| 摘要 |
PURPOSE: A method for manufacturing a high-strength hot rolled steel sheet with superior bending resistance and surface properties and a hot rolled steel sheet manufactured by the same are provided to optimize cooling and shot blasting conditions of a hot rolled steel sheet by adding boron and tin as steel components. CONSTITUTION: A method for manufacturing a high-strength hot rolled steel sheet with superior bending resistance and surface properties comprises a step of shot blasting on the surface of a hot rolled steel sheet using shot balls of 0.1-0.4mm at a shot speed of 40-65m/sec. The hot rolled steel sheet comprises carbon of 0.001-0.006 weight%, manganese of 0.05-0.3 weight%, phosphorus of 0.001-0.020 weight%, sulfur of 0.020 weight% or less, aluminum of 0.01-0.07 weight%, nitrogen of 0.001-0.004 weight%, boron of 0.001-0.003 weight%, tin of 0.05-0.25 weight%, and iron and inevitable impurities of the remaining amount, satisfying 0.5Δ[(B(%)/11)/(N(%)/14)]Δ1.5. |
