JP4297354B2 - Boiler panel heating apparatus and method - Google Patents

Description

  The present invention relates to a boiler panel heating apparatus for heating a boiler panel by a moving heating method for welding a single-sided alloy coating applied thereto, and a method for manufacturing an alloy-coated boiler panel.

The boiler panel is a plate-pipe composite panel for making up a furnace housing with a cooling water passage in various boilers, and a large number of sheets are welded in a vertical and horizontal manner to form a furnace housing.
The boiler panel is coated with an alloy such as a nickel self-fluxing alloy on one side in order to improve the durability of the inner surface of the furnace housing.
The alloy coating of the boiler panel is formed by a preceding spraying step and a subsequent welding heating step (melting treatment step) in order to form efficiently. That is, first, in the thermal spraying process, the coating forming alloy material is sprayed over the entire area of one side of the boiler panel or over most of the one side, and then in the welding heating process (melting process), the moving heating is performed to heat the alloy coating to the welding temperature. Is done.

  First of all, in the case of boiler tubes that have a simpler structure than boiler panels and have been used for many years, in the era when the operating temperature of the boiler was lower than in recent years and the erosion and corrosion environment in the furnace was not so severe, It has been a common usage form to use a steel pipe for boilers (low alloy steel pipe) in consideration of the high temperature usability regarding characteristics. Stainless steel pipes and titanium pipes have also been used for applications that require corrosion resistance, but they are not used frequently because they are expensive.

In recent years, there has been an increase in the number of boilers that recover and use waste heat, and as a result, there has been a problem of erosion (wear) due to combustion dust. As a countermeasure against this problem, self-fluxing alloys with excellent wear resistance have been developed. The specifications for applying thermal spray coating are beginning to be widely used.
However, the self-fluxing alloy coating described above is a coating as it is formed by thermal spraying using, for example, an HVOF (High Velocity Oxygen Fuel) sprayer (that is, it is porous and has pinholes reaching the base material. A self-fluxing alloy coating that has been subjected to a melt treatment after thermal spraying, which is often used in other applications (for example, rollers for metal plate processing lines). It is a coating that is transformed from quality to denseness, eliminates the pinholes and exhibits a sufficient environmental barrier function, and is a typical example of “welding coating”).

The reason why the application of a self-fluxing alloy coating to a boiler tube is rare is that when the boiler tube is welded and used, thermal shock cracking is likely to occur in the welding coating due to rapid local temperature rise during welding operations. For this reason, an extraordinary difficult operation is required in which the entire tube is preheated in the furnace and then the high-temperature tubes are joined together by welding.
However, in recent boilers, not only erosion but also the problem of corrosion (corrosion) has become more serious with the demand for high-temperature combustion to make exhaust gases harmless. In the form of supply, the situation has become increasingly eager.

  As an example, Japanese Patent Laid-Open No. 10-170194 discloses a configuration in which a self-fluxing alloy coating is applied to a boiler tube. And the structure (The 3rd page 4th column 15th-16th line of the said gazette of the said gazette) which the non-sprayed part about 50 mm is provided in the edge part of a boiler tube, and this part is used here is employ | adopted. In addition, after the welding, the above-mentioned non-sprayed portion is treated with a protector material instead of covering (same fourth column, lines 24 to 26). The above processing requires special order of protector material (for example, made of alumina) with excellent erosion resistance or fitting work in a narrow boiler. Cost.

In addition, it is not unthinkable to use a factory prefabricated self-fluxing alloy unsprayed coated boiler tube by welding at the construction site and then subject it to melting treatment by induction heating etc. This is a difficult problem due to the difficulty of heating the joint part.
Incidentally, since the reheating cracking occurs when the melting process of the self-fluxing alloy is not performed by simultaneous simultaneous melting or unidirectional melting, induction heating is indispensable for in-situ implementation.

