| 摘要 |
<p>PURPOSE: A high carbon steel and a manufacturing method thereof are provided to improve strength and toughness with an ultrafine ferrite grain structure by controlling alloy components and process conditions. CONSTITUTION: A high carbon steel manufacturing method is as follows: a step for reheating a steel slab composed of 0.43-0.47 wt.% of C, 0.15-0.35 wt.% of Si, 1.1-1.3 wt.% of Mn, 0.02 wt.% or less of Al, 0.2 wt.% or less of Ni, 0.3 wt.% or less of Cu, 0-0.2 wt.% of Cr, 0.05 wt.% or less of Mo, 0.08-0.15 wt.% or less of V, and the rest of Fe and inevitable impurities(S110); a step for primarily cooling the reheated steel to a temperature right above a recrystalization finishing temperature at 5-10°C/sec(S120); a step for hot-rolling the primarily cooled steel to 850-950°C of a FDT(Finishing Delivery Temperature)(S130); a step for secondarily cooling the hot-rolled steel to 550-650°C(S140); and a step for winding the secondarily cooled steel(S150). [Reference numerals] (AA) Start; (BB) End; (S110) Reheating of slab; (S120) Primary cooling; (S130) Hot rolling; (S140) Secondary cooling; (S150) Coiling</p> |
