CN112059465A - Connecting structure for reactor container and welding process - Google Patents

Abstract

The invention discloses a connecting structure for a reactor vessel, comprising: the inner connecting pipe is positioned in the reactor container, and the inner side wall of the inner connecting pipe is provided with an annular first groove; an annular second groove is formed in the inner side wall of the outlet connecting pipe, one end of the outlet connecting pipe is welded with the inner connecting pipe, and the other end of the outlet connecting pipe penetrates through the reactor container and extends out of the reactor container; after the outlet connecting pipe is welded to the inner connecting pipe, the first bevel and the second bevel form a third bevel; the invention provides a connecting structure for a reactor vessel and a welding process suitable for 360-degree full-position automatic argon arc welding single-side welding and double-side forming of the inner wall of a pipe, wherein a tungsten electrode can be accurately aligned to a welding seam by combining the automatic searching function of the tungsten electrode of a welding machine for touching the side wall of a groove, the groove with wide process parameters and the specific welding process are adopted to obtain good welding seam quality, the welding defects caused by human factors are reduced, and the production rate is improved.

Description

Connecting structure for reactor container and welding process

Technical Field

The invention relates to the field of nuclear power, in particular to a connecting structure for a reactor container and a welding process.

Background

The thorium-based molten salt reactor is the main reactor type of the molten salt reactor in six reactor types of the international forum of the fourth generation nuclear energy system, and is considered to be one of the safest reactor technologies in the future. The energy produced by the fission of 1 kg of thorium is equivalent to the heat produced by burning 3500 tons of standard coal, so that the fuel efficiency of thorium is very high. The all-position butt TIG inner welding (non-consumable electrode gas shielded arc welding) is adopted for field installation of the inlet and outlet connecting pipes of the novel thorium-based molten salt reactor vessel and the internal connecting pipes of the heat exchanger, the depth of a welding line is 411mm, and the position of the butt welding line is shown in figure 1. The external space of the product structure is limited, so that the pipe cannot be welded externally; because the inner diameter of the pipe is small, a high-temperature-resistant molten pool observation system cannot be additionally arranged inside the pipe, only blind welding can be carried out on an inner hole, a molten pool cannot be observed in the welding process, welding parameters cannot be adjusted in real time, the process difficulty is greatly increased, and a groove and a welding process which can deal with group misalignment and gaps and have wide process parameter windows are designed for solving the problems in the prior art.

Disclosure of Invention

The invention aims to provide a connecting structure and a welding process for a reactor container, which can enable a tungsten electrode to accurately align a welding seam by combining an automatic searching function of a tungsten electrode of a welding machine touching the side wall of a groove, obtain good welding seam quality by adopting the groove with wide process parameters and a specific welding process, reduce welding defects caused by human factors and improve the productivity.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a connection structure for a reactor vessel, comprising:

the inner connecting pipe is positioned in the reactor container, and the inner side wall of the inner connecting pipe is provided with an annular first groove;

an annular second groove is formed in the inner side wall of the outlet connecting pipe, one end of the outlet connecting pipe is welded with the inner connecting pipe, and the other end of the outlet connecting pipe penetrates through the reactor container and extends out of the reactor container;

and after the outlet connecting pipe is welded to the inner connecting pipe, the first bevel and the second bevel form a third bevel.

Optionally, the third bevel is a U-shaped bevel, a V-shaped bevel or a Y-shaped bevel.

Optionally, a filler weldment is provided within the third cut.

Optionally, the filler weldment includes a first bead that is welded to the junction of the inner nozzle and the outlet nozzle.

Optionally, the filler weldment includes a number of second beads welded to the first groove and a number of third beads welded to the second groove.

Optionally, the filler weldment includes a number of fourth beads welded to the first groove, a number of fifth beads welded to the second groove, and a number of sixth beads welded between the fourth beads and the sixth beads.