  Next, the single-sided alloy coated boiler panel (boiler furnace panel) which is the main heat treatment target of the present invention will be described. FIG. 5 shows the structure, (a) is an external view of an uncoated surface (alloy material non-sprayed surface), (b) is an external view of a coated surface (alloy material sprayed surface), and (c) is a coated surface. An enlarged external view of both end portions, (d) is an end view thereof, (e) is an enlarged view of a corner portion of the covering surface, and (f) is an end view thereof. This boiler panel 10 is formed by forming an alloy coating 14 on one side of a steel panel 11 (metal base material) and leaving the other side as a base material, and connecting a plurality of pieces at the site when assembling the furnace housing. Adjacent ends are welded together.

  That is, the steel panel 11 (plate material-pipe material composite panel) includes a plate portion 12 (plate material) that forms a connection with a pipe portion 12 (tube material) that forms a cooling water channel, and forms a basic unit of a furnace housing with a cooling water channel. (5 and 6 in the illustrated example) are alternately arranged and closely connected by welding connection or the like, and for erosion resistance, on one side (required protection part) that becomes the furnace inner wall In this case, a coating 14 made of an alloy material is formed almost all over. The alloy coating 14 is made of a relatively inexpensive nickel self-fluxing alloy material and is applied by an efficient thermal spraying method. In the case of a general boiler panel, the steel panel 11 has a length of about 4000 to 6000 mm, a width of about 400 to 500 mm, a diameter of the pipe portion 12 of about 25 to 75 mm, and a wall thickness of about 3 to 7 mm. The thickness of the plate part 13 is about 3 to 7 mm.

  Thus, in the case of a boiler panel, since it is a composite configuration in which tubes and plates are alternately arranged, and generally has a large size (for example, 0.5 m × 6 m), the above in the case of a boiler tube. Incorporation of a practical auxiliary member corresponding to a protector is further difficult, and there is also a problem of complicated shape distortion associated with the melting treatment after spraying (see, for example, Patent Document 2 or Patent Document 3), and prefabricated welding coating. The situation was that it was difficult to think about the use of the product itself.

  For this reason, a heating method for a water-cooled panel segment that heats a boiler panel to be heat-treated to a desired temperature using a high-frequency induction heating device having an inductor as a heating element for local heating while moving the boiler panel in a longitudinal direction is as follows. Although it has been developed (see Patent Document 3), there has been no apparatus or method that makes it highly compatible with the melting treatment of the alloy coating of boiler panels. Conventionally, the main focus has been to remove deformation caused by non-uniform heat distribution, and no consideration has been given to bimetallic deformation, which will be described later, due to the fact that the boiler panel has only one surface. It is.

JP-A-10-170194 Japanese Patent Laid-Open No. 2001-4101 JP 2000-329304 A JP-A-55-144332 JP 56-45220 A

[Unpublished prior patent application 1] Japanese Patent Application No. 2004-88063 However, recently (see unpublished prior patent application 1), an alloy material having excellent erosion / corrosion resistance over the entire area of protection (usually one side). An alloy-coated boiler part has been developed that has a heat-resistant crack and does not cause thermal shock cracking even when welded. In addition, a welding method for self-fluxing alloy-coated boiler parts that can be welded to connect boiler parts that have a self-fluxing alloy weld coating over the entire area without causing thermal shock cracking has become possible. . And along with that, more advanced practical application is desired for the manufacturing method of the alloy coated boiler panel that performs welding heating for melting treatment on the boiler panel by the moving heating method, and the boiler panel heating apparatus suitable for it. Become.

  However, in the melting process of the boiler panel coated with the single-sided alloy coating, if the conventional heating method is used as described above, the difference in the thermal expansion coefficient between the base material and the coating is caused. There remains a complaint that the resulting bimetallic deformations occur frequently. To give a specific example, FIG. 6 shows the case where the boiler panel 10 is heated using a general induction heating device, (a) is an external view of the coated surface side, and (b) is an end view. is there. In this case, the inductor 25 as a heating element is particularly developed for the boiler panel 10, and its coil shape is adapted to the cross-sectional shape of the boiler panel 10. Then, the boiler panel 10 is placed horizontally and supported at both ends, and the inductor 25 is induction-heated to the welding temperature by applying high-frequency current to the inductor 25 while moving the inductor 25 along the boiler panel 10. .

