JP2012207288A - Pipe externally coated with self-fluxing alloy and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a self-fluxing alloy outer cladding tube capable of efficiently producing a self-fluxing alloy outer cladding tube in which a good self-fluxing alloy film having no damage is formed on the outer surface of a metal tube having a straight portion and a curved portion. Provide a method.
A method of manufacturing a self-fluxing alloy outer surface coated tube in which a self-fluxing alloy film obtained by spraying a self-fluxing alloy and performing heat remelting treatment is formed on the outer surface of a metal tube having a straight portion and a curved portion. Then, a first step of forming a self-fluxing alloy film on the outer surface of the straight portion of the straight metal pipe using an automatic self-fluxing alloy sprayer and the like, and forming a self-fluxing alloy film in the first step The second step of bending the straight metal pipe coldly to form a bent portion, and forming a self-fluxing alloy film on the outer surface of the bent portion of the metal pipe bent in the second step by hand And a third step.
[Selection] Figure 1

Description

  The present invention relates to a method for producing a self-fluxing alloy outer surface coated tube in which a self-fluxing alloy film obtained by spraying a self-fluxing alloy and performing heat remelting treatment is formed on the outer surface of a metal tube having a straight portion and a curved portion, and The present invention relates to a self-fluxing alloy outer surface cladding tube.

  As a metal tube having a straight portion and a curved portion, for example, there is a meandering tube (boiler tube) used in a power generation device, a boiler, or the like. Boiler tubes are used for heat recovery in thermal power plants, incinerators, coke dry fire extinguishing equipment, and the like. Specifically, the boiler tube is exposed to high-temperature combustion gas, and a fluid such as circulating water is circulated inside the boiler tube, so that the turbine is driven by the heat of the combustion gas via the circulating water. . The outer surface of the boiler tube is subject to corrosion due to high-temperature combustion gas and erosion wear due to heated dust, so that self-fluxing alloy with excellent corrosion resistance and wear resistance and good thermal conductivity is sprayed and heated and remelted. It is preferable to form a molten alloy film. As means for forming a film on the outer surface of the meandering pipe, those described in Patent Documents 1 and 2 have been proposed.

The film forming means described in Patent Document 1 meanders the thermal spraying torch provided on the thermal spray head while moving the thermal spray head along the meandering pipe through the meandering pipe through the through hole of the thermal spraying head provided on the moving body. The coating material is sprayed on the outer surface of the meandering tube by rotating around the tube, and a coating is automatically formed continuously on the outer surface of the meandering tube.
The film forming means described in Patent Document 2 forms a film on the outer surface of a linear metal tube, fuses the film, and then forms a predetermined metal tube having a film formed on the linear outer surface. Is bent at a high temperature of 400 to 1000 ° C. to form a meandering tube.

JP 9-316623 A JP-A-10-140320

  However, in the film forming means described in Patent Document 1, the size of the equipment is increased, the size of the metal tube that can form the film is small, and the number of meandering tubes used in power generation and boilers is small and large, so this is practical. Can not. Moreover, in the film forming means described in Patent Document 2, in order to bend a predetermined portion of the metal tube having a film formed on the outer surface at a high temperature of 400 to 1000 ° C., mechanical destruction of the coating, melting damage, Damage such as cracks will occur. In addition, bending at a high temperature of 400 ° C. or higher is not practical because facilities and work are difficult. From these facts, in reality, a straight metal tube was bent to form a meandering tube, and a self-fluxing alloy film was manually formed on the entire outer surface of the meandering tube. If so, it is difficult to form a self-fluxing alloy film on the surface of adjacent pipes between adjacent pipes, that is, close to each other. The self-fluxing alloy outer surface cladding tube could not be produced efficiently.

  The problem to be solved by the present invention is that a self-fluxing alloy film obtained by spraying a self-fluxing alloy and performing heat remelting treatment on the outer surface of a metal tube having a straight part and a curved part is formed. An object of the present invention is to provide a self-fluxing alloy outer surface cladding tube manufacturing method and a self-fluxing alloy outer surface cladding tube capable of efficiently manufacturing an alloy outer surface cladding tube.