Optionally, the filler weldment includes a number of seventh passes, a number of eighth passes, a number of ninth passes, and a number of tenth passes, the seventh pass being welded to the first cut, the tenth pass being welded to the second cut, the eighth and ninth passes being welded between the seventh pass and the tenth pass.

In another aspect, the present invention also provides a welding process applied to the above-mentioned connection structure of a reactor vessel, including:

respectively preprocessing the first groove and the second groove;

introducing a set amount of protective gas;

spot welding is carried out on the joint of the inner connecting pipe and the outlet connecting pipe, so that the relative position between the inner connecting pipe and the outlet connecting pipe is fixed, wherein the first groove and the second groove form a third groove;

backing welding is carried out on the joint of the inner connecting pipe and the outlet connecting pipe;

and performing filling welding on the inner connecting pipe and the outlet connecting pipe, wherein a welding bead formed by the filling welding is filled into the third slope.

Optionally, the backing weld specifically includes: starting arc starting welding from O degrees, and welding from a first area to a sixth area in a preset direction to receive an arc, wherein a polar coordinate system is established by taking any point in the axial direction of the inner connecting pipe or the outlet connecting pipe as a pole and taking a connecting line from the pole to the lowest point of the third groove as a polar axis, the first area is 0-beta, the second area is beta-90 degrees, the third area is 90-180 degrees, the fourth area is 180-270 degrees, the fifth area is 270-360 degrees, the sixth area is 0-beta, and the beta is 3-10 degrees.

Optionally, the fill soldering tool comprises:

s101, starting arc welding from an angle gamma 1, and performing arc closing from a first area to a sixth area along the welding direction, wherein the arc closing position is located in a beta angle range;

s102, starting arc welding from an angle- (gamma 2+ beta), and performing arc-ending from a first area to a sixth area along the welding direction, wherein the arc-ending position is located in a beta angle range;

s103, repeating the step S101 and the step S102 for a plurality of times.

Compared with the prior art, the invention has at least one of the following advantages:

the invention provides a connecting structure for a reactor vessel and a welding process suitable for 360-degree full-position automatic argon arc welding single-side welding and double-side forming of the inner wall of a pipe, wherein a tungsten electrode can be accurately aligned to a welding seam by combining the automatic searching function of the tungsten electrode of a welding machine for touching the side wall of a groove, the groove with wide process parameters and the specific welding process are adopted to obtain good welding seam quality, the welding defects caused by human factors are reduced, and the production rate is improved.

Drawings

FIG. 1 is a schematic structural diagram of a conventional product;

FIG. 2 is a schematic structural diagram of a welded groove according to an embodiment of the present invention;

FIG. 3 is a schematic view of a backing weld zone in accordance with an embodiment of the present invention;

FIG. 4 is a schematic view of a welding zone of an odd-numbered layer of filling welding according to an embodiment of the present invention;

FIG. 5 is a schematic view of even-numbered welding zones of a fill weld in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of a bead distribution according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments of fig. 1 to 6. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise scale for the purpose of facilitating and distinctly aiding in the description of the embodiments of the present invention. To make the objects, features and advantages of the present invention comprehensible, reference is made to the accompanying drawings. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the implementation conditions of the present invention, so that the present invention has no technical significance, and any structural modification, ratio relationship change or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or field device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or field device. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or field device that comprises the element.

Referring to fig. 1 to 6, the present embodiment provides a connection structure for a reactor vessel, including:

the inner connecting pipe 1 is positioned in the reactor vessel, and the inner side wall of the inner connecting pipe is provided with an annular first groove 3;

an annular second groove 4 is formed in the inner side wall of the outlet connecting pipe 2, one end of the outlet connecting pipe is welded with the inner connecting pipe 1, and the other end of the outlet connecting pipe penetrates through the reactor vessel and extends out of the reactor vessel;

and when the outlet connecting pipe 2 is welded to the inner connecting pipe 1, the first bevel 3 and the second bevel 4 form a third bevel 5.

