Driving force for martensitic transformation in steels

Abstract

The free energy change accompanying martensite formation at the M_s temperature of steels ∆F_M1^γ→α′ is evaluated using various thermodynamic methods together with relatively accurate and recent thermodynamic data. ∆F_M1^γ→α′ has been found to be rather less than was originaliy believed, and varies between −900 and −1400 J mol⁻¹ as a function of the carbon content; however, the variation is not monotonic.