THE EFFECT OF AUSTENITE VOLUME FRACTION ON THE DEFORMATION RESISTANCE OF 409 STAINLESS STEELS DURING HOT-STRIP ROLLING

The mill log data obtained from the hot-strip rolling of 409 stainless steels were analyzed in order to investigatethe effect of the chemical composition on the deformation resistance. The results showed that the deformationresistance depended sensitively on the austenite stabilizing capability of the material chemistry, suggestingthe austenite volume fraction as a dominant factor in controlling the deformation resistance. Deformationresistance ratio (DRR) was defined as a ratio of the deformation resistance of a two-phase (ferritic+austenitic)microstructure to that of a fully ferritic microstructure. The dependence of DRR on the austenite volumefraction appeared to be linear, which was also observed by the plane strain compression tests performed on thelaboratory specimens with various austenite volume fractions. The implication of this result is that during thehot-strip rolling of 409 stainless steels with a two-phase microstructure, these steels are likely to deform in anequal-strain manner.