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Publication numberUS2994605 A
Publication typeGrant
Publication dateAug 1, 1961
Filing dateMar 30, 1959
Priority dateMar 30, 1959
Publication numberUS 2994605 A, US 2994605A, US-A-2994605, US2994605 A, US2994605A
InventorsGill Robert F, Wukusick Carl S
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
High temperature alloys
US 2994605 A
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Description  (OCR text may contain errors)

Aug. 1, 1961 R. F. GILL ETAL HIGH TEMPERATURE ALLOYS Filed March 30, 1959 M9 8 7 6 i 4 3 2 26V QX kkwwkkw $393k l moo "F TEMPE HA TUFrE [/vvE/v ToRs: RQBERT F G/LL, CARL S. WUKUS/C/f,

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United States Patent 2,994,605 HIGH TEMPERATURE ALLOYS Robert F. Gill, Schenectady, N.Y., and Carl S. Wuknsick,

Cincinnati, Ohio, assignors to General Electric Company, a corporation of New York Filed Mar. 30, 1959, Ser. No. 802,783 6 Claims. (Cl. 75--171) This invention relates to high temperature alloys for use at temperatures of over 1000 F. and to a process for improving the characteristics of such alloys. More particularly, it relates to alloys which have desirable high temperature, tensile, yield and creep-rupture strengths, and high creep-rupture ductilities, which are structurally stable and have low embrittlement in service, are readily fabricated by welding, are resistant to steam corrosion and have a coeflicient of thermal expansion which will match that of ferritic materials.

The family of alloys containing 40 to 80 percent nickel, 10 to percent chromium, balance-iron, is well known. Also known is the improvement of the creep-rupture strength of such alloys by the addition of combinations of columbium (niobium) and titanium and aluminum to produce an age hardening reaction which requires a twostep heat treatment such as a high temperature treatment to dissolve the titanium bearing constituents followed by a lower temperature treatment to reprecipitate the titanium containing component in a controlled manner to achieve high strengths. Alloys so constituted and treated have high tensile, yield and creep-rupture strengths and low creep-rupture ductilities. Omission of the titanium and aluminum results in improved creep-rupture ductility but substantially lowered tensile, yield, and creep-rupture strengths. Table I below shows the rupture stress at 1100" F. and 100,000 hours and the creep-rupture ductility in 1,000 hours at 1100 F. for three alloys of the above family.

The first of the above alloys was heat treated for one hour at 1800 F. and air-cooled and the second alloy was heated at 2050 F. for one hour and air-cooled. The third alloy was heated at 2100 F. for from two to four hours, water quenched and then aged for 24 hours at 1550 F. and for 20 hours at 1300 F.

While the above alloys have suitable properties for some purposes, it is desirable in many applications such as in steam turbine partitions or nozzles to provide creeprupture strength of the order of 43,000 psi along with a creep-rupture ductility of at least 10 percent so that lighter structural members can be used with not only a saving of material, but increased efficiency as where the alloy is to be used in steam turbine partitions and similar applications. The relatively complex heat treatment required to produce the characteristics of the above alloys is also time consuming and costly and where the alloys are to be fabricated by welding and require a stress relief heat treatment, the properties developed by the solution treating and aging cycle are often destroyed in the process.

From the above it will be evident that there is a definite need for alloys of the above general type which will have desirable high temperature characteristics which can be developed by a simple heat treatment and which "ice will not be degraded by subsequent treatment such as by welding or by stress relief heat treatments during fabrication. A principal object, therefore, of the invention is to provide such alloys.

Briefly, the invention comprises alloys for high temperature service which are readily and simply heat treated, have high tensile and yield strength, high creep-rupture strength and high creep-rupture ductility. Furthermore, the alloys are readily malleable and are stress relief annealed without destruction of their desirable physical properties, low tendency toward embrittlement, resistance to corrosion and a thermal coeflicient of expansion which will closely match that of ferritic materials. The alloys have the following percent by weight composition:

Specific Examples Range (Percent) (Percent) 40-80 69. 5 49. 86 10-25 14. 05 14. 63 0. 25-5. 0 l. 9 1. 97 0. 5-8. 0 2. 3. 22 0. 5-8. 0 3. 42 3. 27 0 75 max 0. 024 093 0 25-3. 0 0.88 1. 19 2 0 max 0.35 0.30 2 0 max 0.72 0. 51 0. 2 max. 0.03 0. 035 remainder remainder remainder The alloys are annealed at 1920 F. for about one-half hour and air cooled. A typical annealing temperature range for such alloys is from 1600 F. to 2100 F. at times varying from about one-half hour to one hour per inch thickness of the piece.

Those features of the invention which are believed to be patentable are set forth specifically in the claims appended hereto. The invention Will, however, be better understood and further objects and advantages thereof revealed from a consideration of the following description and the drawing in which the single figure is a plot showing the improved high temperature creep-rupture strength of the present alloys.

