STATIC RECRYSTALLIZATION AND GRAIN-GROWTH OF A STAINLESS AUSTENITIC STEEL

Static Recrystallization (SR), is here used as a way to get an ASTM [1] 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 degrees C) and analyzed them in terms of recrystallized fraction (quantitative metallography) using to classic Avrami equation. We observed some lime exponents (k) smaller than 1, which goes against Avrami's theory, which only describes equal or above 1 exponents. The time for half recrystallization (t(0.5)) 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 = A, + alpha.t(n) type of equation, where alpha is a variable involving Q, an activation energy, through an Arrhenius equation.