高强钢激光搭接焊接接头组织及显微硬度  

Microstructure and microhardness of laser overlap welded joint of high strength steel sheets

作　　者：刘庆永[1] 杜雁冰[1] 郭健[1] 夏明生[1] 

机构地区：[1]唐山钢铁集团有限责任公司技术中心,河北唐山063016

出　　处：《焊接》2017年第6期61-65,共5页Welding & Joining

摘　　要：采用光纤激光器对汽车工业中常用的双相钢HC450/780DPD+Z和低合金高强钢HC420LA进行激光搭接焊试验,探索焊缝附近微观组织和显微硬度转变,并研究不同焊接速度对焊缝显微硬度的影响。结果表明,焊缝附近微观组织主要包括熔化区、热影响区和母材三部分。焊接速度一定时,从母材到焊缝,HC420LA的显微硬度变化趋势为先增加后保持不变,HC450/780DPD+Z的显微硬度变化趋势为先增加后减小再保持不变。而随着焊接速度的增加,HC420LA焊缝显微硬度先增加后保持不变,HC450/780DPD+Z焊缝显微硬度先增加后减小。Dual-phase steel DP780+Z and low alloy high strength steel HC420LA are commonly used in automobile industry,the research about laser overlap welding was carried out in this paper by using fiber laser welding system.The microstructure and microhardness near the weld were analyzed,and the influence of different welding speed on microhardness of weld were also studied.Results show that the microstructure of the joint mainly includes fusion zone,heat affected zone and base material.The microhardness of HC420LA steel shows the increasing trend from base material to weld at constant laser power.However the changing trend of DP780+Z is first increasing and then decreasing.With the increase of welding speed,the microhardness of HC420LA increases,and that of DP780+Z first increases and then decreases.

关 键 词：激光焊 搭接 焊接速度 显微硬度 

分 类 号：TG456.7[金属学及工艺—焊接]