HEAT RESISTANT LOW-ALLOY STEEL HAVING IMPROVED STRENGTH AT HIGH TEMPERATURE AND IMPROVED RESISTANCE TO CORROSION BY HYDROGEN

摘要

PURPOSE:To obtain a heat resistant low-alloy steel having superior strength at high temp. and superior resistance to corrosion by hydrogen under high pressure by adding specified percentages of C, Mn, V, Cr, Mo, Si and P to Fe and specifying the relation between the Cr and Mo contents. CONSTITUTION:A heat resistant low-alloy steel consisting of, by weight, 0.08- 0.20% C, 0.3-1.5% Mn, 0.2-0.4% V, 1.0-2.0% Cr, 1.5-3.2% Mo, 1.0% Si, =0.006% P and the balance Fe with inevitable impurities is prepd. In the composition, the relation between Cr% and Mo% exists in the range defined by a point A (1.0, 3.2), a point B (1.0, 2.3), a point C (1.8, 1.5), a point D (2.0, 1.5) and a point E (2.0, 2.2) in the diagram.