  When the amount of deformation was measured for the boiler panel 10 thus melted (see FIG. 7, in each graph, the alternate long and short dash line indicates the displacement before the thermal spraying of the alloy, the alternate long and two short dashes line indicates the displacement after the thermal spraying of the alloy, and the solid line indicates the melting In the distribution along the longitudinal direction Z of the displacement in the thickness direction X, ie, the thickness direction displacement ΔX (see FIG. 7A), the displacement in the width direction Y, ie, the displacement in the width direction, is shown. The distribution of ΔY along the longitudinal direction Z (see FIG. 7B) is about 10 mm at the maximum, and the distribution along the width direction displacement Y of the thickness direction displacement ΔX (see FIG. 7C) is about 5 mm at the maximum. It was. If such a large deformation remains, when connecting the boiler panels 10 by welding or the like, it is necessary to forcefully perform the alignment work of the panel edges, which are the welded parts, for the furnace housing construction work. Not only is it time-consuming, but large internal stress remains as a cause of later deformation in the finished furnace.

  Therefore, in order to provide a single-sided alloy-coated boiler panel with good straightness and flatness, a boiler panel heating device and an alloy-coated boiler panel are installed so that the melting process can be performed while correcting the deformation of the boiler panel even to a bimetallic deformation. It is a technical problem to devise a heating method in manufacturing.

  The boiler panel heating device of the present invention (initial claim 1) was devised in order to solve such a problem. A heating element for local heating, its moving means, and a boiler panel to be heat-treated. A boiler panel heating apparatus that sequentially heats the boiler panel while moving the heating element in a longitudinal direction of the boiler panel. As a means, a tow tool for pulling the boiler panel in the longitudinal direction, and a position forcing tool for restricting displacement of the boiler panel in two axial directions that are arranged in the longitudinal direction and intersect each other in the longitudinal direction. It is characterized by having.

  Moreover, the boiler panel heating device (initial claim 2) of the present invention is the boiler panel heating device according to the above-mentioned initial claim 1, and further, the position forcing tools respectively force the boiler panel. As the position, an initial displacement allowable position corresponding to the initial displacement of the boiler panel, a retreat position for avoiding interference with the heating operator, and a displacement correction position for eliminating the initial displacement can be adopted. That's it.

  Furthermore, the method for manufacturing an alloy-coated boiler panel according to the present invention (initial claim 3) was devised in order to solve the above-described problem. An alloy deposition coating is applied by spraying an alloy on one side of the boiler panel. Then, the boiler panel is heated in a form in which a heating agent for local heating is moved in the longitudinal direction, and the deposited coating is heated and melted to form a welded coating. In this method, during the heating, the boiler panel is pulled by the pulling tool in the longitudinal direction, and the position forcing tool is used to restrict the displacement in the biaxial direction intersecting the longitudinal direction at many points. It is characterized by correcting.

  Moreover, the manufacturing method (initial claim 4) of the alloy-coated boiler panel of the present invention is the manufacturing method of the alloy-coated boiler panel according to the initial claim 3, and the manufacturing of the alloy-coated boiler panel according to claim 3. The method is used to manufacture an alloy-coated boiler panel, and then the alloy-coated boiler panel is sequentially heated in the longitudinal section of the boiler panel while extruding in the longitudinal direction while applying a bending moment thereto. The bent portion is provided by performing a process of bending the heated portion so that a trough is formed on the alloy coating side by an operation of going.

