Martensitic transformation behavior of hot-deformed Fe–32% Ni alloy

The martensitic transformation behavior of hot-deformed Fe–32% Ni alloy was investigated by measurement of electrical resistance and X-ray diffraction. As the strain increases, the austenite goes through from the work-hardened to the partial dynamically recrystallized then to the completed dynamically recrystallized. The martensitic transformation characteristics depend on the austenitic states. The work-hardening in small strain is helpful to martensitic transformation due to the low dislocation density and little lattice distortion, while the high dislocation density and severe lattice distortion by the increase in strain will hinder the martensitic nucleation. Once dynamic recrystallization (DRX) takes place, the martensitic transformation will be enhanced again, which is related to the heterogeneous dynamic substructures. The growing DRX grain can enhance the martensitic nucleation due to the low dislocation density near its grain boundary.