New Equation for Prediction of Martensite Start Temperature in High Carbon Ferrous Alloys

Abstract

Since previous equations fail to predict M (S) temperature of high carbon ferrous alloys, we first propose an equation for prediction of M (S) temperature of ferrous alloys containing > 2 wt pct C. The presence of carbides (Fe3C and Cr-rich M C-7(3)) is thermodynamically considered to estimate the C concentration in austenite. Especially, equations individually specialized for lean and high Cr alloys very accurately reproduce experimental results. The chemical driving force for martensitic transformation is quantitatively analyzed based on the calculation of T (0) temperature.