JPH10230415A - Surface treating method for metal bent pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treating method for a metal bent pipe by which built-up layer thickness can be set to prescribed thickness and durable metallic layers of prescribed components for which metallurgical joints of extremely small dilution ratios are performed can be easily and surely formed when durable metallic layers such as abrasion proof layers and corrosion-resistant layers are welded and formed on the surfaces at the inside and outside of the metal bent pipe which is exposed to severe abrasion environments and corrosion environments. SOLUTION: In the surface treating method of a metal bent pipe 1, a durable metallic material applied is melted by induction heating and a durable metallic layer 3a is formed by welding this molten durable metallic material on the whole surface or the partial surface of the internal surface of the metal bent pipe 1 by arranging this metal bent pipe 1 in the longitudinal direction, applying powder and granular durable metallic material mixed with fixing agent to the whole surface or the partial surface of the internal surface, energizing a coil 2 connected to an AC power source by an enclosing arrangement around the metal bent pipe 1 and moving at least one of the metal bent pipe 1 and the coil 2 in the bent axial direction of the metal bent time 1, when the durable metallic layer 3a made by a metallurgical joint is formed on the whole surface or the partial surface of the internal surface of the metallic bent pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a surface of a metal bent tube, and more particularly to a method for imparting excellent durability to the inside and outside surfaces of a metal bent tube exposed to a friction environment or a corrosive environment in various industries. Improvement of surface treatment method for

[0002]

2. Description of the Related Art In order to transport raw materials and product materials in the manufacturing industry such as steel, cement, etc., when they are transported through metal pipes using a so-called pipeline facility or when they are pressure-fed, such materials are used. The eroded portion, whatever its shape, is exposed to a wear environment, and the degree of wear is particularly remarkable in the case of a bent metal pipe. Also, chemistry,
In industrial fields such as petrochemicals, water treatment, and power generation, there are corrosive environments and high-temperature heating environments due to chemical reactions and a wide variety of weakly acidic atmospheres, and corrosive wear, fine cracks, heat loss, etc. on the inner and outer surfaces of metal curved tubes. There is always the danger of occurring.

By the way, as a countermeasure against such abrasion or corrosion, a special material according to a countermeasure purpose generally called cladding is mechanically or metallurgically adhered or welded to the inner surface or outer surface of the bent metal pipe. I have. Thus, the most widely used welding method for metallurgical joining is the overlay welding method. In the case of forming a wear-resistant layer, arc welding using a welding rod or a welding wire as a filler metal is used. In general, even when forming a corrosion-resistant layer, a predetermined corrosion-resistant material can be melted and welded by an arc welding method, a gas welding method, or a plasma powder overlay method. Explosive bonding or rolling and crimping methods are sometimes used for cladding, which has a large number of market demands, such as stainless steel materials and titanium materials, but the types of cladding materials are limited.

[0004] When the arc welding method is used to form the wear-resistant layer, the heat input inevitably causes penetration into the metal bent tube side as the base material, and the wear-resistant material is diluted. Therefore, there is a problem that a chemical component is reduced due to each dilution ratio according to each welding condition.Furthermore, wear-resistant overlay welding materials generally have high weld cracking susceptibility, and have a predetermined thickness in one pass or one layer. Multi-layer welding requires complicated work in terms of heat management and construction method, which is not preferable.

However, in one-pass, single-layer welding, the wall thickness is often limited to a range of 3 to 5 mm from the principle thereof, and the presence and fluctuation of the dilution ratio stabilize the target wear resistance. Not only is it difficult, but also the required wear-resistant layer is extremely diluted near the inner and outer surfaces of the metal bent tube, which is the base metal, and in addition, the wall thickness is limited to a thickness range of 3 to 5 mm, When a thinner or thicker layer thickness is required, it is extremely difficult and complicated means is required.

On the other hand, when forming a corrosion-resistant layer, unlike a wear-resistant layer, a layer thickness such as a wear-resistant layer is not required in design to prevent static corrosion wear and cracking.
A layer thickness of 1 mm may be satisfactory. However, the corrosion-resistant layer has a small variation error range of the target component, the diluted layer is not considered as a corrosion-resistant layer, and the component value required in the conventional overlay welding method in which the component value varies in the thickness direction of the layer is one. Despite being about 2 mm, 5 to 3
There is a variety of problems in that a buildup layer of about 7 mm must be formed, an expensive special alloy material must be welded in a larger amount than necessary, and the construction cost must be increased.

