Method and apparatus for performing a localized post-weld heat treatment on a thin wall metallic cylinder
AssigneeKeystone Engineering Company
InventorWayne H. Tuttle
Life of this patent
Estimating the term…
Abstract
A method of performing a localized post weld heat treatment on a weld seam in a thin wall metallic body may include attaching thermocouples to the outside surface of the weld seam and covering the weld seam with a thermal insulating blanket. Cooling bands are attached to the outside of the body on both sides of the weld seam. An inert atmosphere enclosure with inlet and exhaust ports is fitted over the weld seam, thermal insulating blanket, and cooling bands. A power supply and control system for an induction coil or coils situated in close proximity to the weld seam are actuated and the weld seam is subjected to a heat treatment without thermally affecting regions of the metallic body adjacent to the weld seam and external to the cooling bands.
Claims20
A method comprising:
- providing a metallic body with a weld seam, the weld seam having an internal surface and an external surface;
- covering the external surface of the weld seam with an insulating blanket;
- attaching at least two cooling bands for cooling to the external surface of the body with at least one cooling band attached on each side of the weld seam;
- surrounding the weld seam, insulating blanket, and cooling bands with an inert atmosphere enclosure;
- providing an inert atmosphere within the inert atmosphere enclosure;
- providing an inert atmosphere over the internal surface of the body;
- positioning at least one induction coil proximate the weld seam and external to the inert atmosphere enclosure;
- activating the induction coil to subject the weld seam to a heat treatment schedule while cooling regions external to the weld seam with the cooling bands;
- and
- sensing temperature of the weld seam with a temperature sensor and controlling power supplied to the induction coil as a function of the sensed temperature.
An apparatus for performing a localized post-weld heat treatment on a weld seam in a thin wall metallic body with an internal and external surface, the apparatus comprising:
- a thermal insulating blanket covering the external surface of the weld seam;
- at least two cooling bands for cooling on the external surface of the body with at least one cooling band positioned on each side of the weld seam;
- an inert atmosphere enclosure, with an inlet port and an exhaust port, surrounding the cooling bands, the thermal blanket, and the weld seam;
- an inert gas source attached to the inlet port;
- an inert gas atmosphere over the internal surface of the body;
- an induction coil positioned outside the inert atmosphere enclosure proximate the weld seam;
- a temperature sensor positioned to sense temperature of the weld seam;
- and
- a power supply and control system electrically connected to the induction coil and the temperature sensor to supply power to the induction coil as a function of sensed temperature of the weld seam to provide localized post-weld heat treatment.
Dependencies are inferred from the claim text.