The alloys of the invention are prepared by melting in any usual manner the prescribed constituents under an inert gas such as argon, krypton, etc. under vacuum or in air, small amounts of titanium and magnesium being added, typically in the amount of the order of 0.2 percent each and boron typically in the amount of 0.005 percent for deoxidation and desulfurization. The ingots as cast were about 4 inches by 4 inches by 11 inches and were swaged at 1900 F. to 2100 F. to round bars onehalf to three-quarters of an inch in diameter.

Shown in Table II below are indicated room temperature properties of various alloys. The present preferred alloys are designated Examples 1 and 2. Example 3 is essentially the same as Example 1 except that the aluminum was omitted and Example 4 is a prior art alloy having 72 percent nickel, 16 percent chromium, 8 percent iron, 0.14 percent titanium, 0.17 percent manganese, 0.36 percent silicon, 0.04 percent carbon and 2.4 percent columbium.

Table II Yield Strength Tensile Percent Percent Alloy Strength Elonga- Reduction (p.s.i.) 0.2% 0.02% tion in Area Shown in the drawing are the rupture strengths of the alloys of the above examples after 100,000 hours at various temperatures. It will be noted that at 1100 F. the present preferred alloys have creep-rupture strengths of 43,000 to 45,000 psi. whereas the alloy of Example 3 which is substantially the same except for the absence of aluminum has a corresponding value of only about 34,000 psi. A typical prior art alloy (Example 4) containing columbium and titanium among its constituents has a creep-rupture strength under the same conditions of only about 23,000 psi.

Not only is the creep-rupture strength of the present alloys much improved but the creep-rupture ductility is an etficacious 10 percent. Steam turbine partitions and other parts made of the present alloy which is simply annealed as described are readily welded without loss of desirable physical characteristics. Furthermore, their relatively low thermal coeflicient of expansion permits the making of fabricated or welded structures using such alloys in composition with ferritic alloys which have a similar thermal coeflicient of expansion. The present alloys further resist any tendency toward embrittlement which is commonly present in alloys of similar strength in high temperature service.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An alloy for high temperature service consisting essentially of, by weight, from about 40 to 80 percent nickel, about 10 to 25 percent chromium, about 0.25 to 5 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, about 0.5 to 8 percent of a material selected from the group consisting of molybdenum, tungsten and mixtures thereof, a maximum of about 0.75 percent titanium, about 0.25 to 3.0 percent aluminum, a maximum of about 2.0 percent manganese, a maximum of about 2.0 percent silicon, a maximum of about 0.2 percent carbon, with the remainder iron.

2. An alloy for high temperature service consisting essentially of, by weight, about 69.5 percent nickel, about 14.05 percent chromium, about 1.9 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, about 2.75 percent molybdenum, about 3.42 percent tungsten, about 0.024 percent titanium, about 0.88 percent aluminum, about 0.35 percent manganese, about 0.72 percent silicon, about 0.03 percent carbon, with the remainder iron.

3. An alloy for high temperature service consisting essentially of, by weight, about 49.86 percent nickel, about 14.63 percent chromium, about 1.97 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, about 3.22 percent molybdenum, about 3.27 percent tungsten, about 0.093 percent titanium, about 1.19 percent aluminum, about 0.30 percent manganese, about 0.51 percent silicon, about 0.035 percent carbon, with the remainder iron.

4. An alloy for high temperature service consisting essentially of, by weight, from about 40 to percent nickel, about 10 to 25 percent chromium, about 0.25 to 5 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, from about 0.5 to 8 percent of a material selected from the group consisting of molybdenum, tungsten and mixtures thereof, a maximum of about 0.75 percent titanium, about 0.25 to 3.0 percent aluminum, a maximum of about 2.0 percent manganese, a maximum of about 2.0 percent silicon, a maximum of about 0.2 percent carbon, with the remainder iron, said alloy being capable of being heat treated, in a one-step process, at temperatures of from about 1600 F. to about 2100 F.

5. An alloy for high temperature service consisting essentially of, by weight, about 69.5 percent nickel, about 14.05 percent chromium, about 1.9 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, about 2.75 percent molybdenum, about 3.42 percent tungsten, about 0.024 percent titanium, about O.88 percent aluminum, about 0.35 percent manganese, about 0.72 percent silicon, about 0.03 percent carbon, with the remainder iron, said alloy being annealed at about 1920 F. for from about one-half hour to one hour per inch of thickness.

6. An alloy for high temperature service consisting essentially of, by weight, about 49.86 percent nickel, about 14.63 percent chromium, about 1.97 percent of a material selected from the group consisting of columbium and tantalum and mixtures thereof, about 3.22 percent molybdenum, about 3.27 percent tungsten, about 0.093 percent titanium, about 1.19 percent aluminum, about 0.30 percent manganese, about 0.51 percent silicon, about 0.035 percent carbon, with the remainder iron, said alloy being annealed at about 1920 F. for from about onehalf hour to one hour per inch of thickness.

