焊接位置对激光-电弧复合焊接底部驼峰的影响  

Effect of Welding Position on Bottom Hump of Laser-arc Composite Welding

作　　者：张君豪 朱宗涛[1] 刘瑞琳 刘云祺 ZHANG Junhao;ZHU Zongtao;LIU Ruilin;LIU Yunqi(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,成都610031

出　　处：《精密成形工程》2024年第5期174-181,共8页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52275384);四川省重点研发计划(重大科技专项)(2022YFG0086)。

摘　　要：目的通过改变焊接位置来抑制底部驼峰的形成进而降低生产成本。方法使用高速摄像机观察平向焊接和横向焊接2种不同焊接位置下熔池的匙孔和底部驼峰的形成过程,并对底部凸起受到的金属蒸气反冲压力、熔融金属重力以及表面张力进行受力分析。结果在S355J2W耐候钢的激光-电弧复合焊接平焊过程中,受金属蒸气反冲作用力的影响,熔融金属迅速从匙孔底部排出,流入匙孔底部凸起区域,底部凸起的增长速度极快,仅需7.5 ms即可形成大尺寸的驼峰。而在横向焊接中,匙孔前壁凸起数量减少,导致金属蒸气反冲压力减小,匙孔排出的熔融金属量减少,底部凸起的增速减缓,在13.6 ms时才达到最大高度,使驼峰在底部熔池凝固之前难以形成。结论采用横向焊接的方式可以有效避免驼峰的产生,降低生产成本。同时,该方式在焊缝背部成形效果方面也表现良好,为优化焊接工艺提供了重要参考。The work aims to mitigate bottom hump by altering the welding position,thereby achieving cost reduction in the production process.A high-speed camera was used to observe the formation process of keyholes and bottom hump in the weld pool under both flat and horizontal welding positions.A force analysis was conducted to examine the impact on the bottom pro-trusion,considering forces such as metal vapor recoil pressure,molten metal gravity,and surface tension.During the laser-arc hybrid welding process of S355J2W weathering steel with a flat welding position,influenced by the metal vapor recoil force,molten metal swiftly evacuated from the bottom of the keyhole,streaming into the region of the bottom protrusion.The bottom protrusion exhibited rapid growth,forming a substantial hump in a mere 7.5 ms.Contrastingly,in the case of transverse welding,the reduced number of front-wall protrusions in the keyhole resulted in diminished metal vapor recoil pressure.This led to a de-crease in the amount of molten metal expelled from the keyhole,consequently slowing down the growth rate of the bottom pro-trusion.The maximum height was reached at 13.6 ms,making it challenging for the hump to form before solidification of the bottom weld pool.The utilization of the horizontal welding method proves effective in preventing hump and thereby reducing production costs. Simultaneously, it has demonstrated favorable outcomes in shaping the back of the weld seam, offering crucial insights for optimizing the welding process.

关 键 词：激光-电弧复合焊接 高速摄像 焊接位置 底部驼峰 受力平衡 

分 类 号：TG456[金属学及工艺—焊接]