HIGH-STRENGTH AUSTENITE-BASED HIGH-MANGANESE STEEL MATERIAL AND MANUFACTURING METHOD FOR SAME

A preferable aspect of the present invention provides a high-strength austenite-based high-manganese steel material and a manufacturing method for the same, the steel material containing 20-23 wt% of manganese (Mn), 0.3-0.5 wt% of carbon (C), 0.05-0.50 wt% of silicon (Si), 0.03 wt% or less (excluding 0%) of phosphor (P), 0.005 wt% or less (excluding 0%) of sulfur (S), 0.050 wt% or less (excluding 0%) of aluminum (Al), 2.5 wt% or less (including 0%) of chromium (Cr), 0.0005-0.01 wt% of boron (B), 0.03 wt% or less (excluding 0%) of nitrogen (N), and the balance Fe and other inevitable impurities, wherein a stacking fault energy (SFE) represented by relational formula 1 below is 3.05 mJ/m2 or more; a microstructure comprises, in area fraction, 95% or more (including 100%) of austenite; and a modified crystal grain system is contained in, in area fraction, 6% or more in an austenite recrystal grain. [Relational formula 1] SFE (mJ/m2) = -24.2 + 0.950∗Mn + 39.0∗C - 2.53∗Si - 5.50∗Al - 0.765∗Cr, wherein Mn, C, Cr, Si, and Al each represent weight% of each component]