保护气对微合金C-Mn钢激光焊接接头组织和性能的影响  

Influence of Shielding Gas on Microstructure and Property of Laser Welded Joint of Microalloyed C-Mn Steel

作　　者：曾盼林 王晓南[1] 章顺虎[1] 张敏[2] 陈长军[2] 

机构地区：[1]苏州大学沙钢钢铁学院,江苏苏州215201 [2]苏州大学机电工程学院,江苏苏州215021

出　　处：《中国激光》2017年第4期53-60,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(51305285);中国博士后基金面上项目(2016M601877)

摘　　要：通过微合金C-Mn钢的焊接试验,研究了不同保护气对激光焊接接头组织和性能的影响。结果表明,在相同的激光焊接热输入条件下,N_2、Ar、空气三种保护气焊接均可获得全熔透焊缝,但N_2气保护条件下焊缝区凹陷最为明显。焊缝区组织均以板条马氏体为主。空气环境下焊缝区形成少量针状铁素体,夹杂物数量明显多于N_2和Ar气保护下焊缝的,且大尺寸的夹杂物比例较高。三种情况下,焊接接头的平均显微硬度和强度均高于母材的,但是空气环境下焊缝的平均硬度略小于N_2或Ar气保护下焊缝的。The influence of different shielding gases on microstructure and property of laser welded joint is studied by the weld test of microalloyed C-Mn steel. The results show that, under the same condition of laser weld heat input, full-penetration weld seams can be obtained by three different shielding gases of Nz, Ar and air, but the sags in the weld zone shielded by N2 are the most obvious. The microstructures of the weld zone are mainly lath martensite. In the weld seam formed in the air, there are a few acicular ferrites, the number of inclusions is more than that shielded by N2 and At, and the ratio of large scale inclusion is relatively high. In all three cases, the mean microhardness and tensile strength of the welded joint are higher than that of the base metal, while the mean microhardness of the weld seam in the air is smaller than that when shielded by Nz or Ar.

关 键 词：激光技术 激光焊接 力学性能 保护气 针状铁素体 

分 类 号：TG456.7[金属学及工艺—焊接]