QP980高强钢小光斑激光焊接接头组织与性能研究  

Study on Microstructure and Properties of QP980High Strength Steel Joint Welded by Small Laser Spot Welding

作　　者：杨景卫 陈嘉乐 李涛 肖辉 乔健 Yang Jingwei;Chen Jiale;Li Tao;Xiao Hui;Qiao Jian(School of Mechatronic Engineering and Automation,Foshan University,Foshan528000,Guangdong,China;Jihua Laborary,Foshan528200,Guangdong,China)

机构地区：[1]佛山科学技术学院机电工程与自动化学院,广东佛山528000 [2]季华实验室,广东佛山528200

出　　处：《应用激光》2023年第5期37-42,共6页Applied Laser

基　　金：国家自然科学基金(51805084,52265062);广东省教育厅科技计划项目(2022KTSCX125,2022KCXTD029);云浮市科技计划项目(2021A090103);季华实验室科技计划项目(X220391TH220);佛山科学技术学院自由探索基金(2021ZYTS06)。

摘　　要：采用光斑直径为0.1 mm的激光束对2 mm厚QP980先进高强钢进行激光焊接。借助光学显微镜、扫描电子显微镜、万能材料试验机和显微硬度计等工具,研究焊接速度对接头成形、组织演变及力学性能的影响,研究发现,随着焊接速度的减小,横截面形貌从“钉”形逐渐过渡为“沙漏”形,最后变为“直筒”形。焊缝熔化区马氏体形态粗大,热影响区主要由较为细小的马氏体构成,硬度均高于母材;回火区由于母材马氏体发生分解,使得该区域硬度比母材低,但随着速度的增加,马氏体分解程度逐渐降低。由于焊缝的硬化,焊接接头断后延展率降低,不同焊接速度下的拉伸断口形貌表明均为韧性断裂。The influence of welding speed on joint formation,microstructure evolution,and mechanical properties of 2mm thick QP980high strength steel were studied by using a laser beam with a spot diameter of 0.1mm.It was found that with the decrease of welding speed,the cross section morphology change from nail shape to hourglass shape,and finally to straight cylinder shape.The weld melting zone is composed of coarse martensite,and the heat affected zone is mainly composed of fine martensite.The hardness is higher than that of the base metal.The hardness of the tempering zone is lower than that of the base metal due to the decomposition of martensite in the original base metal.However,with the increase of welding speed,the decomposition degree of martensite decreases gradually.Due to the hardening of the weld,the elongation after fracture of the welded joint decreases.The tensile fracture morphology at different welding speeds shows that it is ductile fracture.

关 键 词：先进高强钢 激光焊接 微观组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]