激光焊接热循环的试验分析

Experimental investigation on thermal cycle of laser welding

在标定测试的基础上,利用最小二乘法拟合得到了热电偶的热电特性方程.通过设计焊接绝缘夹具及补偿温度测量值的动态误差,试验得到焊缝热影响区的实际热循环曲线.将高温等离子体简化为点热源,薄板焊接时的热源简化为线热源,采用叠加原理建立激光焊接高强度钢板的热循环数学模型后,对模型进行解析计算,获得了热影响区的理论热循环曲线.通过实测热循环曲线与理论曲线的对比、实际焊缝宽度与理论焊缝宽度的验证后认为,点线热源模型能反映激光焊接高强度钢板的热循环过程,为激光焊接的深入研究奠定了基础.

Based on the assignment test,the thermoelec-tric equation was obtained by least squares theory.Through designing the insulation clamping and the temperature offset of dy-namic error,the actual thermal cycle curve was obtained in heat-affected zone of laser welding.By high-temperature plasma being simplified as a dot heat resource and heat resource being linear for welding of thin plate,the mathematical model of laser welding for high strength steel was established and analyzed based on the principle of superposition,and the theoretical thermal cycling curve of welded seam in heat-affected zone was achieved.The comparison between the actual thermal cycling curve and theoret-ical thermal cycling curve and that between the actual weld width and the theoretical weld width indicated that the dot heat re-source and linear heat resource model can explain the thermal cycle process of laser welding for high-strength steel.