| 摘要 |
<p>A method for manufacturing a high carbon steel sheet having excellent strength and toughness without using expensive alloy elements, and a high carbon steel sheet having excellent strength and toughness manufactured by the method is provided. A high carbon steel sheet comprises, by weight percent, 0.25 to 0.55% of C, 0.5 to 1.2% of Mn, 0.4% or less of Si, 2.0% or less of Cr, 0.01 to 0.1% of Al, 0.012% or less of S, 48/14x[N]% or more of Ti, 0.0005 to 0.0050% of B, 0.006% or less of N with the balance of Fe and other inevitable impure elements, and satisfies a condition of 48/14x[N] to 0.03% of Ti in case of 0.0005<=B<=(11/14)x[N]%. A manufacturing method of a high carbon steel sheet comprises the steps of: manufacturing a steel for heat treatment comprising, by weight percent, 0.25 to 0.55% of C, 0.5 to 1.2% of Mn, 0.4% or less of Si, 2.0% or less of Cr, 0.01 to 0.1% of Al, 0.012% or less of S, 48/14x[N]% or more of Ti, 0.0005 to 0.0050% of B, 0.006% or less of N with the balance of Fe and other inevitable impure elements, and satisfying a condition of 48/14x[N] to 0.03% of Ti in case of 0.0005<=B<=(11/14)x[N]%; heating the steel for heat treatment at a temperature of 1250 deg.C or less, and hot rolling the heated steel; and coiling the hot rolled steel sheet in a temperature range of 640 to 700 deg.C.</p> |
