U型环激光淬火的温度场与组织场仿真研究  

Simulation Study of Temperature Field and Microstructure Field for Laser Quenching of U-shaped Rings

作　　者：林洲游 郑朴 郑思源 金杨福 Lin Zhouyou;Zheng Pu;Zheng Siyuan;Jin Yangfu(StateGrid Wenzhou Power Supply Company,Wenzhou,Zhejiang 325000,China;College of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310014,China)

机构地区：[1]国网浙江省电力有限公司温州供电公司,浙江温州325000 [2]浙江工业大学材料科学与工程学院,浙江杭州310014

出　　处：《应用激光》2022年第12期119-128,共10页Applied Laser

基　　金：国网浙江省电力有限公司科技项目资助(5211WZ2000X3)。

摘　　要：U型环使用过程中因过度磨损而发生失效已成为断线、掉线事故的主要原因,激光淬火作为一种绿色强化技术可有效提高U型环耐磨性能。利用COMSOL Multiphysics建立U型环激光淬火的温度场与组织场仿真预测模型,以探究激光辐照时间对U型环淬火过程中温度场、淬火场的分布影响。所建立模型通过试验对比验证,仿真预测结果与试验结果拟合较好。仿真预测结果表明:U型环中心横、纵截面上温度场均呈月牙状分布并随辐照时间增长而向U型环内部扩散。U型环淬火后表层为细小的淬火马氏体组织,随深度增加,过渡区组织为淬火马氏体及少量铁素体组织。U型环最高温度及淬硬区底部深度、表面积与激光辐照时间呈正相关,当激光辐照时间为7 s时,最高温度达到1434℃,底部深度达到3.12 mm,表面积达到817 mm^(2),覆盖U型环弯曲段92.21%的上表面面积,可有效提高U型环耐磨性能。5000 W激光功率、24 mm×18 mm激光光斑尺寸工艺条件下,U型环激光淬火时间窗口为3~7 s。Due to the excessive wear,the failure of U-shaped rings has become the main cause of wire breaking and dropping.Laser quenching is a green strengthening technology that can effectively improve the wear resistance of U-shaped rings.COMSOL Multiphysics is used to establish a simulation prediction model of temperature field and microstructure field for laser quenching U-shaped rings in this study.This model is used to investigate the influence of laser irradiation time on the distribution of temperature field and quenching field during the laser quenching U-shaped rings process.The model is verified by experimental comparison,and the simulation prediction results fit well with the experimental results.The simulation prediction results show that the temperature fields in the cross and longitudinal sections of the U-shaped rings′center are crescent-shaped and diffuse into the inner U-ring with the increase of irradiation time.The surface layer of U-shaped rings after quenching is the fine quenched martensite structure.With the increase of depth,the microstructure in the heat affected zone is quenched martensite and a small amount of ferrite.The maximum temperature of U-shaped rings,the bottom depth and the surface area of the laser hardened zone are positively correlated with laser irradiation time.When the laser irradiation time is 7 s,the maximum temperature reaches 1434°C,the bottom depth reaches 3.12 mm,and the surface area reaches 817 mm^(2) covering 92.21%of the upper surface area of the bending section of the U-shaped rings,which can effectively improve the wear resistance of U-shaped rings.Under the conditions of 5000 W laser power and 24 mm×18 mm laser spot size,the laser quenching time window of U-shaped rings is 3~7 s.

关 键 词：U型环 激光淬火 有限元仿真 温度场 组织场 

分 类 号：TG156.33[金属学及工艺—热处理]