激光表面淬火对铬钼铸铁组织和硬度的影响  

Effect of laser hardening on microstructure and hardness of CrMo cast iron surface

作　　者：张永辉 张双杰 王伟 马世博 闫华军 Zhang Yonghui;Zhang Shuangjie;Wang Wei;Ma Shibo;Yan Huajun(Hebei Key Laboratory of Material Near-net Forming Technology,School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang Hebei 050018,China;Hebei Automobile Stamping Die Technology Innovation Center,Botou Hebei 062150,China;Automobile Stamping Die Engineering Research Center,Botou Hebei 062150,China;Hebei Automobile Stamping Die Industrial Technology Research Institute,Botou Hebei 062150,China)

机构地区：[1]河北科技大学材料科学与工程学院河北省材料近净成形技术重点实验室,河北石家庄050018 [2]河北省汽车冲压模具技术创新中心,河北泊头062150 [3]汽车冲压模具工程研究中心,河北泊头062150 [4]河北省汽车冲压模具产业技术研究院,河北泊头062150

出　　处：《金属热处理》2022年第11期160-164,共5页Heat Treatment of Metals

基　　金：河北省重点研发计划(19251019D);河北省自然科学基金(E2021208025);河北省高层次人才(A202101016);石家庄市科学技术研究与发展计划(206080167A)。

摘　　要：采用TH-3DC3000型激光加工系统对铬钼铸铁进行了激光表面淬火处理,研究了不同激光功率和扫描速度对铬钼铸铁显微组织、表面硬度及硬化层深度的影响。结果表明,经激光表面淬火后,铬钼铸铁的组织由硬化区、过渡区和基体3个区域组成,硬化区组织为隐晶马氏体、残留奥氏体和球状石墨,过渡区组织为隐晶马氏体、珠光体和球状石墨,基体组织为铁素体、珠光体和球状石墨。在激光表面淬火未对试件产生过热影响时,激光功率的增大和扫描速度的降低均会提升铬钼铸铁的表面硬度和硬化层深度。在5 mm×20 mm的矩形激光光斑下,确定最优的参数组合为激光功率2300 W、扫描速度0.003 m/s,采用该参数组合对铬钼铸铁进行激光淬火处理时,表面硬度为760 HV0.3,硬化层平均硬度为724 HV0.3,硬化层深度可达1.4 mm以上。TH-3 DC3000 laser processing system was used to laser hardening treatment on CrMo cast iron.The effects of different laser power and scanning speed on microstructure,surface hardness and hardened layer depth of CrMo cast iron were studied.The results show that after laser hardening,the microstructure of CrMo cast iron consists of three regions,which are hardened zone,transition zone and matrix.The microstructure of hardened zone is cryptocrystalline martensite,retained austenite and spherical graphite.The microstructure of transition zone is cryptocrystalline martensite,pearlite and spherical graphite.The microstructure of matrix is ferrite,pearlite and spherical graphite.When laser surface hardening does not have overheating effect on the test piece,the increase of laser power and the decrease of scanning speed will improve the surface hardness and hardened layer depth of the CrMo cast iron.Under the rectangular laser spot of 5 mm×20 mm,the optimal parameter combination is determined as laser power of 2300 W and scanning speed of 0.003 m/s.When this parameter combination is used for laser hardening of the CrMo cast iron,the surface hardness is 760 HV0.3,the average hardness of the hardened layer is 724 HV0.3,and the depth of hardened layer is more than 1.4 mm.

关 键 词：铬钼铸铁 激光表面淬火 激光参数 显微组织 硬度分析 

分 类 号：TG115[金属学及工艺—物理冶金] TG143[金属学及工艺—金属学]