COMPOSITION OF STRUCTURAL STEEL

摘要

The present invention relates to a structural steel composition which comprises 0.15-0.35 wt% of carbon (C), 0.2-2.0 wt% of vanadium (V), and 5.0-9.0 wt% of cobalt (Co). The environmental friendly structural steel of the present invention having ultra high strength, high toughness, and corrosion resistance is able to simplify a process while increasing hardness, impact toughness, tensile strength, corrosion resistance, and yield strength by controlling the content of carbon (C) and vanadium (V) even though cobalt (Co) is reduced approximately from 14 wt% to 7 wt% in a weight ratio. The present invention is able to remarkably achieve the above purpose by being actively applied to various kinds of industries through cost reduction required in ultra high strength structural steel business by simplifying a process and reducing cobalt (Co) which is an expensive strategic element.