POSCO Holdings Inc.
TI- AND NB-ADDED FERRITIC STAINLESS STEEL EXCELLENT IN LOW-TEMPERATURE TOUGHNESS OF WELDS

Abstract:

A Ti, Nb-added ferritic stainless steel with excellent low-temperature toughness of weld zone according to an embodiment of present disclosure includes, in percent (%) by weight of the entire composition, C: 0.004 to 0.015%, N: 0.004 to 0.015%, Si: 0.01 to 0.7%, Mn: 0.01 to 0.7%, P: 0.0001 to 0.04%, S: 0.0001 to 0.005%, Cr: 10 to 30%, Al: 0.005 to 0.04%, Ti: 0.1 to 0.5%, Nb: 0.1 to 0.6%, Ca: 0.0001 to 0.003%, the remainder of iron (Fe) and other inevitable impurities, satisfies the following equation (1), and Al--Ca--Ti--Mg--O-based oxide and Ti--Nb--C--N carbonitride containing the oxide have an average diameter of 3 to 10 .mu.m and a distribution density of 4/mm.sup.2 or more. {(Ti+0.5*Nb)*(C+N)}/Al>0.25 (1)