References Cited in the file of this patent UNITED STATES PATENTS 2,299,871 Baird Oct. 27, 1942 2,513,469 Franks et al. July 4, 1950 2,747,993 Johnson May 29, 1956 2,777,766 Binder Jan. 15, 1957 2,781,264 Gresham et al. Feb. 12, 1957

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2299871 *Mar 31, 1941Oct 27, 1942Crobalt IncCutting metal alloy
US2513469 *May 9, 1946Jul 4, 1950Union Carbide & Carbon CorpAlloy articles for use at high temperatures
US2747993 *Dec 26, 1951May 29, 1956Gen ElectricHigh temperature nickel-base alloy
US2777766 *Jun 4, 1952Jan 15, 1957Union Carbide & Carbon CorpCorrosion resistant alloys
US2781264 *Oct 20, 1953Feb 12, 1957Rolls RoyceNickel chromium base alloy and a stationary turbine blade made therefrom
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3151981 *Feb 26, 1962Oct 6, 1964Int Nickel CoNickel-chromium-cobalt alloy
US3167426 *May 4, 1961Jan 26, 1965Freche John CNickel-base alloy
US3276866 *Apr 14, 1964Oct 4, 1966Freche John CNickel-base alloy containing mo-w-al-cr-ta-zr-c-nb-b
US3322534 *Apr 30, 1965May 30, 1967Int Nickel CoHigh temperature nickel-chromium base alloys
US3466171 *Jul 18, 1966Sep 9, 1969Int Nickel CoNickel-chromium-niobium alloy
US3497349 *Sep 19, 1966Feb 24, 1970Gen Motors CorpAir castable nickel alloy valve
US3516826 *Aug 14, 1968Jun 23, 1970Int Nickel CoNickel-chromium alloys
US3619183 *Mar 21, 1968Nov 9, 1971Int Nickel CoNickel-base alloys adaptable for use as steam turbine structural components
US3930904 *Oct 29, 1974Jan 6, 1976The International Nickel Company, Inc.Nickel-iron-chromium alloy wrought products
US4026699 *Feb 2, 1976May 31, 1977Huntington Alloys, Inc.Matrix-stiffened heat and corrosion resistant alloy
US4058416 *Feb 9, 1977Nov 15, 1977Huntington Alloys, Inc.Matrix-stiffened heat and corrosion resistant wrought products
US4225364 *Jun 22, 1978Sep 30, 1980The United States Of America As Represented By The United States Department Of EnergyHigh strength nickel-chromium-iron austenitic alloy
US4231795 *Jun 22, 1978Nov 4, 1980The United States Of America As Represented By The United States Department Of EnergyChromium, iron, molybdenum, and niobium
US4236943 *Jun 22, 1978Dec 2, 1980The United States Of America As Represented By The United States Department Of EnergyPrecipitation hardenable iron-nickel-chromium alloy having good swelling resistance and low neutron absorbence
US4243412 *Jun 7, 1979Jan 6, 1981Sybron CorporationNickel base, corrosion resistance
US4248629 *Aug 22, 1978Feb 3, 1981Acieries Du Manoir PompeyNickel- and chromium-base alloys possessing very-high resistance to carburization at very-high temperature
US4443406 *May 24, 1982Apr 17, 1984Hitachi, Ltd.Heat-resistant and corrosion-resistant weld metal alloy and welded structure
US4487743 *Aug 20, 1982Dec 11, 1984Huntington Alloys, Inc.Improved notch rupture strength; control of silicon
US4685978 *Nov 17, 1983Aug 11, 1987Huntington Alloys Inc.Heat treatments of controlled expansion alloy
US4784831 *Aug 4, 1986Nov 15, 1988Inco Alloys International, Inc.Carburization resistant of iron, nickel, chromium alloys
DE2906163A1 *Feb 17, 1979Jan 10, 1980Westinghouse Electric CorpHochfeste austenitische nickel-chrom- eisen-legierung
DE3234090A1 *Sep 14, 1982Apr 28, 1983United Technologies CorpEinkristall-gegenstand aus einer superlegierung auf nickelbasis
EP0066361A2 *Apr 14, 1982Dec 8, 1982Inco Alloys International, Inc.Corrosion resistant high strength nickel-based alloy
EP0601915A1 *Dec 2, 1993Jun 15, 1994Sima S.A.Nickel base alloy of the quaternary system Ni-Fe-Cr-Mo, gamma prime precipitation-hardening and resisting to corrosive environments, typically occurring in the oil industry
Classifications
U.S. Classification420/448, 420/586.1, 420/451, 420/453
International ClassificationC22C30/00, C22C19/05
Cooperative ClassificationC22C30/00, C22C19/055
European ClassificationC22C19/05P4, C22C30/00