Spray, arc welding process, casting bug fixes there are some limitations spray workability is good, but easy to crack, thermal deformation, annealing phenomena such as color and mother too different, combined with The principle of mechanical bonding, the bonding strength relative arc Welding Electrode low. Arc welding welding repair effect and select the electrode is directly related to the workability of the Z308 and crack the do not produce well, but the differences difficult to weld up the marks and colors and the mother has been eliminated, and the price is high; Z248 ordinary cast iron electrode workability and crack did not produce is not good. Traditional welding repair welding repair insulation to large castings warming up before the casting process of welding and welding caused some inconvenience, the overall analysis, some of the problems in the process of traditional welding repair casting defects can not be completely repaired, the different parts of the different quality requirements, should be selected according to the actual situation. Machine Tool bug fixes, the experiments show that in the non-processing surface should be chosen carefully processing the surface should avoid using. The use of cold welding to repair the defects of the casting is a new technology, the castings in the repair process does not heat up, no deformation, cracks, welding point metal compact, no hard spots, no annealing phenomenon can be Any machining. The choice of fill material from the constraints of the material, fill material choices through different materials, can achieve to weld up the point of performance, the unity of the color with the parent. Fill material and maternal metallurgical bonding, combined with high strength, does not produce off, welding quality casting products quality standards, is worthy of extensive promotion of a new technology, the defect repair for Machine Tool Practice has proved that can be widely applications, to meet the requirements of quality standards. However, cold Welding Wire, repair welding process for the Φ1.5-Φ1.2mm welding, up at repeated melting accumulation process, in the process of a large area of ??defect repair, the repair efficiency is the only factor restricting its widely applications. Casting the specific circumstances, within a certain range the size of the defect can be applied directly casting defect repairing machine for welding repair for large defects, it is recommended the traditional welding repair process and cold welding compound application, namely the use of the cold welding machine to solve the traditional welding fill process surface cracks, surface processability and color differences, the majority of castings can weld up the meaning, and eventually completely solve the problem of repair of casting defects. In short, the correct application of cold welding and other welding equipment to repair casting defects, reduce the waste of casting defects caused by remelting, increase economic benefits for the enterprise, has practical significance for the state to reduce energy consumption!