FE-MN-C-BASED TWIP STEEL HAVING REMARKABLE MECHANICAL PERFORMANCE AT VERY LOW TEMPERATURE, AND PREPARATION METHOD THEREOF

摘要

The present invention relates to a Fe-Mn-C-based twinning-induced plasticity steel (hereinafter, referred to as "TWIP steel") having remarkable mechanical performance at a very low temperature of -100 °C or lower and also at room temperature, and a preparation method thereof. According to the present invention, the TWIP steel comprises 13-24 wt% of Mn, 0.4-1.2 wt% of C, and the balance of Fe and inevitable impurities, is prepared by groove rolling, and comprises elongated grains in which a microstructure is elongated in the rolling direction, wherein the average grain size is 1 mum or less in the direction perpendicular to the rolling direction of the elongated grains.