阅读说明：本技术 一种冷装合金管拆除方法 (Cold-packed alloy pipe dismantling method ) 是由 侯冬冬 江才林 张茂龙 张敏 苏平 吕映宾 罗庆 朱志华 于 2021-10-26 设计创作，主要内容包括：本发明提供一种冷装合金管拆除方法,用于将冷装试件的合金管通过焊接加热方法自冷装基座的冷装孔中拆除；包含步骤：S1、在合金管内部通过焊接方法对焊接作业段的内壁母材进行加热,使合金管焊接作业段内壁母材局部熔化；S2、完成焊接作业段的焊接作业后停止焊接,合金管焊接作业段内壁局部熔化的母材凝固收缩,使合金管的外壁外径尺寸相应减小,合金管与冷装孔之间形成间隙配合；S3、通过重力或吊装力等外力将合金管与冷装基座分离,完成拆除。本发明可以方便高效地拆除冷装合金管,对冷装基体不造成损伤,具有过程稳定、拆除效率高、拆除成本低、节省人力等优点,具有较好的实用性和经济价值。(The invention provides a method for removing a cold-packed alloy pipe, which is used for removing the alloy pipe of a cold-packed test piece from a cold-packed hole of a cold-packed base by a welding and heating method; comprises the following steps: s1, heating the inner wall base metal of the welding operation section in the alloy pipe by a welding method to locally melt the inner wall base metal of the welding operation section of the alloy pipe; s2, stopping welding after the welding operation of the welding operation section is completed, solidifying and shrinking the partially melted base metal on the inner wall of the welding operation section of the alloy pipe, correspondingly reducing the outer diameter of the outer wall of the alloy pipe, and forming clearance fit between the alloy pipe and the cold charging hole; and S3, separating the alloy pipe from the cold-packed base through external forces such as gravity or hoisting force and the like, and finishing the dismantling. The cold-charging alloy pipe dismantling device can conveniently and efficiently dismantle the cold-charging alloy pipe, does not damage a cold-charging base body, has the advantages of stable process, high dismantling efficiency, low dismantling cost, labor saving and the like, and has better practicability and economic value.)

1. A cold-charging alloy pipe dismantling method is used for dismantling an alloy pipe of a cold-charging test piece from a cold-charging base through a welding and heating method; the cold-charging base is provided with a vertically through cold-charging hole with the inner diameter smaller than the outer diameter of the alloy pipe, the alloy pipe is inserted into the cold-charging hole to form a cold-charging test piece, and the end part of one side of the alloy pipe, which is inserted into the cold-charging hole, is a cold-charging end; it is characterized by comprising the following steps:

s1, heating the base metal of the inner wall of the welding operation section in the alloy pipe by a welding method to locally melt the base metal of the inner wall of the welding operation section of the alloy pipe;

s2, stopping welding after the welding operation of the welding operation section is completed, solidifying and shrinking the partially melted base metal on the inner wall of the welding operation section of the alloy pipe, correspondingly reducing the outer diameter of the alloy pipe, and forming clearance fit between the alloy pipe and the cold charging hole;

and S3, separating the alloy pipe from the cold-mounted base through external forces such as gravity or hoisting force and the like, and finishing the dismantling.

2. The method for removing cold-packed alloy tubes as claimed in claim 1, wherein the welding operation section is a tube body region between the tube body of the alloy tube and the cold-packed end from a height level with the top end of the cold-packed base.

3. The method for removing a cold alloy charged pipe according to claim 1, further comprising, before step S1, step S01:

and arranging a cooling medium near the cold charging hole to perform pre-cooling and cooling in the whole welding process, so that the cold charging base is prevented from being deformed and damaged due to local thermal stress in the welding process.

4. The method for removing a cold charge alloy pipe according to claim 3, wherein the cooling medium is liquid nitrogen or dry ice.

5. The cold alloy pipe dismantling method according to claim 1 or 3, further comprising, between steps S1 and S2, step S02:

and monitoring the temperature of the pipe wall of the alloy pipe and the cold-charging base in the welding process, if the temperature of the inner wall of the cold-charging hole is too high or the temperature difference is too large, and possibly causing the cold-charging base metal to generate thermal deformation and damage, stopping welding, strengthening cooling measures or adjusting a cooling area so as to balance a temperature field and reduce or eliminate the thermal stress and deformation of the cold-charging base.

6. The method for removing cold-packed alloy tubes as claimed in claim 1, wherein a filler material is added in the welding process in step S1 to increase the amount of shrinkage of the inner wall of the welded segment of the alloy tube.

7. The method for removing a cold alloy charging pipe according to claim 3, further comprising, before step S01, step S001:

and placing the cold-charging end of the cold-charging test piece on a horizontal table board downwards or upwards, and enabling the axis of the alloy pipe to be vertical to the horizontal table board.

