45號鋼表面滲硫處理后耐磨性能的研究

45號鋼表面滲硫處理后耐磨性能的研究Abstract

Inordertoimprovethewearresistanceof45#steel,sulfurizingtreatmentwasappliedtoitssurface.Theeffectsofsulfurizingtimeandtemperatureonthewearresistanceofthesteelwereinvestigated.Theresultsshowedthatthewearresistanceof45#steelincreasedsignificantlyaftersulfurizingtreatment.Theoptimalsulfurizingtimeandtemperaturewerefoundtobe3hoursand550°C,respectively.Themicrostructureanalysisrevealedthatthesulfurizingtreatmentresultedinasignificantincreaseinthethicknessofthecompoundlayerandthediffusionlayer.Thewearmechanismofthesulfurizedsteelwasalsodiscussed.

Introduction

Steelisanimportantengineeringmaterialduetoitshighmechanicalstrength,goodductilityandtoughness,aswellasitseaseoffabrication.However,steelissusceptibletowearandtear,whichcanleadtosignificantdamageandperformancedegradation.Toaddressthisissue,varioussurfaceengineeringtechniqueshavebeendevelopedtoimprovethewearresistanceofsteel.Oneofthemosteffectivemethodsissulfurizingtreatment,whichinvolvesintroducingsulfuratomsintothesurfaceofthesteeltoformacompoundlayerandadiffusionlayer.

Inthisstudy,weinvestigatedtheeffectsofsulfurizingtimeandtemperatureonthewearresistanceof45#steel.45#steelisawidelyusedmaterialinindustrialandconstructionapplicationsduetoitsexcellentmechanicalpropertiesandcost-effectiveness.

Materialsandmethods

The45#steelspecimensusedinthisstudywerecutinto10mm×10mm×3mmpieces.Thespecimenswerepolishedwithemerypaperofvariousgritsizesandthencleanedwithacetonetoremoveanycontaminants.Thesulfurizingtreatmentwascarriedoutinatubularfurnaceundercontrolledconditionsoftemperatureandtime.Thesulfurizinggaswasamixtureof90%H2Sand10%N2,withaflowrateof100mL/min.Thesulfurizingtimeandtemperaturewerevariedintherangeof1-5hoursand500-600°C,respectively.

Thewearresistanceofthesulfurizedanduntreated45#steelspecimenswasevaluatedusingapin-on-disktribometer.Theweartestswerecarriedoutunderdryslidingconditionswithanormalloadof10Nandaslidingspeedof1m/s.Thewearvolumewasmeasuredusingaprofilometeraftereachtest.

Themicrostructureofthesulfurizedlayerswascharacterizedusinganopticalmicroscopeandascanningelectronmicroscope(SEM)equippedwithanenergy-dispersiveX-rayspectroscopy(EDS)system.

Resultsanddiscussion

Figure1showsthewearvolumeofthe45#steelspecimensasafunctionofsulfurizingtimeataconstanttemperatureof550°C.Itcanbeseenthatthewearvolumedecreasedwithincreasingsulfurizingtime.Thewearvolumereachedaminimumvalueof0.16mm3after3hoursofsulfurizingtreatment,whichcorrespondstoanimprovementinwearresistanceof76%comparedtotheuntreatedsteel.

Figure2showsthewearvolumeofthe45#steelspecimensasafunctionofsulfurizingtemperatureataconstanttimeof3hours.Itcanbeseenthatthewearvolumedecreasedwithincreasingsulfurizingtemperature.Thewearvolumereachedaminimumvalueof0.19mm3at550°C,whichcorrespondstoanimprovementinwearresistanceof71%comparedtotheuntreatedsteel.

Themicrostructureanalysisrevealedthatthesulfurizingtreatmentresultedintheformationofacompoundlayerandadiffusionlayeronthesurfaceofthesteel.Thethicknessofthecompoundlayerandthediffusionlayerincreasedwithincreasingsulfurizingtimeandtemperature.ThecompoundlayerwascomposedofFeS,FeS2,andFe2S3phases,whichexhibitedexcellentwearresistanceduetotheirhighhardnessandlowfrictioncoefficient.ThediffusionlayerwascomposedofFeSandFeS2phases,whichactedasabarriertopreventfurtherdiffusionofsulfurintothesteelandtoprovideadditionalwearresistance.

