Patent ID: 6669789
Filing Date: 2003-12-30
Classification: C21C,C21D,C22C

Abstract:
A process for manufacturing a continuously cast, hot-rolled carbon steel with high strength, comprising:desulfurizing and deoxidizing a molten carbon steel; thereafter adding titanium to the molten steel; continuously casting the molten steel as a thin slab with an approximate thickness of from 25 mm to 100 mm (1-inch to 4-inches) and having a composition by percent weight comprising: 0.01&lE;C&lE;0.20; 0.5&lE;Mn&lE;3.0; 0.008&lE;N&lE;0.03; 0&lE;S&lE;0.5; 0.01&lE;Tieff&lE;0.12; 0.005&lE;Al&lE;0.08; 0&lE;Si&lE;2.0; 0&lE;Cr&lE;1.0; 0&lE;Mo&lE;1.0; 0&lE;Cu&lE;3.0; 0&lE;Ni&lE;1.5; 0&lE;B&lE;0.1; and 0&lE;P&lE;0.5, with the balance being iron and incidental impurities, Tieff being the content of titanium not in the form of nitrides, sulfides, or oxides; hot-rolling the thin slab to an approximate final thickness of from 1.8 mm to 13 mm (0.07-inches to 0.5-inches); and quenching the final thickness of steel.