等离子和激光表面合金化对灰铸铁组织性能的影响.pdfVIP

HotWorkingTechnology2016，Vo1．45，No．6

等离子和激光表面合金化对灰铸铁组织性能的影响

缪亚锋，郑志镇，李建军，赵航

(华中科技大学材料成形与模具技术国家重点实验室，湖北武汉430074)

摘要：采用等离子束和激光表面合金化对灰铸铁表面进行强化。利用三点弯曲试验测试合金化层抗弯性能，采用

金相显微镜、显微硬度计、SEM和XRD等仪器对其微观组织、硬度断口形貌和相组成进行分析。研究结果表明：灰铸铁

等离子束表面合金化层由奥氏体和莱氏体组成，而激光合金化层几乎全部为奥氏体。在相同功率密度下，采用等离子束

表面合金化处理后的合金化层较厚；合金化层的硬度最大值均为次表面；Fe3C和Eric的存在使得等离子束合金化层

的硬度比激光合金化层高；等离子柬合金化层断裂方式为解理断裂，而激光合金化层为韧性断裂。

关键词：灰铸铁；表面合金化；微观组织；硬度；三点弯曲

DOI：10．14158／j．cnki．1001--3814．2016．06．057

中图分类号：TG156．99；TG143．6文献标识码：A文章编号：1001．3814(2016)06．0202．04

EffectonMicrostructureandPropertiesofGrayCastIronbyPlasmaandLaser

SurfaceAlloying

MIAOYafeng，zHENGZhizhen，LIJianjun，ZHAOHang

(StateKeyLaboratoryofMaterialProcessingandDieandMouldTechnology，HuazhongUniversityofSciencenad

Technoloyg，Wuhna430074，Chnia)

Abstract：Plasmanadlasersurfacealloyingwereusedtostrengthenthesurfaceofgraycastiron．Thethree-pointbending

testswereappliedotmeasurehteflexuralbehavior．Themicrostructure，hardness，fracturemorpholoygnadphasecomposition

ofthealloyinglayerswereanalyzedbymeatllographicmicroscope，microharndessmeter，scannnige~crtonmicroscope

(SEM)nadX-raydifffactometer(XRD)．neresultsindicatehtatplasmaalloyinglayeriscomposedofaustenitenadledeburite．

Themicrostructureoflaseralloyinglayerismainlyaustenite，nadthehticknessofplasmaalloyinglayerishtickerhtnalaser

alloyinglayerwimhtesanlepowerdensiyt．Themaximummicrohradnessofalloyinglayerappearsathtesecond-surfacelayer

whichhasacertaindistancetohtesurface．BecauseofhteexistenceofFe3CandC3niplasmaalloyinglayer，its

microhradnessishigherthanhtatoflaseralloyinglayer．Thefracturemodeofplasmaalloyinglayeriscleavagefracture，but

thelasersisductilefracture．

Keywords：graycastiron；surfacealloying；microstructure；hrandess；three-poin