(3)为减少应力,防止裂纹,尽量使焊接区处于低温状态,应采用短弧退焊法(图3),对其进行分段施焊,每段长20～30mm,施焊时应首尾相接,并在焊缝中心收弧,对于两层或多层填满的焊缝,应将上下两层的焊道错开施焊. (3) In order to reduce stress, prevent cracks, try to make the welding zone at a low temperature, arc welding method should be used (Figure 3), its segmented welding, each length 20 ~ 30mm, welding should be tail Phase, and arc in the center of the weld, for two or more layers of weld, staggered welding of upper and lower two layers of welding.