Q235和镀锌钢板氩弧钎焊电弧形态及其比热流分布对比分析

Comparative Analysis of Q235 and Galvanized Steel Sheets in Arc Configuration and Heat Flux Distribution under Arc Brazing

在电弧钎焊的高速摄像中发现Q235钢和镀锌钢板的电弧呈现不同的电弧形态,在相同钎焊参数下镀锌钢板电弧的有效加热半径要比Q235的大。产生这种不同的原因主要是镀锌钢板在电弧钎焊过程中其表面镀锌层的蒸发产生大量金属Zn蒸汽充斥于电弧气氛之中,导致电弧直径增大,根据电弧空间热流的高斯分布规律可知镀锌钢板表面单位面积吸收的能量减少,热流密度峰值降低。最后根据实际钎焊过程得出Q235钢板和镀锌钢板在钨极氩弧加热情况下的板材吸收的净能量公式,并用有限元软件数值模拟法和热电偶测温法得出电弧加热后的镀锌钢板和Q235钢板表面中心点的热循环曲线,验证了公式的正确性。

By means of photographing arc brazing process, it has been found that the arc configuration of galvanized steel sheet and Q235 steel sheet is different; the effective heating region of galvanized steel sheet is larger than Q235 steel sheet at same brazing parameters. Because the galvanized layer vaporized under arc heating, the Zn steam entered in the are space, the arc diameter is increased. Based on Gauss distribution, the arc energy of galvanized steel sheet in unit area is less than Q235 steel, and the maximum heat flux is decreased too. At last, two formulas about the net energy that galvanized steel and Q235 steel can obtain are conducted according to practical brazing process. In addition, the thermal circulation of the sheets on the center spot is obtained by numerical simulation measure and thermocouple measure respectively, it has been concluded that the two formulas are correct.