In such a boiler panel heating device of the present invention (initial claim 1) and an alloy-coated boiler panel manufacturing method (initial claim 3), the alloy coating formed by spraying or the like is moved on one side of the boiler panel. During heating for the melting process to be welded by the heating method, in order to fix the boiler panel and to strongly correct the deformation of the panel, the boiler panel is pulled in the longitudinal direction of the panel, which is also the moving direction of the heating element. Since the displacement in the biaxial direction intersecting with the longitudinal direction is regulated at a large number of locations with respect to the boiler panel, the shape of the boiler panel softened along with the heating can be adjusted simultaneously. At that time, the alloy coating is not damaged.
Therefore, according to the present invention, a boiler panel with good straightness and flatness can be provided.

Moreover, in the boiler panel heating apparatus (initial claim 2) of the present invention, the initial displacement allowable position corresponding to the initial displacement of the boiler panel is set as a position where each position forcing tool is forced with respect to the boiler panel. By holding at least three positions, a retract position that avoids interference with the heating element and a displacement correction position that eliminates initial displacement, a hard panel must be By holding it at the initial displacement allowable position reasonably, when the heating element approaches during heating, avoid unwanted interference at the retracted position, and after heating, force the softened panel to the displacement correction position. It is possible to eliminate the displacement that causes the displacement after cooling and fix the shape by cooling and hardening.
By adopting the three positions in this way, it is possible to accurately control the displacement of the boiler panel by a standardized method and, by extension, a programmed method if necessary.
The boiler panel heating apparatus of the present invention is particularly useful for heating for welding the alloy coating of the boiler panel, but is not limited to this application. It is also useful for heating for tempering, granulating heat treatment, etc.) in both cases with and without alloy coating.

  Further, in the method for manufacturing an alloy-coated boiler panel according to the present invention (initial claim 4), when a bending step is also performed after the heating step for alloy coating welding, the boiler panel is placed in the longitudinal direction during the bending step. While heating while extruding and bending the heated part so that a trough is formed on the alloy coating side, the straightness of the boiler panel is improved by the alloy coating welding heating process (melting process) prior to the bending process Therefore, even if it is a bending process with extrusion, it can be bent stably. Moreover, since it is a bending deformation in a state where it is softened by heating, there is no occurrence of an undesirable situation in which the alloy coating breaks.

  The configuration of an embodiment of the boiler panel heating apparatus of the present invention will be described with reference to the drawings. 1 (a) is a schematic external view (plan view) of the coated surface side where the boiler panel 10 is set in the boiler panel heating device 20, and FIG. 1 (b) is a schematic external view (side view) of the lateral side surface. (C)-(e) is the symbol figure of the position forced cylinder 21 for shape adjustment, (f) is an enlarged view of the corner part of the coating surface of the boiler panel 10, (g) is a partial enlarged view of the panel 10 end surface. It is.

  This boiler panel heating device 20 (see FIGS. 1 (a) and 1 (b)) is an extension of a moving heating type high frequency induction heating device. As a known basic part, the boiler panel heating device 20 is used as a heating element for local heating. An inductor 25, a power supply unit (not shown) for supplying a high-frequency power to the inductor 25 via a cable, and a moving means (not shown) for moving the inductor 25 in the longitudinal direction Z along the boiler panel 10 are provided. The inductor 25 is made of a water-cooled coil made of copper tube or the like, and its coil shape is adapted to the cross-sectional shape of the boiler panel 10 so that it can be loosely fitted to the boiler panel 10 and moved. Yes.

The fixing means of the boiler panel 10 to be heat-treated has been expanded so as to also serve as a shape adjusting means for correcting the deformation of the boiler panel 10, both of which are newly introduced traction tools 22 to 24 and position forcing tools 21, 21...
The traction tools 22 to 24 are mainly composed of a traction cylinder 22 such as a hydraulic cylinder capable of producing a large thrust of 10 kN to 100 kN (see FIGS. 1A and 1B), and a rod which is an operating member is provided. The boiler panel 10 is temporarily connected to one end by a pulling engagement tool 23 and the other end of the boiler panel 10 is temporarily connected to a fixing member 24 by another pulling engagement tool 23 to be vertically long with respect to the boiler panel 10. A desired tensile force can be applied in the direction Z.

