Friction spot sealing of a defect area in a workpiece

Patent metadata

Field	Value
Publication number	US-2018222000-A1
Application number	US-201715423899-A
Country	US
Kind code	A1
Filing date	Feb 3, 2017
Priority date	Feb 3, 2017
Publication date	Aug 9, 2018
Grant date	—

Abstract

A method for reducing leakage through a defect area of a reactor component (or other workpiece), apparatus for performing the method, and product formed therefrom are disclosed. The method includes forming first and second spot material portions on the reactor component by friction-sealing first and second parts of a consumable structure to first and second positions of the reactor component. The friction-sealing includes pressing the consumable structure against the first and second positions of the reactor component while using a machine to rotate and/or oscillate the consumable structure, and moving the consumable structure away from the reactor component in between the forming the first and second spot material portions. The first and second positions of the reactor component are different and include a portion of the defect area. At least one of the first and second spot material portions overlaps the portion of the defect area.

First claim

1 . A method for reducing leakage through a defect area defined in a reactor component, the method comprising:
forming a first spot material portion on the reactor component by friction-sealing a first part of a consumable structure to the reactor component at a first position of the reactor component, the friction-sealing the first part including pressing the consumable structure against the first position of the reactor component while using a machine to at least one of rotate and oscillate the consumable structure; moving the consumable structure away from the reactor component to face a second position of the reactor component; and forming a second spot material portion on the reactor component by friction-sealing a second part of the consumable structure to the reactor component at the second position of the reactor component, the friction-sealing the second part including pressing the consumable structure against the second position of the reactor component while using the machine to at least one of rotate and oscillate the consumable structure, the first and second positions of the reactor component being different positions and including a portion of the defect area such that at least one of the first and second spot material portions overlaps the portion of the defect area.

2 . The method of claim 1 , wherein the friction-sealing the first part includes pressing the consumable structure against the first position of the reactor component while using the machine to rotate the consumable structure in a non-oscillatory manner.

3 . The method of claim 1 , wherein the friction-sealing the first part includes pressing the consumable structure against the first position of the reactor component while using the machine to oscillate the consumable structure in one of a linear and a rotational manner.

4 . The method of claim 1 , wherein
the reactor component includes at least one of stainless steel, carbon steel, nickel-based steel, low-alloy steel, and chromium-based steel, a thickness of the first spot material portion is in a range of 0.1 mm to 6.0 mm, and a width of the first spot material portion is in a range of 1 mm to 25 mm.

5 . The method of claim 1 , wherein
the consumable structure includes at least one metal, the forming the first spot material portion by friction-sealing includes pressing the consumable structure against the first position of the reactor component using a pressure, a contact time, and a motion speed of the consumable structure that are sufficient to plasticize the first part of the consumable structure without heating the reactor component above a melting point of the reactor component, and the motion speed corresponds to one of a rotational speed, a rotational oscillation frequency, and a linear oscillation frequency.

6 . The method of claim 5 , wherein
the consumable structure includes a same material as the reactor component, the consumable structure has a rod shape, and a diameter of the consumable structure is a range from 1 mm to 25 mm.

7 . The method of claim 5 , wherein
the consumable structure has a rod shape, and the consumable structure includes at least one noble metal.

8 . The method of claim 1 , wherein
at least one of the forming the first spot material portion and the second spot material portion is performed while the reactor component is underwater, the reactor component is an internal reactor component for use inside the reactor, the reactor component has been highly irradiated, and the reactor is a nuclear reactor.

9 . The method of claim 8 , wherein the reactor component is a shroud.

10 . The method of claim 8 , wherein the reactor component is a steam separator.

11 . The method of claim 1 , further comprising:
forming a bridge over at least part of the defect area without using a fusion welding process, wherein the defect area is one of a crack, an opening, and a gap defined in the reactor component, the forming the bridge includes forming a plurality of spot material portions on the reactor component by friction-sealing parts of the consumable structure on different parts of the reactor component along the defect area while using the machine to position and at least one of rotate and oscillate the consumable structure, each of the plurality of spot material portions overlaps another one of the plurality of spot material portions in a pattern that overlaps the defect area, and the forming the bridge includes the forming a first spot material portion and the forming a second spot material portion.

12 . The method of claim 11 , wherein
the forming the bridge includes forming the bridge to have a width and a length that are greater than a width and a length of the defect area such that at least one of the plurality of spot material portions bonds to locations of the reactor component that are adjacent to the defect area, and the forming the bridge includes moving the consumable structure away from contacting the reactor component after forming one of the plurality of spot material portions and repositioning the consumable structure to contact a different part of the reactor component before forming a next spot material portion among the plurality of spot material portions.

13 . The method of claim 1 , further comprising:
forming a bridge over a region of the reactor component without using a fusion welding process, wherein the region of the reactor component includes the defect area, the forming the bridge includes forming a plurality of spot material portions on the reactor component by friction-sealing parts of the consumable structure to different parts of the region of the reactor component while using the machine to position and at least one of rotate and oscillator the consumable structure, each one of the plurality of spot material portions partially overlaps at least one other spot material portion among the plurality of spot material portions to form a pattern that corresponds to the region of the reactor component, and the forming the bridge includes the forming a first spot material portion and the forming a second spot material portion.

14 . The method of claim 13 , wherein the forming the bridge includes moving the consumable structure away from contacting the reactor component after forming one of the plurality of spot material portions and repositioning the consumable structure to contact a different part of the reactor component before forming a next spot material portion among the plurality of spot material portions.

15 . The method of claim 1 , further comprising:
coupling the consumable structure to the machine before the forming a first spot material portion, wherein the machine includes a motor.

16 . The method of claim 1 , further comprising:
mapping locations of a plurality of defects in the defect area using an instrument; selecting defects among the plurality of defects based on at least one dimension of the plurality of defects; forming bridges over the selected defects without using a fusion welding process, wherein the forming the bridges includes forming a plurality of spot material portions on the reactor component by friction-sealing parts of the consumable structure to different parts of the reactor component while using the machine to position and at least one of rotate and oscillate the consumable structure, the forming the bridges includes retracting the consumable structure from the reactor component after forming each corresponding one of the plurality of spot material portions and repositioning the consumable structure to contact a different

Assignees

• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Offer Henry Peter

Classifications

• B23K20/26

  Auxiliary equipment · CPC title

• B23P6/04 Primary

  Repairing fractures or cracked metal parts or products, e.g. castings · CPC title

• B23K20/1215

  for other purposes than joining, e.g. built-up welding · CPC title

• B23K20/129

  specially adapted for particular articles or work · CPC title

• G21C19/207

  Assembling, maintenance or repair of reactor components (G21C3/334 takes precedence) · CPC title