通常在设计阶段就可以防止焊接变形 ,例如 ,将焊缝设置在中心轴附近、减少焊缝数量和采用对称焊接工艺。如果上述方法在设计中行不通 ,则可采用以下任何一种工艺来防止变形 : 零件预定位 零件预弯 采用约束工艺的选择受零部件尺寸和复杂程度、约束设备的价格以及是否要限制残余 Welding deformations are usually prevented during the design phase, for example, by placing the weld near the center axis, reducing the number of welds and using a symmetrical welding process. If the above approach does not work in the design, then either of the following processes can be used to prevent distortion: Pre-positioning of parts Pre-bending Selection of the process of restraint depends on the size and complexity of the parts, the price of the restraint equipment, and whether residuals are to be restrained