The mechanical properties of gray cast iron depend largely on its microstructure.The microstructure of grey cast iron without inoculation treatment is unstable, the mechanical properties are low, and the thin wall of casting is easy to appear white mouth.Inoculating treatment is essential to ensure the consistency of casting quality.

The amount of inbreeding agent used in cast iron inoculation treatment has little influence on the chemical composition of cast iron, but great influence on the microstructure of cast iron, so the mechanical properties and physical properties of grey cast iron can be improved obviously.