STEEL SHEET FOR LINE PIPE AND METHOD OF MANUFACTURING THE SAME

摘要

Disclosed are a steel sheet for a line pipe having excellent resistance to hydrogen-induced cracking by inhibiting a band structure and refining grains via the adjustment of alloy components and the control of process conditions; and a manufacturing method thereof. The steel sheet for a line pipe according to the present invention is composed of: 0.04-0.07 wt% of C; 0.1-0.3 wt% of Si; 1.0-1.2 wt% of Mn; 0.01 wt% or less of P; 0.001 wt% or less of S; 0.01-0.05 wt% of S_Al; 0.01-0.02 wt% of Nb; 0.01-0.02 wt% of Ti; 0.001-0.004 wt% of Ca; a remaining amount of Fe; and other inevitable impurities, wherein the final microstructure has the composite grains including polygonal ferrite and pearlite, and the polygonal ferrite grains account for 85% or greater in terms of a section area ratio.