Structure and phase composition of the Fe-Cr-Mn-alloys

Solid state transformations and properties of Fe alloy containing Cr 4-8, Mn <= 40, and C <= 0.05% were studied by using x-ray diffraction, microstructure, and dilatometry. After quenching from 11500 alloys containing 4% Cr and no Mn consisted of large α-martensite platelets. Alloys containing 4 Cr and 15.9% Mn consisted of α- and epsilon-martensite, and γ-solid solution. The 3-phase structure was retached in alloys containing <= 19.4% Mn. Magnetic permeability decreased for alloys containing >= 13% Mn and was near zero at 24% Mn. Microstructure of alloys containing 24.3% Mn consisted of γ-solid solution and epsilon-phase. During cooling to room-temperature., epsilon-martensite was not obtained in alloys containing 8% Cr. During continuous heating and cooling, a significant hysteresis in the α-γ transformation was observed in alloys containing 4-8% Cr