| 摘要 |
Disclosed are a steel plate having excellent anti-aging and low yield ratio properties, and a manufacturing method thereof. The manufacturing method comprises steps of: (a) reheating a slab plate composed of 0.00-0.025 wt% of carbon (C), 1.0-2.0 wt% of manganese (Mn), 0.08 wt% or less of phosphorus (P), 0.01 wt% or less of sulfur (S), 0.2-0.8 wt% of aluminum (Al), one or more of 0.3<=[Cr]+0.3[Mo]<=2.0 (wherein [] is wt% of a component) of chrome (Cr) and molybdenum (Mo), and the remainder consisting of Fe and inevitable impurities; (b) hot-rolling the reheated slab plate at the temperature of Ar3 point or greater; (c) coiling the hot-rolled plate at 680-750 deg. C; (d) cold-rolling the coiled plate after picking the plate; and (e) cooling the cold-rolled plate after annealing the cold-rolled plate at 810-850 deg. C. |
