Abstract Fiber laser welding of austenitic and ferritic stainless steel was performed based on response surface methodology to systemically analyze the effect of process parameters on the weld characterizations. The laser welding input parameters were selected (laser power, welding speed and nozzle stand of distance) while the tensile strength of the joint and temperature near the molten pool were considered as the main responses. Variation of nozzle distance about 5 mm had less effect on the temperature domain near the molten pool and weld tensile strength. Increasing the nozzle distance and moving the focal point position to the upper surface of the sheet surface led to the notable improvement of the tensile strength about 20 percent. In other words, transition of the focal point thorough the material thickness clearly reduced the joint strength due to creating more volume of martensitic micro-structure and finally cracking during the tensile test from HAZ region of ferritic steel. The interaction of the laser power and welding speed had noticeable impact on the molten pool temperature. Evidently, the rate of temperature reduction due to an increased welding speed is greater at higher laser power. Among the investigated parameters, the welding speed had the highest effects on the tensile strength of the joint. Increasing the laser power from 300 to 360 W raised the tensile strength about 20%. Interaction of the laser power and welding speed resulted in about 300 °C of the temperature reduction due to an increased welding speed at higher laser power of 395 W variation of nozzle distance at different lase power levels less effect about 5 percent in comparison to the welding speed versus nozzle distance although the similar trend was observed for both of them.

中文翻译：

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使用响应面法研究工艺参数对 AISI304 和 AISI 420 板材光纤激光焊接机械性能和温度分布的影响

摘要 基于响应面法对奥氏体和铁素体不锈钢进行光纤激光焊接，系统分析了工艺参数对焊接特性的影响。选择激光焊接输入参数（激光功率、焊接速度和喷嘴距离），同时考虑接头的抗拉强度和熔池附近的温度作为主要响应。喷嘴距离约 5 mm 的变化对熔池附近的温度域和焊缝抗拉强度的影响较小。增加喷嘴距离并将焦点位置移动到片材表面的上表面导致拉伸强度显着提高约20％。换句话说，由于在铁素体钢的 HAZ 区域进行拉伸试验期间产生更多的马氏体显微组织和最终开裂，焦点穿过材料厚度的过渡明显降低了接头强度。激光功率和焊接速度的相互作用对熔池温度有显着影响。显然，在更高的激光功率下，由于焊接速度增加而导致的温度降低率更大。在研究的参数中，焊接速度对接头抗拉强度的影响最大。将激光功率从 300 W 增加到 360 W，拉伸强度提高了约 20%。