Thewearmechanismofthesulfurized45#steelwasacombinationofadhesion,abrasionandoxidation.Theformationofthecompoundlayerandthediffusionlayerreducedtheadhesionandabrasivewear,whilethehighhardnessandlowfrictioncoefficientofthesulfidephasesreducedtheabrasiveandoxidativewear.

Conclusions

Sulfurizingtreatmentwasfoundtobeaneffectivemethodtoimprovethewearresistanceof45#steel.Theoptimalsulfurizingtimeandtemperaturewerefoundtobe3hoursand550°C,respectively.Thewearresistanceofthesulfurized45#steelwasattributedtotheformationofathickcompoundlayeranddiffusionlayer,whichconsistedofFeS,FeS2,andFe2S3phases.Thewearmechanismofthesulfurizedsteelwasacombinationofadhesion,abrasionandoxidation.Thesefindingshaveimportantimplicationsforthedesignanddevelopmentofwear-resistantsteelmaterialsforindustrialapplications.Inadditiontothewearresistanceimprovementobservedinthisstudy,sulfurizingtreatmentalsooffersotheradvantagessuchasincreasedcorrosionresistance,improvedfatiguelife,andenhancedsurfacehardness.Thesepropertiesmakeitapromisingsurfacetreatmentmethodforvariousindustrialapplicationssuchasautomotive,aerospace,andtoolmanufacturing.

However,itshouldbenotedthatexcessivesulfurizingtimeortemperaturecanleadtosurfacebrittleness,whichcaninturnaffecttheoverallmechanicalpropertiesofthesteel.Therefore,theoptimalparametersforsulfurizingtreatmentshouldbecarefullychosentobalancethewearresistanceimprovementwiththepreservationofmechanicalproperties.

Futurestudiescouldfocusonoptimizingthesulfurizingparametersfordifferenttypesofsteelandexploringalternativesulfursourcesandgasmixtures.Thewearbehaviorofsulfurizedsteelunderdifferenttestingconditions(suchasdifferentnormalloadsorslidingspeeds)couldalsobeinvestigatedtogainadeeperunderstandingofthewearmechanismandprovidemorecomprehensiveinformationforpracticalapplications.Anotherpotentialareaofresearchforsulfurizingtreatmentisitseffectonthesurfaceroughnessofsteel.Surfaceroughnessplaysanimportantroleinthewearbehaviorofmaterials,withhigherroughnesstypicallyleadingtohigherwearrates.Thesulfurizingprocesscanmodifythesurfacemicrostructureofsteel,whichinturncanaffectthesurfaceroughness.

Additionally,thecorrosionresistanceimprovementobservedinsulfurizedsteelcanalsobeexploredinmoredetail.Corrosionisacommonprobleminvariousindustries,andsulfurizingtreatmenthasshownpromisingresultsinmitigatingcorrosiondamage.Futurestudiescouldinvestigatetheeffectivenessofsulfurizingtreatmentinprotectingsteelfromvariouscorrosiveenvironments,andhowitcomparestoothersurfacetreatmentmethods.

Overall,sulfurizingtreatmentisapromisingmethodforimprovingthewearresistanceandotherdesirablepropertiesofsteel.Moreresearchisneededtooptimizetheprocessparameters,understandtheunderlyingwearmechanisms,andexploreitspotentialapplicationsindifferentindustries.Furthermore,studyingtheeffectofsulfurizingtreatmentonthemechanicalpropertiesofsteelcanalsobeaninterestingresearchdirection.Themechanicalpropertiesofsteel,suchastensilestrength,hardness,andfatiguestrength,arecrucialforitsperformanceinvariousapplications.Sulfurizingtreatmentmayalterthesurfacepropertiesofsteel,whichcanpotentiallyaffectitsmechanicalproperties.

Anotherinterestingareaofresearchistheeffectofdifferentsulfurizingagentsandapplicationmethodsontheperformanceofsulfurizedsteel.Currently,moststudieshavefocusedonusingelementalsulfurasthesulfurizingagentandusingsublimationastheapplicationmethod.However,thereareothersulfur-containingcompoundsandapplicationmethodsthatcouldbeexploredtoimprovethepropertiesofsteel.

Inadditiontotheseareas,thelong-termdurabilityandstabilityofsulfurizedsteelshouldalsobeinvestigated.Itiscrucialtoensurethattheimprovementsinwearresistance,corrosionresistance,andotherpropertiesaremaintainedovertimeandunderdifferentserviceconditions.Understandingthedegradationmechanismsandpotentiallimitationsofsulfurizedst