The Second Stage of the α → γ Transformation during Slow Heating of Metastable Fe–Ni Alloys. Fine Structure of Dispersed γ-Martensite Plates

The structure of the Fe–Ni alloy formed in the initial stage of transformation of the internal structure of α crystal during heating has been analyzed. A complex multistep character of the formation of intermediate multilayer martensite phase (3R + 18R + ε) is established. Its formation mechanism is compared with the known behavior of the calorimetric slow heating curve of metastable Fe–32%Ni alloy, existing initially in the α + γ state.