Tie shaft for gas turbine engine and flow forming method for manufacturing same
AssigneeUnited Technologies Corporation
InventorsDaniel Benjamin, Steve A. McLeod, Daniel R. Kapszukiewicz, Larry James Timmons, Paul D. Genereux
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Abstract
A method is disclosed for manufacturing a tie shaft for aero or land based gas turbine engine. The method includes flow forming a tie shaft preform to produce a tie shaft. In one example, the tie shaft includes a nickel alloy cylindrical wall having a length to diameter ratio of at least 6:1, wherein the diameter is an average outer diameter. The wall includes a minimum effective strain of 0.3 in/in (7.6 mm/mm), and a grain size is in the range of G4 to G16 per ASTM E112. The wall includes a roll formed threaded surface having a thread roughness of less than 1260 μin (32 microns).
Claims13
A method of manufacturing a tie shaft for a gas turbine engine comprising:
- melting a nickel alloy using vacuum induction melting;
- vacuum arc remelting the nickel alloy to produce a tie shaft preform;
- flow forming the tie shaft preform to produce a near net shape tie shaft, wherein the tie shaft preform has a wall thickness, the flow forming step reducing the preform wall thickness by a minimum of 30%;
- and
- rolling threads onto the tie shaft to produce a threaded surface, wherein the threaded surface has a thread roughness of less than 1260 μin.
A method of manufacturing a tie shaft for a gas turbine engine comprising:
- melting a steel alloy using vacuum induction melting;
- vacuum arc remelting the steel alloy to produce a tie shaft preform;
- flow forming the tie shaft preform to produce a near net shape tie shaft, wherein the tie shaft preform has a wall thickness, the flow forming step reducing the preform wall thickness by a minimum of 30%;
- and
- rolling threads onto the tie shaft to produce a threaded surface, wherein the threaded surface has a thread roughness of less than 1260 μin.
Dependencies are inferred from the claim text.