POSCO Holdings Inc.
HIGH-STRENGTH STRUCTURAL STEEL HAVING EXCELLENT COLD BENDABILITY, AND MANUFACTURING METHOD THEREFOR

Abstract:

A high-strength structural steel having excellent cold bendability, according to one embodiment of the present invention, comprises, by wt %, 0.02-0.1% of C, 0.01-0.6% of Si, 1.7-2.5% of Mn, 0.005-0.5% of Al, 0.02% or less of P, 0.01% or less of S, 0.0015-0.015% of N, and the balance of Fe and other inevitable impurities, wherein an outer surface layer part and an inner central part thereof are microstructurally divided in a thickness direction, the surface layer part can comprise tempered austenite as a matrix structure, and the central part can comprise bainitic ferrite as a matrix structure.