  In order to solve the above-mentioned problems, a method for manufacturing a self-fluxing alloy outer surface cladding tube according to the present invention is obtained by spraying a self-fluxing alloy on the outer surface of a metal tube having a straight part and a curved part and performing a heat remelting treatment. A method of manufacturing a self-fluxing alloy outer surface coated tube having a self-fluxing alloy film formed thereon, the first step of forming the self-fluxing alloy film at a location to be the straight portion of the outer surface of a linear metal tube; A second step of cold bending the linear metal tube on which the self-fluxing alloy film is formed in the first step to form the bent portion; and a bent portion of the metal tube bent in the second step. And a third step of forming the self-fluxing alloy film on the outer surface.

  In this way, in the first step, the self-fluxing alloy film is formed at the location that becomes the straight portion of the outer surface of the straight metal tube, so that it can be easily constructed manually and automatically. It is also possible to automatically perform using a general-purpose automatic self-fluxing alloy coating apparatus for spraying and remelting the self-fluxing alloy, for example, an apparatus described in JP-A-8-1059. In the second step, the self-flux formed on the outer surface of the portion that becomes the straight portion in order to form the bent portion by cold bending the straight metal tube in which the self-fluxing alloy film was formed in the first step. The bent portion can be formed by bending a metal tube without causing mechanical damage such as cracks in the alloy film. Then, since the self-fluxing alloy film is formed on the outer surface of the curved part in the third step, the laborious self-fluxing alloy film work is only required on the outer surface of the curved part having a shorter length than the straight part. Therefore, the self-fluxing alloy outer surface coated tube in which a good self-fluxing alloy film without damage is formed on the outer surface of the metal tube having the straight part and the curved part can be efficiently manufactured.

  In this case, the self-fluxing alloy film in the first step can be formed by using an automatic self-fluxing alloy coating machine, and the self-fluxing alloy film in the third step can be manually formed. Further, the bending of the metal pipe in the second step is performed by holding the ends of the two straight portions adjacent to both ends of the portion where the bent portion is formed with a bending tool, and the bending tool in the first step. The self-fluxing alloy film is not formed by gripping the outer surface of the end of the straight portion of the metal tube to be gripped, and the self-fluxing alloy is formed on the outer surface of the bent portion of the metal tube and the outer surface of the gripping margin in the third step. A film can be formed. Furthermore, in the first step and / or the third step, when spraying the self-fluxing alloy, the end portion of the outer surface of the metal tube where the self-fluxing alloy film is not formed can be covered with a masking tape.

  In order to solve the above-mentioned problem, the self-fluxing alloy outer surface coated tube according to the present invention is obtained by spraying a self-fluxing alloy on the outer surface of a metal tube having a straight portion and a curved portion and performing a heat remelting treatment. A self-fluxing alloy outer surface coated tube on which a molten alloy film is formed, wherein the self-fluxing alloy film on the outer surface of the straight portion is formed at a location that becomes the straight portion on the outer surface of the straight metal tube, and The self-fluxing alloy film on the outer surface of the part is formed on the outer surface of the curved part formed by cold bending a linear metal tube in which a self-fluxing alloy film is formed at the location to be the straight part. It is characterized by that.

  As described above, the self-fluxing alloy film on the outer surface of the linear portion is formed at a location that becomes the linear portion of the outer surface of the linear metal tube, and the linear metal tube is bent and bent in a cold manner. Therefore, mechanical destruction such as cracks does not occur in this self-fluxing alloy film. The self-fluxing alloy film on the outer surface of the curved part takes time, but only the outer surface of the curved part, which is shorter than the straight part, is sufficient. Therefore, the self-fluxing alloy outer surface coated tube in which a good self-fluxing alloy film without damage is formed on the outer surface of the metal tube having the straight part and the curved part can be efficiently manufactured.

  ADVANTAGE OF THE INVENTION According to this invention, the self-fluxing alloy outer surface cladding tube in which the favorable self-fluxing alloy membrane | film | coat which does not have a damage on the outer surface of the metal pipe which has a linear part and a curved part is formed can be manufactured efficiently.

