DUPLEX STAINLESS STEEL EXCELLENT IN DEEP DRAWING QUALITY

摘要

According to an embodiment of the present invention, duplex stainless steel with excellent deep drawing properties comprises: 0.01-0.17 wt% of C; 0.2-1.0 wt% of Si; 3-11 wt% of Mn; 18-22 wt% of Cr; 0.05-0.25 wt% of N; and the remainder consisting of Fe and inevitable impurities. The duplex stainless steel includes a component making Modified Md_30 indicated by the formula below less than Critical Md_30. (Modified Md_30 = 551 - [462 * (C + N) / (1 - 0.01 * Φ)] - 9.2 * Si - 8.1 * Mn - 13.7 * Cr - 29 * Ni - 29 * Cu - 18.5 * Mo, Critical Md_30 = 2 * Φ - 20, Φ (%) = -60.9 - 148 * C - 1.30 * Mn - 10.7 * Ni - 4.57 * Cu + 5.77 * Si + 7.20 * Cr -144 * N + 11.4 * Mo; where each element in the formulas means wt%). The purpose of the present invention is to provide the duplex stainless steel having an improved dual phase structure.