Thermodynamically Based Prediction of the Martensite Start Temperature for Commercial Steels

A thermodynamic method for predicting the martensite start temperature of commercial steels is developed. It is based mainly on information on M s from binary Fe-X systems obtained from experiments with very rapid cooling, and M s values for lath and plate martensite are treated separately. Comparison with the experimental M s of several sets of commercial steels indicates that the predictive ability is comparable to models based on experimental information of M s from commercial steels.