STEEL FOR LINE PIPE HAVING SUPERIOR STREE CORROSION CRACKING RESISTANCE IN ENVIRONMENTAL LAID UNDERGROUND

摘要

PURPOSE:To improve stress corrosion cracking resistance in the environment where laid under ground, by incorporating prescribed percentage of C, Si, Mn, Cr, Ni, and Cu. CONSTITUTION:The titled steel for a line pipe consists of, by weight, =0.5% C, =0.35% Si, 0.1-1% Mn, 0.3-1.5% Cr, 0.2-1% Ni and/or 0.1-0.5% Cu, and the balance. Fe. This steel has superior stress corrosion cracking resistance in the environment where laid under ground, so the material for a line pipe having durability can be obtained at a low cost.