CO2气体保护的激光焊接12mm厚低碳钢板

采用CO2 作为保护气体消除大熔深激光焊接低碳钢时易发生的气孔问题 ,并对比研究了CO2 和Ar气保护条件下 12mm厚低碳钢板激光焊缝的组织和韧性。焊接试验利用 4kWNd :YAG激光器 ,采用双面深熔焊的方法 ,焊接条件为 4kW激光功率和0 .3 ,0 .5m/min的焊接速度。冲击试验采用一种自行设计的带侧面缺口的三缺口冲击试样 ,以保证断裂全部发生在焊缝。结果表明 ,利用CO2 作保护气体焊接低碳钢板 ,可以有效消除大熔深激光焊接时的气孔问题 ,并获得比Ar气保护下硬度较低 ,冲击韧性高的焊缝。研究工作为解决大功率激光深熔焊时容易发生的气孔问题提供了一条有效途径

Nd: YAG Laser Welding of 12 mm Low-Carbon Steel Plate with CO2 Shielding Gas

CO 2 gas was used as the shielding gas to eliminate porosities in deep penetration laser welding of low carbon steel in this paper.By using a 4 kW Nd:YAG laser,both sides welding of 12mm carbon steel plate was performed under the welding speed of 0.3 and 0.5m/min,using CO 2 and Argon respectively as the shielding gas.The chemical compositions,microstructure and hardness distribution of weld metal were analyzed.The impact toughness of weld metal was evaluated by conducting a kind of non standard three notches impact test,which test piece is apt to fracture within weld metal without deviating into the nearby base metal during impact test.The experimental results show that by using CO 2 as the shielding gas,it is not only possible to reduce or eliminate the porosities in weld metal,but also to reduce the hardness and increase the impact value of laser welds.