Activation Energy for Hot Deformation of 15-5 PH Stainless Steel

摘要

By applying the new quantum mechanics and relativistic mathematical model, proposed hy Munoz-Andrade, on the experimental results reported previously by Aghaie-khafri and Adhami [5], the true activation energy for hot deformation of 15-5 PH stainless steel is obtained over the temperature range of 900-1150°C and strain rates varying between 0.001 and 0.5s"1. It is interesting to contrast the results of this theoretical work with the main results of the apparent activation energy obtained for the same data, but applying the common methodology. It is shown that the true activation energy increased as the hot deformation is increased. Moreover, the true activation energy decreased as the strain rate is increased. The mean value of the true activation energy (289 kJ/mol) at high strain rate, ξ=0.5s~(-1), for dynamic recrystallization over the temperature range of 900-1150°C is in a closed agreement with the value of activation energy for self-diffusion in y iron (280 kJ/mol) in dissimilarity of the result of the apparent activation energy (492±21 kJ/mol) obtained beforehand by Aghaie-khafri and Adhami. The results obtained in this work by the quantum mechanics and relativistic mathematical model are widely satisfactory; because essentially they are over the crucial limitations of the common methodology to obtain the activation energy at each thermo-mechanical metalworking condition.