  The position forcing tools 21, 21,... Are a plurality of position forcing cylinders 21 arranged in a line. In the illustrated example (see FIGS. 1A and 1B), five position forcing cylinders 21 are arranged at equal pitches in the longitudinal direction Z of the boiler panel 10 to form one row, and three rows are provided. Thus, a total of fifteen position forcing cylinders 21 are incorporated. The position forcing cylinder 21 in the first row (see FIG. 1A) is installed with a working member such as a rod in the lateral width direction Y in the direction orthogonal to the longitudinal direction Z, and the boiler panel 10 in the direction Y It is designed to regulate the displacement. The second- and third-row position forcing cylinders 21 (see FIG. 1B) are installed with a working member such as a rod facing the thickness direction X in a direction orthogonal to the longitudinal direction Z, and the direction Although the displacement of the boiler panel 10 to X is regulated, the displacement in the thickness direction X is regulated in both the second and third rows by sandwiching the boiler panel 10 in opposite directions from both sides.

  Each of the position forcing cylinders 21 is composed of a hydraulic cylinder or the like, and an operating member such as a rod tip can take at least the following three positions. That is, as positions for forcing the boiler panel 10 to be displaced, initial displacement allowable positions X1 and Y1 (see FIG. 1C) corresponding to the initial displacement of the boiler panel 10 and an inductor 25 (heating operator) Retreat positions X2 and Y2 (see FIG. 1 (d)) that avoid interference with the rod and the like, and displacement correction positions X3 and Y3 (see FIG. 1 (e)) that eliminate the initial displacement of the boiler panel 10, respectively. It can be taken with the positioning set to.

  The retreat positions X2 and Y2 are positions where the rod has fully retracted, but the initial displacement allowable positions X1 and Y1 and the displacement correction positions X3 and Y3 are positions where the rod has advanced. Since the displacement correction positions X3 and Y3 correspond to the ideal boiler panel 10 without distortion, the displacement correction positions X3 and Y3 are immediately determined from the design outside dimensions of the boiler panel 10 and the like. On the other hand, since the initial displacement allowable positions X1 and Y1 are adapted to various deformation states, each boiler panel 10 that has actually finished thermal spraying must be determined again in accordance with the actual product. Thus, since the initial displacement allowable positions X1 and Y1 and the displacement correction positions X3 and Y3 are both in the rod advance position, the positioning is different. For example, the rod stop position can be independently adjusted for each position forcing cylinder 21. This is realized by means of attaching a single stopper and switching the stopper according to the selection of the displacement forcing position.

  The boiler panel 10 (see FIGS. 1 (f) and (g)) is not a part of the boiler panel heating device 20, but is a heat treatment target, but is placed with tension applied by the traction tools 22 to 24. A through hole 15 for inserting the engagement pin of the traction engagement tool 23 is formed at the end so that the engagement and disengagement of the traction engagement tool 23 can be performed easily and reliably. For example, perforations are formed at both ends of the plate portion 13. When the through hole 15 is closed with a backing plate or a bolt when the boiler panel 10 is welded and connected later to construct the boiler furnace housing, the boiler panel 10 is used as it is. If 15 is in the way, a longer boiler panel 10 having a margin is used in preparation for subsequent cutting off.

  The alloy coating 14 of the boiler panel 10 may be formed by spraying a self-fluxing alloy in the same manner as in the prior art, and a superalloy material (JIS G4901, 4902) at one end of the surface as in the invention of the unpublished prior patent application 1. ) And the remaining part of one side may be sprayed with a nickel self-fluxing alloy material (JIS 8303). The steel panel 11 may be exposed in a part of the same as the other surface. Other aspects of the boiler panel 10 may be the same as described above.