8. The method for removing a cold-charged alloy pipe according to claim 1, wherein the welding method is manual/automatic argon tungsten-arc welding, plasma welding or laser welding.

9. A cold alloy pipe dismantling method as claimed in claim 1, wherein said welding mode is circumferential welding, arc starting welding is started from an arbitrary position, single layer/multilayer welding is performed in a counterclockwise/clockwise direction, each welding pass is full circle/intermittent welding, the next welding pass is performed in a continuous/intermittent welding state, and after the welding is completed, annular welding passes are axially distributed on the inner wall of the welding operation section in a single layer or in multiple layers uniformly.

10. A method for removing a cold charge alloy pipe according to claim 1, wherein the welding mode is axial welding, arc starting welding is performed from any position, single layer/multilayer welding is performed in the axial direction, the next welding is performed in a continuous/intermittent welding state, and after the welding is completed, welding passes parallel to the axial line are uniformly distributed in a single layer or in multiple layers along the circumferential direction on the inner wall of the welding operation section.

Technical Field

The invention relates to the technical field of nuclear power equipment, in particular to a method for dismantling a cold-charging alloy pipe.

Background

Nuclear island main equipment such as an evaporator and a voltage stabilizer of a nuclear power plant generally needs to be cold-packed with alloy pipes such as nickel-based alloy pipes and alloy steel pipes in the equipment due to technical requirements in the aspects of technical parameters, assembly accuracy and the like. The alloy pipe cold-charging method is shown in figure 1, the outer diameter of the alloy pipe 1 is D1, and the side, to be cold-charged, of the alloy pipe 1 is a cold-charging end 11; the cold-mounted base 2 is provided with a cold-mounted hole 21, the inner diameter of the cold-mounted hole 21 is D2, D1> D2, and the assembling interference magnitude of 0.04-0.06 mm exists; before cold charging, one side of a cold charging end 11 of the alloy pipe 1 is immersed in liquid nitrogen for heat preservation for 15-20 min, so that the outer diameter of the alloy pipe 1 is shrunk to a cold charging size D1 ', D1' < D2; then, inserting the alloy pipe 1 from the cold charging end 11 into the cold charging hole 21 for assembling, and assembling the alloy pipe 1 and the cold charging base 2 into a cold charging test piece; after assembly, the alloy pipe 1 gradually returns to room temperature to cause the outer wall to expand and form interference fit with the cold-assembling hole 21, and cold assembly is completed.

In the production, transportation or installation process of the cold-packed test piece, part of the cold-packed alloy pipes 1 may have assembly precision deviation or be damaged due to collision, so that the service capacity of a product assembly is lost, and therefore the cold-packed alloy pipes 1 which do not meet the requirements need to be disassembled, and the alloy pipes which are intact are re-cold-packed, so that the service performance of the product can be met. However, due to the size interference fit between the cold-assembled alloy pipe 1 and the cold-assembled base 2, the cold-assembled alloy pipe 1 is difficult to disassemble by a conventional disassembling method on the premise of not damaging the cold-assembled base 2, so that the disassembling efficiency is low, the base metal of the cold-assembled base 2 is easy to damage, and the working hour consumption and the economic loss are caused.

Disclosure of Invention

The invention aims to provide a method for removing a cold-charge alloy pipe, which can conveniently and efficiently remove the cold-charge alloy pipe, does not damage a cold-charge base body, has the advantages of stable process, high removal efficiency, low removal cost, labor saving and the like, and has better practicability and economic value.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a cold-charging alloy pipe dismantling method is used for dismantling an alloy pipe of a cold-charging test piece from a cold-charging base through a welding and heating method; the cold-charging base is provided with a vertically through cold-charging hole with the inner diameter smaller than the outer diameter of the alloy pipe, the alloy pipe is inserted into the cold-charging hole to form a cold-charging test piece, and the end part of one side of the alloy pipe, which is inserted into the cold-charging hole, is a cold-charging end; comprises the following steps:

s1, heating the base metal of the inner wall of the welding operation section in the alloy pipe by a welding method to locally melt the base metal of the inner wall of the welding operation section of the alloy pipe;

s2, stopping welding after the welding operation of the welding operation section is completed, solidifying and shrinking the partially melted base metal on the inner wall of the welding operation section of the alloy pipe, correspondingly reducing the outer diameter of the alloy pipe, and forming clearance fit between the alloy pipe and the cold charging hole;

and S3, separating the alloy pipe from the cold-mounted base through external forces such as gravity or hoisting force and the like, and finishing the dismantling.

Further, the welding operation section is a pipe body area between the alloy pipe body and the cold charging end from the height which is parallel and level with the top end of the cold charging base.

Preferably, step S01 is further included before step S1:

and arranging a cooling medium near the cold charging hole to perform pre-cooling and cooling in the whole welding process, so that the cold charging base is prevented from being deformed and damaged due to local thermal stress in the welding process.

