Internal friction study on fcc/hcp martensitic transformations in thermomechanically treated Fe-28Mn-6Si-5Cr-0.53Nb-0.06C (mass%) alloys

We have studied the temperature dependence of the internal friction and Young's modulus of the Fe-28Mn-6Si-5Cr-0.53Nb-0.06C (mass%) alloys with or without NbC precipitates produced by three thermomechanical treatments: (i) solution treatment, (ii) rolling at 870 K and subsequent aging at 1070 K, and (iii) rolling at 1070 K, in the vicinity of the forward (M s) and the reverse (A s) martensitic transformation temperatures using a dynamic mechanical analyzer (DMA). The specimen subjected to rolling at 870 K and subsequent aging showed the highest M s temperature and the largest amount of the hcp martensite. The solution treated specimen showed the lowest M s temperature and the minimum amount of the martensite. The magnetic susceptibility measurements made by means of a superconducting quantum interference device (SQUID) revealed that the martensitic transformation is hindered by the preceding magnetic transition from the paramagnetic (cubic) phase to the antiferromagnetic (tetragonal) phase