In this embodiment, the third bevel 5 is a U-shaped bevel, a V-shaped bevel or a Y-shaped bevel.

In this embodiment, a filling weldment is arranged in the third opening.

In this embodiment, the filler weldment comprises a first bead which is welded to the junction of the inner nozzle 1 and the outlet nozzle 2.

In this embodiment, the filler weldment includes a plurality of second beads welded to the first groove 3 and a plurality of third beads welded to the second groove 4.

In this embodiment, the filler weldment includes a plurality of fourth beads welded to the first groove 3, a plurality of fifth beads welded to the second groove, and a plurality of sixth beads welded between the fourth beads and the sixth beads.

In this embodiment, the filler weldment includes a plurality of seventh beads, a plurality of eighth beads, a plurality of ninth beads, and a plurality of tenth beads, and the seventh bead is welded to the first cut, the tenth bead is welded to the second cut, and the eighth beads and the ninth beads are welded between the seventh beads and the tenth beads.

In another aspect, the present invention also provides a welding process applied to the above-mentioned connection structure of a reactor vessel, including:

respectively preprocessing the first groove and the second groove 4, cleaning the peripheries of the first groove 3 and the second groove 4 by adopting alcohol or acetone, cleaning the surfaces of the grooves and the outer walls of the pipes, and cleaning the surfaces and edges to be welded without water stain, oxides, oil stain and slag and other foreign substances which possibly influence the welding quality; assembling a test piece and a gas back protection tool at the groove, controlling the gap and the misalignment of a groove group within 1mm, ensuring that no misalignment exists at an overhead welding position and a vertical downward welding position, and ensuring that the misalignment is located at a flat welding position as much as possible.

Introducing a set amount of protective gas, introducing 99.99% pure argon before welding, wherein the gas flow is 10-40L/min, and the gas introduction time is more than or equal to 5 min.

And spot welding the joint of the inner connecting pipe 1 and the outlet connecting pipe 2 to fix the relative position between the inner connecting pipe 1 and the outlet connecting pipe 2, wherein the first groove 3 and the second groove 4 form a third groove 5, the welding grooves are subjected to non-wire-added positioning spot welding every 90 degrees, the spot welding current is 60A, the arc length is 2mm, and the spot welding time is 1.5-2 s.

Backing welding is carried out on the joint of the inner connecting pipe 1 and the outlet connecting pipe 2, a welding gun is inserted into the pipe by a movable welding machine and is aligned with the center of a welding seam (the contact position of the inner connecting pipe 1 and the outlet connecting pipe 2), the diameter of a tungsten rod of the welding gun is phi 3.2mm, the length of the tungsten rod is 13-20 mm, the angle of the welding gun is adjusted to 0 degree in the figure 2, the machine head walks once along the welding seam of a workpiece according to a set welding procedure, the distance between the welding gun, a tungsten electrode, a wire feeding nozzle and the groove is checked, and all parts are adjusted to proper positions.

In this embodiment, the backing weld specifically includes: starting arc starting welding from O degrees, and welding from a first area to a sixth area along a preset direction to receive an arc, wherein a polar coordinate system is established by taking any point in the axial direction of the inner connecting pipe 1 or the outlet connecting pipe 2 as a pole and taking a connecting line from the pole to the lowest point of the third groove 5 as a polar axis, the first area is 0-beta, the second area is beta-90 degrees, the third area is 90-180 degrees, the fourth area is 180-270 degrees, the fifth area is 270-360 degrees, the sixth area is 0-beta, and the beta is 3-10 degrees.

