JP2003225775A - Long metal member joining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long metal member joining device capable of uniformizing (homogenizing) the structure of the metal by averaging the difference of hardness between a heat affected zone generated when joining the end parts of long metal members and a heat unaffected zone or the like, and suppressing the manufacturing cost of a joined long metal member. <P>SOLUTION: The heat affected zones 1A and 2A formed in a butted end are hardened by the liquid phase diffusion welding (temperature rise to the liquid phase diffusion welding temperature) of base materials 1 and 2. The heat affected zones 1A and 2A are re-heated with an induction heating coil 5a to raise the temperature to the tempering temperature (the heat treatment temperature) lower than the liquid phase diffusion welding temperature. In this process, the induction heating coil 5a (a heating unit 5) is continuously moved along the axial direction of the base materials 1 and 2 outside the heat affected zones 1A and 2A with a moving unit 6. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for joining long metal materials such as oil well pipes and plant pipes.

[0002]

2. Description of the Related Art For example, oil well pipes used in oil wells and gas wells, and metal long pipes (for example, 10 to 20) as plant pipes used in chemical plants, petrochemical plants, etc.
The stainless steel pipe of m) is laid as a pipeline extending from several hundred m to several km with its end faces joined one after another. And as the joining method in such a case, screw fastening method (mechanical coupling), butt welding method,
Friction welding method, diffusion welding method and the like are known.

Among these, in the welding method except the screw fastening method, for example, high frequency induction heating (induction heating coil)
Using a heating unit that rapidly heats the base material (metal long tube)
The butt ends or the insert material sandwiched between the butt ends can be heated to the joining temperature (melting temperature or the like), and the end faces can be joined efficiently in a short time.

[0004]

By the way, in such an end face butt joint, a heat affected zone associated with the rapid heating is formed at the butt end of the base material. When the butt ends of the base materials or insert materials are heated to the joining temperature and then air-cooled (air-cooled) to butt-join the end faces, depending on the material of the base materials, the heat effect during this air-cooling period In some cases, the part becomes hardened and becomes harder than the non-heat-affected part (intermediate part of the base metal) at room temperature. For example, 13
This tendency is remarkable in martensitic stainless steels represented by% Cr stainless steel (SUS420J2 specified in JIS G4303), and carbon steel for machine structure (S45C specified in JIS G4051).
The same phenomenon may occur depending on the conditions.

Such a difference in hardness between the heat-affected zone and the non-heat-affected zone of the base material may cause a hindrance during processing and use of the joined long metal material joined body. is there. For example, when using the above-mentioned long metal pipe as pipeline for pipeline,
When performing the pipe expanding step of expanding the pipe inner diameter after joining, cracks or cracks may occur in the hardened heat-affected zone. It is possible to prevent the heat-affected zone of the base material from becoming hardened and prevent these defects from occurring by adopting the slow cooling means in a special environment.However, special equipment is required for the joining device. I need
In addition, since a long gradual cooling period (standby time) is required for the joining process, the laying cost of the metal long material joined body (here, pipeline) may increase.

An object of the present invention is to homogenize (homogenize) the structure by averaging the hardness difference between the heat-affected zone and the non-heat-affected zone, which occurs when the ends of the long metal strip are joined. Another object of the present invention is to provide a metal long material joining apparatus capable of suppressing the manufacturing cost of the metal long material joined body.

[0007]

Means for Solving the Problems and Effects of the Invention In order to solve the above problems, one embodiment of the apparatus for joining long metal strips according to the present invention is a first and a second long metal to be joined. A base material holding part that holds the end surfaces of members (hereinafter referred to as base materials) directly or indirectly via an insert material, and a butt end of the base material or the insert material is heated to the bonding temperature. A heating unit that rapidly heats to warm, and, after joining the base materials, the base material in which a heat-affected zone is formed in a predetermined range at the butt ends across a bonding interface,
The heating unit that reheats the heat-affected zone to raise the temperature to a heat treatment temperature lower than the joining temperature, and a moving unit that relatively or intermittently moves along the axial direction of the base material. It is characterized by having.

In order to solve the above problems, another embodiment of the apparatus for joining long metal members according to the present invention is the first and second long metal members to be joined (hereinafter referred to as the base material). ) Of the base material holding portion for holding the end faces of each other directly or indirectly via the insert material, in order to raise the butt end of the base material or the insert material to the bonding temperature,
After the joining of the heating portion for rapid heating by high-frequency induction heating and the base material, the heat-affected portion of the base material having a heat-affected portion formed in a predetermined range at the butt end across the joining interface. A heating unit for reheating to raise the temperature to a heat treatment temperature lower than the bonding temperature, a moving unit for continuously or intermittently moving along the axial direction of the base material,
It is characterized by having.

