| 摘要 |
A super high intensity steel sheet capable of maximizing precipitation hardening by maintaining ferrite transformation temperature formed at the temperature range from the end of a rolling process to a cooling process through controlling a process condition and adding carbide elements for several seconds and a manufacturing method for the same are disclosed. The manufacturing method for the super high intensity steel sheet according to the present invention comprises a step of: 1) re-heating a slab board consisting of 0.04 to 0.10 weight % of carbon (C), less than 0.3 weight % of silicon (Si), 1.0 to 2.5 weight % of manganese (Mn), less than 0.01 weight % of phosphorus (P), less than 0.01 weight % of sulfur (S), less than 0.01 weight % of vanadium (V), 0.05 to 0.3 weight % of niobium (Nb), less than 0.15 weight % of titanium (Ti), less than 0.5 weight % of molybdenum (Mo), 0.001 to 0.005 weight % of nitrogen (N), residual ferrum (Fe) and impurities; 2) hot-rolling the re-heated slab board at the finishing delivery temperature of 800 to 900°C after rough-rolling the slab board; and 3)winding the slab board after cooling the hot-rolled slab board. [Reference numerals] (AA) START; (BB) END; (S110) Slab reheating; (S122) Rough-rolling; (S124) Finish-rolling; (S130) Cooling/coiling |
