Hot working of two AISI 304 steels: a comparative study

The hot deformation behavior was studied of two austenitic stainless steels (AISI 304 type) with different carbon contents (0.02 and 0.087%). An analysis of the parameters describing the hot flow curves and their quantification at each strain stage was carried out. The comparative study of the two steels showed no significant effect of the carbon content on the conditions for the onset of dynamic recrystallization or on dynamic recrystallization kinetics, although the Avrami exponent was clearly dependent on the hot forming conditions. Also, peak and steady state stresses were relatively insensitive to the amount of carbon. However, the work hardening and dynamic recovery behavior showed clear differences, depending on the alloy, especially at high temperatures and low strain rates, where the steel with the higher carbon content showed higher work hardening and dynamic recovery rates.