农业机械上的连杆、飞轮、风扇、传动轴以及脱粒机滚简、粉碎机转子等都是作高速运转的重要部件。当这些零部件发生裂纹或损坏时，不能随意用电弧施焊，应该考虑采取诸如凿削、铆接或更换新件等方法，以免产生下列不良后果： １．应力集中　有一辆轮式拖拉机的风扇叶出现裂纹， Connecting rods, flywheels, fans, driveshafts, and threshing machines on agricultural machinery are rolling and shredding rotors are all important components for high-speed operation. When these parts are cracked or damaged, they are not to be arc-welded at all. Consideration should be given to methods such as chiseling, riveting or replacement of new parts in order to avoid the following adverse consequences: 1. Stress concentration There is a wheeled tractor fan blade cracks,