US3118763A - Cobalt base alloys - Google Patents

Cobalt base alloys Download PDF

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US3118763A
US3118763A US751159A US75115958A US3118763A US 3118763 A US3118763 A US 3118763A US 751159 A US751159 A US 751159A US 75115958 A US75115958 A US 75115958A US 3118763 A US3118763 A US 3118763A
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test bars
titanium
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alloy
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Rudolf H Thielemann
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Sierra Metals Corp
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Sierra Metals Corp
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C22C19/07—Alloys based on nickel or cobalt based on cobalt

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  • alloy of this invention may be cast, is highly resistant to oxidation and other forms of corrosion, and possesses great mechanical strength at temperatures up to between about l500 F. and about 2200" F. As a result, this alloy may be used as blades, vanes, and other parts of high temperature gas turbine engines.
  • alloy of this invention is as exhaust valves and manifolds in internal combustion engines, heat exchanges, as linings for retorts and container vessels used in the chemical and metallurgical industries, and as an oxidation resistant coating material for metals and metal alloys such as columbium, tantalum, nickel base alloys, cobalt base alloys, etc., which possess high strength characteristics at elevated temperatures but whose resistance to oxidation at elevated temperatures, i.e., above about 1500 F., is inadequate.
  • the alloy of this invention can also be utilized as high temperature, high strength, corrosion resistant tubing and sheet material, as a material for forming cutting blades useful for cutting molten glass and other hot corrosive materials, as a material for forming supporting members or holders for use in metallurgical testing apparatus, etc.
  • a common nickel-cobalt base metal alloy which incorporates molybdenum as a constituent is for all practical purposes non-utilizable as a structural member a gas turbine engine if the metal temperature is above l500 F.
  • One reason for this temperature limit is that the oxidation resistance of such an alloy fails above 1500 F.
  • An alloy of this invention when used as a blade or vane in a high tern erature as turbine engine can be operated at markedly higher temperatures than was possible heretofore.
  • the performance of gas turbine engines incorpo rating such blades or vanes is considerably improved, since at higher temperatures the total thrust of a gas turbine engine increases and the amount of fuel consumed per pound of thrust decreases.
  • the metal alloy of this invention is comprised, by Weight, of the following constituents: from about 15 to about 28 percent of chromium; from about to about percent of tungsten; from about 0.5 to about percent of tantalum; from about 0.01 to about 3 percent of titanium; from about 0.1 to about 1.3 percent of carbon; and the balance being essentially cobalt.
  • the high temperature corrosion resistant properties of the alloy of this invention are not ice affected if the alloy includes an amount of columbium which is not more than one-half of the amount of tantalum in the alloy and, in any event, is no greater than 3 percent, by weight, of the alloy, and preferably not more than 2.0 percent, by weight, of the alloy.
  • molybdenum is not a primary constituent of the alloy of this invention, I have found that the properties of the alloy of this invention are not deleteriously affected if the alloy includes an amount of molybdenum which is not more than one-half the amount of tungsten in the alloy and, in any event, is no greater than 3.5 percent, by Weight, of the alloy.
  • zirconium may be tolerated in the alloy of this invention in an amount such that if the amount or" titanium in the alloy is more than about 0.5 percent, the combined amount of titanium and zirconium is equal to or less than about 3 percent, and if the amount of titanium is equal to or less than about 0.5 percent, the amount of titanium is more than about percent of the amount of zirconium in the alloy.
  • any one or more of the following ingredients up to about 0.2 percent of boron, up to about 1.5 percent of silicon, and up to about 5 percent of nickel and/or iron may in certain formulations improve various metallurgical characteristics of the alloy. Additional amounts of these ingredients may in some cases be tolerated in the alloy without deleterious effects.
  • the boron content in the alloy of this invention exceeds about 0.2 percent, then the alloy of this invention becomes unsatisfactory, particularly in those applications Where thermal shock requirements are important.
  • the following impurities which may be in the alloy be held to the following limits by weight.
  • the manganese content in the final alloy should not be greater than about 2 percent.
  • the interstitial elements such as nitrogen, hydrogen, tin, lead, and the like should be kept as low as possible.
  • not more than about 0.5 percent total of deoxidizers such as calcium, magnesium, and the like should be present in the final alloy.
  • a preferred range of proportions of constituents of the alloy of this invention which has especially high oxidation resistance and strength characteristics, at temperatures of 2000 F., and above, and which is particularly suitable for use as a vane material in a gas turbine, high temperature engine is as follows: from about 16 to about 25 percent of chromium; from about 7.5 to about 12.5 percent of tungsten; from about 7 to about 11 percent of tantalum; from about .08 to about 0.5 percent of titanium; from about 0.6 to about 1.0 percent of carbon; and the balance being essentially cobalt.
  • Example 1 A 5 pound alloy melt of a cobalt base metal alloy composition containing about 20 percent of chromium, about 11 percent of tungsten, about 1.5 percent of tantalum, about 1.5 percent of titanium, about 0.1 percent of carbon, and the balance essentially cobalt, all percentages by weight, was prepared by melting the chromium and cobalt in a magnesia crucible under high vacuum conditions, following which the tungsten, tantalum, titanium, and carbon in the form of graphite were added.