In the case where the base material is a bent metal tube, not shown, a method of overlay-welding the inner surface of the bent metal tube by semi-automatic welding or manual welding while gradually rotating the bent metal tube. However, in the case of this method, the height of the welding torch that can be used is limited due to the bending of the metal tube as the base material, the torch does not go to the back, and the arc point as it goes into the back Further, according to the thermal spray coating method, there is a serious problem that the projection angle of the preheated particles becomes more unsuitable as the projection angle becomes deeper, and the yield of the welding powder becomes extremely poor.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been developed to solve the above-mentioned various problems in the prior art, and has been developed to solve the above-mentioned problems. When a durable metal layer such as an abrasion-resistant layer or a corrosion-resistant layer is formed by welding on the inner and outer surfaces, a predetermined metallurgical bond with a very small dilution ratio can be set to a desired thickness of the build-up layer. It is an object of the present invention to provide a surface treatment method for a bent metal tube that can easily and reliably form a durable metal layer of a component.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, the present invention provides a durable metal layer formed by metallurgical bonding on the whole or a part of the inner surface of a bent metal pipe. When forming the metal bent tube is disposed vertically, a powdery and durable metal material mixed with a binder is applied to the entire inner surface or a part of the inner surface thereof, and the metal bent tube is formed around the bent metal tube. A coil connected to an AC power supply is arranged and encircled to energize the coil, and at least one of the metal bent tube and the coil is moved in the bending axis direction of the metal bent tube, or both the metal bent tube and the coil are moved. By moving in the opposite direction, the applied durable metal material is induction-heated and melted, and the melted durable metal material is welded to the entire surface or a part of the inner surface of the metal bent tube to be durable. Surface treatment method for bent metal tubes characterized by forming a conductive metal layer It is intended to provide.

In order to solve the above-mentioned problems and achieve the object, the present invention provides a method for forming a durable metal layer formed by metallurgical bonding on the inner surface of a metal bent tube. A bent core material having an outer diameter smaller than the inner diameter is inserted into the bent metal tube to form a gap between the inner surface of the bent metal tube and the outer surface of the core material. Is filled with a powdery or powdery durable metal material mixed with a fixing material, the metal bent tube is arranged vertically, and a coil connected to an AC power supply is arranged around the metal bent tube. By energizing the coil and moving at least one of the metal bent tube and the coil in the bending axis direction of the metal bent tube, or by moving both the metal bent tube and the coil in the opposite direction, The above-mentioned durable metal material filled in is melted by induction heating. The present invention provides a surface treatment method for a metal bent tube, comprising: forming a durable metal layer on an inner surface of the metal bent tube by removing a core material after welding a metal material to an inner surface of the metal bent tube. is there.

Further, in order to solve the above-mentioned problems and to achieve the object, the present invention provides a method for forming a durable metal layer formed by metallurgical bonding on the entire outer surface or a part of the outer surface of a bent metal tube. Then, the metal bent tube is disposed vertically, and a powdery and durable metal material mixed with a binder is applied to the entire outer surface or a part of the outer surface thereof, and connected to an AC power source around the metal bent tube. Encircling the coil and energizing the coil, and moving at least one of the metal bent tube and the coil in the bending axis direction of the metal bent tube, or moving both the metal bent tube and the coil in the opposite direction In this way, the applied durable metal material is induction-heated and melted, and the melted durable metal material is welded to the entire outer surface or a part of the outer surface of the metal bent tube to form a durable metal layer. Provided is a method for surface treatment of a metal curved tube characterized by forming Than it is.

Further, in order to solve the above-mentioned problems and achieve the object, the present invention provides a method for forming a durable metal layer formed by metallurgical bonding on a surface outside a bent portion of a metal bent tube. An arc-shaped or groove-shaped bent metal cover is joined to the outer surface of the bent portion of the metal bent tube, and the inner surface of the metal cover and the outer surface of the bent portion of the bent metal tube are joined to each other. A gap is formed therebetween, and the gap is filled with a powdery or powdery durable metal material mixed with a fixing agent. Encircling a coil connected to an AC power supply and energizing the coil, and moving at least one of the metal bent tube and the coil in the direction of the bending axis of the metal bent tube, or both the metal bent tube and the coil By moving in the opposite direction, the above-mentioned durable metal filled in the gap. Providing a surface treatment method for a metal curved tube, characterized in that a material is induction-heated and melted, and the melted durable metal material is welded to the gap to form a durable metal layer on the gap. Things. In the present invention, “granular” refers to “a powder alone”, “a granule alone”, and “a mixture of a powder and a granule”.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention, and the present invention is applied to a wear environment. The exposed curved metal tube 1 is vertically disposed movably in the direction of the curved axis, and a powder made of an abrasion-resistant material mixed with a glass-based fixing agent on the entire inner surface or a part of the inner surface of the curved metal tube 1. After the material is applied to a uniform or non-uniform thickness over the entire surface, a coil 2 connected to an AC power supply is disposed at a predetermined position around the metal curved tube 1 so as to enclose the coil 2 and energize the coil 2. 1
And the metal curved pipe 1 and the induction heating by moving to the song axial direction (direction of arrow A _1), the metal bends 1 by melting the coating powder material by thermal energy of the metal bends 1
When the movement of the metal bent tube 1 and the energization of the coil 2 are stopped after being welded to the inner surface of the metal bent tube, the weld metal solidifies and is uniformly or unevenly formed on the entire inner surface or a part of the inner surface of the metal bent tube 1. A durable metal layer 3a made of a wear-resistant layer is formed. In addition, a small amount of a slag-making agent (slag component) may be added for smooth welding.

