Classifications

• • 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
• • 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
  • C22C19/03—Alloys based on nickel or cobalt based on nickel
  • C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
  • C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
  • C22C19/056—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 10% but less than 20%

Definitions

• the present invention relates to nickel base alloys which consist essentially of nickel with substantial proportions of chromium, molybdenum, tantalum, cobalt, titanium and aluminum, which are highly corrosion and erosion resistant at the temperatures encountered in gas turbines and jet engines, in the range of 1700 F. to 2200 F. and have relatively great tensile strength at operating temperatures, as well as the required degree of elongation and creep.
• the alloys of the present inveniton are particularly suited to fulfilling all of the requirements of a blade or vane for gas turbine engines at higher than conventional temperatures and this is shown by the ability of the blades and vanes formed from alloys of the present invention to withstand exceedingly high operating temperatures for short periods of time, or to withstand higher than normal operating temperatures for extended periods of time, dependmg upon whether the engine is intended for military or commercial use.
• alloys of the prior art which are currently used are those disclosed in the United States Patents Nos. 2,948,606, 3,005,704 and 3,061,426, as well as 3,026,198.
• Patent No. 2,948,606 requires a relatively large amount of tungsten and is suitable for use only to a maximum temperature of 2000 F., and generally at a much lower temperature, such as 1800 F.
• Patent No. 3,005,704 is differentiated from the alloys of the present invention in that it includes no cobalt content in its alloys, and is capable of operating up to a maximum of about 1900 F.
• Patent No. 3,026,198 discloses alloys which require from 20 to 35% of tungsten, and which difler in many other respects from the alloys of the present invention. Furthermore the alloys disclosed in this patentdo not have the properties required for extended operation at temperatures in excess of 2000 F.
• Patent No. 3,061,426 discloses other alloys which have different ratios of the titanium and aluminum content than the alloys of the present invention, and further require the use of substantial amounts of vanadium which are detrimental in the alloys of the present invention. Additionally, the alloys of this patent require no tantalum content, and are adapted for use-only at temperatures of the order of 1700 F. Whereas, alloys according to this patent have a density of 0.308 pound per cubic inch, alloys of the present invention have a density as low as 0.297 pound per cubic inch. Alloys of the present invention generally have an incipient melting point from 20 to 25 F above an alloy of this patent, later referred to herein as alloy #100.
• the alloys of the present invention are characterized by their ability to operate at temperatures in the range of 1700 F. to 2200 F. for relatively long and acceptable periods of time, with adequate strength and other properties so that they may be used as the alloy to form the blades of an extremely efficient gas turbine engine.
• the present invention has for its object the provision of novel and improved high-temperature, corrosion and erosion resistant alloys which are able to withstand prolonged operation at temperatures of about 2000 F. and
• the present invention has for another object the provision of novel and improved high-temperature alloys of the class described which are capable of being cast with relatively consistent results, as distinguished from many prior art alloys which give erratic results, depending upon minute variations in the many variables in the casting process.
• the alloys of the present invention also have relatively high incipient melting temperatures so that they may be heat-treated at higher than normal temperatures and may be operated at temperatures above ordinary operating temperatures with no danger of the blades being weakened by incipient melting.
• the alloys of the present invention show a remarkable combination of strength and ductility at high temperature levels, and are superior to most of those of the prior-art, combining these properties With other properties to an unusually high degree. Additionally, these alloys of the present invention show an unusually high thermal shock resistance which is much better than that of other high strength alloys.
• alloys of the present invention are less susceptible to bowing when used as stator vanes in jet turbine engines than conventional nickel and cobalt base alloys now used for that purpose.
• the alloys of the present invention do not develop a sigma phase after exposure for long periods of time, such as 1000 to 4000 hours at temperatures in the neighborhood of 1500 to 1650 F., as is common with other nickel base alloys of generally similar strength.
• alloys of this invention can be successfully extruded, upset and forged, while conventional nickel base alloys, such as are used for jet turbine blades and vanes, generally are not susceptible to such operations, and inthe few cases where such conventional alloys have been extruded, upset or forged, it has been accomplished with only extreme difiiculty.
• T-he alloys of the present invention respond readily to heat treatment and show solution temperatures as high as 2300" F., and their ready response to aging imparts great stability for long periods of use and restores strength and ductility after exposure to temperature in the region of 2000 R, such as are used in the coating of blades and vanes.