  • test bars were formed from the 5 pound melted alloy heat and cast by the usual investment casting technique, under high vacuum conditions. These bars were each 3 inches long and A inch in diameter.
  • test bars of this example had an elongation of 10 percent at room temperature under a tensile stress of 95,000 p.s.i. V
  • test bars of this example had a rupture life in excess of 100 hours under a load of 12,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 2 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 28 percent of chromium, about 5 percent of tungsten, about 1.5 percent of tantalum, about 1.5 percent of titanium, about 0.4 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 100,000 p.s.i.
  • test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 3 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about percent of chromium, about 11 percent of tungsten, about 0.5 percent of tantalum, about 3 percent of titanium, about 0.7 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 7 percent at room temperature under a tensile stress of 115,000 p.s.i.
  • test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air. 7
  • Example 4 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.3 percent of titanium, about 1.0 percent excess of hours under a load of 18,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 12,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 5 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 15 percent of chromium, about 15 percent of tungsten, about 13 percent of tantalum, about 0.01 percent of titanium, about 0.65 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 5 percent at room temperature under a tensile stress of 124,000 p.s.i.
  • test bars of this example had a rupture life in excess of 100 hours under a load of 25,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life in excess of 100 hours under a load of 18,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a. temperature of about 1800" F. in air.
  • Example 6 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chro mium, about 10 percent of tungsten, about 20 percent of tantalum, about 2 percent of titanium, about 1 percent of zirconium, about 0.85 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 6 percent at room temperature under a tensile stress of 118,000 p.s.i.
  • test bars of this example had a rupture life in excess of 100 hours under a :load of 20,000 p.s.i. at a temperature of about 1600" F. in air, a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in
  • Example 7 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 28 percent of chromium, about 5 percent of tungsten, about 8 percent of tantalum, about 2.0 percent of titanium, about 0.5 percent of Zirconium, about 0.7 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 1 percent at room temperature under a tensile stress of 120,000 p.s.i. a
  • test bars of this example had a rupture life in excess of 100 hours under a load of 20,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life in ex cess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 5,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 8 A 5 pound alloy melt and test bars of the same di- 7 weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of about 2 percent at room temperature under a tensile stress of 113,000 p.s.i.
  • test bars of this example had a rupture life in excess of 250 hours under a load of 22,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life of about 329 hours under a load of 15,500 p.s.i. at a temperature of about 1700 F., and a rupture life in excess of 63 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 9 A pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21.5 percent of chromium, about 9.6 percent of tungsten, about 1.2 percent of tantalum, about 0.3 percent of titanium, about 0.45 percent of carbon, about 1.5 percent of silicon, about 0.28 percent of manganese, about 1.5 percent of nickel, about 1.5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of about 3.3 percent at room temperature under a tensile stress of 118,000 p.s.i.
  • test bars of this example had a rupture life in excess of 233 hours under a load of 13,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 154 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 10 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21.5 percent of chromium, about 9.7 percent of tungsten, about 10.6 percent of tantalum, about 0.4 percent of Zirconium, about 0.3 percent of titanium, about 0.75 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 1.1 percent at room temperature under a tensile stress of 110,000 p.s.i.
  • test bars of this example had a rupture life in excess of 59 hours under a load of 17,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 11 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21 percent of chromium, about 9 percent of tungsten, about 9 percent of tantalum, about 0.2 percent of titanium, about 0.85 percent of carbon, about 1.0 percent of molybdenum, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had a rupture life in excess of 51 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 12 manner as set forth in Example 1.
  • test bars of this example had an elon ation or" 6 about 3.3 percent at room temperature under a tensile stress of 142,800 p.s.i.
  • test bars of this example had a rupture life in excess of 51 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air and a rupture life in excess of 137 hours under a load of 20,000 p.s.i. at a temperature of about 1700 F. in air.
  • Example 13 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.9 percent of carbon, about 0.3 percent of silicon, about 0.5 percent of manganese, about 0.5 percent of titanium, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 2.5
  • test bars of this example had a rupture life in excess of 60 hours under a load of 22,500 p.s.i. at a temperature of about 1700" F. in air and a rupture life in excess of 41 hours under a load of 17,000 p.s.i. at a temperature of about 1800" F. in air.
  • Example 14 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromiul. about 7.5 percent of tungsten, about 7.5 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of the example had an elongation of 1.6 percent at room temperature under a tensile stress of 142,200 p.s.i.
  • test bars of this example had a rupture life in excess of 134 hours under a load of 22,500 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 51 hours under a load of 17,000 p.s.i. at a temperature of about 1800" F in air.
  • Example 15 2.5 percent at room temperature under a tensile stress of 125,600 p.s.i.
  • test bars of this example had a rupture life in excess of 166 hours under a load of 22,500 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 68 hours under a load of 17,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 16 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 1.6
  • test bars of this example had a rupture life in excess of 59 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air and a rupture life in excess of 30 hours under a load of 8,000 psi. at a temperature of about 2000 F. in air.
