Thermally induced martensite properties in Fe-29 percent Ni-2 percent Mn alloy were investigated according to martensitic transformation kinetics, morphology, magnetism of both austenite and martensite phases and also in terms of martensitic transformation start temperatures (M_s) for different austenite grain sizes of alloy. Kinetics of the transformation was found to be athermal. Also only lenticular martensite morphology was observed during investigations. On the other hand, Mossbauer spectra revealed a paramagnetic character for austenite phases and a ferromagnetic character for thermally induced martensitic phases. Determined M_s temperatures were found to be at -128 deg C for large grained samples and -135 deg C for small grained samples.
展开▼
