无电焊接热循环测试研究

利用热电偶测试了无电焊接过程中同一厚度钢板不同位置、不同厚度钢板同一位置处的焊接热循环曲线，探讨了无电焊接热循环规律及焊接母材厚度对无电焊接热循环的影响。研究表明：无电焊接时，焊件上不同位置点的热循环曲线与电弧焊基本相似。但相较而言，无电焊接在加热阶段的升温速度与冷却阶段的降温速度均显著小于电弧焊。无电焊接过程中，焊件上离焊缝中心线越近，其升温速度越大，峰值温度越高，冷却速度也越大，这一变化规律与电弧焊时完全一致。无电焊接时，焊接热量沿横向的传热速度远大于其沿纵向的传热速度，这使得焊件厚度对无电焊接的影响较为显著，也是焊件厚度增加将导致焊接难度显著增大的根本原因。

Study on Heat Cycle of Non-electric Welding

The thermocouple is used to test the heat cycle curves of the different points on the weldments with the same thickness, as well as the heat cycle curves of the same point on the weldments with the different thickness during the non-electric welding process. The heat cycle rule as well as the influence of the weldments thickness on heat cycle of non-electric welding are studied and discussed. The results show that the non-electric welding heat cycle curves of the tested points are similar to that of the arc welding. Whereas, the heating rate and cooling rate of the non-electric welding are both much smaller than that of the arc welding. During the non-electric welding process, the closer the tested point to the central weld line is, the bigger the heating rate, the higher the peak value of temperature, and the bigger the cooling rate too. This changing law is identical with that of the arc weld. The horizontal heat transfer velocity is much bigger than the vertical one,which makes the thickness of the weldments has the great influence on the non-electric welding. That＇s why the increase of thickness of the weldments will make them much more difficult to be welt.