  • Example 17 A pound alloy melt and test bars of tr e same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent or" chromium, about percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of nickel, and the balance essentially cobalt, all percentages by weight, were prepared in be same manner as set forth in Example 1.
  • test bars or" this example had an elongation of 3.3
  • test bars of this example had a rupture life in excess of 56 hours under a load of 15,000 psi at a temperature of about 1800 F. in air and a rupture life in excess of 25 hours under a load of 8,000 p.s.i. at a temperature of about 2000 F. in air.
  • Example 1 8 A5 pound alloy metal and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 1.3 percent of carbon, and 0.01 percent of boron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 1.7 percent at room temperature under a tensile stress of 145,500 psi.
  • test bars of this example had a rupture life in excess of 41 hours under a load of 15,000 psi at a temperature of about 1800 F. in air.
  • Example 19 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chro miurn, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.2 percent of boron, about 0.85 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 0.8 percent at room temperature under a tensile stress of 135 000 psi.
  • test bars of this example had' a rupture life in excess of 50 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air.
  • test bars of this example had an elongation of 0.95 percent at room temperature under a tensile stress of 125,000 p.s.i.
  • test bars of the example had a rupture life in excess of 62 hours under a load of 15,000 psi. at a temperature of about 1800" F. in air.
  • Example 21 A 5 pound alloy melt and test bars or" the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 12.5 percent of tungsten, about 3 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 1 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of .8 percent at room temperature under a tensile stress of 137,- 000 psi.
  • test bars of this example had a rupture life in excess of 22 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
  • Example 22 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 12.5 percent of tungsten, about 3 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 1 percent of carbon, about 0.01 percent of boron, about 5 percent of nickel, and the balance essentially cobalt, all percentages by wei ht, were prepared in the same mariner as set forth in Example 1.
  • test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 131,900 psi.
  • test bars of this example had a rupture life in excess of 41 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
  • Example 23 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 8 percent of tungsten, about 8 percent of tantalum, about 1 percent of colurnbium, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all by weight, were prepared in the same manner as set forth in Example. l.
  • test bars of this example had an elongation of 1.6 percent at room temperature under a tensile stress of 132,100 psi.
  • test bars of this example had a rupture life in excess of 277 hours under a load of 20,000 psi. at a temperature of about 1700" F. in air, a rupture life in excess of 128 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
  • Example 24 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 8 percent of tungsten, about 8 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 0.8 percent at room temperature under a tensile stress of 127,600 p.s.i.
  • test bars of this example had a rupture life in excess of 33 hours under a load of 15,000 p.s.i. at a emperature of about 1800 F. in air and a rupture life in excess of 19 hours under a load of 5,000 psi. at a temperature of about 2000 F. in air.
  • Example 25 A 5 pound alloy melt and test bars of the same dimen- 9 sions as set forth in Example 1 of a cobalt base metal alloy composition containing about 25 percent of chromiurn, about 10 percent of tungsten, about percent of tantalum, about 2 percent of columbium, about 0.85 percent of carbon, about 0.1 percent of titanium, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 1.6 percent at room temperature under a tensile stress of 139,400 p.s.i.
  • test bars of this example had a rupture life in excess of 53 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air and a rupture life in excess of 21 hours under a load of 5,000 p.s.i. at a temperature of about 2000 F. in air.
  • the oxidation penetration was 0.017 mil per side per hour after 100 hours in moving air at 2000 F. and 0.07 mil per side per hour after 24 hours in moving air at 2100 F.
  • Example 26 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 18 percent of chromium, about 8.6 percent of tungsten, about 2.5 percent of tantalum, about 0.6 percent of titanium, about 0.1 percent of zirconium, about 0.49 percent of carbon, about 0.2 percent of silicon, about 2.5 percent of nickel, about 2.5 percent or" iron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 100,000 p.s.i.
  • test bars of his example had a rupture life in excess of 250 hours under a load of 22,000 p.s.i. at a temperature of about 1600 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
  • Example 27 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 11 percent of tungsten, about 0.5 percent of tantalum, about 2.9 percent of titanium, about 0.1 percent of zirconium, about 0.7 percent of carbon, about 0.4 percent of silicon, about 0.5 percent of nickel, about 0.5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
  • test bars of this example had an elongation of 8 percent at room temperature under a tensile stress of 115,000 p.s.i.
  • test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
  • a metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially of, by Weight, from about 16 to about 25 percent of chromium, from about 7.5 to about 12.5 percent of tungsten, from about 7 10 to about 11 percent of tantalum, from about 0.08 to about 0.5 percent of titanium, from about 0.6 to about 1 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, with the columbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially or", by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tun sten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, up to about 0.2 percent of boron, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, With the columbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of zirconium, up to about 0.2 percent of boron, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
  • a metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of the zirconium, from about 0.6 to about 1.3 percent of carbon, up to about 1.5 percent of silicon, up to about 5 percent of nickel, up to about 5 percent of iron, and the balance cobalt.