Preferably, the cooling medium is liquid nitrogen or dry ice.

Preferably, between steps S1 and S2, step S02 is further included:

and monitoring the temperature of the pipe wall of the alloy pipe and the cold charging base in the welding process, if the temperature is too high or the annular temperature difference is too large, stopping welding, and strengthening cooling measures or adjusting a cooling area so as to balance a temperature field and reduce or eliminate the thermal stress and deformation of the cold charging base.

Preferably, a filling material is added in the welding process in step S1 to increase the shrinkage of the inner wall of the alloy pipe welding operation section.

Preferably, step S001 is further included before step S01:

and placing the cold-charging end of the cold-charging test piece on a horizontal table board downwards or upwards, and enabling the axis of the alloy pipe to be vertical to the horizontal table board.

Preferably, the welding method is manual/automatic argon tungsten-arc welding, plasma welding or laser welding.

Preferably, the welding mode is circumferential welding, starting arc welding from any position, performing single-layer/multilayer welding along the anticlockwise/clockwise direction, each welding bead is full-circle/discontinuous welding, performing next welding in a continuous/intermittent welding state, and after the welding is completed, performing annular welding beads along axial single-layer distribution or multilayer uniform distribution on a welding operation section.

Preferably, the welding mode is axial welding, starting arc starting welding from any position, carrying out single-layer/multi-layer welding along the axial direction, carrying out next welding in a continuous/stop welding state, and after the welding is finished, carrying out single-layer distribution or multi-layer uniform distribution on welding beads parallel to the axial line in the circumferential direction in the welding operation section.

In summary, compared with the prior art, the cold-charging alloy pipe dismantling method provided by the invention has the following beneficial effects:

1. by adopting the method of heating the inner wall of the cold-charging alloy pipe through electric arc or laser welding, the base metal on the inner wall of the alloy pipe is locally melted, the pipe wall of the base metal of the alloy pipe is contracted, and the outer wall of the cold-charging alloy pipe and the cold-charging base hole form clearance fit, so that nondestructive dismounting is realized, the dismounting effect is good, the success rate is high, the cold-charging base is not damaged, and the production cost is saved;

2. the method has the advantages of no need of large-scale equipment and complex technology, simple and easy realization of the demolition method, low demolition cost, high demolition efficiency, labor saving, and better economic value and practicability.

Drawings

FIG. 1 is a schematic structural diagram of a conventional cold-pack test piece in the prior art;

FIG. 2 is a front sectional view of the circumferential welding of a cold-set test piece according to the present invention;

FIG. 3 is a top sectional view of circumferential welding of a cold-set test piece according to the present invention;

FIG. 4 is an axial welding front section view of a cold-set test piece of the present invention;

FIG. 5 is a top sectional view of the axial weld of the cold-set test piece of the present invention.

Detailed Description

The method for removing the cold charging alloy pipe provided by the invention is further described in detail with reference to the attached drawings and the detailed description. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are simplified in form and not to precise scale, and are only used for convenience and clarity to assist in describing the embodiments of the present invention, but not for limiting the conditions of the embodiments of the present invention, and therefore, the present invention is not limited by the technical spirit, and any structural modifications, changes in the proportional relationship, or adjustments in size, should fall within the scope of the technical content of the present invention without affecting the function and the achievable purpose of the present invention.

It is to be noted that, in the present invention, relational terms such as first and second, and the like are 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 apparatus 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 apparatus.

With reference to fig. 2 to 5, the present embodiment provides a method for removing a cold-packed alloy tube, which is used for removing an alloy tube 1 of a cold-packed test piece from a cold-packed base 2 by a welding and heating method; the cold-charging base 2 is provided with a vertically through cold-charging hole 21 with the inner diameter smaller than the outer diameter of the alloy pipe 1, the alloy pipe 1 is inserted into the cold-charging hole 21 of the cold-charging base 2 in a cold-charging manner to form a cold-charging test piece, and the end part of one side of the cold-charging hole 21, into which the alloy pipe 1 is inserted, is a cold-charging end 11; in this example, the dimensions of the alloy tube 1 are: the outer diameter is 110mm, the wall thickness is 12mm, and the height of the welding operation section 12 is 180 mm; comprises the following steps:

1. as shown in the attached figures 2 and 4, the cold charging end 11 of the cold charging test piece is placed on a horizontal table top in an upward or downward mode, and the axis of the alloy pipe 1 is perpendicular to the horizontal table top;

2. arranging a cooling medium (such as liquid nitrogen or dry ice) near a cold charging hole 21 of the cold charging base 2 to carry out pre-cooling and cooling in the whole welding process, and preventing the cold charging base 2 from being deformed and damaged due to local thermal stress caused by rapid temperature rise of a welding part in the welding process;

3. heating the base metal (the term of the welding field is used for the welded part) on the inner wall of the welding operation section 12 in the alloy pipe 1 by a welding method, so that the base metal on the inner wall of the welding operation section 12 of the alloy pipe 1 is locally melted; the welding operation section 12 is a pipe body area between the height of the pipe body of the alloy pipe 1 from the top end of the cold-charging base 2 to the cold-charging end 11.

