The Properties of Carbon in White Cast Iron
White cast iron, also known as non-malleable cast iron, is a type of cast iron containing a high amount of carbon and nearly no alloying element. When white cast iron is cooled rapidly, the carbon forms into small particles within a matrix of iron and forms structures known as hypereutectic carbides or graphite.
White cast iron is generally less malleable and ductile than grey cast iron and is virtually impossible to machine or forge into shape. Despite its limited malleability, white cast iron has several unique properties such as strength, corrosion resistance, and abrasion resistance that make it a popular choice for many industries.
Strength: White cast iron has a higher tensile strength than grey cast iron due to its hypereutectic carbides. The carbides present in white cast iron provide a greater resistance to shear and tensile forces, making it stronger than other types of cast iron.
Corrosion Resistance: White cast iron is highly resistant to environmental damage from exposure to the elements due to its higher levels of chromium, manganese, and nickel. These elements provide white cast iron with enhanced corrosion protection in comparison to other types of cast iron.
Abrasion Resistance: The combination of hypereutectic carbides and chromium, manganese, and nickel make white cast iron a superior choice for wear resistance. The hard carbide particles intermixed with the softer iron create an extremely hard and abrasive surface, allowing white cast iron to resist wear from heavy impacts and abrasive media.
Heat Resistance: White cast iron has the ability to withstand higher temperatures than grey cast iron due to its higher levels of chromium and molybdenum. These elements increase the temperature range of white cast iron, allowing it to withstand temperatures up to 900°C (1,700°F).
White cast iron is an ideal choice for a variety of industrial applications due to its strength, corrosion resistance, abrasion resistance and heat resistance. It is commonly used to manufacture components such as cylinders and valves in the mining and oil & gas industries, as well as producing heavy-duty components for construction and agricultural machinery.