In principle, the above-mentioned durable metal 3a is formed by melting the powder material by the action of heat energy on the inner surface of the metal bent tube 1 that has been induction-heated due to the relationship between the current carrying capacity and time. This is performed by welding and solidifying on the inner surface of the tube 1.

(Example) Next, an example corresponding to the first embodiment of the present invention will be described. For example, a case in which a durable metal layer 3a made of a wear-resistant layer is welded to the inner surface of a metal bent tube 1 for transferring and pressing raw concrete and grime stone by using the following powder material as a wear-resistant material:
A surrounding coil 2 as shown in FIG.
An embodiment in which a high-frequency power source of Z · 30 KW is connected and energization processing is performed is described below. Metal curved tube; SGP 150A, outer diameter φ165.2mm, long elbow (JIS), moving speed 50mm / min Powder material: iron powder-based powder 50%, tungsten carbide (W ₂ C) 50% (particle size -250 ~ 4 mm High-frequency oscillator condition; Coil load voltage: 360 V, coil load current 170 A Under the above conditions, the durable metal layer 3a consisting of a wear-resistant layer having a welding layer thickness of 2 mm is shown in FIG. A wear-resistant metal bent pipe for transferring and pumping a concrete material having such a cross-sectional shape and formed on the inner surface outside the bent portion of the metal bent pipe 1 was obtained. transfer,
Performance of wear-resistant metal bent pipe for pumping: The service life was about 80 times as long as that of a metal bent pipe for concrete pumping composed of a conventional hardened bend pipe.

FIG. 2 shows a second embodiment of the present invention, which is different from the first embodiment in that the metal bent tube 1 is not moved and the coil 2 is moved to the second position. in moving the same speed as the metal bent tube 1 in one embodiment, be only a point is moved to the song axial direction of the metal bent tube 1 (the direction of arrow a _2), other exemplary conditions first This embodiment is the same as the embodiment, and the performance of the metal tube after the embodiment and the treatment is also the same as the above embodiment. Therefore, the same means are denoted by the same reference numerals.

FIG. 3 shows a third embodiment of the present invention. The difference from the first and second embodiments is that both the metal bent tube 1 and the coil 2 are simultaneously reversed. be a point that is moved at the same speed in the direction, in this embodiment, it moves the metal curved pipe 1 in the direction of the arrow a _1,
Are different from the coil 2 at the point is moved in the arrow A ₂ direction, therefore, differs from the embodiment of the first embodiment only in the following points. Therefore, the same means are denoted by the same reference numerals.

(Examples) Examples corresponding to the third embodiment described above include a metal bent tube 1, a powder material, a coating thickness of the powder material, high-frequency oscillator conditions of the coil 2, and durability including a wear-resistant layer. Since the thickness of the welded layer of the metal layer 3a and the like are the same as those in the example of the first embodiment, the same reference numerals are given to the same means.
Since the means for simultaneously moving both the coil 2 and the coil 2 in the opposite direction is employed, the processing time can be reduced to about half.

It should be noted that (a), (b), (c), and (c) of FIG.
(D) illustrates the cross-sectional shape of the durable metal layer 3a formed of the wear-resistant layer formed on the inner surface of the metal bent tube 1 according to the first, second, and third embodiments. In addition, these shapes are selected and formed according to the conditions such as the use place or transfer of the metal bent tube 1, the type, shape, size, transfer, and pumping speed of the conveyed material. Is what you do.

