HYDROGEN ATTACK RESISTING LOW ALLOY STEEL FOR HIGH-TEMPERATURE AND HIGH-PRESSURE EQUIPMENT

摘要

PURPOSE:To obtain a hydrogen attack resisting low alloy steel for high-temp. and high-pressure equipment in which strength, weldability, and toughness are secured and hydrogen attack resistance is improved at a low cost by specifying a composition consisting of C, Si, Mn, Mo, V, Al, B, N, Ca, and Fe. CONSTITUTION:This steel is a hydrogen attack resisting low alloy steel for high-temp. and high-pressure equipment which has a composition consisting of, by weight, 0.05-0.20% C, 0.01-0.30% Si, 0.20-1.5% Mn, 0.11-0.4% Mo, 0.11-0.3% V, 0.005-0.05% Al, 0.0003-0.0030% B, 0.001-0.005% N, 0.001-0.010% Ca, and the balance Fe with inevitable impurities and further containing, if necessary, 0.005-0.1% Nb and/or 0.005-0.1% Ti, and further, this steel has superior strength, toughness, weldability, and hydrogen attack resistance well balanced with each other.