| 摘要 |
<p>The present invention relates to section steel and a manufacturing method thereof, wherein the section steel can have a high low-temperature impact property by an alloy element control without using a thermo mechanical control process (TMCP). The manufacturing method of the section steel according to the present invention comprises: a step of reheating steel at a temperature of 1150-1250°C; a step of finish-hot-rolling the reheated steel under the condition of a finish rolling temperature (FRT) of 840-880°C; and a step of cooling the hot-rolled steel, wherein the steel comprises 0.08-0.12 wt% of C, 0.25-0.35 wt% of Si, 1.3-1.4 wt% of Mn, 0.01-0.04 wt% of Al, at most 0.015 wt% of P, at most 0.005 wt% of S, 0.1-0.2 wt% of Ni, at most 0.1 wt% of Cr, at most 0.15 wt% of Cu, 0.01-0.06 wt% of V, at most 0.008 wt% of N, and remnants of Fe and inevitable impurities. [Reference numerals] (AA) Start; (BB) End; (S110) Reheat (1150-1250°C); (S120) Hot-roll (840-880°C); (S130) Cool (air-cool)</p> |