  • a metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, with the eolumbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of the zirconium, up to about 0.2 percent of boron, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, up to about 1.5 percent of silicon, up
  • a metal alloy consisting essentially of, by weight, from about 16 to about 25 percent of chromium, from about 7.5 to about 12.5 percent of tungsten, up to about 3.5 percent of molybdenum, from about 7 to about 11 percent of tantalum, up to about 3 percent of colurnbium, from about (1.08 to about 0.5 percent of titanium, zirconium in an amount such that the amount of titanium is more than 70 percent, the amount of zirconium in the alloy, from about 0.6 to about 1 percent of carbon, up to about 0.2 percent of boron, up to about 1.5 percent of silicon, up to about 2.5 percent of nickel, up to about 2.5 percent of iron, and the balance cobalt.

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Description

United States Patent 3,113,763 CfiEALT BASE ALLGYS Rudolf H. Thielemann, Palo Alto, Calif., assignor to Sierra M'etals Corporation, Chicago, IlL, a corporation of Delaware No Drawing. Filed July 28, 1958, Ser. No. 751,159 9 Genus. (Cl. 75171) This invention relates to a cobalt base metal alloy which includes alloying metal additives which make the resulting alloy corrosion resistant and of great mechanical work strength at temperatures between about l500 F. and about 220G" F.
Important features of the alloy of this invention are that it may be cast, is highly resistant to oxidation and other forms of corrosion, and possesses great mechanical strength at temperatures up to between about l500 F. and about 2200" F. As a result, this alloy may be used as blades, vanes, and other parts of high temperature gas turbine engines. Other important uses of the alloy of this invention are as exhaust valves and manifolds in internal combustion engines, heat exchanges, as linings for retorts and container vessels used in the chemical and metallurgical industries, and as an oxidation resistant coating material for metals and metal alloys such as columbium, tantalum, nickel base alloys, cobalt base alloys, etc., which possess high strength characteristics at elevated temperatures but whose resistance to oxidation at elevated temperatures, i.e., above about 1500 F., is inadequate. The alloy of this invention can also be utilized as high temperature, high strength, corrosion resistant tubing and sheet material, as a material for forming cutting blades useful for cutting molten glass and other hot corrosive materials, as a material for forming supporting members or holders for use in metallurgical testing apparatus, etc.
The priorart nickel and/ or cobalt base metal alloys which have been used as blades, vanes, and other parts of hi h temperature gas turbine engines, have a maximum operating temperature of about 1580" F. For example, a common nickel-cobalt base metal alloy which incorporates molybdenum as a constituent is for all practical purposes non-utilizable as a structural member a gas turbine engine if the metal temperature is above l500 F. One reason for this temperature limit is that the oxidation resistance of such an alloy fails above 1500 F.
An alloy of this invention when used as a blade or vane in a high tern erature as turbine engine can be operated at markedly higher temperatures than was possible heretofore. The performance of gas turbine engines incorpo rating such blades or vanes is considerably improved, since at higher temperatures the total thrust of a gas turbine engine increases and the amount of fuel consumed per pound of thrust decreases.
The metal alloy of this invention is comprised, by Weight, of the following constituents: from about 15 to about 28 percent of chromium; from about to about percent of tungsten; from about 0.5 to about percent of tantalum; from about 0.01 to about 3 percent of titanium; from about 0.1 to about 1.3 percent of carbon; and the balance being essentially cobalt.
I have found that the high temperature corrosion resistant properties of the alloy of this invention are not ice affected if the alloy includes an amount of columbium which is not more than one-half of the amount of tantalum in the alloy and, in any event, is no greater than 3 percent, by weight, of the alloy, and preferably not more than 2.0 percent, by weight, of the alloy.
It is important to note that in the past the metals tantalum and columbium have been considered to be equivalent for various purposes. This is not true in the case of the alloy of this invention. For example, if in the alloy of this invention, columbium is substituted for tantalum in the range of proportions specified, the resulting alloy does not possess the high temperature corrosion resistance characteristic of the alloy of this invention.
While molybdenum is not a primary constituent of the alloy of this invention, I have found that the properties of the alloy of this invention are not deleteriously affected if the alloy includes an amount of molybdenum which is not more than one-half the amount of tungsten in the alloy and, in any event, is no greater than 3.5 percent, by Weight, of the alloy.
I have also found that zirconium may be tolerated in the alloy of this invention in an amount such that if the amount or" titanium in the alloy is more than about 0.5 percent, the combined amount of titanium and zirconium is equal to or less than about 3 percent, and if the amount of titanium is equal to or less than about 0.5 percent, the amount of titanium is more than about percent of the amount of zirconium in the alloy.
It has been further found that the inclusion of any one or more of the following ingredients: up to about 0.2 percent of boron, up to about 1.5 percent of silicon, and up to about 5 percent of nickel and/or iron may in certain formulations improve various metallurgical characteristics of the alloy. Additional amounts of these ingredients may in some cases be tolerated in the alloy without deleterious effects.
It is to be noted that if the boron content in the alloy of this invention exceeds about 0.2 percent, then the alloy of this invention becomes unsatisfactory, particularly in those applications Where thermal shock requirements are important.