It is a side view which shows the self-fluxing alloy outer surface cladding tube of an example embodiment which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a side view for demonstrating the process of manufacturing the self-fluxing alloy outer surface cladding tube of an example of this embodiment, (a) is a figure which shows a linear metal tube, (b) is a linear part of a linear metal tube The figure which shows the state which formed the self-fluxing alloy film in the outer surface of the location used as (c) is a figure which shows the state which bent the metal tube which formed the self-fluxing alloy film in the location used as a linear part.

  Hereinafter, an embodiment of a self-fluxing alloy outer surface cladding tube according to the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, a self-fluxing alloy outer surface coated tube 1 as an example of this embodiment is formed by forming self-fluxing alloy films 5a and 5b on the outer surface of a metal tube 2 having a straight portion 3 and a curved portion 4. is there. The self-fluxing alloy outer surface cladding tube 1 is a meandering tube (boiler tube) formed by bending a steel tube having a diameter of about 30 to 80 mm used in a power generation device, a boiler, or the like. In the example shown in FIG. 1, the self-fluxing alloy outer surface coated tube 1 is a portion where the self-fluxing alloy films 5 a and 5 b are not formed on the outer surface (the white portion on the right side in FIG. 1) is inside the boiler furnace wall. It is a place where it is not necessary to form the self-fluxing alloy films 5a and 5b at a place reaching (or inside the furnace wall and outside the furnace wall). The self-fluxing alloy outer surface cladding tube 1 is not limited to this, although the width meandering from side to side is long from the bottom to the top. The self-fluxing alloy outer surface cladding tube 1 is not particularly limited as long as it has at least one straight portion 3 and one curved portion 4. In this embodiment, the meandering tube shown in the drawing is used. explain.

  The self-fluxing alloy films 5a and 5b are formed by spraying a self-fluxing alloy on the outer surface of the metal tube 2 and further heating and remelting. As the self-fluxing alloy, a well-known alloy can be used. For example, a Ni-based alloy, Ni-Cr-based alloy, or Co-based alloy provided with self-fluxing by blending B or Si as flux generating components, or these An alloy containing WC cermet or the like may be used for the purpose of improving wear resistance. The thickness of the coating is not particularly limited, and is set to about 0.5 to 3 mm after the heat remelting treatment, for example.

  The self-fluxing alloy films 5a and 5b are formed in different steps in the straight portion 3 and the curved portion 4. That is, the manufacturing method of the self-fluxing alloy outer surface coated tubes 5a and 5b of the present embodiment is a self-fluxing alloy at a location that becomes the straight portion 3 on the outer surface of the straight metal tube 2 as shown in FIGS. The first step of forming the coating 5a (see FIGS. 2A and 2B) and the straight metal pipe 2 on which the self-fluxing alloy coating 5a is formed in the first step are bent and bent. 2nd process (refer FIG.2 (c)) which forms the part 4, and 3rd process which forms the self-fluxing alloy film 5b in the outer surface of the curved part 4 of the metal pipe 2 bent by the 2nd process. I have.

  The first step is a step of forming a self-fluxing alloy film 5 a on the outer surface of the linear metal tube 2. The location where the self-fluxing alloy coating 5a is formed in the first step is a location that becomes the straight portion 3 when the self-fluxing alloy outer surface coated tube 1 is formed, and becomes the straight portion 3 that forms the self-fluxing alloy coating 5a. When the straight metal tube 2 is gripped with a bending tool and bent in the second step among the points (in the example shown in FIG. 1 excluding the white part where the self-fluxing alloy film is not formed on the outer surface) 2 is a portion excluding the gripping margin 6, that is, the portion gripped by the bending tool. The gripping margin 6 differs in bending process depending on the metal tube and the bending radius. For example, the axial length of the metal tube 2 is about 50 mm. The thermal spraying machine is not particularly limited as long as the self-fluxing alloy can be sprayed on the outer surface of the metal tube 2 to form a self-fluxing alloy film, and a known gas flame spraying machine, plasma spraying machine, HVOF spraying machine, and the like are known. Things can be used.

