Iron Alloy Casting

Iron is hard, brittle, fairly fusible, and is used to produce other alloys, including steel. The following table provides all the features of iron as a material.

 

Iron is a metal extracted from iron ore using blast furnace, and is almost never found in the free elemental state.

 

Cast Iron

Cast iron has already been mentioned above. This section deals with the types of iron and steel which are produced as a result of the steel-making process.

 

Wrought iron

If all the carbon is removed from the iron to give high purity iron, it is known as wrought iron. Wrought iron is quite soft and easily worked and has little structural strength. It was once used to make decorative gates and railings, but these days mild steel is normally used instead.

 

Steel, manganese steel, stainless steel and titanium steel are the most popular and widely used alloys of iron.

 

Steel is a mixture of iron and carbon. The amount of carbon may range from 0·1% to 1·5% giving steels of different properties. The exact composition of the steel can be monitored by atomic emission spectroscopy during production.

 

Low Carbon Steel

Low carbon steel (less than 0·25% carbon) is called mild steel. Mild steel is cheap, strong and easily shaped. It is the main metal for construction and is used to make bridges, buildings, ships and vehicles.

 

High carbon Steel

High carbon steel (more than 0·5% carbon) is stronger than mild steel but it is more brittle. High carbon steel is used to make tools and cutters.

 

Steel has the disadvantage of needing a protective coating (for example paint) or it will react with oxygen in the air and rust. Rusting is the reverse of the process in the blast furnace - see rusting.

 

Manganese Steel

Manganese steel is an alloy of iron (84%), manganese (15%) and carbon (1%). Manganese steel is extremely hard and is used for railway points and dredging equipment.

 

Stainless Steel

Stainless steel is an alloy of iron (80%), chromium (15%), nickel (4%) and carbon (0·5 to 1%). Stainless steel is strong and hard, with a very high resistance to corrosion (due to chromium). It is used for cookware, cutlery and industrial chemical plant.

 

Titanium Steel

Titanium steel alloy may contain 0·5 to 2% titanium with varying amounts of other metals including chromium, nickel and vanadium. Titanium steel is very hard and finds uses in aircraft and armour plating.