Characteristic of a steel that it becomes partially or fully hardened (martensitic) when cooled in air from above its critical point. Not necessarily applicable when the object to be hardened has considerable thickness.
glossary
glossary
American Iron and Steel Institute
A material in which the atoms are capable of transforming into two or more crystalline structures at different temperatures.
Change from one crystal structure of a metal to another that has different physical properties.
Adding a metal or alloy to another metal or alloy.