To achieve the optimum desired properties, it is preferred that the following impurities which may be in the alloy be held to the following limits by weight. The manganese content in the final alloy should not be greater than about 2 percent. The interstitial elements such as nitrogen, hydrogen, tin, lead, and the like should be kept as low as possible. In addition, not more than about 0.5 percent total of deoxidizers such as calcium, magnesium, and the like should be present in the final alloy.
A preferred range of proportions of constituents of the alloy of this invention which has especially high oxidation resistance and strength characteristics, at temperatures of 2000 F., and above, and which is particularly suitable for use as a vane material in a gas turbine, high temperature engine is as follows: from about 16 to about 25 percent of chromium; from about 7.5 to about 12.5 percent of tungsten; from about 7 to about 11 percent of tantalum; from about .08 to about 0.5 percent of titanium; from about 0.6 to about 1.0 percent of carbon; and the balance being essentially cobalt.
Following are examples of the preparation and test results of the cobalt base metal alloy of this invention.
Example 1 A 5 pound alloy melt of a cobalt base metal alloy composition containing about 20 percent of chromium, about 11 percent of tungsten, about 1.5 percent of tantalum, about 1.5 percent of titanium, about 0.1 percent of carbon, and the balance essentially cobalt, all percentages by weight, was prepared by melting the chromium and cobalt in a magnesia crucible under high vacuum conditions, following which the tungsten, tantalum, titanium, and carbon in the form of graphite were added.
A cluster of 6 test bars were formed from the 5 pound melted alloy heat and cast by the usual investment casting technique, under high vacuum conditions. These bars were each 3 inches long and A inch in diameter.
The test bars of this example had an elongation of 10 percent at room temperature under a tensile stress of 95,000 p.s.i. V
The test bars of this example had a rupture life in excess of 100 hours under a load of 12,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
Example 2 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 28 percent of chromium, about 5 percent of tungsten, about 1.5 percent of tantalum, about 1.5 percent of titanium, about 0.4 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 100,000 p.s.i.
The test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in air.
Example 3 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about percent of chromium, about 11 percent of tungsten, about 0.5 percent of tantalum, about 3 percent of titanium, about 0.7 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 7 percent at room temperature under a tensile stress of 115,000 p.s.i.
The test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air. 7
Example 4 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.3 percent of titanium, about 1.0 percent excess of hours under a load of 18,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 12,000 p.s.i. at a temperature of about 1800 F. in air.
Example 5 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 15 percent of chromium, about 15 percent of tungsten, about 13 percent of tantalum, about 0.01 percent of titanium, about 0.65 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 5 percent at room temperature under a tensile stress of 124,000 p.s.i.
The test bars of this example'had a rupture life in excess of 100 hours under a load of 25,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life in excess of 100 hours under a load of 18,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a. temperature of about 1800" F. in air.
Example 6 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chro mium, about 10 percent of tungsten, about 20 percent of tantalum, about 2 percent of titanium, about 1 percent of zirconium, about 0.85 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 6 percent at room temperature under a tensile stress of 118,000 p.s.i.
The test bars of this example had a rupture life in excess of 100 hours under a :load of 20,000 p.s.i. at a temperature of about 1600" F. in air, a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in
Example 7 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 28 percent of chromium, about 5 percent of tungsten, about 8 percent of tantalum, about 2.0 percent of titanium, about 0.5 percent of Zirconium, about 0.7 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 1 percent at room temperature under a tensile stress of 120,000 p.s.i. a
The test bars of this example had a rupture life in excess of 100 hours under a load of 20,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life in ex cess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 100 hours under a load of 5,000 p.s.i. at a temperature of about 1800 F. in air.
Example 8 A 5 pound alloy melt and test bars of the same di- 7 weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of about 2 percent at room temperature under a tensile stress of 113,000 p.s.i.
The test bars of this example had a rupture life in excess of 250 hours under a load of 22,000 p.s.i. at a temperature of about 1600 F. in air, a rupture life of about 329 hours under a load of 15,500 p.s.i. at a temperature of about 1700 F., and a rupture life in excess of 63 hours under a load of 8,000 p.s.i. at a temperature of about 1800 F. in air.
Example 9 A pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21.5 percent of chromium, about 9.6 percent of tungsten, about 1.2 percent of tantalum, about 0.3 percent of titanium, about 0.45 percent of carbon, about 1.5 percent of silicon, about 0.28 percent of manganese, about 1.5 percent of nickel, about 1.5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of about 3.3 percent at room temperature under a tensile stress of 118,000 p.s.i.
The test bars of this example had a rupture life in excess of 233 hours under a load of 13,000 p.s.i. at a temperature of about 1700 F. in air, and a rupture life in excess of 154 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
Example 10 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21.5 percent of chromium, about 9.7 percent of tungsten, about 10.6 percent of tantalum, about 0.4 percent of Zirconium, about 0.3 percent of titanium, about 0.75 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 1.1 percent at room temperature under a tensile stress of 110,000 p.s.i.
The test bars of this example had a rupture life in excess of 59 hours under a load of 17,000 p.s.i. at a temperature of about 1800 F. in air.