  The film obtained by spraying the self-fluxing alloy is further subjected to heat remelting treatment such as high-frequency induction heating, so that a self-fluxing alloy film 5a having a dense, hard, high adhesion, uniform thickness, and smooth surface can be obtained. It is formed. The formation of the self-fluxing alloy film 5a is not particularly limited. For example, the self-fluxing alloy film 5a may be formed using a masking tape. In this case, a masking tape is wound around the outer periphery of the end portion where the self-fluxing alloy film 5a is not formed, and after the thermal spraying, the masking tape is removed and a heat remelting process is performed. As a result, the self-fluxing alloy film 5a can be accurately formed only at the target location. In addition, if formation of the self-fluxing alloy film 5a in the first step, that is, spraying / remelting is automatically performed using a general-purpose automatic self-fluxing alloy coating apparatus, a uniform self-fluxing alloy film 5a is more efficiently obtained. It can be obtained and is preferable.

  The second step is a step of forming the curved portion 4 by bending the linear metal tube 2 on which the self-fluxing alloy film 5a is formed in the first step in a cold manner. The method for bending the metal tube 2 in a cold manner is not particularly limited. For example, the metal tube 2 may be pressed against a mold while being clamped by clamps that are two bending tools. Good. As a result, the metal tube 2 is bent to form the bent portion 4 to form a meandering tube.

  The third step is a step of forming a self-fluxing alloy film 5b on the outer surface of the bent portion 4 of the metal tube 2 bent in the second step. The location where the self-fluxing alloy film 5 b is formed is the outer periphery of the curved portion 4, but when there is a grip margin 6, the outer periphery and the grip margin 6. The thermal spraying machine used for spraying the self-fluxing alloy is not particularly limited as long as the self-fluxing alloy film 5b can be formed by spraying the self-fluxing alloy on the outer surface of the metal tube 2, and among those exemplified in the first step, A hand-held type can be used.

  Also in the third step, after forming a self-fluxing alloy film, the film is subjected to heat remelting treatment such as high-frequency induction heating in the same manner as in the first process, so that it is dense and hard and has high adhesion. It is possible to form the self-fluxing alloy film 5b having a uniform surface and a smooth surface. Further, the boundary between the place where the self-fluxing alloy film 5b is formed and the place where the self-fluxing alloy film 5b is not formed in the third step may be formed in any way, for example, using a masking tape. In this case, the masking tape is wound around the outer periphery of the end portion where the self-fluxing alloy film 5b is not formed in the third step, and after the thermal spraying, the masking tape is removed and a heat remelting process is performed.

  In this way, in the first step, the self-fluxing alloy film 5a is formed at the location that becomes the straight portion 3 on the outer surface of the straight metal tube 2, so that it can be easily constructed by hand, It is also possible to carry out automatically using a general-purpose automatic self-fluxing alloy coating apparatus that automatically sprays and remelts the self-fluxing alloy, for example, an apparatus described in JP-A-8-1059. In the second step, the straight metal tube 2 on which the self-fluxing alloy film 5a is formed in the first step is cold-worked to form the curved portion 4, so that the outer surface of the portion that becomes the straight portion 3 is formed. The bent portion 4 can be formed by bending the metal tube 2 without causing mechanical damage such as cracks in the formed self-fluxing alloy film 5a. That is, the self-fluxing alloy film 5a on the outer surface of the straight portion 3 is formed at a location that becomes the straight portion 3 on the outer surface of the straight metal tube 2, and the straight metal tube 2 is cooled in the cold. When the bent portion 4 is formed by bending, mechanical damage such as cracks does not occur.

