高强钢厚板激光-GMAW复合双面同步横焊特性研究

Research on the Characteristics of Double-Sided Hybrid Laser-GMAW Synchronous Horizontal Welding of High-strength Thick Steel Plates

针对30 mm厚船用高强钢10Ni5Cr Mo V对接接头横焊应用需求,开展激光-熔化极气体保护电弧(Gas metal arc welding,GMAW)复合双面同步横焊特性研究。研究结果表明,针对横焊位姿因重力、非对称坡口对熔滴、电弧的影响,利用激光对电弧的吸引和收缩作用,通过减小光-丝间距,有效地抑制了电弧侧壁燃弧,熔滴在电磁力和等离子流力的作用下,稳定过渡到熔池中,实现了熔滴过渡稳定性控制,解决了激光-GMAW复合横焊位姿电弧偏离和熔滴下落等过程控制难题与侧壁未熔合问题;厚板激光-GMAW复合双面同步横焊包括打底层和填充层焊接,其中打底层焊接是保证接头焊接质量的关键;采用激光-GMAW复合双面同步横焊新方法,4道焊接完成了30 mm厚船用高强钢10Ni5Cr Mo V横焊位姿的高强、高效连接。焊缝表面成形良好,无裂纹、未焊透和侧壁未熔合等缺陷。接头的抗拉强度高于母材,且其–50℃冲击吸收能量为57.3 J。

A double-sided hybrid laser-gas metal arc welding（GMAW） synchronous welding technology is systematic studied against the application of 30 mm thick,shipbuilding high-strength steel 10Ni5CrMoV butt joint in horizontal welding. The results show that against the effect of the gravity in horizontal position and the unsymmetrical groove on the behavior of droplet and arc,the problems such as deviation of arc,landing location of droplet and lack of sidewall fusion in the hybrid laser-GMAW horizontal welding process are solved by using the influence of laser on the arc shape. The deviation of the arc can be effectively suppressed by decreasing the distance between the laser and the wire because the arc could be effectively attracted and compressed when the distance is shorter. Therefore,the electromagnetic force and the plasma drag force promote the droplet transferred to the weld pool. The double-sided hybrid laser-GMAW synchronous horizontal welding includes root pass and filling pass welding,and the root pass welding is the key to guarantee the welding quality. The results also indicate that a 30 mm thick,shipbuilding high-strength steel 10Ni5CrMoV is welded by the novel,high-strength and high-efficient double-sided hybrid laser-GMAW synchronous welding with 4 passes. Excellent weld surface and welded joints without crack,incomplete penetration and lack of sidewall fusion defect are achieved. The ultimate tensile strength of the welded joint is higher than that of the base metal. Additionally,the impact toughness absorbed energy value of the welded joint is 57.3 J at–50 ℃.