THERMODYNAMIC STABILITY OF THE HCP STRUCT URE IN FE AND ITS ALLOYS - AN APPROACH BASED ON MODELING MARTENSITIC-TRANSFORMATION DATA

The paper deals with the problem of obtaining thermodynamic informatio n for the hcp phase in Fe and Fe-rich binary alloys. This structure is not stable under ordinary conditions, but can be obtained through a m artensitic transformation in Fe-Mn alloys by quenching from high tempe rature. A new thermodynamic approach is tested, which involves a combi nation of experiments and Gibbs energy modelling. The predictions of t he method are compared with those obtained by analysing thermodynamica lly the pressure vs. temperature phase diagram of Fe.