Effect of the Heating Rate on the Austenite Formation Kinetics by Isoconversion Method in Cr–Mo–V Steel

The kineticsKinetics of austenite formationAustenite formation in a Cr–Mo–V low-alloy medium-carbon steelCarbon steel was determined by dilatometric analysis under continuous and isochronous heating conditions. The dilatometric analysis was carried out at different heating rates, and it was observed that austenite formationAustenite formation occurs in two stages: (1) decompositionDecomposition of carbides and (2) transformation of ferrite into austenite. It was also shown that the critical temperaturesTemperature for austenite formationAustenite formation increase with increasing heating rate. Likewise, the continuous heating transformation diagram was constructed from the critical temperaturesTemperature, indicating the transformation zones during austenite formationAustenite formation. The degree or volume fraction of austenite formed was determined as a function of the heating rate and the temperatureTemperature per transformation stage. Finally, an iso-conversion method was implemented to determine the activation energiesActivation energy in stages at 50% transformation.