HIGH STRENGTH STEEL PLATE FOR STRUCTURE WITH A GOOD SEAWATER CORROSION RESISTIVE PROPERTY AND METHOD OF MANUFACTURING THEREOF

摘要

The present invention provides a high strength steel plate for a structure and a method of manufacturing the same, wherein the high strength steel plate for a structure comprises, by wt%, not less than 0.03% but less than 0.1% of C, not less than 0.1% but less than 0.8% of Si, not less than 0.3% but less than 1.5% of Mn, not less than 0.5% but less than 1.5% of Cr, not less than 0.1% but less than 0.5% of Cu, not less than 0.01% but less than 0.08% of Al, not less than 0.01% but less than 0.1% of Ti, not less than 0.05% but less than 0.1% of Ni, not less than 0.002% but less than 0.07% of Nb, 0.03% or less of P, 0.02% or less of S, and the balance of Fe and unavoidable impurities, and has a microstructure comprising, by area fraction, 20% or more of bainite, less than 80% of polygonal ferrite and acicular ferrite in total, and less than 10% of pearlite and MA as the other phases.