White Cast Iron
White cast iron is a type of cast iron that is characterized by its white, hard and brittle properties. It is primarily used to produce components with intricate shapes and thin walls due to its good machinability. It is well known for its resistance to wear and corrosion as well as its ability to withstand high temperatures.
White cast iron is produced by carefully controlling the cooling rate of molten cast iron to prevent the formation of graphite crystals. This is achieved by creating a fast cooling rate during the casting process. As the molten cast iron cools rapidly, the carbon atoms are prevented from forming graphite crystals that results in the material being white in color and extremely hard and brittle in texture. The chemical composition of the metal is similar to grey cast iron, however white cast iron typically contains a higher percentage of carbon.
White cast iron is commonly used in applications where wear and corrosion are problems. Its high component hardness and abrasion resistance makes it suitable for applications such as gyratory crusher mantle liners, engine lifter and brake blocks, valves and piston rings. Additionally, it has good heat transfer properties and anti-corrosive properties, which makes it ideal for applications such as smoke stacks and boilers, engine exhaust systems and pipeline components.
White cast iron is not suitable for all applications, as the high hardness and brittleness of the metal means that components may fracture during mechanical handling or shock. It is also not suitable for applications where a higher strength is required. Due to the brittle nature of the material, the ductility is very low.
White cast iron is generally more expensive than most other cast iron metals due to the addition of manganese in the casting process. It is also vulnerable to stress corrosion cracking, so it needs to be protected from water and other corrosive elements.
In conclusion, white cast iron is a brittle, hard and white metal that is commonly used in applications where wear and corrosion are problems. It has good machinability, heat transfer and anti-corrosive properties. However, due to its brittle nature, components made from white cast iron are susceptible to stress corrosion cracking, so precautions must be taken to protect them. It is generally more expensive than other cast iron metals due to the addition of manganese.
