在焊道表面两侧作一空腔。利用焊接时的加热使水汽化 ,不仅使焊道而且使热影响区的冷却速度减慢。文章通过试验确定了最佳的空腔尺寸 ,此时可防止冷裂纹的产生。 Make a cavity on both sides of the bead surface. Water is vaporized by heating during welding, so that not only the weld bead but also the cooling rate of the heat-affected zone is slowed down. The article determines the best cavity size through experiments, at this time to prevent the generation of cold cracks.