Peening Device for Peening Welds Inside Steel Submarine Pipes, Process for Producing Steel Submarine Pipes Using Such a Device, and Submarine Connection Pipe

Abstract

A peening device suitable for peening annular weld zones inside undersea pipes, the device comprising at least one peening tool, with at least one hammer actuated to perform radial reciprocating movement in translation for peening against the inside surface of the pipe and/or said weld, wherein: said peening tool has a single hammer; and said hammer is pivotally mounted so as to be capable of varying its angle of inclination relative to the surface for peening; and said device includes a carriage suitable for moving in axial longitudinal translation XX inside a pipe and for supporting means for moving said peening tool in longitudinal and radial translation, and in rotation relative to said carriage; and said hammer co-operates with means for actuating radial reciprocating movements in translation by peening by making use of electromagnetic energy and reciprocating motion inside a solenoid coil, preferably also in co-operation with a spring.

1 - 19 . (canceled) 
     
     
         20 . A peening device suitable for peening the insides of undersea pipes made of steel assembled by annular welding of abutting ends of unitary pipe elements, the weld beads being made from the outside of the pipe, said device comprising at least one peening tool suitable for moving in longitudinal axial translation XX in the axial direction of the pipe, and in rotation about said axial longitudinal axis XX of the pipe in the vicinity of said welds inside the pipe, said peening device having at least one hammer comprising:
 a main body constituting a flyweight of elongate shape in a longitudinal direction Y1Y1 for reciprocating movement in translation of said hammer relative to the peening tool and relative to the inside surface of the pipe and the weld for peening; and 
 a rounded element of curvature of convex shape at the end of said flyweight and secured thereto, said rounded element being suitable for coming into contact with said surface for peening, thereby creating impacts in the form of craters under the effect of the kinetic energy of said hammer when it is actuated for peening by performing said reciprocating movements in translation in the radial direction; 
 wherein: 
 a) said peening tool has a single hammer; and 
 b) said hammer is pivotally mounted so as to be capable of varying the angle of inclination of said elongate flyweight and of varying said direction Y1Y1 of relative reciprocating movement in translation of said hammer relative to the radial direction YY; and wherein 
 c) said device comprises:
 a first carriage suitable for moving in axial longitudinal translation XX inside a pipe; 
 said first carriage supporting means for moving said peening tool in relative axial longitudinal translation XX relative to said first carriage; 
 said first carriage supporting means for implementing relative rotation of said peening tool relative to said first carriage about said axial longitudinal axis XX of the pipe; and 
 said first carriage supporting means for moving said peening tool in said radial movement YY relative to said first carriage; and 
 
 d) said peening tool includes means for actuating peening by said radial reciprocating movement in translation by implementing electromagnetic energy, the hammer comprising a said main body made of magnetic material suitable for reciprocating in both directions inside a stationary solenoid coil along the axial direction of said solenoid corresponding to said longitudinal direction Y1Y1 of said hammer under the effect of a magnetic field created inside the solenoid when said solenoid is powered with DC alternately in both directions, said main body also preferably co-operating with a spring. 
 
     
     
         21 . The device according to  claim 20 , wherein the electrical power supply of the solenoid is controlled by a digital control circuit enabling the peening energy to be adapted as a function of the position of the hammer as determined by a sensor. 
     
     
         22 . The device according to  claim 20 , wherein:
 said first carriage is motor driven and supports a first shaft disposed inside the pipe in said axial longitudinal direction XX of the pipe; and   said first shaft supports at least transverse guidance support or means preferably in the form of a beam, suitable for guiding the movement of at least one second carriage in radial translation in a transverse direction perpendicular to said axial longitudinal direction XX, said second carriage supporting said peening tool and said second carriage preferably including means suitable for maintaining said peening tool in a position facing the inside surface of said pipe;   said first shaft includes drive means for causing it to perform controlled rotation about its own said axial longitudinal axis XX so as to be capable of moving said radial transverse guide support and said peening tool in relative rotation over the entire circumference of the inside surface of the pipe; and   said first shaft is preferably suitable for being driven in relative translation relative to said first carriage in said axial longitudinal direction XX of the pipe, at least over a said limited distance L.   
     
     
         23 . The device according to  claim 20 , wherein said first carriage is driven by a motor powered from outside the pipe by an umbilical connection, and said first carriage has wheels pressed against the inside surface of the pipe and guiding said axial longitudinal movement in translation of said first carriage inside the pipe, said wheels being connected to an axial main body of the first carriage by a system of arms mounted as hinged parallelograms. 
     
     
         24 . The device according to  claim 23 , wherein said system of arms mounted as hinged parallelograms comprises three parallelogram structures, each carrying two wheels in alignment on the axial direction XX of the pipe, the three parallelogram structures preferably being distributed uniformly at 120° from one another, and being actuated synchronously by springs or actuators so that the main body of said first carriage remains substantially on the axis XX of said pipe. 
     
