激光-电弧复合焊接20mm厚高强钢的成形机理研究

Research on Forming Mechanism of 20mm Thick EH36 Steel by Laser-Arc Hybrid Welding

采用激光-电弧复合焊接方法对20 mm厚EH36高强钢进行焊接。在不开坡口的对接方式下,研究激光功率、焊接速度、送丝速度对焊缝成形的影响,并使用高速摄影对焊接过程中的电弧和等离子体进行观察分析,结果表明,焊缝熔深的波动程度随着激光功率的增加而逐渐增加。激光功率的增加使得对焊丝的辐射、加热作用增强,导致焊丝的熔化速率加快;小范围内提高焊接速度对背部驼峰的产生具有抑制作用,并有利于减小焊缝正面的凹陷深度;大电流焊接时,焊缝正面的凹陷深度随着送丝速度的增加先减小而后增大。较大的送丝速度下产生的电弧力以及焊丝端部对熔池的扰动是导致焊缝正面凹陷、成形变差的主要原因。

This study investigates the weld formation of 20mm thick EH36 high-strength steel using laser-arc hybrid welding.The weld forming characteristics under various laser powers,welding speeds,and wire feeding speeds were examined under a non-groove butt joint configuration.The arc and plasma characteristics during welding were analyzed and observed through high-speed photography.The results show that the fluctuation of weld penetration increases with the increase of laser power.The increase of laser power enhances the heating and radiation of welding wire,resulting in the acceleration of welding wire melting rate;Increasing the welding speed in a small range has a certain inhibiting effect on the back hump defect,and is conducive to reducing the degree of underfill;In high current welding,the concavity of the underfill decreases first and then increases with the increase of wire feeding speed.The arc force generated at higher wire feeding speed and the disturbance of the welding wire end to the weld pool are the main reasons for the underfill and poor formation of the weld.