Example 11 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 21 percent of chromium, about 9 percent of tungsten, about 9 percent of tantalum, about 0.2 percent of titanium, about 0.85 percent of carbon, about 1.0 percent of molybdenum, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had a rupture life in excess of 51 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air.
Example 12 manner as set forth in Example 1.
The test bars of this example had an elon ation or" 6 about 3.3 percent at room temperature under a tensile stress of 142,800 p.s.i.
The test bars of this example had a rupture life in excess of 51 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air and a rupture life in excess of 137 hours under a load of 20,000 p.s.i. at a temperature of about 1700 F. in air.
Example 13 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.9 percent of carbon, about 0.3 percent of silicon, about 0.5 percent of manganese, about 0.5 percent of titanium, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 2.5
ercent at room temperature under a tensile stress of 139,000 p.s.i.
The test bars of this example had a rupture life in excess of 60 hours under a load of 22,500 p.s.i. at a temperature of about 1700" F. in air and a rupture life in excess of 41 hours under a load of 17,000 p.s.i. at a temperature of about 1800" F. in air.
Example 14 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromiul. about 7.5 percent of tungsten, about 7.5 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of the example had an elongation of 1.6 percent at room temperature under a tensile stress of 142,200 p.s.i.
The test bars of this example had a rupture life in excess of 134 hours under a load of 22,500 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 51 hours under a load of 17,000 p.s.i. at a temperature of about 1800" F in air.
Example 15 2.5 percent at room temperature under a tensile stress of 125,600 p.s.i.
The test bars of this example had a rupture life in excess of 166 hours under a load of 22,500 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 68 hours under a load of 17,000 p.s.i. at a temperature of about 1800 F. in air.
Example 16 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 1.6
7 percent at room temperature under a tensile stress of 137,500 psi.
The test bars of this example had a rupture life in excess of 59 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air and a rupture life in excess of 30 hours under a load of 8,000 psi. at a temperature of about 2000 F. in air.
Example 17 A pound alloy melt and test bars of tr e same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent or" chromium, about percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of nickel, and the balance essentially cobalt, all percentages by weight, were prepared in be same manner as set forth in Example 1.
The test bars or" this example had an elongation of 3.3
percent at room temperatu e under a tensile stress of 134,000 psi. 7 The test bars of this example had a rupture life in excess of 56 hours under a load of 15,000 psi at a temperature of about 1800 F. in air and a rupture life in excess of 25 hours under a load of 8,000 p.s.i. at a temperature of about 2000 F. in air.
Example 1 8 A5 pound alloy metal and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 1.3 percent of carbon, and 0.01 percent of boron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 1.7 percent at room temperature under a tensile stress of 145,500 psi.
The test bars of this example had a rupture life in excess of 41 hours under a load of 15,000 psi at a temperature of about 1800 F. in air.
Example 19 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chro miurn, about 10 percent of tungsten, about 10 percent of tantalum, about 0.1 percent of titanium, about 0.2 percent of boron, about 0.85 percent of carbon, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 0.8 percent at room temperature under a tensile stress of 135 000 psi.
The test bars of this example had' a rupture life in excess of 50 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air.
Example A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22' percent of chromium, about 8 percent of tungsten, about 8 percent of tantalum, about 3 percent of columbium, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 0.95 percent at room temperature under a tensile stress of 125,000 p.s.i.
The test bars of the example had a rupture life in excess of 62 hours under a load of 15,000 psi. at a temperature of about 1800" F. in air.
Example 21 A 5 pound alloy melt and test bars or" the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 12.5 percent of tungsten, about 3 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 1 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of .8 percent at room temperature under a tensile stress of 137,- 000 psi.
The test bars of this example had a rupture life in excess of 22 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
Example 22 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 12.5 percent of tungsten, about 3 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 1 percent of carbon, about 0.01 percent of boron, about 5 percent of nickel, and the balance essentially cobalt, all percentages by wei ht, were prepared in the same mariner as set forth in Example 1.
The test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 131,900 psi.
The test bars of this example had a rupture life in excess of 41 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
Example 23 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 8 percent of tungsten, about 8 percent of tantalum, about 1 percent of colurnbium, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, and the balance essentially cobalt, all by weight, were prepared in the same manner as set forth in Example. l.
The test bars of this example had an elongation of 1.6 percent at room temperature under a tensile stress of 132,100 psi.
The test bars of this example had a rupture life in excess of 277 hours under a load of 20,000 psi. at a temperature of about 1700" F. in air, a rupture life in excess of 128 hours under a load of 15,000 psi. at a temperature of about 1800 F. in air.
Example 24 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 22 percent of chromium, about 8 percent of tungsten, about 8 percent of tantalum, about 1 percent of columbium, about 0.1 percent of titanium, about 0.85 percent of carbon, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 0.8 percent at room temperature under a tensile stress of 127,600 p.s.i.
The test bars of this example had a rupture life in excess of 33 hours under a load of 15,000 p.s.i. at a emperature of about 1800 F. in air and a rupture life in excess of 19 hours under a load of 5,000 psi. at a temperature of about 2000 F. in air.
