Abstract

High-power lasers are very effective in welding of plates thicker than 10 mm due to the keyhole mode. High-power intensity generates a vapor-filled cavity which provides substantial penetration depth. Due to the narrow and deep weld geometry, there is susceptibility to high hardness and weld defects. Imperfections occur due to keyhole instability. A 16-kW disk laser was used for single-pass welding of 12- to 15-mm thick plates in a butt joint configuration. Root humping was the main imperfection and persisted within a wide range of process parameters. Added arc source to the laser beam process may cause increased root humping and sagging due to accelerated melt flow. Humping was mitigated by balancing certain arc and other process parameters. It was also found that lower welding speeds (< 1.2 m/min) combined with lower laser beam power (< 13 kW) can be more positive for suppression of humping. Machined edges provided more consistent root quality and integrity compared with plasma cut welded specimens. Higher heat input (> 0.80 kJ/mm) welds provided hardness level below 325 HV. The welded joints had good Charpy toughness at − 50 °C (> 50 J) and high tensile strength.

中文翻译：

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12毫米和15毫米厚结构钢的激光电弧混合焊接

摘要

由于锁孔模式，大功率激光在焊接厚度大于10 mm的板材时非常有效。高功率强度会产生充满蒸汽的空腔，从而提供足够的穿透深度。由于窄而深的焊缝几何形状，容易造成高硬度和焊缝缺陷。由于锁眼孔的不稳定性，会出现缺陷。使用16 kW圆盘激光器对接配置中的12至15 mm厚板的单道焊接。根峰隆起是主要缺陷，并且在各种工艺参数中均存在。由于加速的熔体流动，在激光束工艺中添加电弧源可能会导致根部驼峰和下垂增加。通过平衡某些电弧和其他工艺参数，减轻了蜂鸣现象。还发现较低的焊接速度（<1.2 m / min）和较低的激光束功率（< 13 kW）可以更有效地抑制驼峰。与等离子切割焊接试样相比，机加工边缘可提供更一致的根部质量和完整性。更高的热量输入（> 0.80 kJ / mm）焊缝可提供低于325 HV的硬度等级。焊接接头在− 50°C（> 50 J）时具有良好的夏比韧性和高拉伸强度。