Microstructures et Recristallisation
J. Phys. IV 05 (1995) C3-29-C3-38
Recristallisation Statique et Croissance de Grain d'un Acier Austénitique InoxydableH. Tsukahara1, A.-M. Chaze1, C. Levaillant2 and S. Hollard3
1 Ecole des Mines de Paris, CEMEF, B.P. 207, 06904 Sophia-Antipolis, France
2 Ecole des Mines d'Albi Carmaux, 81013 Albi CT cedex, France
3 FORTECH, B.P. 173, 09102 Pamiers cedex, France
Static Recrystallization (SR), is here used as a way to get an ASTM  grain size of 3 or so. Making a prediction of the effect of both deformation and temperature on the kinetics of the SR phenomena is the first step toward a global microstructure prediction at the end of the manufacturing sequence. It is the main goal of the study here after described. In this study, we did hot compression tests (950-1200°C) and analyzed them in terms of recrystallized fraction (quantitative metallography) using to classic Avrami equation. We observed some time exponents (k) smaller than 1, which goes against Avrami's theory, which only describes equal or above 1 exponents. The time for half recrystallization (t0.5) has also been determined, according to C.M. Sellars method and reached a satisfactory, experiment-calculation agreement. After completion of the recrystallization, the Grain Growth phenomenon occurs. Thanks to a wide study of thermal annealings, we found a A=A0+α.tn type of equation, where α is a variable involving Q, an activation energy, through an Arrhenius equation.
© EDP Sciences 1995