The structure of casting materials mainly includes the following aspects:
Gray cast iron: Gray cast iron is the most widely used and highest-yield type of cast iron, accounting for more than 80% of the market share. It contains flake graphite, high compressive strength, but relatively low tensile strength. Gray cast iron is very sensitive to cooling rate, and changes in wall thickness have a significant impact on its mechanical properties. Due to its poor thermal stability, it is not suitable for use in high-temperature environments.
Vermicular graphite cast iron: The graphite morphology of vermicular graphite cast iron is between flake and spherical, showing a worm shape. Its comprehensive mechanical properties are better than those of gray cast iron, and it is suitable for the manufacture of parts in harsh environments, especially those with large temperature gradients. Vermicular graphite cast iron is less sensitive to cooling rate and has good thermal conductivity and process performance.
Spheroidal graphite cast iron: Ductile cast iron is obtained through special spheroidizing and inoculation treatments, and the graphite is spherical. Its comprehensive performance is comparable to that of steel, and its strength, plasticity and elastic modulus are better than those of gray cast iron, and its wear resistance is also higher. Although sensitive to cooling rate, its high thermal stability enables it to be used in high temperature environments.
Casting alloy materials: such as ZG40Cr9Si2, which belongs to the high chromium cast iron category, are mainly used to manufacture parts that withstand high temperature, high pressure and strong wear. This type of material has excellent heat resistance and wear resistance.
