Hot Rolled Steel Sheet And Method For Manufacturing The Same

Abstract: ABSTRACT “HOT ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME” The present invention relates to a hot rolled steel sheet consisting of, in mass%,C: 0.05% to 0.15%, Si: 0% to 0.2%, Al: 0.5% to 3.0%, Mn: 1.2% to 2.5%, P: 0% to 0.1%, S: 0% to 0.01%, N: 0% to 0.007%, Ti: 0.03% to 0.10%, Nb: 0.008% to 0.06%, V: 0% to 0.12%,one or more of Cr, Cu, Ni, and Mo: 0% to 2.0% in total, B: 0% to 0.005%, one or more of Ca, Mg, La, and Ce: 0% to 0.01% in total, total amount of Si and Al: 0.8 × (Mn-1)% or more, total amount of Ti and Nb: 0.04% to 0.14%, and the balance: Fe and impurities, wherein, in a structure of steel, a total area ratio of martensite and retained austenite is 3% to 20%, an area ratio of ferrite is 50% to 96%, and an area ratio of pearlite is 3% or less, and wherein, in a superficial layer part, the thickness in a sheet thickness direction of a region in which a network-like oxide is present is less than 0.5 μm, and a maximum tensile strength is 720 MPa or more.

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