| 摘要 |
Disclosed are a high strength steel sheet with excellent plating and bending properties, which has the high strength more than the tensile strength of 980 MPa, and a method of manufacturing the same. The method of manufacturing a high strength steel sheet according to the present invention includes the following steps of: manufacturing a hot rolled steel sheet by reheating, hot rolling, and cooling a slab plate consisting of 0.08 to 0.13 wt% of carbon, 0.1 to 0.3 wt%, of silicon, 1.8 to 2.3 wt% of manganese, 0.2 to 0.5 wt% of chrome, 0.06 to 0.09 wt% of molybdenum, 0.02 to 0.06 wt% of niobium, 0.01 to 0.04 wt% of titanium, 10 to 40 ppm of Boron, and remainder iron and other inevitable impurities; cold rolling the hot rolled steel sheet; annealing and heat treating the cold rolled plate at the temperature of 770 to 850°C; primarily cooling the annealed and heat-treated plate up to the temperature of 490 to 550°C; over aging the primarily cooled plate at the temperature of 420 to 550°C; and secondarily cooling the over aged plate. [Reference numerals] (AA) Start;(BB) End;(S110) Manufacture a hot rolled steel sheet;(S120) Cold rolling;(S130) Annealing heat treatment;(S140) Primary cooling;(S150) Over aging treatment;(S160) Secondary cooling |
