American Iron and Steel Institute 1018 steel is one of the most common low-carbon, simple steels though it technically contains enough carbon to qualify as a mild steel, which it is sometimes classified as. It has a very simple chemistry, containing just three elemental additives in addition to impurities. Because of the simple chemistry this steel is very inexpensive.
Like all steels, 1018 contains mostly iron and some carbon. The AISI steel classification for simple steels lists the carbon content explicitly (0.18 per cent). It also contains 0.6 to 0.9 per cent manganese to slightly increase the toughness since it lacks enough carbon to properly harden. Additionally, it can contain up to 0.04 per cent and 0.05 per cent of the impurities phosphorous and sulphur.
AISI 1018 has a density of .128 Kilogram per cubic inch and a specific gravity of 7.82. Typically available in hot rolled form, it has a maximum elongation of 36 per cent before breaking.
Thermal and Electrical Properties
The specific heat of AISI 1018 is 0.116 Btu per pound per degree Fahrenheit. The mean coefficient of thermal expansion is 6.7 and the thermal conductivity is 51.9W/m-K. The electrical resistivity is 0.0000159 ohmn centimetres.
The overall tensile strength of 1018 is 345 MPa and the yield strength is 275 MPa. The Modulus of Elasticity is 200 GPa. The bulk modulus is 140 GPa.