STEEL FOR LINE PIPE HAVING SUPERIOR STRESS CORROSION CRACKING RESISTANCE

摘要

PURPOSE:To manufacture the steel for a line pipe laid under the ground and having excellent stress corrosion cracking resistance by using as material low carbon steel containing specific amounts of Ni. CONSTITUTION:The steel used for a line pipe laid under the ground contains, by weight, 0.003-0.10% C, 0.50% Si, 0.80% Mn, 0.03% P, 0.01% S, 1.5-8% Ni, and 0.07% Al, or further contains 1 or =2 kinds among 0.005-0.10% Zr, 0.03% REM, and 0.0010-0.0050% Ca, or 1 or =2 kinds among 0.50% Cu, 0.50% Cr, 0.30% Mo, 0.10% Nb, 0.10% V, 0.005-0.10% Ti and 0.0005-0.0020% B, or the above elements in combination. The steel for a line pipe excelling in stress corrosion cracking resistance can be obtained.