At present, the common methods for repairing wear and tear on metal surfaces in China are bushing, pitting, surfacing, brush plating, thermal spraying, laser cladding, etc. The emergence of these metal surface repair methods has promoted the improvement and development of technical processes, and has also been restricted due to complex process conditions and on-site environment. In the face of emergencies, huge equipment, complex disassembly and other equipment problems, these processes are obviously Excessive heart but insufficient strength. The repair effect of inserting bushings and pitting is poor, and it is rarely used at present. Now briefly analyze several other metal surface repair methods:

1. Surfacing (repair welding) process

Surfacing is a welding process in which a metal layer with wear resistance, corrosion resistance and heat resistance is deposited on the surface or edge of the workpiece. Different workpieces and surfacing electrodes must use different surfacing processes to obtain satisfactory surfacing results. The most common problem encountered in surfacing welding is cracking, which usually requires heat treatment and machining after surfacing welding. The biggest disadvantage of repair welding is the concentration of thermal stress and the large heat-affected zone, which can easily cause shaft deformation.

2. Thermal spraying process

Thermal spraying is a metal surface repairing method, spraying the molten spraying material through high-speed airflow to atomize the surface of the part to form a sprayed layer. Thermal spraying requires professional spraying tools. The main disadvantage of thermal spraying is that the bonding strength between the sprayed layer and the substrate is insufficient, the sprayed layer has defects such as pores, and it is not easy to process.

3. Brush plating process

The brush plating process is the process of obtaining a coating on the surface of the workpiece through electrolysis. The advantage of this metal surface repair method is that it can be repaired online, but the disadvantages are very obvious. The brush coating of the brush plating process is limited by the amount of wear, and the brush plating thickness of the brush plating coating is usually less than 0.2mm. When the amount of wear is greater than 0.2mm, the brush plating efficiency will drop exponentially, and when the brush plating layer is too thick, the brush plating layer is easy to fall off during use and the service life is short.