Effect of a dc magnetic field on the isothermal martensitic transformation in the Fe-24%Ni-4%Mn alloy

Abstract
Effects of a dc magnetic field on the isothermal martensitc transformation in the region of the kinetic maximum of the Fe-24%Ni-4%Mn alloy and on the martemsitic transformation at a liquid-helium temperature were studied. It was shown that a dc magnetic field markedly affects the isothermal martensitic transformation. In particular, it shifts the temperature range of the martensitic transformation and the kinetic maximum toward higher temperatures and initiates the nucleation of isothermal martensite crystals and their subsequent growth upon isothermal holding. A dc magnetic field of a sufficiently high strength causes the intense formation of athermal martensite at the liquid-helium temperature, at which no transformation develops without a magnetic field. A comparison of the effects of the pulse and dc magnetic fields on the martensitic transformation in the alloys with martensite transformation isothermal kinetics was carried out.