     
         25 . The device according to  claim 20 , wherein said convex element is a body of revolution with section of spherical, oval, or parabolic shape, preferably spherical, made of a steel or metallic carbide of greater hardness than said main body of the hammer, and said convex element presents a small dimension in cross-section, in particular a diameter that is small relative to said main body of the hammer. 
     
     
         26 . The device according to  claim 20 , having a plurality of peening tools, each comprising a single said hammer, each peening tool being suitable for being moved independently, and each hammer being suitable for being controlled to perform peening independently. 
     
     
         27 . The device according to  claim 26 , having two peening tools, said first shaft supporting two said second carriages each supporting one said peening tool on a common said transverse guidance support. 
     
     
         28 . The device according to  claim 26 , having four peening tools, said first shaft supporting two said transverse guidance supports offset in the longitudinal and rotary directions, each of said guidance supports being suitable for guiding the movement of two said second carriages in radial translation, each carriage supporting a single said peening tool. 
     
     
         29 . A method of making undersea steel pipes, the method comprising assembling unit pipe elements by end-to-end butt welding, the weld beads of steel or metal alloy of said welds being disposed on the outside of the pipe, wherein localized peening is performed inside the pipe to increase the compression of the steel or the metal at said welds and on the adjacent peripheral inside surface of the pipe on either side of the welds so as to create a swath of peened surface over a limited distance L in the axial longitudinal direction XX of said pipe, preferably a distance L that is not less than the width of the weld, inside the pipe, plus on either side a width lying in the range 1 mm to 10 mm, said peening being performed by creating a plurality of impacts, preferably in the form of adjacent overlapping craters covering the entire surface of said swath, with a device having at least one peening tool according to claim  1 . 
     
     
         30 . The method according to  claim 29 , wherein the weld comprises a main weld bead outside the pipe and a projection or internal seam of smaller thickness projecting from the inside of the pipe, and said peening is performed at least in the transition zone between the inside surface of said seam at the back of the weld bead and the adjacent inside surface of the pipe, by varying the angle of inclination β of the longitudinal direction Y1Y1 of movement in translation of said hammer relative to said direction YY of movement in radial translation of said second carriage. 
     
     
         31 . The method according to  claim 29 , wherein material is removed by prior winding or milling of the inside surface of the pipe and of the weld bead over the surface for peening, prior to said peening. 
     
     
         32 . The method according to  claim 29 , wherein said peening is performed in such a manner as to establish compression or increase compression over a thickness of 0.2 mm to 2 mm in said inside surface of the pipe and of said weld. 
     
     
         33 . The method to  claim 29 , wherein the limited distance L represents one to three times the thickness of the pipe. 
     
     
         34 . The method according to  claim 29 , wherein peening is performed in such a manner as to obtain a compression stress greater that 5 MPa, preferably greater than 50 MPa, over the entire peened surface. 
     
     
         35 . The method according to  claim 29 , wherein:
 said first carriage is moved in translation inside said pipe in said longitudinal axial direction XX, such that said peening tool is substantially positioned so as to be capable of performing peening in said weld zone and on either side thereof over a said distance L for peening astride said weld in said longitudinal axial direction XX; then   said peening tool is moved against or close to the inside surface of the pipe by moving said peening tool in radial translation YY; then   said peening tool is moved in rotation about said axial longitudinal axis XX over the circumference of the inside surface of the pipe; and then   where appropriate, the peening tool is moved in relative translation in the axial longitudinal direction XX relative to said first carriage so as to perform the peening and compression over the entire peened surface.   
     
     
         36 . The method according to  claim 29 , comprising the following successive steps:
 1) in a workshop on land, assembling the respective ends of at least two unit pipe elements together end-to-end by said welding, in order to form pipe strings; and   2) at sea, on board a laying ship fitted with a J-lay tower, assembling respective ends of said strings together by said welding to form a pipe.   
     
     
         37 . An undersea bottom-to-surface connection pipe comprising unit pipe elements that are assembled end-to-end by welding, wherein at least a portion of the pipe includes zones containing said assembly welds between unit pipe elements in which zones the welding comprises a main weld bead outside the pipe with a projection or internal seam of smaller thickness projecting from the inside of the pipe, and in which zones a swath of the inside surface of the pipe in the vicinity of said welds and on either side thereof is peened over a distance L by a plurality of impacts in the form of adjacent overlapping craters covering the entire surface of said swath, the inside surface of said swath being put into uniform compression so as to eliminate any residual traction stresses due to the welding operation, using the method according to  claim 30 . 
     
     
         38 . The undersea bottom-to-surface connection pipe according to  claim 36 , that is a catenary pipe of the SCR type having at least a portion that includes the zone in contact with the bottom and extending over at least 100 m and preferably 200 m above the bottom that has been assembled by a method according to  claim 30 .