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拖拉机的气缸体、气缸盖、变速箱壳体及后桥壳体等零件都是采用优质铸铁制成,但制造这类基础零件金属耗量多,加工复杂,难度很大,成本十分昂贵。这类零件在使用中如出现裂纹、折断、破洞等损坏时,若能采用焊接方法修复,则既经济又方便,十分合算。 铸铁性脆、机械强度低、塑性差,因液态转变极快,则对冷却速度非常敏感,其可焊性较差,所以在焊修中容易产生以下问题:一是焊缝容易产生白口组织,
Tractor cylinder block, cylinder head, gearbox housing and rear axle housing and other parts are made of high quality cast iron, but the manufacture of such basic metal parts and more consumption, complex processing, difficult, costly. Such parts in the use of such as cracks, broken, broken holes and other damage, if the welding method can be repaired, both economical and convenient, very cost-effective. Cast iron brittle, low mechanical strength, poor plasticity, due to fast liquid change, the cooling rate is very sensitive to the poor weldability, so prone to welding repair the following problems: First, the weld is likely to produce white tissue ,