| 摘要 |
<p>PURPOSE: A thick hot-rolled steel plate for spiral line pipe having high toughness and strength and a manufacturing method of the same are provided to improve toughness and strength by controlling the growth of grain by adding titanium. CONSTITUTION: A thick hot-rolled steel plate for spiral line pipe having high toughness and strength comprises S 0.002 weight%, C less than 0.03~0.10 weight%, Si 0.01~0.50 weight%, Mn 1.20~2.00 weight%, P less than 0.03 weight%, Ni 0.10~0.50 weight%, Cu less than 0.30 weight%, Nb less than 0.02~0.10 weight%, V 0.01~0.2 weight%, Ti 0.01~0.10 weight%, Cr 0.1~0.50 weight%, Mo less than 0.1~0.5 weight%, and the impurity. The impurity rest is inevitable less than N 0.010 weight%.</p> |
