Effects of welding parameters on weld geometry during high-power laser welding of thick plate
Effects of welding parameters on weld geometry during high-power laser welding of thick plate
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DOI：
10.1007/s00170-015-6813-z
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发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
Shichun Li;Genyu Chen;Cong Zhou
中科院分区：
文献类型：
--
作者：
Shichun Li;Genyu Chen;Cong Zhou
在厚板大功率激光深熔焊接过程中，研究了不同焊接条件下焊缝截面的几何特征。利用高速摄影和X射线成像系统观察了熔池金属行为，研究了焊缝横截面的形成机理。随着焊接速度的增加，焊缝宽度和深度逐渐减小，焊缝截面形状由大头形逐渐变为针状。激光焊接过程中，激光束焦点位置的变化导致熔池行为的变化，从而导致焊缝截面形状的变化。高温金属液在熔池顶面和中间深度处的聚集，使熔池的传热效率提高，从而使熔宽增大。熔池表面金属液行为稳定，导致传热效率低，焦点位置在金属内部时，焊缝外观完好。
During high-power deep-penetration laser welding of thick plate, the geometrical characteristics of weld cross section were investigated under different welding conditions. The molten metal behaviors were observed by using the high-speed camera and X-ray imaging system to study the formation mechanism of weld cross section. With the increase of welding speed, the width and depth of weld seam decreased, and the geometry of weld cross section changed from big-head shape to needle-like shape. The change of focal position of laser beam led to the variation of molten metal behavior which thus resulted in different geometries of weld cross sections during laser welding. The accumulation of high-temperature molten metal at both the top surface of molten pool and the middle depth of molten pool could lead to a higher heat-transferring efficiency of the molten metal which could lead to a wider weld width. The stable molten metal behavior on the molten pool surface resulted in a low heat-transferring efficiency, and the sound appearance of weld seam could be obtained when the focal position was inside the metal.