| 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.
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