FIG. 5 shows a fourth embodiment of the present invention, in which a metal curved tube 1 exposed to a wear environment is movably arranged in the direction of its curved axis. A tubular or rod-shaped core material 4 made of ceramic or sand mold or a tubular or rod-shaped core material 4 coated with a release agent on the outer surface is placed between the inner surface of the metal bent tube 1 and the outer surface of the core material 4. A gap having a size equivalent to the thickness of the required durable metal layer is provided and inserted into the gap, and a powder and granule mixture of a powder body and a granular body having a diameter of about 1 to 9 mm as an abrasion-resistant material mixed with a fixing agent in the gap. A material is pressurized and filled, and a coil 2 connected to an AC power supply is arranged at a predetermined position around the metal bent tube 1 so as to energize the coil 2 and to place the metal bent tube 1 in the bending axis direction ( Arrow A
₁ ), the metal tube 1 is induction-heated, and the thermal energy of the metal tube 1 melts the powder-particle mixed material and welds the material to the inner surface of the metal bent tube 1. When the movement of the coil 2 and the energization of the coil 2 are stopped, the weld metal solidifies to form a durable metal layer 3b made of a wear-resistant layer on the inner surface of the metal bent tube 1. Thereafter, the core 4 Is crushed and removed to obtain (a) in FIG.
(B) An abrasion-resistant metal bent tube having a durable metal layer 3b having a uniform thickness or a non-uniform thickness as shown in FIG.

Example Next, an example corresponding to the fourth embodiment will be described. For example, in a transportation pipe of steel grit or silica grit of a casting sand blasting machine used in the foundry industry, the inner surface of the metal bent pipe 1 according to the fourth embodiment has a uniform shape as shown in FIG. Durable metal layer 3b consisting of a wear-resistant layer having a cross-sectional shape with a thickness
In this example, a welding process was performed by connecting a high frequency power supply having a frequency of 400 KHZ / 30 KW to a surrounding coil 2 as shown in FIG. Is shown below. Metal tube; SGP 150A, outer diameter φ165.2mm, long elbow (JIS), wall thickness 8.1mm, moving speed 40mm / min Powder mixed material; powder material: Co (cobalt) heat-resistant high alloy (Stellite No.6) (Grain size 80-300 mesh) Granular material; Tungsten carbide 20% (0.5-2mm) Coating thickness; 4mm Core material (tubular); φ140mm, wall thickness 5mm High frequency oscillator condition; Coil load voltage: 360V, Coil load current 150A, Coil inner diameter φ180mm Under the above conditions, a durable metal layer 3b consisting of a wear-resistant layer with a welding layer thickness of 4mm is provided on the inner surface of the metal bent tube 1, and a metal bend for transporting steel grit or silica grit of a casting sand blasting machine. When used as a tube, the service life was at least five times that of a conventional high chromium cast iron tube.

FIG. 6 shows a fifth embodiment of the present invention. The difference from the fourth embodiment is that the metal bent tube 1 is not moved and the coil 2 is moved to the fourth position. in moving the same speed as the metal bent tube 1 in the embodiment, there is only a point is moved to the song axial direction of the metal bent tube 1 (the direction of arrow a _2), other implementations conditions of the fourth This is the same as the embodiment, and the performance of the metal tube after the example and the treatment is also the same as that in the fourth embodiment. Therefore,
The same means are denoted by the same reference numerals.

FIG. 7 shows a sixth embodiment of the present invention, which is different from the fourth and fifth embodiments in that both the metal bent tube 1 and the coil 2 are simultaneously reversed. be a point that is moved at the same speed in the direction, in this embodiment, it moves the metal curved pipe 1 in the direction of the arrow a _1,
Are different from the coil 2 at the point is moved in the arrow A ₂ direction, therefore, differs from the embodiment example of the fourth embodiment only in the following points. Therefore, the same means are denoted by the same reference numerals.

(Embodiment) For an embodiment corresponding to the above-mentioned sixth embodiment, the metal bent tube 1, the powder / particle mixed material, the applied thickness of the powder / particle mixed material, the high frequency oscillator condition of the coil 2, the durable metal Since the thickness of the welded layer of the layer 3b is the same as that of the example in the fourth embodiment, the same reference numerals are given to the same means, but in this embodiment, the metal bent tube 1 and the coil 2 Are simultaneously moved in opposite directions, so that the processing time can be reduced to about half.

In each of the fourth to sixth embodiments, as shown in FIGS.
In order to make the thickness of the welded layer of the durable metal layer 3b on the inner surface uniform or uneven, the central axis of the metal bent tube 1 and the central axis of the core material 4 must be concentric or eccentric. Can be adjusted as desired.

