The variation in critical temperatures for the formation of austenite when increasing the heating rate was studied by dilatometry. The analysis was performed at heating rates between 10 and 90ºC/s. Empirical equations are herein proposed for calculating Ac3 with respect to the heating rate. The results showed that an increase in the heating rate had no influence on Ac1, but Ac3 increased 115ºC. The equations proved to be of a more general use, as they also predicted the results of works on other steels with high values of correlation coefficients.
Austenitization; kinetics; fast heating; dilatometry
