Effect of Melt Quenching on Martensite Transformation in Fe-Ni Alloy

The main features of martensite transformation in melt-quenched Fe-31.4% Ni alloy on cooling below room temperature have been studied. It is found that the ribbon 50~60 (mu)m thick, prepared by spinning technique, is a natural composite in which isothermal and surface martensite are not formed, while athermal martensite forms at lower temperature, all factors being the same, as compared to the alloy of the same composition and grain size, prepared by recrystallization.