  A method for manufacturing an alloy-coated boiler panel using the boiler panel heating apparatus 20 of this embodiment will be described with reference to the drawings. FIGS. 1A and 1B show the external appearance of an alloy-coated boiler panel 10 set on a boiler panel heating device 20, wherein FIG. 1A is a plan view and FIG. 1B is a side view. FIG. 2 shows a state in which the boiler panel 10 is moving and heated using the boiler panel heating device 20, wherein (a) is a plan view (appearance view on the coated surface side), and (b) is a side view ( FIG. Further, FIG. 3 is a schematic view and a graph of the deformation state of the boiler panel 10 in which the alloy coating 14 is melted by the method for manufacturing the alloy-coated boiler panel, and (a) is a vertically long thickness-direction displacement ΔX. The direction Z distribution, (b) is the longitudinal direction Z distribution of the lateral direction displacement ΔY, and (c) is the lateral direction Y distribution of the thickness direction displacement ΔX.

  In this case, as a melting process of the alloy coating 14 of the boiler panel 10, it is common to heat the alloy coating 14 of the boiler panel 10 to the welding temperature while moving the inductor 25 in the longitudinal direction Z of the boiler panel 10. Although it is the same as the moving heating method, unlike the prior art, since the boiler panel heating device 20 described above is used, the deformation of the boiler panel heating device 20 is corrected as follows.

That is, when the boiler panel 10 is set in the boiler panel heating device 20 (see FIGS. 1A and 1B), both ends of the boiler panel 10 are connected to the traction tools 22 to 24 and tension is applied to the boiler panel 10. Is done. This tension, in terms of average stress, although the time of setting a 40N / mm ² before and after, then during heating 30~40N / mm ² approximately, is variably adjusted in the longitudinal 40N / mm ² at the time of cooling after completion of heating The

  Further, when the boiler panel 10 is set, each position forcing cylinder 21 supports the boiler panel 10 at the initial displacement allowable positions X1, Y1. Since the initial displacement allowable positions X1 and Y1 correspond to the initial displacement of the boiler panel 10, the boiler panel 10 is supported in a state in which the deformation is allowed. It is supported without.

  Further, (see FIG. 2), when the inductor 25 approaches while the inductor 25 is moving, the position-forcing cylinder 21 is temporarily retracted to the retracted positions X2 and Y2 by the rods and the like. And if the inductor 25 is passed over, a rod etc. will advance to the displacement correction position X3, Y3. As a result, the corresponding part of the boiler panel 10 is placed at an ideal position where the initial displacement has been eliminated, and accordingly, the boiler panel 10 undergoes reverse post-cooling deformation that cancels out the initial displacement, and a temporary corresponding to it. Although stress is generated inside, there is a portion softened by high-frequency heating in the inductor 25 in the immediate vicinity of the stress. Therefore, the stress is moderated and the boiler panel 10 does not leave harmful stress. The shape is deformed to eliminate the initial displacement.

  Thus, when the moving heating using the inductor 25 is finished and the cooling is further finished, in the boiler panel 10, the alloy coating 14 is firmly welded to the steel panel 11 by the melting process, and is densely modified, and Such an alloy coating 14 is appropriately subjected to displacement correction processing without causing damage such as cracking, that is, melt processing is performed while correcting even bimetallic deformation, and a boiler panel having good straightness and flatness. become.

  Incidentally, when the amount of deformation of the boiler panel 10 subjected to the melting treatment by the apparatus and method of the present invention was measured (see FIG. 3, in each graph, the alternate long and short dash line indicates the displacement before the alloy spraying, and the two-dot chain line indicates the alloy spraying. In the longitudinal direction Z distribution of thickness direction displacement ΔX (see FIG. 3A), the maximum length is about 5 mm, and in the longitudinal direction Z distribution of lateral direction displacement ΔY (see FIG. 3). 3 (b)), the maximum was about 2 mm, and the horizontal direction displacement Y distribution of the thickness direction displacement ΔX (see FIG. 3C) was about 2 mm.

