Alloy for composite tubing in fluidized-bed coal combustor
AssigneeInco Alloys International, Inc.
InventorsCurtis S. Tassen, Gaylord D. Smith
Life of this patent
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Abstract
A composite tube structure having an inner substrate alloy and an outer, corrosion resistant alloy suitable for use in fluid-bed coal combustion reactors to form a water wall around at least a portion of the periphery of the fluid bed zone. The outer, corrosion resistant alloy centers around a composition of 0.1% carbon, 0.2% silicon, 0.5% manganese, 22% chromium, 3.8% aluminum, 0.4% titanium, 0.05% nitrogen, 0.2% molybdenum, 32% nickel, balance iron.
Claims8
A thermally stable hot-corrosion-resistant alloy comprising up to about 0.4% carbon, up to about 0.5% silicon, up to about 1% manganese, about 19.5% to about 24% chromium, about 3.2% to about 4.4% aluminum, about 0.1% to about 1.0% titanium, up to about 0.2% nitrogen, up to about 0.5% molybdenum, about 30% to about 35% nickel, up to about 1% copper, up to about 0.3% rare earth metal, up to about 0.5% zirconium, balance essentially iron.
A composite boiler tube having an inner wall made of an alloy meeting the specifications of the boiler code and an exterior wall made of a thermally stable, hot corrosion resistant alloy comprising up to about 0.4% carbon, up to about 0.5% silicon, up to about 1% manganese, about 19.5% to about 24% chromium, about 3.2% to about 4.4% aluminum, about 0.1% to about 1.0% titanium, up to about 0.2% nitrogen, up to about 0.5% molybdenum, about 30% to about 35% nickel, up to about 1% copper, up to about 0.3% rare earth metal, up to about 0.5% zirconium, balance essentially iron.
A composite structure with a substrate having superimposed thereon a layer of an alloy comprising up to about 0.4% carbon, up to about 0.5% silicon, up to about 1% manganese, about 19.5% to about 24% chromium, about 3.2% to about 4.4% aluminum, about 0.1% to about 1.0% titanium, up to about 0.2% nitrogen, up to about 0.5% molybdenum, about 30% to about 35% nickel, up to about 1% copper, up to about 0.3% rare earth metal, up to about 0.5% zirconium, balance essentially iron.
Dependencies are inferred from the claim text.