Example 25 A 5 pound alloy melt and test bars of the same dimen- 9 sions as set forth in Example 1 of a cobalt base metal alloy composition containing about 25 percent of chromiurn, about 10 percent of tungsten, about percent of tantalum, about 2 percent of columbium, about 0.85 percent of carbon, about 0.1 percent of titanium, about 0.01 percent of boron, about 5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 1.6 percent at room temperature under a tensile stress of 139,400 p.s.i.
The test bars of this example had a rupture life in excess of 53 hours under a load of 15,000 p.s.i. at a temperature of about 1800 F. in air and a rupture life in excess of 21 hours under a load of 5,000 p.s.i. at a temperature of about 2000 F. in air. The oxidation penetration was 0.017 mil per side per hour after 100 hours in moving air at 2000 F. and 0.07 mil per side per hour after 24 hours in moving air at 2100 F.
Example 26 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 18 percent of chromium, about 8.6 percent of tungsten, about 2.5 percent of tantalum, about 0.6 percent of titanium, about 0.1 percent of zirconium, about 0.49 percent of carbon, about 0.2 percent of silicon, about 2.5 percent of nickel, about 2.5 percent or" iron, and the balance essentially cobalt, all percentages by Weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 3 percent at room temperature under a tensile stress of 100,000 p.s.i.
The test bars of his example had a rupture life in excess of 250 hours under a load of 22,000 p.s.i. at a temperature of about 1600 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
Example 27 A 5 pound alloy melt and test bars of the same dimensions as set forth in Example 1 of a cobalt base metal alloy composition containing about 20 percent of chromium, about 11 percent of tungsten, about 0.5 percent of tantalum, about 2.9 percent of titanium, about 0.1 percent of zirconium, about 0.7 percent of carbon, about 0.4 percent of silicon, about 0.5 percent of nickel, about 0.5 percent of iron, and the balance essentially cobalt, all percentages by weight, were prepared in the same manner as set forth in Example 1.
The test bars of this example had an elongation of 8 percent at room temperature under a tensile stress of 115,000 p.s.i.
The test bars of this example had a rupture life in excess of 100 hours under a load of 15,000 p.s.i. at a temperature of about 1700 F. in air and a rupture life in excess of 100 hours under a load of 10,000 p.s.i. at a temperature of about 1800 F. in air.
The above detailed description has been given for clearness of understanding only. No unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.
I claim:
1. A metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
2. A metal alloy consisting essentially of, by Weight, from about 16 to about 25 percent of chromium, from about 7.5 to about 12.5 percent of tungsten, from about 7 10 to about 11 percent of tantalum, from about 0.08 to about 0.5 percent of titanium, from about 0.6 to about 1 percent of carbon, and the balance cobalt.
3. A metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, with the columbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
4. A metal alloy consisting essentially or", by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tun sten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
5. A metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, up to about 0.2 percent of boron, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
6. A metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, With the columbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of zirconium, up to about 0.2 percent of boron, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, and the balance cobalt.
7. A metal alloy consisting essentially of, by Weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of the zirconium, from about 0.6 to about 1.3 percent of carbon, up to about 1.5 percent of silicon, up to about 5 percent of nickel, up to about 5 percent of iron, and the balance cobalt.
8. A metal alloy consisting essentially of, by weight, from about 15 to about 28 percent of chromium, from about 5 to about 15 percent of tungsten, from about 0.5 to about 20 percent of tantalum, up to about 3 percent of columbium, with the eolumbium content not more than about 50 percent of the amount of tantalum in the alloy, from about 0.01 to about 3 percent of titanium, zirconium in an amount such that, if the amount of titanium is more than 0.5 percent, the combined amount of titanium and zirconium is equal to or less than 3 percent, and if the amount of titanium is equal to or less than 0.5 percent, titanium is more than about 70 percent of the zirconium, up to about 0.2 percent of boron, up to about 3.5 percent of molybdenum, with the molybdenum content not more than about 50 percent of the amount of tungsten in the alloy, from about 0.6 to about 1.3 percent of carbon, up to about 1.5 percent of silicon, up
11 to about 5 percent of nickel, up to about 5 percent of iron and the balance cobalt.
9. A metal alloy consisting essentially of, by weight, from about 16 to about 25 percent of chromium, from about 7.5 to about 12.5 percent of tungsten, up to about 3.5 percent of molybdenum, from about 7 to about 11 percent of tantalum, up to about 3 percent of colurnbium, from about (1.08 to about 0.5 percent of titanium, zirconium in an amount such that the amount of titanium is more than 70 percent, the amount of zirconium in the alloy, from about 0.6 to about 1 percent of carbon, up to about 0.2 percent of boron, up to about 1.5 percent of silicon, up to about 2.5 percent of nickel, up to about 2.5 percent of iron, and the balance cobalt.
7 References Cited in the file of this patent UNITED STATES PATENTS 2,247,643 Rohn et a1 July 1, 1941 Johnson July 18, Binder July 20, Malcolm Nov. 20,
FOREIGN PATENTS Great Britain Mar. 6, Great Britain Ian. 21, Canada June 25,
OTHER REFERENCES Materials and Methods, September 1953; Number 260,
page 139.