  When the deformation is reduced to this extent, when the boiler panels 10 are connected to each other by welding or the like, the alignment operation of the panel edges, which are welded parts, can be completed by alignment and alignment that does not require bending force. Work can be done easily and quickly, and the residual stress in the finished boiler furnace housing is also small.

Other embodiment of the manufacturing method of the alloy covering boiler panel of this invention is described referring drawings. FIG. 4 shows the state of a boiler panel bending process that is additionally performed as necessary after the above boiler panel heating process, (a) is a plan view of the apparatus, etc., (b) is a side view, (c) ) Is a perspective view of the boiler panel 10 after bending.
In this bending step, in order to form the boiler panel 10 used at the boundary between the side wall portion and the ceiling portion of the boiler furnace, the alloy coating is performed by the above-described method for manufacturing an alloy coated boiler panel using the boiler panel heating device 20. This is applied to the boiler panel 10 after the 14 melting process.

  A boiler panel bending apparatus 30 used in the bending process (see FIGS. 4A and 4B and Patent Documents 4 and 5) includes an extrusion slider 31 that pushes the boiler panel 10 forward from the rear, and the boiler panel 10 from both sides. A pair of guide rollers 32 that sandwich and define the extrusion direction, an induction coil 33 for high-frequency heating installed near the guide rollers 32, a means for clamping the front end and the intermediate portion of the boiler panel 10, and a rotary arm 34 are arranged. And a bending moment adding mechanism.

  When the boiler panel 10 is set in the boiler panel bending apparatus 30, the surface on which the alloy coating 14 is formed is set toward the turning center side of the rotary arm 34, and in this state, the induction coil 33 is energized with high frequency while the boiler panel 10 is set. 10 is pushed out in the longitudinal direction by the extrusion slider 31 and the portion of the boiler panel 10 that is induction-heated at the induction coil 33 is bent by rotating the rotary arm 34 by the thrust and bending the extruded portion of the boiler panel 10. Is bent to the alloy coating 14 side, the boiler panel 10 is bent, and the alloy coating 14 comes to the inner peripheral side (see FIG. 4C).

  The heating in the bending process is performed more gently than the heating in the previous melting process. That is, in the melting process described above, the alloy coating 14 is heated to the welding temperature (for example, about 1050 ° C.). In this bending process, the temperature of the alloy coating 14 is increased in order to avoid reheat cracking of the alloy coating 14. The softening temperature is lower than the welding temperature (the temperature at which the panel is easily plastically deformed, for example, about 950 ° C.). With such a temperature setting, even if the boiler panel 10 is bent, it does not crack and does not peel off. In addition, since the straightness of the boiler panel 10 is improved in the preceding melting process, the boiler panel 10 is stably extruded and the bending state is stabilized even if the process involving extrusion is performed in the bending process. So bend in a beautiful arc shape.

[Others]
In the above embodiment, the hydraulic position forcing cylinder 30 is used as the position forcing tool. However, the position forcing tool is not limited thereto, and may be other electric type or mechanical type, for example, a mechanical type. The jack may be driven by an electric motor drive and a rotary linear motion conversion mechanism, and in the simplest example, for example, a bolt may be moved forward and backward by hand. The same applies to the traction tool, and the traction tool is not limited to the traction cylinder 20.
Moreover, in said embodiment, although the inductor 25 of the high frequency induction heating apparatus was mentioned as a heating operator, a heating operator is not necessarily restricted to it and can move and heat in the vertical direction Z of the boiler panel 10. Any other material may be used, for example, a line burner using a gas heating flame.

  Furthermore, in the above-described embodiment, the boiler panel 10 is disposed in a state in which FIG. 1A is a plan view and FIG. 1B is a side view, that is, in a state where the covering surface is up and the non-covering surface is down. Although it set to the boiler panel heating apparatus 20, a set state is not restricted to it. For example, the boiler panel heating device 20 is in a state in which both the coated surface and the non-coated surface of the boiler panel 10 face sideways, that is, in a state where FIG. 1 (a) is a side view and FIG. The panel 10 may be placed for heating.

