HOT ROLLED HIGH TENSILE STRENGTH STEEL PLATE SUPERIOR IN FATIGUE PROPERTY AT SHEARED END AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a hot rolled high tensile strength steel plate superior in fatigue property at sheared end conforming to thinning of the hot rolled high tensile strength steel plate having a high strength of at least 690 Mpa and its manufacturing method. ;SOLUTION: The hot rolled high tensile steel plate superior in fatigue property at sheared end contains, by weight %, 0.03-0.2 C, ≤0.4 Si, 0.5-2.5 Mn, and also one or at least two kinds selected from those of 0.03-0.2 Ti, 0.01-0.2 Nb, 0.01-0.2 V, and one or at least two kinds selected from those of 0.15-0.6 Cu, 0.15-0.4 Ni, 0.1-0.6 Cr, 0.1-0.4 Mo. In the hot rolled high tensile steel plate, a volume percentage of martensite is at least 3%, and that of pearlite is not more than 5%.;COPYRIGHT: (C)2001,JPO