Details
Material hierarchy: Metal - Ferrous metal
Cast iron is an alloy of iron and carbon (2%−4%) used in casting (primarily sand casting). Silicon is also present in the alloy (in amounts from 0.5% to 3%), and other elements are often added also, to obtain desirable properties in the cast part. Cast iron is available in several different forms, of which gray cast iron is the most common; its applications include blocks and heads for internal combustion engines.
Cast iron is an iron alloy containing from 2.1% to about 4% carbon and from 1% to 3% silicon. Its composition makes it highly suitable as a casting metal. In fact, the tonnage of cast iron castings is several times that of all other cast metal parts combined (excluding cast ingots made during steelmaking that are subsequently rolled into bars, plates, and similar stock). The overall tonnage of cast iron is second only to steel among metals.
There are several types of cast iron, the most important being gray cast iron. Other types include ductile iron, white cast iron, malleable iron, and various alloy cast irons. Ductile and malleable irons possess chemistries similar to the gray and white cast irons, respectively, but result from special treatments to be described below.
Carbon and silicon compositions for cast irons, with comparison to steels (most steels have relatively low silicon contents — cast steels have the higher Si content). Ductile iron is formed by special metling and pouring treatment of gray cast iron, and malleable iron is formed by heat treatment of white cast iron.
Cast Iron is any iron alloy that contains from 2 to 4 per cent carbon and from 1 to 3 per cent silicon. Because of its high carbon content, solid cast iron cannot be shaped, no matter how hot it is heated. This kind of iron is made into useful objects by pouring the liquid metal into molds and letting it harden. Cast iron's hardness, low cost, and ability to absorb shocks make it an important construction material.
Subtypes
Gray Cast Iron
Ductile Iron
White Cast Iron
Malleable Iron
Alloy Cast Iron