Referring to fig. 3, the backing weld zone starts from 0 ° to start the arc welding, and the arc welding starts from one zone to six zones in the counterclockwise direction, and the arc welding position should be within the range of the angle β. The welding direction may also be clockwise, in which case the welding sector is opposite to that of fig. 3; during backing welding, after the groove at two sides contacted by the tungsten electrode is automatically found to the central position, the distance between the tungsten rod and the workpiece is adjusted and confirmed through an endoscope; welding parameters are shown in a table 1, and during welding, non-swing straight-forward welding is adopted, and the welding process is as follows: the second zone is transited from the horizontal welding to the vertical upward welding stage, so that the welding current and the welding speed can be properly increased; when three areas are vertically welded to the overhead welding position, the wire feeding speed and the welding current need to be properly reduced; the wire feeding speed and the welding current are properly increased from the overhead welding stage to the vertical downward welding stage in the fourth zone and the fifth zone; when the welding reaches six zones, the arc-stopping part covers the welding bead at the arc-starting part as much as possible. Cooling the welding line to room temperature, and observing the backing weld through an endoscope to form the welding line; visual inspection and liquid penetration inspection (outer wall) of the weld seam was performed after backing weld.

TABLE 1 backing weld welding parameters

Partition sequence number

A

II

III

Fourthly

Five of them

Six ingredients

Partition angle

0°～β

β～90°

90°～180°

180°～270°

270°～360°

360°～(360°+β)

Welding speed (mm/min)

70～90

70～100

80～100

70～90

70～90

70～90

Wire feed speed (mm/min)

250～400

300～500

200～350

250～400

250～400

250～400

Peak current (A)

110～130

120～160

110～150

120～160

120～160

120～160

Base value current (A)

55～80

60～90

60～90

60～90

60～90

60～90

Arc voltage (V)

9～11

9～11

9～11

9～11

9～11

9～11

And performing filling welding on the inner adapter tube 1 and the outlet adapter tube 2, wherein a weld bead formed by the filling welding is filled into the third bevel 5.

In this embodiment, the filling welding tool includes:

s101, starting arc welding from an angle gamma 1, and performing arc closing from a first area to a sixth area along the welding direction, wherein the arc closing position is located in a beta angle range;

s102, starting arc welding from an angle- (gamma 2+ beta), and performing arc-ending from a first area to a sixth area along the welding direction, wherein the arc-ending position is located in a beta angle range;

s103, repeating the step S101 and the step S102 for a plurality of times.

In figure 4, gamma 1 is 15-30 degrees, beta is 3-10 degrees; in figure 5, gamma 2 is 15-30 degrees, and beta is 3-10 degrees.

And (3) welding and partitioning:

referring to fig. 4, the first layer of the filling weld starts from the angle γ 1 and is arc-welded from the first zone to the sixth zone along the welding direction, and the arc-welding point is located within the angle β.

Referring to fig. 5, in order to avoid the arc starting and closing position of the first layer and reduce welding deformation, the second layer of the filling welding is arc-started from the angle- (γ 2+ β), and the arc is closed from the first area to the sixth area along the welding direction, and the arc closing position is located within the range of β;

the third layer of the filling welding is consistent with the first layer of the subarea, the fourth layer of the filling welding is consistent with the second layer of the subarea, and the like of the subsequent filling layer.

The welding direction may be clockwise, in which case the weld zone is opposite to that of fig. 4 and 5.

In the welding process, multilayer multi-pass non-swing welding is adopted, a filling welding seam row is shown in figure 6, welding passes of the side wall are firstly welded during welding of each layer, and then welding passes between the welding passes of the side wall are welded.

When filling welding, firstly finding out the central position of the welding seam, and adjusting the welding seam to the position of the welding seam to be welded under the assistance of an endoscope. After welding, repair welding can be carried out through corresponding remelting parameters if the side wall of the welding seam is not fused or the layers are not fused through an endoscope;

the welding parameters are shown in the table 2, and the welding process is as follows:

the second zone is transited from the horizontal welding to the vertical upward welding stage, so that the welding current and the welding speed can be properly increased; when three areas are vertically welded to the overhead position, the wire feeding speed and the welding current need to be properly reduced, and the welding speed needs to be increased; the wire feeding speed and the welding current are properly increased from the overhead welding stage to the vertical downward welding stage in the fourth zone and the fifth zone; when the welding reaches six zones, the arc-stopping part covers the welding bead at the arc-starting part as much as possible.

