In cemented carbide processing industry, plasma torch is one of the main surface treatment methods, plasma torches can be widely used in petroleum, chemical, engineering machinery, mining machinery, and other industries, such as some valves sealing surface surfacing, oil drill pipe, bearing and other wear repairs, its application prospects are very wide. Plasma torch welding has its own unique performance and characteristics, let's take a look.
Plasma torch welding can also be called plasma cladding, plasma spray welding is the use of plasma arc as a heat source to melt the added metal so that it and the matrix metal as a combination of metallurgy of a cladding method. Plasma torch is using welding torch tungsten electrode as the cathode current and substrate as current between the anode plasma as heat and would be welding heat transferred to the surface of the workpiece, and the thermal region into welding powder, make its melting after deposition on the surface of welding, so as to realize the parts surface strengthening and hardening process.Compared with other cladding technologies, plasma torch:
1. Compared with TIG welding, plasma torch welding has strong penetration controllability, high cladding speed, and higher productivity. After cladding, the interface between the substrate material and the cladding material is a metallurgical bonding state, with high bonding strength, low heat input, and a small dilution rate. More importantly, due to the poor current carrying capacity of tungsten electrodes, a large current in argon arc welding will cause tungsten electrode melting and evaporation, and its particles may enter the molten pool and cause pollution, while tungsten electrode in plasma cladding needs to bear small current.
2. Compared with manual arc welding, although it is slightly less flexible and convenient in the application, it has obvious advantages in production efficiency. Moreover, manual arc welding has greater labor intensity, which affects the health of welders, and the product quality is greatly affected by the level of welders and the quality of electrodes.
3. Compared with submerged arc welding, the flexibility of the welding position is relatively large. In addition, plasma arc itself has the advantages of arc core heat concentration, arc stability, low dilution rate.
4. Compared with another surfacing welding, there is less intermelting between the substrate material and the cladding material in the process of plasma torch, and the change of the characteristics of the cladding material is small.
In addition, using powder as a cladding material can improve the design freedom of the alloy, make the cladding material possible, and thus greatly improve the wear resistance, high-temperature resistance, and corrosion resistance of the workpiece. Therefore, plasma torch welding is widely used in new products manufacturing and equipment remanufacturing in petroleum, chemical industry, engineering machinery, mining machinery, and other industries.