To provide a method for manufacture of a cast steel material for pressure vessel, in which the creep rupture strength of CrMoV cast steel is increased to a value equal to or higher than that of the conventional one and further toughness is improved, and a pressure vessel using this cast steel mate rial.
The cast steel material for pressure vessel has a composition consisting of, by weight, 0.02-0.05% carbon, 0.05-0.15% silicon, 0.5-0.8% manganese, 0.5-1.8% chromium, 1.0-0.8% molybdenum, 0.1-0.2% vanadium, 0.5-3% tungsten, 0.5-3% cobalt, 0.001-0.04%, in total, of niobium and/or tantalum, ≤0.008% phosphorus as impurity, ≤0.003% sulfur as impurity, inevitable impurities, and the balance iron. Further, the pressure vessel is produced by using this cast steel material.
FUJITA AKIJI
KAMATA MASATOMO
KITAGAWA IKUJIRO
TASHIRO YASUNORI
MORINAKA KOUJI
JAPAN CASTING FORGING CORP