| 摘要 |
Disclosed are fire-resistant steel capable of ensuring excellent high temperature yield performance by controlling an alloy component and a process condition; and a method of manufacturing the same. According to the present invention, the fire-resistant steel is formed with at least one of 0.06-0.08 wt% of carbon (C), 0.1-0.3 wt% of silicon (Si), 1.1-1.3 wt% of manganese (Mn), equal to or less than 0.015 wt% of phosphorous (P), equal to or less than 0.003 wt% of sulfur (S), 0.3-0.4 wt% of chromium (Cr), 0.3-0.4 wt% of molybdenum (Mo), 0.02-0.03 wt% of niobium (Nb), 0.035-0.045 wt% of vanadium (V), and the remaining consisting of iron (Fe) and inevitable impurities. The final microstructure has a composite organization including ferrite, pearlite, and bainite. The bainite organization has a cross-sectional area rate equal to or less than 3%. |
