Cast iron refers to the general term for alloys composed of iron, carbon, silicon, etc. In these alloys, the carbon content exceeds the saturated carbon content of the austenite at the eutectic temperature.

From the composition point of view, the main difference between cast iron and steel is that cast iron contains higher carbon and silicon than carbon steel, and the content of impurity elements such as sulfur and phosphorus is also higher. In general, wc=2.5%~4.0%, wSi= 1.0%~3.0%, wMn=0.3%~1.2%, ws≤0.05%~0.15%, wp≤0.05%~1.0%.

Common cast iron has excellent casting properties, simple production process and low cost, so it is widely used.