FIGS. 9 to 11 show seventh to ninth embodiments of the present invention, respectively. The main difference from the above fourth to sixth embodiments is that the present invention is different from the fourth to sixth embodiments. The point is that the means for crushing and removing the core material 4 is omitted, and a means capable of repeatedly using the core material 4 is employed.

In other words, in these embodiments, a mold release agent is applied to the outer surface of the metal curved tube 1 vertically arranged movably in the curved axis direction, and is the same as the curved axis of the metal curved tube 1. The bent tubular or bent rod-shaped core material 4 fixedly arranged in the direction,
A gap having a size equivalent to the required thickness of the durable metal layer is provided between the inner surface of the metal bent tube 1 and the outer surface of the core material 4 and inserted there between, according to the fourth to sixth embodiments. Similarly, a powdery / granular mixed material is charged into the gap under pressure, and a coil 2 connected to an AC power supply is arranged at a predetermined position around the metal bent tube 1 so as to enclose the coil 2 and energize the coil 2. in a state of fixing the child member 4, as shown in FIG. 9, moving only metal bent tube 1 in the song axial direction (direction of arrow a ₁₎ (the seventh embodiment) or FIG. as shown in 10, or moving only coil 2 songs axial direction (the direction of arrow a ₂₎ (eighth embodiment), or as shown in FIG. 11, both of metal bent tube 1 and coil 2 songs axial move (arrow a _1, a ₂ direction) (ninth embodiment) induced pressure to the metal bent pipe 1 by And, after welded to the inner surface of the metal bends 1 and melting the granular mixed material by thermal energy of the metal bends 1, move the coil 2 of metal bent tube 1 and coil 2
When the current supply to the metal tube is stopped, the weld metal solidifies to form a durable metal layer 3b made of a wear-resistant layer on the inner surface of the metal bent tube 1. Thereafter, the metal bent tube 1 is removed from the core tube 4. By detaching, (a) of FIG.
(B) An abrasion-resistant metal bent pipe having a uniform or non-uniform durable metal layer 3b on its inner surface as shown in (b).

Embodiments corresponding to the above-described seventh to ninth embodiments are the same as the above-described embodiments corresponding to the above-described fourth to sixth embodiments, and therefore description thereof is omitted. Since the core material 4 used in each embodiment does not need to be pulverized and removed, there is an advantage that the trouble can be omitted and the core material 4 can be used repeatedly and repeatedly.

FIG. 12 shows a tenth embodiment of the present invention, in which a durable metal layer made of a corrosion-resistant and heat-resistant layer is provided on the outer peripheral surface of a metal bent tube 1 exposed to a corrosive environment and a high-heat environment. The present invention relates to a case in which a bent metal tube 1 is vertically arranged movably in a direction of a curved axis thereof, and the outer surface of the bent metal tube 1 is made of a corrosion-resistant and heat-resistant material mixed with a glass-based fixing agent. After the powder material is applied to a predetermined thickness, a coil 2 connected to an AC power supply is arranged at a predetermined position around the metal bent tube 1 to energize the coil 2 and to bend the metal bent tube 1. metal bent pipe 1 and the induction heating by moving in the axial direction (direction of arrow a _1), by the thermal energy of the metal bends 1 by melting the coating powder material is welded to the outer surface of the metal bends 1 Later, when the movement of the metal bent tube 1 and the energization of the coil 2 are stopped, Chakukinzoku is corrosion on the outer surface of the metal bends 1 solidifies, in which durability metal 3c consisting of anti-high heat layer is formed. In addition, a small amount of a slag-making agent (slag component) may be added for smooth welding.

(Example) Next, an example corresponding to the tenth embodiment of the present invention will be described. For example,
A durable metal 3c composed of a corrosion-resistant and heat-resistant layer is formed on the outer surface of a metal bent tube 1 such as a boiler tube used in a chemical plant or a power generation facility by using a powder material of a corrosion-resistant and heat-resistant material. In this case, an embodiment in which a high-frequency power source having a frequency of 400 KHZ and 30 KW is connected to the surrounding coil 2 as shown in FIG. Metal bent tube; STB-340 Outer diameter 42.7mm, wall thickness 3mm, long elbow (JIS), moving speed 50mm / min Powder material: Ni-Cr-B-Si-WC- alloy powder Coating thickness; 2mm High frequency oscillator Conditions; Coil load voltage: 360 V, coil load current 170 A, coil inner diameter φ70 mm Under the above conditions, corrosion resistance with a deposited layer thickness of 1.5 mm, and a durable metal layer 3 c composed of a heat resistant layer uniformly provided on the outer surface, corrosion resistance, A high heat resistant metal bent tube was obtained. The performance of the bent metal pipe; corrosion of the pipe outer surface due to oxidation and high-temperature SOx, and wear due to flying high-temperature dust were significantly reduced.

