High-strength low-alloy cast steel and its heat treatment method

摘要

PURPOSE: To produce a high strength low alloy cast steel used as the material for steam turbine casing and pressure vessels for thermal power generation and to provide a method for heat treating the same cast steel. ;CONSTITUTION: This high strength low allay cast steel is the one having a compsn. contg., by weight, 0.05 to 0.11% carbon, 0.15 to 0.35% silicon, 0.5 to 0.8% magnanese, 0.8 to 2.8% chromium, 0.1 to 1.2% molybdenum, 0.1 to 0.3% vanadium, 0.5 to 3% tungsten, 0.5 to 3% cobalt, niobium or tantalum by 0.01 to 0.06% in total, 0.001 to 0.005% boron, ≤0.008% phosphorus as impurities, ≤0.006% sulfur as impurities, and the balance iron with inevitable impurities.;COPYRIGHT: (C)1996,JPO