中、大壁厚钢管焊接热影响区的形状就像一个沙漏 ,在壁厚方向造成表面过热而中心低温现象 ,从而限制焊接速度。通过对V形角、弹复量 (结构应力 )、焊接速度和频率等影响因素的研究 ,利用电磁温度场致发射显微镜对焊点具有代表性的温度分布区进行了二维分析 ,用焊点处的等温曲线表示了结果。 Medium and large thick-walled steel pipe heat affected zone shape like an hourglass in the wall thickness caused by the surface overheating and the center of the low temperature phenomenon, thus limiting the welding speed. Through the study of the influencing factors such as V-shaped angle, elastic mass (structural stress), welding speed and frequency, the temperature distribution region representative of the solder joint was analyzed by using the electromagnetic field emission microscope. The isotherm at the end shows the result.