Patent ID: 6485679
Filing Date: 2002-11-26
Classification: C22C,F28F

Abstract:
An austenitic stainless steel alloy having high creep rupture strength at elevated temperatures over long periods of time, good steam oxidation resistance, good fire side corrosion resistance and sufficient structural stability, the alloy having a composition comprising, in wt. %:0.04 to 0.10% carbon; not more than 0.4% silicon; not more than 0.6% manganese; 20 to 27% chromium; 22 to 32% nickel; not more than 0.5% molybdenum; 0.20 to 0.60% niobium; 0.4 to 4.0% tungsten; 0.10 to 0.30% nitrogen; 0.002 to 0.008% boron; 0.003 to 0.05% aluminum; 2-3.5% Cu; 0.5-3% Co; at least one of magnesium and calcium in an amount less than 0.010%; and the balance iron and normal steelmaking impurities.