| 摘要 |
<p>Disclosed are a steel plate which controls alloy content and process conditions to refine austenite crystal grains, increases a cross section reduction rate when stretched at high-temperature in order to have excellent mechanical behaviors and forging formability, and a method of manufacturing the same. According to the present invention, a method of manufacturing a steel plate includes: reheating a slab formed of 0.35-0.40 wt% of carbon (C), 0.5-0.7 wt% of silicon (Si), 1.3-1.5 wt% of manganese (Mn), equal to or less than 0.03 wt% of phosphorus (P), 0.045-0.065 wt% of sulfur (S), equal to or less than 0.2 wt% of nickel (Ni), 0.1-0.2 wt% of chrome (Cr), equal to or less than 0.06 wt% of molybdenum (Mo), equal to or less than 0.25 wt% of copper (Cu), equal to or less than 0.01 wt% of titanium (Ti), 0.01-0.03 wt% of aluminum (Al), and the remainder consisting of iron (Fe) and inevitable impurities at a temperature in the range of 1100-1200°C; hot-rolling the reheated slab at a finish rolling temperature in the range of 700-900°C; and cooling the hot-rolled slab up to a temperature in the range of 450-600°C.</p> |