1 shows the structure of a boiler panel heating device according to an embodiment of the present invention, in which (a) is a schematic external view of a coated surface when a boiler panel is set in the boiler panel heating device, and (b) is an external view of a lateral side. Schematic diagrams, (c) to (e) are symbol diagrams of a position forcing cylinder for shape adjustment, (f) is an enlarged view of a corner portion of the covering surface of a boiler panel, and (g) is a partially enlarged view of a panel end surface. It is. About the boiler panel moving heating method using the boiler panel heating apparatus, (a) is an appearance schematic diagram on the coated surface side, and (b) is an external schematic diagram on the side surface side. The deformation | transformation state of the boiler panel which performed the melting process of the alloy coating with the boiler panel heating apparatus and method is shown, (a)-(c) both consist of a schematic diagram and a graph, (a) is thickness direction displacement. The distribution in the longitudinal direction, (b) is the distribution in the longitudinal direction of the displacement in the width direction, and (c) is the distribution in the width direction of the displacement in the thickness direction. About other embodiment of this invention, the boiler panel bending process after a boiler panel heating process is shown, (a) is a top view of an apparatus etc., (b) is a side view, (c) is a perspective view of the boiler panel after a process. FIG. The structure of a boiler panel is shown, (a) is an external view of an uncoated surface, (b) is an external view of a coated surface, (c) is an external view of both end portions of the coated surface, (d) is an end view, (e ) Is an enlarged view of the corner portion of the coated surface, and (f) is a partially enlarged view of the end surface. (A) is an external view on the coated surface side, and (b) is an end view of a boiler panel moving heating method in which an inductor of a general induction heating device is adapted to a boiler panel. FIG. 2 shows a deformation state of a boiler panel in which an alloy coating is melted by such an apparatus and method, and (a) to (c) are both schematic diagrams and graphs, and (a) is a vertically long displacement in the thickness direction. The direction distribution, (b) is the longitudinal direction distribution of the lateral width direction displacement, and (c) is the lateral direction distribution of the thickness direction displacement.

Explanation of symbols

10 ... Boiler panel,
DESCRIPTION OF SYMBOLS 11 ... Steel panel, 12 ... Pipe part, 13 ... Plate part, 14 ... Alloy coating, 15 ... Through-hole,
20 ... Boiler panel heating device,
21 ... Cylinder for position forced (position forced tool),
22 ... Towing cylinder (traction tool), 23 ... Towing engagement tool (traction tool),
24 ... Fixing member (traction tool), 25 ... Inductor (heating element),
30 ... Boiler panel bending device,
31 ... Extrusion slider, 32 ... Guide roller, 33 ... Induction coil, 34 ... Rotating arm

Claims (2)

An alloy deposition coating is formed by spraying an alloy on one side of the boiler panel, and then the boiler panel is heated in such a manner that a heating agent for local heating is moved in the longitudinal direction, and the deposition coating is heated and melted. A method for manufacturing an alloy-coated boiler panel in which a welded coating is formed by drilling through holes at both ends of the boiler panel plate prior to heating, and inserting engagement pins of traction tools into the holes. sure, deformed by regulating a displacement said at longitudinal direction tensile while point forced equipment at the boiler panel said pulling tool during the heating of the two-axis direction crossing with the longitudinal direction in a number locations A method of manufacturing an alloy-coated boiler panel, characterized by correcting the above. An alloy-coated boiler panel is manufactured by performing the method for manufacturing an alloy-coated boiler panel according to claim 1 , and then the boiler is pushed out in the longitudinal direction while applying a bending moment to the alloy-coated boiler panel. An alloy-coated boiler, wherein a bent portion is provided by bending the heated portion so that a trough is formed on the alloy-coated side by an operation of sequentially heating a short section in the longitudinal direction of the panel. Panel manufacturing method.

Images