High manganese steel or low carbon alloy steel has better strength and toughness, which can meet the strength and toughness requirements of excavator bucket teeth. If the surface strengthening technology is used to strengthen the surface of this kind of bucket teeth, the working surface of bucket teeth can have better wear resistance and the overall bucket teeth can have better plastic toughness. The traditional surface strengthening methods mainly include hammering, shot peening, explosive explosion, surfacing and so on. With the rapid development of surface technology, spraying technology and spray welding technology have been successfully applied to the surface strengthening treatment of bucket teeth, which greatly improves the performance of bucket teeth.
The thermal process, metallurgical process, solidification, crystallization and phase transformation process of the traditional surfacing metal layer are the same as those of the ordinary fusion welding process.
The difference is that the surfacing is to obtain the surface layer with special properties. Therefore, the surfacing layer and the substrate belong to metallurgical bonding, and the bonding strength is good; The surfacing equipment is simple, easy to weld on site and has great welding flexibility; However, the production efficiency is low, the dilution rate is high, the temperature gradient of the workpiece is large, and it is easy to cause cracking when the surfacing layer is thick. Spraying technology and spray welding technology belong to thermal spraying. Compared with traditional surfacing technology, it has low dilution rate, high deposition rate and high production efficiency, but the equipment cost is high, which is suitable for mass production with high quality requirements. The main difference between spraying technology and spray welding technology is that the bonding between coating and substrate formed by spraying technology belongs to mechanical bonding, and the bonding strength is low; the combination of coating and substrate formed by spray welding technology belongs to metallurgical bonding, and the bonding strength is high.