1. Deformation and hardening mechanisms of austenitic steels

At room temperature, pure iron has a face-centered cubic structure, ferrite or ferα. Between 910 and 1,400°C, the stable phase is austenite or ironγ, with a face-centered cubic structure. The addition of gammagenic chemical elements, such as nickel, manganese, copper, cobalt, etc., stabilizes this phase at room temperature, leading to austenitic steels or duplex austeno-ferritic steels for compositions where the ambient stability range is the two-phase range. Figure 1 illustrates this case for a binary Fe-Ni alloy.