| 摘要 |
Disclosed are a hot-rolled steel sheet having excellent low-temperature toughness and corrosion resistance, and a manufacturing method thereof. According to the present invention, the method to manufacture a hot-rolled steel sheet comprises the steps of: reheating, at a temperature of 1200°C or higher for two hours or longer, a slab plate composed of 0.04-0.06 wt% of carbon (C), 0.1-0.2 wt% of silicon (Si), 0.4-0.8 wt% of manganese (Mn), 0.01 wt% or less of phosphorus (P), 0.001 wt% or less of sulfur (S), 0.02-0.05 wt% of aluminum (Al), 0.04-0.08 wt% of vanadium (V), 0.02-0.05 wt% of niobium (Nb), 0.01-0.02 wt% of titanium (Ti), 0.5-0.7 wt% of chromium (Cr), 0.001-0.003 wt% of calcium (Ca), 0.006 wt% or less of nitrogen (N), and the remainder consisting of iron (Fe) and inevitable impurities; rough-rolling the reheated plate in a temperature region of recrystallizing austenite; finish-rolling the plate having completed the rough-rolling in a non-recrystallizing region of the austenite; and cooling the plate having completed the finish-rolling, and winding the plate at a temperature equal to or lower than 600°C. |