TABLE 2 Filler weld parameters

And (4) polishing the welding track joint and the arc pit area smoothly, and removing the bad tissues, oxides and impurities of the arc pit. And after polishing, residues are cleaned in time, and welding slag fragments cannot exist in a deposited area.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims (10)

1. A connection structure for a reactor vessel, comprising:

the inner connecting pipe is positioned in the reactor container, and the inner side wall of the inner connecting pipe is provided with an annular first groove;

an annular second groove is formed in the inner side wall of the outlet connecting pipe, one end of the outlet connecting pipe is welded with the inner connecting pipe, and the other end of the outlet connecting pipe penetrates through the reactor container and extends out of the reactor container;

and after the outlet connecting pipe is welded to the inner connecting pipe, the first bevel and the second bevel form a third bevel.

2. The connection structure for a reactor vessel according to claim 1, wherein the third bevel is a U-cut, a V-cut, or a Y-cut.

3. A connection arrangement for a reactor vessel according to claim 1 or 2, characterised in that a filler weld is provided in the third cut.

4. A connection structure for a reactor vessel according to claim 3, wherein said filler weldment includes a first bead welded to the junction of said inner nozzle and said outlet nozzle.

5. A connection structure for a reactor vessel according to claim 4, wherein said filler weldment includes a plurality of second beads welded to said first groove and a plurality of third beads welded to said second groove.

6. A connection structure for a reactor vessel according to claim 5, wherein said filler weldment includes a number of fourth passes welded to said first bay, a number of fifth passes welded to said second bay, and a number of sixth passes welded between said fourth passes and said sixth passes.

7. A connection structure for a reactor vessel as recited in claim 6, wherein said filler weldment includes a plurality of seventh beads, a plurality of eighth beads, a plurality of ninth beads, and a plurality of tenth beads, said seventh beads being welded to said first cut, said tenth beads being welded to said second cut, said eighth beads and ninth beads being welded between said seventh beads and said tenth beads.

8. A welding process applied to the connection structure of the reactor vessel according to any one of claims 1 to 7, comprising:

respectively preprocessing the first groove and the second groove;

introducing a set amount of protective gas;

spot welding is carried out on the joint of the inner connecting pipe and the outlet connecting pipe, so that the relative position between the inner connecting pipe and the outlet connecting pipe is fixed, wherein the first groove and the second groove form a third groove;

backing welding is carried out on the joint of the inner connecting pipe and the outlet connecting pipe;

and performing filling welding on the inner connecting pipe and the outlet connecting pipe, wherein a welding bead formed by the filling welding is filled into the third slope.

9. The welding process of claim 8, wherein the backing weld comprises: starting arc starting welding from O degrees, and welding from a first area to a sixth area in a preset direction to receive an arc, wherein a polar coordinate system is established by taking any point in the axial direction of the inner connecting pipe or the outlet connecting pipe as a pole and taking a connecting line from the pole to the lowest point of the third groove as a polar axis, the first area is 0-beta, the second area is beta-90 degrees, the third area is 90-180 degrees, the fourth area is 180-270 degrees, the fifth area is 270-360 degrees, the sixth area is 0-beta, and the beta is 3-10 degrees.

10. Welding process according to claim 8 or 9, wherein said filler welding tool comprises:

s101, starting arc welding from an angle gamma 1, and performing arc closing from a first area to a sixth area along the welding direction, wherein the arc closing position is located in a beta angle range;

s102, starting arc welding from an angle- (gamma 2+ beta), and performing arc-ending from a first area to a sixth area along the welding direction, wherein the arc-ending position is located in a beta angle range;

s103, repeating the step S101 and the step S102 for a plurality of times.

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