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A heat treatment process that will restore the mechanical properties of an aircraft engine article that includes a cast nickel-based superalloy portion welded to a wrought portion. The heat treatment process includes placing an article that includes the nickel-based superalloy cast portion into a he

A heat treatment process that will restore the mechanical properties of an aircraft engine article that includes a cast nickel-based superalloy portion welded to a wrought portion. The heat treatment process includes placing an article that includes the nickel-based superalloy cast portion into a heat treatment chamber, evacuating the chamber to a suitable atmosphere, heating the chamber in a manner that minimizes distortion of the cast portion to a temperature in the range of 1950° F. to 2050° F., holding the temperature in that range for a period of time sufficient to solution all the delta phase precipitates, and then cooling the article to room temperature in a manner that minimizes distortion of the article. After solution heat treatment, the wrought portion of the engine part can be removed and replaced and the engine article can be reprocessed.

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1. A heat treatment process for restoring the properties of an aircraft engine article having a cast portion comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molyb

1. A heat treatment process for restoring the properties of an aircraft engine article having a cast portion comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel and a forged portion that has been subjected to repeated thermal cycles below the δ solvus comprising the steps of:providing an article comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel to be treated;heating the article in a non-oxidative atmosphere, at a rate to minimize distortion of the article, to a temperature in a range of about 975° F. to about 1025° F. and stabilizing the temperature of the article in this temperature range;within 60 minutes of stabilizing the article in the temperature range of about 975° F. to about 1025° F. heating the article to a second temperature in the range of about 1950° F. to about 2150° F.;holding the article at a temperature in the range of about 1950° F. to about 2150° F. for a time sufficient to fully solution precipitates;cooling the article to a temperature in the range of about 1000° F. to about 1200° F. in a protective atmosphere at a rate sufficient to maintain dimensional stability while avoiding the formation of δ phase;cooling the article to room temperature; andremoving the forged portion of the article. 2. The process as in claim 1, wherein the step of heating further includes a non-oxidative atmosphere is a vacuum having a pressure of about 0.5 micron. 3. The process as in claim 1, wherein the process includes welding the treated cast article comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel to new wrought portion article comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel after the cooling step, to yield a repaired article. 4. The process as in claim 3, wherein the process includes heat treating at a temperature in the range of about 1500° F. to about 1600° F, and holding for a first preselected period, followed by lowering the temperature to a temperature in the range of about 1350° F. to about 1450° F. and holding for a second preselected period, followed by lowering the temperature to a temperature in the range of about 1100° F. to about 1200° F. and holding for a third preselected period, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article. 5. The process as in claim 4, wherein the first preselected period is about one hour, the second preselected period is about eight hours, and the third preselected period is about four hours. 6. The process as in claim 1, wherein the process includes welding, after the cooling step, the treated cast article comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, a nd balance nickel to a wrought article, wherein the wrought article is an alloy selected from the group consisting of a nickel-based superalloy having a nominal composition, in weight percent, of about 19 percent chromium, about 12.3 percent cobalt, about 3.8 percent molybdenum, about 3.0 percent titanium, about 1.2 percent aluminum, about 0.01 percent zirconium, about 0.45 percent manganese, about 0.06 percent carbon, about 0.005 percent boron, and balance nickel and a nickel-based superalloy having a nominal composition, in weight percent, of about 19.0 percent chromium, about 10.5 percent cobalt, about 9.5 percent molybdenum, about 3.2 percent titanium, about 1.7 percent aluminum, about 0.01 percent zirconium, about 0.08 percent carbon, about 0.005 percent boron, and balance nickel, to yield a repaired article. 7. The process as in claim 6, wherein the process includes heat treating at a temperature in the range of about 1500° F. to about 1600° F. and holding for a first preselected period, followed by lowering the temperature to a temperature in the range of about 1250° F. to about 1350° F. and holding for a second preselected period, followed by lowering the temperature to a temperature in the range of about 1150° F. to about 1250° F. and holding for a third preselected period, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article. 8. The process as in claim 7, wherein the first preselected period is about one hour, the second preselected period is about eight hours, and the third preselected period is about one hour. 9. The process as in claim 1, wherein the process includes welding the treated cast article of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel to a wrought article comprising a iron-based superalloy having a nominal composition, in weight percent, of about 38 percent nickel, 15 percent cobalt, 0.7 percent aluminum, 1.4 percent titanium, 3 percent niobium, and 41.0 percent iron after the cooling step, to yield a repaired article. 10. The process as in claim 6, wherein the process includes heat treating at a temperature in the range of about 1500° F. to about 1600° F. and holding for a first preselected period, followed by lowering the temperature to a temperature in the range of about 1250° F. to about 1350° F. and holding for a second preselected period, followed by lowering the temperature to a temperature in the range of about 1100° F. to about 1200° F. and holding for a third preselected period, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article. 11. The process as in claim 10, wherein the first preselected period is about one hour, the second preselected period is about eight hours, and the third preselected period is about eight hours. 12. The process as in claim 11, wherein the process includes welding the treated cast article comprising a nickel-based superalloy having a nominal composition, in weight percent, of about 18.5 percent iron, about 18.5 percent chromium, about 5.1 percent niobium, about 3 percent molybdenum, about 0.9 percent titanium, about 0.5 percent aluminum, about 0.04 percent carbon, and balance nickel to a wrought article comprising an iron-based superalloy having a nominal composition, in weight percent, of about 38 percent nickel, about 13 percent cobalt, about 4.7 percent niobium, about 1.5 percent titanium, about 0.15 percent silicon, about 0.03 percent aluminum, and about 42 percent iron after the cooling step, to yield a repaired article. 13. The process as in claim 12, wherein the process includes heat trea ting at a temperature in the range of about 1500° F. to about 1600° F. and holding for a first preselected period, followed by lowering the temperature to a temperature in the range of about 1400° F. to about 1525° F. and holding for a second preselected period, followed by lowering the temperature to a temperature in the range of about 1100° F. to about 1200° F. and holding for a third preselected period, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article. 14. The process as in claim 13, wherein the first preselected period is about one hour, the second preselected period is about sixteen hours, and the third preselected period is about eight hours. 15. The process as in claim 1, wherein the process includes welding the treated cast article comprising a nickel-based superalloy having a nominal composition, in weight percent, to a wrought article comprising an iron-based superalloy having a nominal composition, in weight percent, of about 38.0 percent nickel, about 13.0 percent cobalt, about 4.7 percent niobium, about 1.5 percent titanium, about 0.4 percent silicon, about 0.01 percent carbon, about 0.001 percent boron, and about 42.0 percent iron after the cooling step, to yield a repaired article. 16. The process as in claim 15, wherein the process includes heat treating at a temperature in the range of about 1500° F. to about 1600° F. and holding for a first preselected period, followed by lowering the temperature to a temperature in the range of about 1350° F. to about 1450° F. and holding for a second preselected period, followed by lowering the temperature to a temperature in the range of about 1100° F. to about 1200° F. and holding for a third preselected period, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article. 17. The process as in claim 16, wherein the first preselected period is about one hour, the second preselected period is about eight hours, and the third preselected period is about four hours. 18. The process as in claim 9, wherein the process includes heat treating at a temperature in the range of about 1550° F.±25° F. and holding for about one hour, followed by a heat treatment in the range of about 1325° F.±25° F. for about eight hours, followed by a heat treatment in a temperature in the rage of about 1200° F.±25° F. for about one hour, so as to develop γ′ and γ″, while also relieving welding stresses in the welded article after the step of welding the wrought article to the cast article.