Hardening of wear resistant white cast iron
Wear resistant white cast iron belongs to the category of abrasion resistant cast iron and is the family of hardfacing materials. It can be used for casting wear resistant parts, such as blast furnace hopper, crusher board, hopper liner, liner, grinding wheel, bucket wheel and other big wear resistance parts at the same time. It can also be used for casting forging dies such as hot shear blades and deep drawing dies, and small wear-resistant components such as shaft sleeve and gear. The wear resistance of wear resistant white cast iron is much better than that of other general cast irons, but its brittleness is high and its machinability is poor.
If the strength, toughness and machinability of wear resistant white cast iron can be improved, its application scope will be further expanded. The hardening of wear resistant white cast iron is obtained by means of carburizing and austempering. Through carburizing, the carbon content in the surface layer of wear resistant white cast iron is increased, and the surface forms a conglomerate structure. This structure can not only greatly increase the hardness, but also increase the wear resistance of wear resistant white cast iron.
During austempering, austempering heat treatment can be applied to wear resistant white cast iron to make it simpler and more good and more homogeneous. Austempering heat treatment can not only improve the wear resistance, but also make the impact toughness better. After heat treatment, its wear resistance and impact toughness have been greatly improved.
As is known to all, white cast iron is a kind of iron alloy, and its wear resistance is much higher than that of general cast iron. This is mainly because the surface of wear resistant white cast iron is mainly composed of carbides and carbonitride of complex alloying elements, while there is no graphite or other easily washed away in cast iron. As the saying goes, one point is better than two. That is to say, the wear resistance of white cast iron is better than that of cast iron.
However, white cast iron is not characterized by its high strength, but its low strength characteristics. In other words, its brittleness and poor machinability are its major weaknesses. In order to improve this situation, it is necessary to take measures such as carburizing and austempering. Through carburizing, white cast iron increases the amount of carbon in its surface layer, and forms a conglomerate structure, which can greatly improve its hardness, and also increase its wear resistance.
Meanwhile, austempering can also increase the wear resistance and impact toughness of white cast iron by changing the microstructure, making it more tough, uniform and uniform structure. After such a treatment, its hardness, wear resistance and impact toughness are significantly improved, and its application range is further expanded.
In conclusion, after proper heat treatment, the hardness, wear resistance and impact toughness of wear resistant white cast iron can be significantly improved. At the same time, its application scope can also be expanded because of the improved properties.
