Method for producing a high strength steel with excellent weldability and fatigue strength of the weld

摘要

A method for manufacturing a high tensile strength steel by normally hot rolling or control rolling following the hot rolling of a high tensile strength steel or a slab made thereof containing, in terms of weight %, 0.03 to 0.20 % of C, 0.6 to 2.0 % of Si, 0.6 to 2.0 % of Mn, 0.01 to 0.08 % of Al, 0.0020 % or less of B, 0.002 to 0.008 % or less of N, and, as required, at least one of Cu, Mo, Ni, Cr, Nb, V, Ti, Ca and REM, as well as the remaining portion of Fe and unavoidable impurities, wherein generation of fatigue cracks as welded is restrained at portions of this steel which are affected by welding heat, and development of cracks, if generated, is prevented or restrained.