FIG. 13 shows an eleventh embodiment of the present invention. The difference from the tenth embodiment is that the metal bent tube 1 is not moved and the coil 2 is moved to the first position.
0 moving the same speed as the metal bent tube 1 in the embodiment, there is provided only in that is moved in the song axial direction of the metal bent tube 1 (the direction of arrow A _2), other exemplary conditions 10 This embodiment is the same as the embodiment described above, and the performance of the metal bent tube after the embodiment and the treatment is also the same as that of the embodiment 10. Therefore, the same means are denoted by the same reference numerals.

FIG. 14 shows a twelfth embodiment of the present invention, which is different from the tenth and eleventh embodiments in that both the metal bent tube 1 and the coil 2 are simultaneously opposed. be a point that is moved at the same speed in the direction, in this embodiment, moves the metal curved pipe 1 in the direction of the arrow a _1, differs in that moving the coil 2 in the arrow a ₂ direction Therefore, it is different from the example of the tenth embodiment only in the following points. Therefore, the same means are denoted by the same reference numerals.

EXAMPLE An example corresponding to the twelfth embodiment will be described from the viewpoint of the metal bent tube 1, the powder material, the coating thickness of the powder material, the high-frequency oscillator condition of the coil 2, the corrosion resistance, and the high heat resistance layer. The thickness of the welded layer of the durable metal layer 3c
The same means as in the example of the 0th embodiment are denoted by the same reference numerals, but in this embodiment, means for simultaneously moving both the metal bent tube 1 and the coil 2 in opposite directions. , The processing time can be reduced to about half.

FIG. 15 shows a thirteenth embodiment of the present invention. In the thirteenth embodiment of the present invention, the metal curved tube 1 is bent at the same curvature as that of the metal curved tube 1 on the outer surface of the bent portion of the metal curved tube 1 exposed to a wear environment. A semi-cylindrical bent metal cover 5 having an arc-shaped or groove-shaped cross-section is abutted, and both longitudinal edges thereof are welded to the surface of the metal bent tube 1 to form an inner surface of the metal cover 5. A gap 6 is formed between the metal bent tube 1 and the outside of the bent portion of the metal bent tube 1, and the metal bent tube 1 provided with the metal cover 5 is vertically arranged so as to be movable in the direction of its curved axis. And a powdery or durable metal material having a high abrasion resistance mixed with a powdery agent or a binder is charged or continuously supplied under pressure, and is connected to an AC power source at a predetermined position around the metal bent tube 1. The coil 2 is surrounded and energized, and the metal tube 1 is moved in the direction of its curved axis (arrow A). ₁ ), the metal curved tube 1 and the metal cover 5 are induction-heated, and the thermal energy is used to melt the supplied durable metal material filled and supplied into the gap 6 to thereby melt the durable metal material. After the material is metallurgically welded to the gap, that is, the outer surface of the bent metal tube 1 and the inner surface of the metal cover 5, when the movement of the bent metal tube 1 and the energization of the coil 2 are stopped, the deposited metal in the gap 6 is removed. Is solidified to form a wear-resistant layer durable metal layer 3d having a uniform thickness or a non-uniform thickness on the outer surface of the bent portion of the metal bent tube 1 as shown in FIGS. Things. Note that, in order to prevent the durable metal material from dropping from the lower part of the gap 6, the metal cover 5
May be provided with a bottom plate at the lower end.

(Example) Next, an example corresponding to the thirteenth embodiment of the present invention will be described. For example,
A durable metal layer 3d made of a wear-resistant layer is used on the outer surface of the bent portion of the metal refractory sprayed metal bent tube 1 for repairing a brick mold used in iron making, and a metal cover 5 described below is used. At the same time, in the case where the following powder material was used as the wear-resistant material for welding, an energizing process was performed by connecting a high-frequency power supply having a frequency of 400 KHZ and 30 KW to the surrounding coil 2 as shown in FIG. Show. Metal bend; SGP 80A, an outer diameter Fai89.1Mm, Long elbow (JIS), the moving speed of 30 mm / min metal cover; SS400 × mm ^t, an inner diameter of φ98mm × half powdered material; Ni-based powder 50%, chromium carbide 50%
(Grain size -250 to +60 microns) Gap; 4.5 mm High-frequency oscillator conditions; Coil load voltage 360 V, coil load current 200 A An amorphous refractory sprayed metal curved pipe 1 formed in the shape shown in (a) was obtained, and its performance was about 2 times that of the conventional thick high-manganese steel curved pipe.
It has a wear-resistant service life of 0 times and no unexpected breakage accident during use was observed.

