White cast iron is a type of cast iron that is characterized by its white, hard, and brittle surface. It is called “white” because its fracture surface appears white due to the presence of carbide and cementite in the microstructure. white iron casting cast iron has a high carbon content, typically between 2.5% and 4%, which makes it hard and brittle.
The formula for white cast iron is similar to that of other types of cast iron, which is Fe-C. This means that white cast iron is composed of iron and carbon, with varying amounts of other elements such as silicon, manganese, sulfur, and phosphorus.
The microstructure of white cast iron is formed by the rapid cooling of molten iron during the casting process.
The high carbon content in the molten iron causes the carbon to precipitate out of the liquid and form cementite (Fe3C) and other types of carbides. The rapid cooling prevents the carbon from diffusing out of the carbides, resulting in a hard and brittle microstructure.
White cast iron is not commonly used in modern industrial applications due to its brittle nature and low impact resistance. However, it was widely used in the past for applications such as gears, rollers, and other components that required high hardness and wear resistance.
White cast iron can be produced by controlling the cooling rate during the casting process. The cooling rate can be controlled by using a metal mold with a high thermal conductivity, which allows for faster cooling of the molten iron.
The composition of the cast iron can also be adjusted by adding alloying elements such as chromium, molybdenum, and vanadium, which can improve the toughness and ductility of the material.
In summary, the formula for white cast iron is Fe-C, with varying amounts of other elements such as silicon, manganese, sulfur, and phosphorus. The high carbon content in white cast iron causes the carbon to precipitate out of the liquid and form cementite and other types of carbides. The rapid cooling during the casting process results in a hard and brittle microstructure, which is not commonly used in modern industrial applications.