System and method of producing autofrettage in tubular components using a flowforming process
A method of producing autofrettage in a tubular component provides a tubular workpiece having an inner diameter and an outer diameter and provides at least two rollers having a displacement from one another in an axial direction with respect to the workpiece. The method places the workpiece on a mandrel such that the inner diameter is adjacent to the mandrel. The method also compresses the outer diameter of the workpiece with the rollers at a temperature below a recrystallization temperature of the workpiece using a combination of axial and radial forces so that the mandrel contacts the inner diameter and imparts a compressive hoop stress to the inner diameter of the workpiece.
1. A method of producing autofrettage in a tubular component, the method comprising:
providing a tubular workpiece having an inner diameter and an outer diameter, wherein the workpiece includes at least one of a nickel-based superalloy, a cobalt-based superalloy, and an iron-based superalloy;
providing at least two rollers having a displacement from one another in an axial direction with respect to the workpiece;
placing the workpiece on a mandrel such that the inner diameter is adjacent to the mandrel; and
compressing the outer diameter of the workpiece with the rollers at a temperature below a recrystallization temperature of the workpiece using a combination of axial and radial forces so that the mandrel contacts the inner diameter and imparts a compressive hoop stress of at least 500 MPa to the inner diameter of the workpiece.
2. The method of claim 1 , further comprising subjecting the workpiece to a precipitation hardening heat treatment after compressing the workpiece.
3. The method of claim 1 , wherein the tubular workpiece is produced by rotary forging, radial forging, rotary swaging, or a combination thereof.
4. The method of claim 1 , wherein the mandrel further imparts a rifling to the inner diameter of the workpiece.
5. A tubular component produced according to the method of claim 1 .
6. A method of producing a superalloy tubular component, the method comprising:
providing a tubular workpiece having an inner diameter and an outer diameter, the workpiece made of a superalloy material comprising at least one of a nickel-based superalloy, a cobalt-based superalloy, and an iron-based superalloy;
placing the workpiece on a mandrel such that the inner diameter is adjacent to the mandrel; and
compressing the outer diameter of the workpiece at a temperature below a recrystallization temperature of the workpiece using a combination of axial and radial forces so that the mandrel contacts the inner diameter and imparts a compressive hoop stress of at least 500 MPa to the inner diameter of the workpiece.
7. The method of claim 6 , further comprising subjecting the workpiece to a precipitation hardening heat treatment after compressing the workpiece.
8. The method of claim 6 , wherein the tubular workpiece is produced by rotary forging, radial forging, rotary swaging, or a combination thereof.
9. The method of claim 6 , wherein the mandrel further imparts a rifling to the inner diameter of the workpiece.
10. A tubular component produced according to the method of claim 6 .
11. A method of producing a superalloy gun barrel, the method comprising:
providing a tubular workpiece having an inner diameter and an outer diameter, wherein the inner diameter is about one inch or less and the workpiece is made of a superalloy material comprising at least one of a nickel-based superalloy, a cobalt-based superalloy, and an iron-based superalloy;
placing the workpiece on a mandrel such that the inner diameter is adjacent to the mandrel; and
compressing the outer diameter of the workpiece at a temperature below a recrystallization temperature of the workpiece using a combination of axial and radial forces so that the mandrel contacts the inner diameter and imparts a compressive hoop stress of at least 500 MPa to the inner diameter of the workpiece.
12. The method of claim 11 , further comprising subjecting the workpiece to a precipitation hardening heat treatment after compressing the workpiece.
13. The method of claim 11 , wherein the tubular workpiece is produced by rotary forging, radial forging, rotary swaging, or a combination thereof.
14. The method of claim 11 , wherein the mandrel further imparts a rifling to the inner diameter of the workpiece.
15. The method of claim 11 , wherein compressing the outer diameter is done by a flowforming process, a rotary forging process, a rotary swaging process, or a combination thereof.
16. A superalloy gun barrel produced according to the method of claim 11 .
17. A superalloy liner produced according to the method of claim 11 , the liner to be used within an inner diameter of a gun barrel.