为研究304不锈钢光纤激光焊接模式的影响因素,参考均匀试验设计的思路,以激光功率、焊接速度、离焦量为变量设计了一组试验。通过分析成形的焊缝,获得了光纤激光焊接过程中热导焊和深熔焊的特征形式;定量计算了焊接模式与各焊接参数及其交互作用之间的关系,确定了焊接模式的影响因素。研究结果表明,304不锈钢光纤激光焊共有四种由热输入密度决定的焊缝成形形式。当热输入密度小于43.04 J·mm ^-3时,焊缝为圆弧形,对应的焊接模式为热导焊;当热输入密度大于66.82 J·mm ^-3时,焊缝为钉头形或钉状,对应的焊接模式为深熔焊;存在一种过渡状态,对应的热输入密度处于两种焊接模式的中间值。

In order to investigate the influence factors of the fiber welding modes for 304 stainless steel, a group of experiments with the laser power, welding speed and defocus distance as the variables are designed in accordance with the idea of an uniform experimental design. By the analysis of the formed welds, the characteristic forms of the heat-conduction welding and the deep-penetration welding are obtained in the fiber laser welding process. The relationships among the weld mode, each welding parameter and their interactive action are calculated quantitatively, and the influence factors of the welding modes are determined. The results show that, there are four typical weld formation forms determined by the heat input density for the 304 stainless steel fiber laser welding. The weld has an arc shape when the heat input density is smaller than 43.04 J·mm -3 and the corresponding welding mode is the heat-conduction welding. When the heat input density is larger than 66.82 J·mm -3, the weld has a nail-head or a nail shape and the corresponding welding mode is the deep-penetration welding. Meanwhile, there exists an intermediate mode when the heat input density is between the two values for the above welding modes.