1. Casting glue: simple, extensive castings, general repairs do not require follow-up processing, and there is no special strength and hardness requirements. The added value of this type of casting is relatively low.
2. Welding repair: More than 90% of foundry manufacturers choose welding repair to solve the casting defects encountered in production. Due to the use of metal fillers for repair welding, the performance of the welding repair can basically reach the standard of the base material, and the operation is simple, and the welding repair efficiency is high. It is recognized and trusted by many manufacturers. At present, there are many types of welding machines in the market, and they are mainly used in defect repairing, mainly as follows:
Electric welding machine: the traditional method of welding and repairing cast iron and steel castings.
Advantages: repair large defects, high efficiency.
Disadvantages: The hardness of the solder joints after welding is too high, there are internal stresses, and cracks are prone to occur. Generally, annealing heat treatment is required to meet the processing requirements. In addition, due to the limitation of welding conditions, secondary defects such as pores and slag inclusion are prone to occur inside.
Argon arc welding: precision castings and aluminum alloy die castings are mostly welded by argon arc welding machines. Some mold manufacturing and repair manufacturers also use this welder to repair mold defects.
(1) Advantages: The welding repair efficiency is high, and the accuracy is higher than that of the electric welding machine. There are many types of welding wire, and the most widely used in stainless steel and aluminum alloy products. It can be used for welding with high strength.
(2) Disadvantages: Used for defect repair. When repairing small defects, there are traces on the edge of the molten pool due to excessive impact. Welded steel parts have hard spots. Due to thermal influence, thermal deformation is likely to occur when welding non-ferrous castings or thin-walled parts. Operational technical requirements are high.
3. Cold welding machine: It is a new repair technology born at the beginning of the 21st century. Because the workpiece generates very little heat during the welding repair process, it is called a cold welding machine. After several years of development, the application direction and technology of welding machines have been greatly developed, and they have occupied a large share of the repair market. According to the classification of repair products: placement machine and electric spark surfacing repair machine.
