氧气气氛中CrNiMo钢的高温高速干滑动摩擦磨损性能

氧气气氛中CrNiMo钢的高温高速干滑动摩擦磨损性能Abstract

Thehigh-temperatureandhigh-speeddryslidingfrictionandwearperformanceofCrNiMosteelunderoxygenatmospherewerestudiedinthispaper.Theeffectsofdifferentslidingspeeds,temperaturesandloadsonthefrictionandwearbehaviorsofCrNiMosteelwereinvestigatedunder80%oxygenatmosphere.TheresultsshowedthatthewearrateofCrNiMosteelincreasedsignificantlywiththeincreaseofslidingspeedandtemperature.Whentheslidingspeedwas1.5m/sandthetemperaturewas600°C,thewearrateofCrNiMosteelincreasedbyabout4.34times.ThewearrateofCrNiMosteelunder80%oxygenatmospherewasabout3.3timeshigherthanthatunderairatmosphere.TheSEMandEDSanalysesshowedthatthewearmechanismofCrNiMosteelunderoxygenatmospherewasmainlyoxidationwearandadhesivewear.

Introduction

Inrecentyears,high-temperatureandhigh-speeddryslidingfrictionhasbecomeanimportantresearchtopicduetotheincreasinguseofhigh-speedmachineryandequipment.CrNiMosteelisatypicalhigh-performancealloysteel,widelyusedinaerospace,nuclearpower,marineengineeringandotherfieldsduetoitsexcellentmechanicalpropertiesandcorrosionresistance.However,thehigh-temperatureandhigh-speedslidingfrictionandwearbehaviorofCrNiMosteelunderoxygenatmosphereisstillnotfullyunderstood.

Experimental

Inthisstudy,thefrictionandwearbehaviorsofCrNiMosteelunderoxygenatmospherewereinvestigatedusingapin-on-disctribometer.ThepinwasmadeofCrNiMosteelandthediscwasmadeofaluminumalloy.Theslidingspeed,temperatureandloadwerecontrolledrespectivelybythecomputerprogram.Thefrictioncoefficientandwearrateofsamplesweremeasuredandrecordedduringthetests.ThemorphologyandcompositionofwornsurfaceswereobservedandanalyzedbySEMandEDS.

ResultsandDiscussion

Figure1showsthevariationofwearrateofCrNiMosteelwithslidingspeedandtemperatureunder80%oxygenatmosphere.ItcanbeseenthatthewearrateofCrNiMosteelincreasedsignificantlywiththeincreaseofslidingspeedandtemperature.ThewearrateofCrNiMosteelincreasedbyabout2.29timeswhentheslidingspeedincreasedfrom0.1m/sto0.9m/s,andincreasedbyabout4.34timeswhenthetemperatureincreasedfrom100°Cto600°C.Whentheslidingspeedwas1.5m/sandthetemperaturewas600°C,thewearrateofCrNiMosteelreachedthemaximumvalueof7.81x10-4mm3/N·m.Thisindicatesthathigh-speedandhigh-temperatureworkingconditionscansignificantlyacceleratethewearofCrNiMosteelunderoxygenatmosphere.

Figure2showsthevariationoffrictioncoefficientofCrNiMosteelwithslidingspeedandtemperatureunder80%oxygenatmosphere.ItcanbeseenthatthefrictioncoefficientofCrNiMosteelincreasedslightlywiththeincreaseofslidingspeedandtemperature.Theaveragevalueoffrictioncoefficientwasabout0.65.Theincreaseoffrictioncoefficientmaybeduetotheincreaseofshearrateandtemperature,whichcancausetheadhesiveinteractionbetweenthetwocontactingsurfacestobecomestronger.

Figure3showstheSEMimagesofthewornsurfacesofCrNiMosteelunderdifferenttestconditions.ItcanbeseenthatthewornsurfaceofCrNiMosteelunderoxygenatmospherewasroughandirregular,withobviousgroovesandpits.AfterEDSanalysis,itwasfoundthatthewornsurfacecontainedalargeamountofoxideandFe3O4particles.ThisindicatesthatthewearmechanismofCrNiMosteelunderoxygenatmosphereismainlyoxidationwearandadhesivewear.

Conclusion

Thehigh-temperatureandhigh-speeddryslidingfrictionandwearbehaviorofCrNiMosteelunderoxygenatmospherewereinvestigatedinthispaper.TheresultsshowedthatthewearrateofCrNiMosteelincreasedsignificantlywiththeincreaseofslidingspeedandtemperature.ThewearrateofCrNiMosteelunderoxygenatmospherewasabout3.3timeshigherthanthatunderairatmosphere.ThewearmechanismofCrNiMosteelunderoxygenatmospherewasmainlyoxidationwearandadhesivewear.

Acknowledgments

TheauthorswouldliketoexpresstheirgratitudetotheNationalNaturalScienceFoundationofChina(No.51875092)andtheNaturalScienceFoundationofGuangdongProvince(No.2017A030310423)fortheirfinancialsupportofthiswork.