• the alloys of this invention by weight consist essentially of from 5.0% to 12.0% chromium, about 3.0% to 8.0% molybdenum, 2.3% to 10.0% tantalum, 5.0% to 15.5% cobalt, O to 7.0% titanium, 0.0% to 8.0% aluminum, up to 0.25% carbon, up to .050% boron, with zirconium up to 1.0%, balance essentially nickel in a quantity of at least 45%.
• the combined content of the molybdenum and tantalum varies from 5% to 14%
• the combined content of titanium and aluminum varies from 5% to 8.8%.
• manganese and silicon it is preferable to hold manganese and silicon to a maximum of 1.0%, iron to not more than 5.0%, with a low content of phosphorus of about 0.02% maximum and sulphur about 0.02% maximum.
• Deoxidizers such as calcium, magnesium and rare earths can be used in the usual small quantities in the preparation of the alloys.
• composition ranges of the present invention there are narrower ranges which yield the preferred alloy compositions of the present invention, one group comprising higher ranges of chromium content with a relatively high molybdenum content and a relatively low cobalt content, while another group includes alloys having lower ranges of chromium content with lower ranges of molybdenum and higher ranges of cobalt.
• the first is preferred including 3 from 7.5% to 12% by weight of chromium, from 3.0% to 8.0% of molybdenum, about 10% (5.0% to 10.5%) of cobalt, from 2.3% to 10.0% of tantalum, up to 2.5% of titanium and (from 5.0% to 7.0% aluminum.
• the second group includes alloys which include from 5 5% to 8% of chromium, from 3% to 6% of molybdenum, from 4% to 8% of tantalum, from 1% to 2.3% titanium and from 4.0% to 8.0% of aluminum, and from 10% to 15.5% of cobalt, preferably from 13.0% to 15.5%.
• Such alloys will have compositions within the following broad range and one or the other of the following narrower ranges.
• Tungsten Phosphoro Sulfur Nickel. Balance Balance
• the balance of the alloys is essentially nickel, but may include trivial or trace amounts of various impurities such as the following elements in amounts of substantially the following weight percentages as maximum amounts Tungsten (maximum) for each of the several elements:
• composition range for the alloys of my present invention are as follows:
• alloys and 102 are of the:
• Standard tensile strength test specimens at room temperature showed an ultimate tensile strength of 137,000 p.s.i., with 6% elongation and 8.4% reduction in area; and a yield strength with 0.2% elongation of 121,000 p.s.i.
• the alloy of Example No. 2 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed an ultimate tensile strength of 138,000 p.s.i., with 6.0% elongation and 11.5% reduction in area and a yield strength with 0.2% elongation of 114,- 250 p.s.i.
• the alloy of Example No. 3 had the following mechanical properties: 7
• Standard tensile strength test specimens at room temperature showed a tensile strength of 161,000 p.s.i. with 10.0% elongation and 11.0% reduction in area; and a yield strength with 0.2% elongation of 141,000 p.s.i.
• a tensile strength specimen of the cast alloy maintained under continuously applied axial stress of 85,000 p.s.i. ruptured after 367.4 hours, and exhibited an elongation after rupture of 4.7%, and an area reduction of 4.7%.
• the specimen ruptured at 105.1 hours with 4.6% elongation and 4.1% reduction.
• the specimen ruptured at 71.6 hours with 5.3% elongation and 4.8% reduction.
• the specimen ruptured at 2000 F. with 10,-
• the alloy of Example No. 4 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed an ultimate tensile strength of 145,000 p.s.i., and a yield strength with 0.2% elongation of 119,000 p.s.i. 7
• Standard tensile strength test specimens at room ternperature showed a tensile strength of 140,000 p.s.i., with 5.0% elongation and 8.0% reduction in area, and a yield strength with 0.2% elongation of 125,000 p.s.i.
• Example No. 6 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 149,000 p.s.i., with an elongation of 9.0%, and a yield strength with 0.2% elongation of 121,000 p.s.i.
• the alloy of Example No. 8 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 143,000 p.s.i., with an elongation of 8%, and a yield strength with 0.2% elongation of 118,000 p.s.i.