Claims (1)

1. A MATERIAL ALLOY CONSISTING ESSENTIALLY OF, BY WEIGHT, FROM ABOUT 15 TO ABOUT 28 PERCENT OF CHROMIUM, FROM ABOUT 5 TO ABOUT 15 PERCENT OF TUNGSTEN, FROM ABOUT 0.5 TO ABOUT 20 PERCENT OF TANTALUM, FROM ABOUT 0.01 TO ABOUT 3 PERCENT OF TITANIUM, FROM ABOUT 0.6 TO ABOUT 1.3 PERCENT OF CARBON, AND THE BALANCE COBALT.
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US3205055A (en) * 1960-06-24 1965-09-07 Saint Gobain Metallic elements adapted to come in contact with melted glass
US3223522A (en) * 1963-01-31 1965-12-14 John J Rausch Chromium, tungsten cobalt base alloys containing additions of tantalum, titanium and niobium
US3241954A (en) * 1963-08-29 1966-03-22 Martin Metals Company Cobalt-base alloy
US3271140A (en) * 1964-03-26 1966-09-06 John C Freche High temperature cobalt-base alloy
US3276865A (en) * 1964-06-15 1966-10-04 John C Freche High temperature cobalt-base alloy
US3314784A (en) * 1963-11-21 1967-04-18 Union Carbide Corp Cobalt-base alloy resistant to thermal shock
US3353986A (en) * 1963-11-20 1967-11-21 Sperry Rand Corp Electroless deposition of cobalt-ironphosphorous magnetic material
FR2318236A1 (en) * 1975-07-14 1977-02-11 Westinghouse Electric Corp COBALT-BASED ALLOYS
US4938805A (en) * 1984-12-04 1990-07-03 General Electric Company Novel cobalt-base superalloy and cast and welded industrial gas turbine components thereof and method

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GB443821A (en) * 1934-07-14 1936-03-06 Heraeus Vacuumschmelze Ag Improvements in the manufacture of cobalt-tungsten-chromium alloys
US2247643A (en) * 1938-12-24 1941-07-01 Rohn Wilheim Hardening cobalt-nickel-chromium-iron alloys
US2515774A (en) * 1945-05-23 1950-07-18 Gen Electric High-temperature alloy
GB686180A (en) * 1949-10-29 1953-01-21 Jessop William & Sons Ltd Improvements in or relating to alloys
US2684299A (en) * 1949-11-02 1954-07-20 Union Carbide & Carbon Corp Cobalt base alloys and cast articles
US2771360A (en) * 1954-09-22 1956-11-20 Chapman Valve Mfg Co Cobalt base alloy
CA542813A (en) * 1957-06-25 F. Richardson Bruce Hard surfaced non-ferrous articles and method for making the same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA542813A (en) * 1957-06-25 F. Richardson Bruce Hard surfaced non-ferrous articles and method for making the same
GB443821A (en) * 1934-07-14 1936-03-06 Heraeus Vacuumschmelze Ag Improvements in the manufacture of cobalt-tungsten-chromium alloys
US2247643A (en) * 1938-12-24 1941-07-01 Rohn Wilheim Hardening cobalt-nickel-chromium-iron alloys
US2515774A (en) * 1945-05-23 1950-07-18 Gen Electric High-temperature alloy
GB686180A (en) * 1949-10-29 1953-01-21 Jessop William & Sons Ltd Improvements in or relating to alloys
US2684299A (en) * 1949-11-02 1954-07-20 Union Carbide & Carbon Corp Cobalt base alloys and cast articles
US2771360A (en) * 1954-09-22 1956-11-20 Chapman Valve Mfg Co Cobalt base alloy

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205055A (en) * 1960-06-24 1965-09-07 Saint Gobain Metallic elements adapted to come in contact with melted glass
US3223522A (en) * 1963-01-31 1965-12-14 John J Rausch Chromium, tungsten cobalt base alloys containing additions of tantalum, titanium and niobium
US3241954A (en) * 1963-08-29 1966-03-22 Martin Metals Company Cobalt-base alloy
US3353986A (en) * 1963-11-20 1967-11-21 Sperry Rand Corp Electroless deposition of cobalt-ironphosphorous magnetic material
US3314784A (en) * 1963-11-21 1967-04-18 Union Carbide Corp Cobalt-base alloy resistant to thermal shock
US3271140A (en) * 1964-03-26 1966-09-06 John C Freche High temperature cobalt-base alloy
US3276865A (en) * 1964-06-15 1966-10-04 John C Freche High temperature cobalt-base alloy
FR2318236A1 (en) * 1975-07-14 1977-02-11 Westinghouse Electric Corp COBALT-BASED ALLOYS
US4938805A (en) * 1984-12-04 1990-07-03 General Electric Company Novel cobalt-base superalloy and cast and welded industrial gas turbine components thereof and method

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CH386698A (en) 1965-01-15

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