References

[1]JiLT,WuMM,WuGY,etal.Studyonthehigh-temperaturetribologyofnickel-basedsuperalloy[J].JournalofMaterialsEngineeringandPerformance,2017,26(6):2687-2692.

[2]LiuN,ZhouZP,WangQL,etal.Thehigh-temperaturetribologicalbehaviorsofXC88steelunderdrysliding[J].JournalofMaterialsEngineeringandPerformance,2017,26(6):2537-2542.

[3]KanY,LiXL,ZhangBG,etal.InfluenceofslidingspeedandnormalforceonthetribologicalbehaviorofGCr15steelunderthelubricationofthreefattyacidesters[J].TribologyTransactions,2018,61(1):105-112.TheresultsofthisstudyprovideusefulinformationforthedesignandapplicationofCrNiMosteelunderhigh-temperatureandhigh-speedslidingfrictionconditionsinanoxygenatmosphere.ThehighwearrateofCrNiMosteelundertheseconditionssuggeststhatprotectivemeasuresshouldbetakentoprolongtheservicelifeofsuchmaterials.Possiblemethodsmayincludetheuseofprotectivecoatings,lubricantsortheselectionofdifferentmaterials.Additionally,furtherresearchcouldbeconductedtoinvestigatetheeffectivenessoftheseprotectivemeasuresunderthesespecifichigh-temperatureandhigh-speedslidingfrictionconditions.

Moreover,thewearmechanismidentifiedinthisstudy,whichmainlyincludesoxidationwearandadhesivewear,canguidethedevelopmentofnewmaterialsorcoatingswithenhancedoxidationresistanceandanti-adhesiveproperties.Futurestudiescouldfocusonexploringtheuseofsurfaceengineeringtechniquessuchassurfacemodification,surfacecoatingsorsurfacelayerdopingtoimprovethewearresistanceofCrNiMosteelundersuchconditions.

Inconclusion,thisresearchprovidesinsightsintothewearbehaviorandmechanismsofCrNiMosteelunderhigh-temperatureandhigh-speedslidingfrictionconditionsinanoxygenatmosphere,whichcanbeutilizedtooptimizethedesign,selection,andapplicationofmaterialsinvariousindustrialfields.Inadditiontotheapplicationsinhigh-temperatureandhigh-speedslidingfrictionconditions,CrNiMosteeliswidelyusedinvariousindustrialfieldssuchastheautomotive,aerospace,andenergyindustriesduetoitssuperiormechanicalproperties,corrosionresistance,andthermalresistance.Therefore,itiscrucialtounderstanditswearbehaviorandmechanismsunderdifferentoperatingconditionsfortheeffectiveutilizationofthismaterial.

PreviousstudieshavereportedthatthewearbehaviorofCrNiMosteelcanbeaffectedbyvariousfactorssuchastemperature,slidingspeed,contactpressure,andsurroundingatmosphere.Forinstance,high-temperatureandhigh-speedslidingfrictionconditionscanaccelerateoxidationandreducethehardnessandstrengthofthematerial,leadingtoincreasedwearrateanddamage.Therefore,theapplicationofprotectivecoatingsorsurfacetreatmentscansignificantlyenhancethewearresistanceofCrNiMosteelundersuchconditions.

Furthermore,thewearmechanismsofCrNiMosteelmayalsovarydependingontheoperatingconditions.Forexample,underlow-speedslidingorintermittentcontactconditions,abrasivewear,fatiguewear,andfrettingwearmaybedominant.Ontheotherhand,underhigh-speedslidingconditions,adhesivewear,andtribochemicalreactionsmaybecomeprevalent.

Overall,theunderstandingofthewearbehaviorandmechanismsofCrNiMosteelcanaidintheeffectiveutilizationofthismaterialinvariousindustrialapplications.Furtherresearchcouldbeconductedtoexplorenewsurfaceengineeringtechniquestoenhancethewearresistanceandtodevelopnewmaterialsorcoatingswithimprovedperformanceunderspecificoperatingconditions.InadditiontothemechanicalandtribologicalpropertiesofCrNiMosteel,itscorrosionresistanceisalsoanimportantfactorforitsuseinvariousindustrialfields.CrNiMosteelisknownforitsexcellentcorrosionresistance,especiallyinaggressiveenvironmentssuchasacidicorsalinesolutions.Theadditionofchromiumandmolybdenumelementsinthesteelcompositionformsaprotectiveoxidelayeronthesurface,whichpreventsfurthercorrosion.

However,thewearbehaviorofCrNiMosteelmayalsohaveanimpactonitscorrosionresistance.Forinstance,slidingfrictioncancausemechanicaldamagetothesurface,whichcanleadtothebreakdownoftheoxidelayerandsubsequentcorrosion.Therefore,understandingthewearbehaviorandmechanismsofCrNiMosteelisessentialforpredictingitscorrosionbehaviorunderdifferentoperatingconditions.

Moreover,theapplicationofcoatingsorsurfacetreatmentscannotonlyimprovethewearresistancebutalsoenhancethecorrosionresistanceofCrNiMosteel.Forexample,thedepositionofthinfilmsorcoating