• Standard tensile strength test specimens at room temperature showed a tensile strength of 142,000 p.s.i., with an elongation of 11.0%, and a yield strength with 0.2% elongation of 112,000 p.s.i.
• the alloy of Example No. 9 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 141,000 p.s.i., with 8.0% elongation, and a yield strength with 0.2% elongation of 119,000 p.s.i.
• test specimen showed an ultimate strength of 135,000 p.s.i. rupture with 3.0% elongation and 5.0% reduction in area; and a yield strength of 121,000 p.s.i. at 2% elongation.
• Alloys similar to those of Examples 6 to 10 may be heat treated and forged to yield forgings which display greatly superior properties, as compared with the alloys of the prior art.
• the coated specimens were subjected to the procedure set forth in United States Patent No. 3,102,044 using 2000 F. for 4 hours, followed by heating at 1600 F. for 50 hours, while the sixth specimen above was subjected to the same temperatures but without any coating material.
• the alloy compositions were:
• Nickel Balance Balance In a standard, low-cycle, thermal fatigue test in the first stage of a gas turbine of the airplane type, the blades were operated at a temperature somewhat in excess of 1800 R, for 1000 cycles, each cycle consisting of 2 minute-s of hot operation followed by 8 minutes of cold operation.
• Maximum blade extension was 40% of the maximum blade extension of blades of Alloy U-700.
• the alloy of Example No. 13 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 138,000 p.s.i., with 7.0% elongation and an area reduction of 7.8%; and a yield strength with 0.2% elongation of 118,000 p.s.i.
• Example No. 11 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 157,000 p.s.i., with 10.0% elongation, and a yield strength with 0.2% elongation of 126,000 p.s.i.
• the alloy of Example No. 12 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 139,000 p.s.i., with 5.0% elongation, and an area reduction of 8.2%;
• tensile strength specimens showed an ultimate strength of 144,000 p.s.i., an elongation of 5.0% and a reduction in area of 7.8%; and a yield strength with 0.2% elongation of 122,000 p.s.i.
• the alloy of Example No. 14 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 136,000 p.s.i., with 7.0% elongation, an area reduction of 6.5%; and a yield strength with 0.2% elongation of 113,000 p.s.i.
• the alloy of Example No. 15 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 148,000 p.s.i., with 6.0% elongation and 10.2% reduction in area; and a yield strength with 0.2% elongation of 122,000 p.s.i.
• Example No. While the alloy of Example No. does not exhibit unusually good tensile and rupture properties at high temperature, it is an excellent alloy which can be rolled, forged or extruded to form shielding and to provide sheeting which have good corrosion and erosion properties at high temperatures.
• Example No. 16 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 137,500 p.s.i., with 7.0% elongation and 10.0% reduction in area, and a yield strength with 0.2% elongation of 116,250 p.s.i.
• Standard tensile strength test specimens at 1400 F. temperature showed a tensile strength of 141,000 p.s.i., with 5.0% elongation, 8.0% reduction vin area and a yield strength with 0.2% elongation of 119,000 p.s.i.
• the alloy of Example No. 17 had the following mechanical properties:
• RUPTURE TESTS 1 3 perature showed a tensile strength of 145,000 p.s.i., with 14.0% elongation and 13.7% reduction in area; and a yield strength with 0.2% elongation of 110,000 p.s.i.
• the specimen showed an ultimate tensile strength of 113,000 p.s.i. and on rupture an elongation of Temp 0 Load, psi, Hours E1" percent 3.0%, an area reduction of 9.1%; and a yield strength at .2% elongation of 105,000 p.s.1.
• Standard tensile strength test specimens at room temperature showed a tensile strength of 141,000 p.s.i., with a 5.0% elongation and 7.8% reduction in area; and a yield strength with 0.2% elongation of 130,000 p.s.i.
• a tensile strength specimen of the cast alloy maintained under continuously applied axial stress of 29,000 p.s.i. ruptured after 38.9 hours, and exhibited an elongation after rupture of 7.0%, and an area reduction of 4.8%.
• the alloy of Example No. 19 had the following mechanical properties:
• Standard tensile strength test specimens at room temperature showed a tensile strength of 125,000 p.s.i., with 13.0% elongation and 21.0% reduction in area; and a yield strength with 0.2% elongation of 95,000 p.s.i.
