激光表面预处理对激光焊接接头组织的影响研究  

Effects of Laser Surface Preparation on Microstructure of Laser Welded Joint

作　　者：张海龙 卢庆华[1] 张培磊[1] 张巍 ZHANG Hailong;LU Qinghua;ZHANG Peilei;ZHANG Wei(School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, China)

机构地区：[1]上海工程技术大学材料工程学院

出　　处：《热加工工艺》2018年第9期177-179,187,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51605276);上海市级大学生创新训练资助项目(CS1705013)

摘　　要：利用激光表面预处理技术清除2 mm厚低碳钢的表面油漆等污物,以期改善焊接接头的性能;对预处理后的母材进行激光焊接,对比分析激光表面预处理对激光焊接接头组织的影响。结果表明：表面预处理后,试板表面污物被去除,母材存在一定的热影响区,预处理区的母材组织晶粒细化。较合理的激光表面预处理参数为激光功率3～3.5k W,离焦量450 mm,焊接速度1.8 m/min。激光焊接后,焊缝截面呈＂沙漏状＂。随着预处理激光功率的减小,焊缝宽度减小。激光焊接后,预处理的试样焊缝区柱状晶明显细化,预处理试样的焊缝区显微硬度比未预处理的高。Laser surface preparation was used to remove paint and dirt on low carbon steel surface with thickness of 2 mm in order to improve the property of welded joint. Laser butt welding of the base metal after pretreatment was performed and the effect of laser surface preparation on the microstructure of laser welded joint was compared and analyzed. The results show that the paint and dirt on the steel surface are effectively removed by laser surface preparation, and there is a certain heat affected zone in the base metal, the grain of base metal in preparation zone is refined. The reasonable laser surface preparation parameters are the laser power of 3-3.5 k W, the defocusing amount of 450 mm, and the welding speed of 1.8 m/min. After laser welding, the cross section of the weld shows hourglass shape. With the decrease of laser preparation power, the width of the joint increases. After laser welding, the columnar crystal in weld zone of the pretreated sample is significantly refined, and the microhardness of weld zone of the pretreated sample is higher than that of the untreated one.

关 键 词：表面预处理 激光焊接 显微组织 

分 类 号：TG456.7[金属学及工艺—焊接]