Wherein, the welding can adopt various electric arc or laser welding methods, such as manual/automatic tungsten argon arc welding (GTAW), plasma welding (PAW), laser welding and the like; the welding operation path can adopt paths such as annular and axial paths, and the welding mode can adopt various modes such as spiral, interval, single layer and multilayer; meanwhile, in the welding process, a filling material is not added, and the filling material can also be added to improve the shrinkage of the inner wall of the welding operation section 12 of the alloy pipe 1;

in this embodiment, a non-swing wire-filling-free automatic tungsten argon arc (GTAW) welding method in the prior art is selected, and a wall-collision automatic rotation center finding technology of automatic tungsten argon arc welding is adopted to weld the inner wall of the welding operation section 12 of the alloy pipe 1, and the specific welding method is as follows:

(1) the welding process parameters shown in attached table 1 were used:

TABLE 1 welding Process parameters

(2) Placing an automatic argon tungsten-arc welding gun 3 on the inner wall of a welding operation section 12 of the alloy pipe 1 from the pipe orifice of the alloy pipe 1, automatically searching the position of a welding seam rotation center by touching the inner wall of a groove with a tungsten electrode, then adjusting the welding gun 3 to the position of a welding bead to be welded, and observing and confirming the actual welding space position of the welding gun by using an endoscope;

(3) welding the inner wall of the welding operation section 12 of the alloy pipe 1, wherein two examples of the welding operation path are circumferential and axial:

example 1:

and (3) performing circumferential welding, as shown in the attached drawings 2 and 3 (the middle welding bead in the attached drawing 2 is omitted), starting arc starting welding from any position, performing single-layer or multilayer welding along the anticlockwise or clockwise direction, wherein each welding bead 4 is welded in a whole circle or in an intermittent manner, performing the next welding (namely the welding beads 4 are spirally or at intervals) in a continuous or intermittent welding state, the circumferential welding speed is 50-70 mm/min, and after the welding is completed, uniformly distributing annular welding beads 4 along the axial direction in a single-layer manner or in multiple layers on the inner wall of the welding operation section 12.

Example 2:

and (3) axially welding, as shown in figures 4 and 5 (the middle welding bead in figure 4 is omitted), starting arc welding from any position, axially performing single-layer or multi-layer welding, performing the next welding (namely, the welding bead 4 is spirally or alternately distributed) in a continuous/stop welding state, wherein the axial welding speed is 70-80 mm/min, and after the welding is finished, uniformly distributing the welding beads 4 parallel to the axis in a single-layer or multi-layer mode along the annular direction on the inner wall of the welding operation section 12.

4. Monitoring the temperature of the pipe wall of the alloy pipe 1 and the cold-charging base 2 in the welding process, if the temperature of the inner wall of the cold-charging hole 21 is too high or the temperature difference is too large, and possibly causing the damage of the cold-charging base 2 caused by thermal deformation, stopping welding and strengthening cooling measures or adjusting a cooling area so as to balance a temperature field and reduce or eliminate the thermal stress and deformation of the cold-charging base 2;

5. stopping welding after the welding operation of the welding operation section 12 of the alloy pipe 1 is completed, solidifying and shrinking the partially melted base metal on the inner wall of the welding operation section 12 of the alloy pipe 1 to generate shrinkage stress, so that the outer diameter of the outer wall of the alloy pipe 1 is correspondingly reduced, and the inner diameter of the cold charging hole 21 of the cold charging base 2 is not obviously changed, so that clearance fit is formed between the alloy pipe 1 and the cold charging hole 21;

6. and separating the alloy pipe 1 from the cold-packed base 2 through external force such as gravity or hoisting force and the like to finish the dismantling.

In conclusion, the cold-charging alloy pipe dismantling method provided by the invention has the advantages that the method for heating the inner wall of the cold-charging alloy pipe through electric arc or laser welding is adopted, the base material on the inner wall of the alloy pipe is locally melted, the pipe wall of the base material of the alloy pipe is contracted, and the outer wall of the cold-charging alloy pipe and the cold-charging base hole form clearance fit, so that nondestructive dismantling is realized, the dismantling effect is good, the success rate is high, the cold-charging base is not damaged, and the production cost is saved; the method has the advantages of no need of large-scale equipment and complex technology, simple and easy realization of the demolition method, low demolition cost, high demolition efficiency, labor saving, and better economic value and practicability.

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.