FIG. 16 shows a fourteenth embodiment of the present invention. The difference from the thirteenth embodiment is that the metal bent tube 1 is not moved and the coil 2 is moved to the first position.
3 moving the same speed as the metal bent tube 1 in the embodiment, there is provided only in that is moved in the song axial direction of the metal bent tube 1 (the direction of arrow A _2), other exemplary conditions 13 This embodiment is the same as the thirteenth embodiment, and the performance of the metal tube after the example and the treatment is the same as that of the thirteenth embodiment. Therefore, the same means are denoted by the same reference numerals.

FIG. 17 shows a fifteenth embodiment of the present invention. The difference from the thirteenth and fourteenth embodiments is that both the metal bent tube 1 and the coil 2 are simultaneously opposed. be a point that is moved at the same speed in the direction, in this embodiment, moves the metal curved pipe 1 in the direction of the arrow a _1, differs in that moving the coil 2 in the arrow a ₂ direction Therefore, it differs from the example of the thirteenth embodiment only in the following points. Therefore, the same means are denoted by the same reference numerals.

(Examples) In Examples corresponding to the fifteenth embodiment, the metal bent tube 1, the powder material, the coating thickness of the powder material, the high-frequency oscillator conditions of the coil 2, and the durability of the wear-resistant layer Since the thickness and the like of the welded layer of the metal layer 3d are the same as those of the example in the thirteenth embodiment, the same means are denoted by the same reference numerals. Since the means for simultaneously moving both of them in the opposite direction is employed, the processing time can be reduced to about half.

The main embodiments and examples of the present invention have been described above. However, the present invention is not limited to these embodiments, and the scope of the present invention can be achieved without departing from the gist of the invention. Various design changes are possible within the scope of the present invention, all of which are to be included in the present invention.

[0040]

According to the present invention, since a durable metal layer is formed on the inner and outer surfaces of a bent metal pipe in accordance with the above-described processing method, the following excellent effects are obtained.

(1) When welding and forming a durable metal layer such as a wear-resistant layer or a corrosion-resistant layer on the surface of a required portion inside or outside a metal bent tube exposed to a severe wear or corrosive environment, The layer thickness can be set to a desired thickness, and a metallurgically bonded durable metal layer of a predetermined component with an extremely low dilution rate can be easily and reliably formed.

(2) The metal curved tube is arranged vertically, and the metal curved tube and / or the coil disposed around the metal curved tube are surface-treated while being moved in the curved axis direction of the metal curved tube. Since the means is employed, the metal bent tube is arranged sideways and the surface treatment is performed by welding or spraying with a torch, which is advantageous in terms of space. It can be applied to surface treatment of pipes, and can significantly improve the efficiency and accuracy of surface treatment.

(3) The lower limit of the inner diameter of the metal bent pipe is not significantly limited as in the prior art described above, and the present invention can be easily and reliably applied to the inner surface treatment of a metal bent pipe having a remarkably small diameter.

[Brief description of the drawings]

FIG. 1 is a simplified explanatory diagram of a first embodiment of the present invention.

FIG. 2 is a simplified explanatory diagram of a second embodiment of the present invention.

FIG. 3 is a simplified explanatory diagram of a third embodiment of the present invention.

FIG. 4 (A), (B), (C), (D) shows a durable metal layer formed on the inner surface of a metal bent tube according to the first to third embodiments. 3 is a cross-sectional view showing a different cross-sectional shape of FIG.

FIG. 5 is a simplified explanatory diagram of a fourth embodiment of the present invention.

FIG. 6 is a simplified explanatory diagram of a fifth embodiment of the present invention.

FIG. 7 is a simplified explanatory diagram of a sixth embodiment of the present invention.

FIGS. 8A and 8B are cross-sectional views showing different cross-sectional shapes of a durable metal layer formed on an inner surface of a bent metal tube according to the fourth to sixth embodiments. FIG.

FIG. 9 is a simplified explanatory diagram of a seventh embodiment of the present invention.

FIG. 10 is a simplified explanatory diagram of an eighth embodiment of the present invention.