  In addition, since the self-fluxing alloy film 5b is formed on the outer surface of the curved part 4 in the third step, the laborious self-fluxing alloy film work is performed only on the outer surface of the curved part 4 which is shorter than the straight part 3. That's okay. That is, the bent portion 4 and the self-fluxing alloy film 5b on the outer surface of the gripping margin 6 are troublesome manually, but the portion where the self-fluxing alloy film 5b is formed is shorter than the straight portion 3 in the bent portion 4. Since only the gripping margin 6 is provided, the self-fluxing alloy coatings 5a and 5b can be efficiently formed even if the self-fluxing alloy coating 5b of the curved portion 4 and the gripping margin 6 is carefully formed.

  Therefore, on the outer surface of the metal tube 2 having the straight portion 3 and the curved portion 4, good self-fluxing alloy films 5a and 5b that are not damaged, that is, dense, hard, high adhesion, uniform thickness, and a uniform surface. The self-fluxing alloy outer surface coated tube 1 in which the smooth self-fluxing alloy films 5a and 5b are formed can be efficiently manufactured. In addition, if the self-fluxing alloy film 5a in the first step, that is, thermal spraying / remelting, is automatically performed using a general-purpose automatic self-fluxing alloy coating apparatus, a uniform self-fluxing alloy film 5a can be formed more efficiently. As a result, it is possible to more efficiently manufacture the self-fluxing alloy outer surface coated tube 1 in which the good self-fluxing alloy films 5a and 5b without damage are formed.

  A self-fluxing alloy is formed by spraying the self-fluxing alloy by covering the ends of portions where the self-fluxing alloy coatings 5a and 5b are not formed with masking tape in both the first step and the third step. The coatings 5a and 5b can be accurately formed only at the target location.

DESCRIPTION OF SYMBOLS 1 Self-fluxing alloy outer surface cladding tube 2 Metal tube 3 Straight line part 4 Curved part 5a, 5b Self-fluxing alloy film 6 Grasp

Claims (5)

A method of manufacturing a self-fluxing alloy outer surface coated tube in which a self-fluxing alloy film obtained by spraying a self-fluxing alloy and performing heat remelting treatment is formed on the outer surface of a metal tube having a straight part and a curved part,
A first step of forming the self-fluxing alloy film at a location to be the linear portion of the outer surface of the linear metal tube;
A second step of bending the linear metal tube on which the self-fluxing alloy film is formed in the first step to form the bent portion by cold bending;
A third step of forming the self-fluxing alloy film on the outer surface of the bent portion of the metal tube bent in the second step;
A method for producing a self-fluxing alloy outer surface cladding tube, comprising:   The self-fluxing alloy film in the first step is formed by using an automatic self-fluxing alloy coating machine, and the self-fluxing alloy film in the third step is formed manually. The manufacturing method of the self-fluxing alloy outer surface cladding tube of description. The bending process of the metal tube in the second step is performed by gripping the ends of two straight portions adjacent to both ends of the portion where the curved portion is formed, respectively, with a bending tool,
Without forming the self-fluxing alloy film as a margin for gripping the outer surface of the end of the straight portion of the metal tube gripped by the bending tool in the first step,
The self-fluxing alloy outer surface coated tube manufacturing method according to claim 1 or 2, wherein the self-fluxing alloy film is formed on the outer surface of the bent portion of the metal tube and the outer surface of the gripping margin in the third step.   The said 1st process and / or the said 3rd process WHEREIN: When spraying the said self-fluxing alloy, the edge part of the outer surface of the said metal pipe of the location which does not form the said self-fluxing alloy film was covered with the masking tape. The manufacturing method of the self-fluxing alloy outer surface cladding tube in any one of 1-3. A self-fluxing alloy outer surface coated tube formed with a self-fluxing alloy film obtained by spraying a self-fluxing alloy on the outer surface of a metal tube having a straight part and a curved part, and performing heat remelting treatment,
The self-fluxing alloy film on the outer surface of the linear portion is formed at a location that becomes the linear portion of the outer surface of the linear metal tube,
The self-fluxing alloy film on the outer surface of the curved part is formed on the outer surface of the curved part formed by cold bending a linear metal tube in which a self-fluxing alloy film is formed at the portion to be the straight part. A self-fluxing alloy outer surface cladding tube, characterized in that it is formed.

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