细晶粒钢激光深熔焊接残余应力与裂纹关系分析  

Research in the relationship between the residual stress and cracks for the laser deep penetration welding of fine grained steels

作　　者：刘德政 李炎 王中任 

机构地区：[1]湖北文理学院机械工程学院,襄阳441053

出　　处：《焊接学报》2018年第11期11-16,共6页Transactions of The China Welding Institution

基　　金：湖北省教育厅科学技术研究项目(Q20172603)

摘　　要：残余应力是导致细晶粒钢激光深熔焊时裂纹产生的主要机理之一,对焊接质量有较大影响.文中基于细晶粒钢激光深熔焊实际焊缝金相组织建立热源模型,采用PDA-5500S岛津光谱元素分析仪提取细晶粒钢化学成分,基于吉布斯函数建立细晶粒钢的温度与流变应力耦合本构关系;同时,通过不同焊接参数下焊缝截面试验数据,在热源模型中设置跟踪点,获取焊缝中实时残余应力,研究不同温度下实时残余应力与细晶粒钢流变应力对焊接缺陷的影响.结果表明,在相同温度下当实时残余应力高于材料流变应力时,焊缝内产生裂纹;合理提高焊接速度,可降低细晶粒钢焊缝实时残余应力,提高激光深熔焊接质量.The residual stress has great influence on welding quality and it can result in the formation of the cracks in the weld during laser deep penetration welding. In this paper, the heat source model was established through the analysis for the metallographic structure of the weld of fine grained steel, and the extraction of chemical composition of fine grain steel was conducted by the PDA-5500 S SHIMADZU optical emissions spectrometers. Based on Gibbs function, the coupling constitutive relation between temperature and material flow stress was established. Furthermore, the real-time residual stress was achieved by setting trace points in finite element analysis model based on the analysis of the experimental data for the cross-section of weld bead by different welding parameters. The results show that when the real-time residual stress is higher than the material flow stress at the same temperature, the cracks will occur in the weld bead.The realtime residual stress value can be decreased through the reasonable increase of welding speed, and it can improve the quality of laser deep penetration welding.

关 键 词：细晶粒钢 激光深熔焊 残余应力 吉布斯函数 

分 类 号：TG456.7[金属学及工艺—焊接]