotrollingtemperaturerangeatvariousstrainrates.Flowresistancecurvesduringhot-deformationwereobtained,andstrainratesensitivitiesandactivationenergiesforplasticdeformationwerecalculatedusingthepowerlaw.ItisfoundthattheadditionofAlandSiclearlyincreasesthepeakstressesforthepresentalloys,especiallyat950℃.ButMnhasaminoreffectonthestress-straincurvesandactivationenergywhenitscontentvariesfrom15mass%to22mass%forthepresentalloys.

简介：Coarsening,embrittlementandcorrosionsensitizationinahightemperatureheat-affectedzone(HTHAZ)arethemajorproblemswhen12%chromiumlowcarbonstainlesssteelisbeingwelded,whichinducethedeteriorationoftheimpacttoughnessatalowtemperatureandintergranularcorrosionresistanceproperty.ThisstudyinvestigatesthecorrespondingmicrostructuresinHTHAZwithdifferentchemicalcompositionsandheatinputsthroughthermalsimulationtests.Theresultsshowthatthemartensitecontentincreaseswiththedescendingofferritefactor(FF)whenFFisbelow9.0andheatinputinfluencesthemicrostructureofhighFFsteelinHTHAZ.Martensiteof12%CrstainlesssteelinHTHAZwithonlyNbstabilizationreticularlydistributesatferritegrainboundaries.

简介：InordertosuppressthesurfacecrackinginducedbyCuduringreheatingandhotrollingprocess,Cuenrichmentanditsmigrationatthesteel-scaleinterfacewasinvestigatedduringheatingofsteelcastattemperaturesbetween1000℃and1200℃inN2-O2andN7-H2Oatmospheres.ForoxidationofCucontainingsteel,CuenrichedphasewasformedbythepreferentialoxidationofFeandtheenrichmentandmigrationbehaviorofCudependsontheoxidationtemperature,steelchemistryandatmospherecondition.NiinsteelinducedtheformationofsolidCuandNienrichedphaseatsteel/scaleinterfaceandinscalelayerandtheformationofunevensteel/scaleinterface,whichsuppressestheCuenrichmentbecauseofextrusionofCuenrichedregionbeforetheformationofliquidphase.Ontheotherhand,SnadditionpromotestheliquidCuformationatsteel/scaleinterfaceandpenetrationintograinboundaryofCuenrichedphasebydecreasingsolidustemperatureandsolubilitylimit.Inaddition,foroxidationat1200℃,thebehaviorofCuatandaroundthesteel-scaleinterfacewasfounddependenttoalargeextentonmorphologyoftheoxidescaleformedduringoxidation.Attheearlystageofoxidation,Cu-richphaseformedandaccumulatedatthesteelscaleinterfaceunderbothO2-N2andH2O-N2atmospheres.Astheoxidationproceeded,however,Cuenrichmentatanditsmigrationfromthesteel-scaleinterfacewerevastlydifferentfordifferentoxidizingatmospheres.InthecaseofO2-N2oxidation,anoxidelayerformedinitiallyatthesteelsurface,butsoonafteragapwasdevelopedatthesteel-scaleinterfaceandgrewinitssize,whichpracticallyseparatedthescalefromthesteelsubstrate.Thescalelayerformedunderthisconditionwasporous.TheCu-richphaseinitiallyformedattheinterfacewasfoundmigratingtothescalelayer,leavingnoCu-richphaseattheinterface.InthecaseofH2O-N2oxidation,however,thescalelayerformedwasdenseandtightlyattachedtothesteelsurface,andtheCurich-phasecontinuedto

简介：Theeffectsofthesubstratetemperatureonthedepositionandmicrostructureofthe304stainlesssteel(SS)coldgasdynamicspraying(CGDS)coatingswereinvestigated.Itwasfoundthatthehighersubstratetemperaturecouldincreasethedepositionrateofthe304SSparticles,eventheoxidefilmsexistedattheinterface.Therewasacriticaloxidefilmwithathicknessof3-4μmwhichcouldbedestroyedbytheimpactedparticles.Themicro-hardnessandmicrostructureofthe304SScoatingsunderdifferentsubstratepreheatingtemperatureswerealmostthesame.

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