FIG. 11 is a simplified explanatory diagram of a ninth embodiment of the present invention.

FIG. 12 is a simplified explanatory view of a tenth embodiment of the present invention.

FIG. 13 is a simplified explanatory diagram of an eleventh embodiment of the present invention.

FIG. 14 is a simplified explanatory diagram of a twelfth embodiment of the present invention.

FIG. 15 is a simplified explanatory diagram of a thirteenth embodiment of the present invention.

FIG. 16 is a simplified explanatory diagram of a fourteenth embodiment of the present invention.

FIG. 17 is a simplified explanatory diagram of a fifteenth embodiment of the present invention.

FIGS. 18 (a) and (b) show different half of a durable metal layer formed on a surface outside a bent portion of a metal bent tube according to the thirteenth to fifteenth embodiments. It is sectional drawing which shows an arc-shaped sectional shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal bent pipe 2 Coil 3a / 3b / 3c / 3d Durable metal layer 4 Core material 5 Metal cover 6 Gap

Claims (8)

[Claims] When a durable metal layer formed by metallurgical bonding is formed on the entire inner surface or a part of the inner surface of a bent metal tube, the bent metal tube is disposed vertically, and the entire inner surface or one of the inner surface is formed. A powdery and durable metal material mixed with a bonding agent is applied to the surface of the part, and a coil connected to an AC power supply is arranged around the metal bent tube to energize the coil, and the metal bent tube is By moving at least one of the coils in the direction of the bending axis of the metal bent tube, the applied durable metal material is induction-heated and melted, and the melted durable metal material is entirely coated on the inner surface of the metal bent tube. Alternatively, a surface treatment method for a bent metal tube, wherein a durable metal layer is formed by welding to a part of the surface. 2. The method according to claim 1, wherein both the metal tube and the coil are moved in opposite directions. 3. When forming a durable metal layer formed by metallurgical bonding on the inner surface of a bent metal tube, a bent core material having an outer diameter smaller than the inner diameter of the bent metal tube is placed in the bent metal tube. To form a gap between the inner surface of the bent metal pipe and the outer surface of the core material, and fill the gap with a powdery or powdery durable metal material mixed with a fixing material. In addition, the metal bent tube is disposed vertically, a coil connected to an AC power supply is arranged around the metal bent tube to energize the coil, and at least one of the metal bent tube and the coil is made of metal. By moving in the curved axis direction of the curved tube, the durable metal material filled in the gap is induction-heated and melted, and the fused durable metal material is welded to the inner surface of the metal bent tube, Metal bending characterized by removing a core material and forming a durable metal layer on the inner surface of a metal bending tube Tube surface treatment method. 4. The surface treatment method for a metal curved tube according to claim 3, wherein both the metal curved tube and the coil are moved in opposite directions. 5. When forming a durable metal layer formed by metallurgical bonding on the entire surface or a part of the outer surface of the metal bent tube, the metal bent tube is disposed vertically and the entire outer surface or one of the outer surfaces is formed. A powdery and durable metal material mixed with a bonding agent is applied to the surface of the part, and a coil connected to an AC power supply is arranged around the metal bent tube to energize the coil, and the metal bent tube is By moving at least one of the coils in the direction of the curved axis of the bent metal tube, the applied durable metal material is induction-heated and melted, and the melted durable metal material is applied to the entire outer surface of the bent metal tube. Alternatively, a surface treatment method for a bent metal tube, wherein a durable metal layer is formed by welding to a part of the surface. 6. The surface treatment method for a metal bent tube according to claim 5, wherein both the metal bent tube and the coil are moved in opposite directions. 7. When forming a durable metal layer formed by metallurgical bonding on the outer surface of a bent portion of a metal bent tube, a cross-sectional shape of an arc or groove is formed on the outer surface of the bent portion of the metal bent tube. A bent metal cover is joined to form a gap between the inner surface of the metal cover and the outer surface of the bent portion of the metal bent tube, and a powder or a binder is mixed in the gap. Filled with the powdery and durable metal material, the metal bent tube is arranged vertically, and a coil connected to an AC power supply is arranged around the metal bent tube to energize the coil, By moving at least one of the metal bent tube and the coil in the bending axis direction of the metal bent tube, the durable metal material filled in the gap is induction-heated and melted, and the molten durable metal material is melted. A durable metal layer formed on the gap by welding to the gap. Surface treatment method for genus curved tubes. 8. The surface treatment method for a metal curved tube according to claim 7, wherein both the metal curved tube and the coil are moved in opposite directions.