Method and device for repairing a defective zone of the wall of a metal part and in particular of a tubular part
AssigneeFramatome
InventorJean Pierre Cartry
Life of this patent
Estimating the term…
Abstract
The metal of the wall of the part (13a) in a zone which includes defects such as cracks is melted, over a defined depth, by moving over the surface of the part with the aid of a melting device (21), and then solidified. Next, a surface layer of the metal of the wall of the part (13a) which has been melted and then solidified is subjected to compression by repeated impacts of solid particles. The melting is preferably performed by a transferred-arc plasma (22) and the compression by balls set into motion by a vibrating part. The invention applies in particular to the repair of a tubular adaptor (13a) penetrating the head (1) of a nuclear-reactor vessel.
Claims18
Method for repairing a defective zone of a wall of a metal part having a defective zone, said method comprising the steps of:
- (a) moving a heat-source over said defective zone of said wall;
- (b) melting the metal of said wall in said defective zone over a defined depth through said heat-source;
- (c) allowing said metal after melting to solidify into a solidified metal layer of said wall;
- and
- (d) subjecting at least a surface layer of said solidified metal layer of said wall to compression by repeated impacts of balls set into motion in the vicinity of the solidified metal layer of the wall by vibrating means.
Method for repairing a defective zone of a wall of an adaptor for penetrating a head of a vessel of a pressurized-water nuclear reactor, in which a thermal sleeve is arranged, a metal of said wall exhibiting defects in a defective zone of said wall, said method comprising the steps of:
- (a) cutting said thermal sleeve of said adaptor to be repaired by one of cutting tool, water-jet or electrical-discharge machining;
- (b) extracting said thermal sleeve of said adaptor;
- (c) inspecting an internal surface of said adaptor by one of eddy currents, ultrasound and liquid penetration, so as to locate a zone to be repaired;
- (d) melting with the aid of a heat source and solidifying the metal of said wall of said adaptor, in said defective zone;
- (e) subjecting a surface layer of said metal of said wall of said adaptor, at least in said defective zone, after melting and solidifying, to repeated impacts of balls set into motion in a vicinity of said surface layer by vibrating means;
- (f) inspecting the zone of said adaptor which has been melted, solidified and compressed by using one of eddy currents and ultrasound;
- and
- (g) positioning a new thermal sleeve inside said adaptor.
Device for repairing a defective zone of an internal surface of a tubular part, said device comprising
- (a) a melting device having a generally tubular shape and a diameter which is less than an internal diameter of said tubular part;
- (b) a tool for subjecting said internal surface of said tubular part to compression by repeated impacts of balls, comprising an exciter connected to a high-frequency current source and including a vibrating portion, as well as a vibrating shaft connected to said vibrating portion of said exciter and including an end portion which has a symmetric concave external surface of revolution about an axis of said vibrating shaft and is delimited by two portions of diametrally-enlarged circular cross-section, the diameter of which is less than the internal diameter of said tubular part and means for centering said shaft in coaxial position inside said tubular part;
- and
- (c) means for moving said melting device and said tool in an axial direction of said tubular part.
Dependencies are inferred from the claim text.