HIGH STRENGTH AUSTENITIC-BASED STEEL WITH REMARKABLE TOUGHNESS OF WELDING HEAT-AFFECTED ZONE AND PREPARATION METHOD THEREFOR

摘要

The present invention relates to a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone and a preparation method therefor. One embodiment of the present invention provides: a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone, comprising 0.8-1.5 wt% of C, 15-22 wt% of Mn, 5 wt% or less of Cr (except 0), and the balance of Fe and other inevitable impurities, and further comprising at least one of the following (a) and (b), wherein the microstructure of a welding heat-affected zone comprises 90 % or more of austenite by volume fraction; and a preparation method therefor. (a) Mo: 0.1-1 % and B: 0.001-0.02 % (b) Ti: 0.01-0.3 % and N: 0.003-0.1 %