Iron-chromium-aluminum alloys with improved high temperature properties
AssigneeThe International Nickel Company, Inc.
InventorsRobert Lacock Cairns, John Stanwood Benjamin
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Abstract
A powder metallurgy product comprising iron and chromium, and/or aluminum and characterized by elongated grains that are stable at elevated temperatures. A method of producing such a product, including mechanically alloying a suitable powder charge, consolidating the mechanically alloyed powder, working the consolidated product so as to achieve therein a reduction of at least about 10%; and, then, heating the worked product to produce coarse elongated grains therein. The product produced according to the present invention exhibits good oxidation resistance and good room temperature and elevated temperature strength and ductility.
Claims13
A powder metallurgy product consisting essentially of by weight, at least one element from the group consisting of about 10% to about 40% chromium and about 1% to about 10% aluminum, and up to about 10% nickel, up to about 20% cobalt, up to about 5% titanium, up to about 2% each of rare earth metal, yttrium, zirconium, columbium, hafnium, tantalum, silicon, and/or vanadium, up to about 6% each of tungsten and molybdenum, up to about 0.4% carbon, up to 0.4% manganese, and the balance iron, and further, including, by volume, about 0.1% to about 10% refractory dispersoid material selected from the group consisting of refractory metal oxide, metal carbide, metal nitride, metal boride, and combinations thereof, and having an average particle size of about 50A to 5000A and a melting point of at least about 2750.degree. F., said dispersoid material being in the form of particles distributed substantially uniformly throughout said product;
- said product having a density of at least about 98% theoretical and being characterized by elongated grains about 10 to 100 microns wide and about 50 to 2000 microns long, and said grains being substantially stable at temperatures up to at least about 2400.degree. F., said product being formed by consolidation of a mixture containing dispersoid particles or precursors thereof uniformly distributed through such mixture, and said product exhibiting substantially no loss in room temperature ductility upon exposure to 2400.degree. F for at least about 100 hours.
Mill products, including sheet, bar, wire, tubing and plate, made of an alloy consisting essentially of, be weight, at least one element from the group consisting of about 10% to about 40% chromium and about 1% to about 10% aluminum, and up to about 10% nickel, up to about 20% cobalt, up to about 5% titanium, up to about 2% each of rare earth metal, yttrium, zirconium, columbium, hafnium, tantalum, silicon, and/or vanadium, up to about 6% each of tungsten and molybdenum, up to about 0.4% carbon, up to 0.4% manganese, and the balance iron, and further including, by volume, about 0.1% to about 10% refractory dispersoid material selected from at least one of the group consisting of a rare earth metal oxide, yttrium oxide and zirconium oxide and having an average particle size of about 50A to 5000A said mill products being characterized by elongated grains about 10 to 100 microns wide and about 50 to 2,000 microns long.
A hot consolidated mechanically alloyed product consisting essentially of by weight, at least one element from the group consisting of about 10% to about 40% chromium and about 1% to about 10% aluminum, up to about 10% nickel, up to about 20% cobalt, up to about 5% titanium, up to about 2% each of rare earth metal, yttrium, zirconium, columbium, hafnium, tantalum, silicon, and/or vanadium, up to about 6% each of tungsten and molybdenum, up to about 0.4% carbon, up to about 0.4% manganese, and the balance iron, and further, including, by volume, about 0.1% to about 10% refractory dispersoid material selected from the group consisting essentially of refractory metal oxide, metal carbide, metal nitride, metal boride, and combinations thereof, and having an average particle size of about 50A to 5000A and a melting point of at least about 2750.degree. F., said dispersoid material being in the form of particles distributed substantially uniformly throughout said product;
- said product having a density of at least about 98% theoretical and being characterized by elongated grains about 10 to 100 microns wide and about 50 to 2000 microns long, and said grains being substantially stable at temperaturs up to at least about 2400.degree. F.
A powder metallurgy product consisting essentially of by weight, at least one element from the group consisting of about 10% to about 40% chromium and about 1% to about 10% aluminum, and up to about 10% nickel, up to about 20% cobalt, up to about 5% titanium, up to about 2% each of rare earth metal, yttrium, zirconium, columbium, hafnium, tantalum, silicon, and/or vanadium, up to about 6% each of tungsten and molybdenum, up to about 0.4% carbon, up to 0.4% manganese, and the balance iron, and further, including, by volume, about 0.1% to about 10% refractory dispersoid material selected from at least one of the group consisting of a rare earth metal oxide, yttrium oxide and zircnium oxide, and having an average particle size of about 50A to 5000A, said dispersoid material being in the form of particles distributed substantially uniformly throughout said products;
- said product having a density of at least about 98% theroretical and being characterized by elongated grains about 10 to 100 microns wide and about 50 to 2000 microns long, and said grains being substantially stable at temperatures up to at least about 2400.degree. F.
Dependencies are inferred from the claim text.