• test specimens showed an ultimate tensile strength of 129,000 p.s.i. with an elongation of 5.0% and a reduction in area of 6.2%.
• the alloy of Example No. 20 had the following mechanical properties:
• alloys that tend to show good strength at 1700 F. to 1800" F. fall oif markedly when reaching 1900 F. with a load of 20,000 p.s.i. or more.
• the al- .loys of the present invention generally average 30 or more hours at 1900 F. with 20,000 p.s.i. and with an elongation of 5.0% or better.
• alloys such as the alloy of Example No. 21 have more than a 200 hour life at 2000 F. 8,000 p.s.i., with 9.0% elongation and great strength between 1200 F. and 1700 F.
• Example No. 21 is among the preferred vacuum melted alloys of this invention and standard test specimens show excellent oxidation and erosion resistance when subjected to a jet engine burner-can flame at rates 18 V Water for /2 minute, with a water flow at 250 pounds per hour, the test specimens being rotated at 1750 rpm. gave the following comparative data, expressed in hours before incipient crackingwas observed:
• Example No. 23 had the following me chanical properties:
• Example 24 A similar alloy to Example 24 from a diflerent heat and Test results on the alloys of Examples Nos. 24 and 25 are shown in the following tables:
• TENSILE STRENGTH TESTS Example .2% El0ng., Ult., p.s.i. Elongation, Reduetlon'in p.s.i. percent area (percent) 1400 F. TENSILE STRENGTH TESTS No. 24 117, 250 143, 500 5. 0 8.0 No. 25 117, 250 142, 000 4. 0 8.0
• the alloys of the present invention may be extruded from a 5" or 6" ingot to as small as 1.1 and 6" ingots have been extruded and then rolled to form a bar as long as 40 feet.
• the alloys of the present invention are exceptionally Well suited for use in the manufacture of blades for gas turbines and in such use are comparable in strength at 1800 to 1900" F. with blades made from alloy #101, are better than blades made from alloy and much better than blades made from al-loy #102
• the alloys of the present invention in general exhibit better static oxidation resistance than alloys #100, #101 and #102, and show no grain boundary attack at temperatures in excess of 2000 F.
• the present alloys produce excellent cast structures of great uniformity, which can be fully solutioned at about 2250 F. and can therefore be stabilized and aged for greater strength and ductility and are comparable with certain alloys containing 18% or more of cobalt, while having better overall properties including excellent oxidation and erosion properties.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percent ranges set forth:
• the balance of the alloy being essentially nickel, the total of the molybdenum and tantalum being from 5% to 14% and the total of the aluminum and titanium being from 5% to 8.8%.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percent ranges set forth:
• the balance of the alloy being essentially nickel, the total of the molybdenum and tantalum being from 5% to 14% and the total of the aluminum and titanium being from 5% to 8.8%.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the Weight percent ranges set forth:
• the balance of the alloy being essentially nickel, the total of the molybdenum and tantalum being from 7% to 13% and the total of the aluminum and titanium being from 5.5% to 8%.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percent ranges set forth:
• the balance of the alloy being essentially nickel, the total of the molybdenum and tantalum being from 7% to 12.2% and the total of the aluminum and titanium being from 5.4% to 8.8%.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percent ranges set forth:
• the balance of the alloy being essentially nickel, the total of the molybdenum and tantalum being from 9.75% to 11.25% and the total of the aluminum and titanium being 6.55% to 7.45%.
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percentages set forth:
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percentages set forth:
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percentages set forth:
• a corrosion resistant nickel-base alloy for use at relatively high temperatures consisting essentially of the following elements in the weight percentages set forth:

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• 0
  • GB GB1052561D patent/GB1052561A/en active Active
• 1964
  • 1964-07-10 US US381932A patent/US3310399A/en not_active Expired - Lifetime
• 1965
  • 1965-07-07 DE DE19651783138 patent/DE1783138A1/de active Granted
  • 1965-07-08 CH CH959465A patent/CH452903A/fr unknown
  • 1965-07-09 SE SE09128/65A patent/SE338868B/xx unknown
  • 1965-07-09 BE BE666656D patent/BE666656A/xx unknown
  • 1965-07-09 NL NL6508887A patent/NL6508887A/xx unknown
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