Influence of Annealing Conditions on the Austenite Size at the End of Soaking

Abstract

Influence of chemical composition (C, Mn and Nb) and soaking temperature on the evolution of austenite grain size from a cold-rolled microstructure was studied on several Advanced High Strength Steels. A wide range of soaking temperatures was used to perform the heat treatments. Characterization of prior austenite grain size from the annealed samples using optical and confocal microscopes, Scanning Electron Microscope and Electron Back-Scattered Diffraction. Comparison of different methods was done to validate the methodology and the results were quite satisfactory. Concomitant effects of Manganese, Niobium, Carbon and of soaking temperature on the prior austenite grain size were analyzed and discussed. Important effect of Mn and Nb was underlined.

Evolution of Ms Temperature as a Function of Composition and Grain Size

“…Such methodology for the PAGS measurements was compared and validated with electron backscatter diffraction-reconstructed PAGS in a previous study. [35]…”