Effects of laser pulse energy on surface microstructure and mechanical properties of high carbon steel  

作　　者：熊毅 贺甜甜 李鹏燕 陈路飞 任凤章 Alex A.Volinsky 

机构地区：[1]School of Materials Science and Engineering,Henan University of Science and Technology [2]Collaborative Innovation Center of Nonferrous Metals [3]Institute of Metal Research,Chinese Academy of Sciences [4]Department of Mechanical Engineering,University of South Florida

出　　处：《Journal of Central South University》2015年第12期4515-4520,共6页中南大学学报（英文版）

基　　金：Projects(50801021,51201061)supported by the National Natural Science Foundation of China;Project(144200510009)supported by the Henan Province Program for Science and Technology Innovation Excellent Talents,China;Project(152102210077)supported by the Science and Technology Project of Henan Province,China;Project(2015XTD006)supported by the Science and Technology Innovation Team of Henan University of Science and Technology,China

摘　　要：Surface microstructure and mechanical properties of pearlitic Fe–0.8%C(mass fraction) steel after laser shock processing(LSP) with different laser pulse energies were investigated by scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD) and microhardness measurements.After LSP,the cementite lamellae were bent,kinked and broken into particles.Fragmentation and dissolution of the cementite lamellae were enhanced by increasing the laser pulse energy.Due to the dissolution of carbon atoms in the ferritic matrix,the lattice parameter of α-Fe increased.The grain size of the surface ferrite was refined,and the microstructure changed from lamellae to ultrafine micro-duplex structure(ferrite(α)+cementite(θ)) with higher laser pulse energy,accompanied by the residual stress and microhardness increase.Surface microstructure and mechanical properties of pearlitic Fe–0.8%C（mass fraction） steel after laser shock processing（LSP） with different laser pulse energies were investigated by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray diffraction（XRD） and microhardness measurements.After LSP,the cementite lamellae were bent,kinked and broken into particles.Fragmentation and dissolution of the cementite lamellae were enhanced by increasing the laser pulse energy.Due to the dissolution of carbon atoms in the ferritic matrix,the lattice parameter of α-Fe increased.The grain size of the surface ferrite was refined,and the microstructure changed from lamellae to ultrafine micro-duplex structure（ferrite（α）＋cementite（θ）） with higher laser pulse energy,accompanied by the residual stress and microhardness increase.

关 键 词：pearlitic steel laser shock processing MICROSTRUCTURE MICROHARDNESS residual stress 

分 类 号：TG174.4[金属学及工艺—金属表面处理]