Alloy steels are made of steel combined with other metals such as nickel, chromium, or vanadium. The result of combining the metals is a steel product that has increased hardness, strength, durability, malleability, and resistance to corrosion.

The first alloy was developed by the English physicist Michael Faraday in the 1830s. His experimentation in the area of electromagnetic induction and electrolysis resulted in an iron-chromium alloy. In 1883, English metallurgist Sir Robert Hadfield (1858-1940) invented manganese steel at his father's steelmaking firm. Manganese gave the steel strength and resistance to wear. He also invented silicon steel and other alloy steels. Hadfield erroneously assumed that chromium impaired corrosion resistance, otherwise he might have discovered stainless steel.

An American, Elwood Haynes (1857-1925), developed several steel alloys. In 1881 he invented tungsten chrome steel which retains its strength at high temperatures. A chromium/nickel alloy followed in 1897; in 1900 he introduced one...