超高强钢DP78O盘片激光焊接接头组织与性能研究  

Microstructure and Properties of Ultra-high Strength Steel DP780 Welded by DISC Laser

作　　者：于群[1] 陈铠[1] 肖荣诗[1] 

机构地区：[1]北京工业大学激光工程研究院,北京100124

出　　处：《应用激光》2010年第3期161-166,共6页Applied Laser

基　　金：北京装备制造业研发基地资助项目(项目编号:Z09000400950901);重大专项-超高强钢板热冲压及点焊连接技术研究(项目编号:ZX200904014-72)

摘　　要：采用4000W盘片式Yb:YAG同体激光器,利用激光深熔焊原理对1.2mm厚的超高强钢DP780进行激光对接焊研究。利用光学显微镜、扫描电镜、透射电镜等分析测试手段,研究了DP780激光焊接头的微观组织特点及激光焊参数对接头组织与力学性能的影响规律。结果表明,焊缝组织主要由板条马氏体及贝氏体构成,其大大提高了焊接接头熔合区的显微硬度。在焊接接头存在有软化区,其不会因速度增加而消失,但较高的焊接速度能减小软化区的宽度。焊接接头的抗拉强度要高于母材,熔合区显微硬度的升高是造成接头杯突值下降的主要原因。A ROFIN-SINA DISC Yb ： YAG laser with an output power of 4000W was used to join the ultra-high strength steel DP780 with a thickness of 1.2mm in laser penetration butt welding process. The micro-structural characteristics and influences of laser welding parameters on microstructures and mechanical properties of joints were investigated by means of optical microscope, scanning electron microscopy, transmission electron microscopy and other analytical tests. The results showed that the weld metal mainly included lath martensite and bainite, which greatly improved the micro-hardness of the fusion zone. There was soft zone in the joint, and it would not disappear by increasing the welding speed, but high speed could reduce the width of softened area. The tensil strength of joint was higher than that of base metal, and the erichsen value droped because the microhardness of fusion zone increased obviously.

关 键 词：DP780 盘片激光 焊接接头组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]