COMPOSITE OF STEEL MATERIAL, HOT ROLLED STEEL SHEET WITH HIGH STRENGTH AND METHOD OF MANUFACTURING THE SAME

摘要

PURPOSE: Steel composition, a hot-rolling steel plate with high tension and a manufacturing method thereof are provided to enhance local formability and stretch flange formability simultaneously. CONSTITUTION: A method of manufacturing a hot-rolling steel plate with high tension comprises following steps. A massive slab is manufactured by the dissolving of steel composition. The slab is heated at a temperature of 1100 ~ 1300°C and then is rolled by a hot roller to become thinner. The slab is air-cooled at a temperature of 600 ~ 650°C, is maintained in a furnace and then furnace-cooled at a room temperature. A coil is manufactured at a coiling temperature of 550 ~ 650°C.