ALLOYS OF IRON AND REVERSIBILITY OF MARTENSITIC TRANSFORMATIONS

Abstract

The ongm of irreversibility, reversibility, course and completeness of transformations are discussed using the following alloys of iron as examples: 1. Irreversible transformation: Fe-C, Fe-Ni-C, maraging steel 2. Reversibility in homogeneous solid solutions: Fe-Ni, Fe-Ni-C, Fe-Mn 3. Reversibility due to order or coherent particles: Fe-Pt, Fe-Ni-X, Fe-Ni-Co-Ti 4. Effects of external stress and mechanical properties on Ms 5. Effects of external magnetic fields and magnetism/antiferromagnetism in austenite. The feasibility of shape memory steels is finally discussed.