That is, in the apparatus for joining long metal strips according to the present invention, in order to reheat the heat-affected zone of the base material to a heat treatment temperature lower than the joining temperature, the heat-affected zone of the base material is moved in the axial direction of the base material. Since a moving portion that relatively or intermittently moves the base material and the heating portion along the same is provided, it is possible to reduce the hardness of the heat-affected zone after joining to the hardness of the non-heat-affected zone, for example. it can. In other words, by moving the moving part while reheating the heating part, it is possible to easily achieve the homogenization (homogenization) of the structure by the heat treatment (for example, tempering) at a temperature lower than the joining temperature. It is also possible to suppress the manufacturing cost of the metal long material joined body.

When the butt ends of the base materials or the insert materials are heated to the joining temperature and then air-cooled to butt-join the end faces, the heat-affected zone is hardened during this air-cooling period. In the base material (for example, martensitic stainless steel), the heat-affected zone becomes harder than the non-heat-affected zone at room temperature, so that the above-described effects of homogenizing the structure and suppressing the cost are great.

In reheating the heat affected zone, it is desirable that the reheating temperature of the heating section is adjusted so that the heat treatment temperature becomes the tempering temperature of the base material. By tempering the heat-affected zone of the base material in the quenched state, homogenization (softening) of the structure can be reliably achieved.

Next, when the heat-affected zone of the base material is adjusted to maintain the heat-treatment temperature for at least 10 seconds after the heat-affected zone of the base material reaches the heat-treatment temperature (for example, tempering temperature) by reheating, The heat-affected zone of the material can be sufficiently subjected to heat treatment such as tempering to achieve homogenization of the structure. If the heat treatment temperature is maintained for less than 10 seconds, the heat-affected zone may not be sufficiently heat-treated (for example, tempered) and the structure may not be sufficiently homogenized.

By the way, if the heating unit is constructed by a high frequency induction heating method using an induction heating coil and the heating unit is moved along the axial direction of the base material, the weight of the base material (for example, pipe) becomes large. It suffices to move only the heating part having a small weight along the base material without moving the long metal pipe such as the line pipe. Therefore, it is possible to obtain a joining device in which the base material holding unit and the moving unit are configured to be small and compact and the heating unit moves with high accuracy.

In such a high frequency induction heating system,
When the length of the induction heating coil in the moving direction is L, if the reheating range W by the heating unit is set to be 2 L or more across the bonding interface, the reheating range W is secured wide and tempering, etc. The homogenization of the tissue can be achieved over a wide range. If the reheating range W is less than 2 L across the bonding interface, homogenization of the structure by tempering or the like may not be achieved over a wide range. Further, when the reheating range W exceeds 3 L across the bonding interface, the non-heat-affected zone is reheated (heat-treated), and the non-heat-affected zone is deteriorated in structure by tempering or the like (for example, hardness reduction). Therefore, the reheating range W is preferably 3 L or less across the bonding interface.

Therefore, as a concrete mode using the high frequency induction heating method, the apparatus for joining long metal strips according to the present invention is provided with an end face of a first and second long metal pipe (hereinafter referred to as a base metal). A base material holding part for holding each other in a state of abutting each other via an insert material, a heating part for rapidly heating by high frequency induction heating to raise the temperature of the insert material to a liquid phase diffusion bonding temperature, and a bonding of the base material After that, the heat-affected zone is heated to a heat treatment temperature lower than the liquid-phase diffusion bonding temperature with respect to the base material in which the heat-affected zone is formed in a predetermined range at the butt end across the bonding interface. The heating unit for reheating as much as possible is provided with a moving unit for continuously or intermittently moving along the axial direction of the base material.

As described above, when a long metal pipe used for pipeline pipes (for example, oil well pipes and plant pipes) is used as a base material, cracks in the heat-affected zone in the pipe expanding process
A defect such as a crack is less likely to occur, and an increase in laying cost can be suppressed.

Here, the diffusion bonding is a method in which the base material (long metal tube) is not melted but kept in a solid state at a high temperature to perform the bonding, and solid phase diffusion bonding and liquid phase diffusion bonding are used. Is roughly divided into The solid phase diffusion bonding method is a bonding method in which base materials are directly butted to each other and pressed so that plastic deformation is not generated as much as possible, and mutual diffusion of atoms generated between bonding surfaces (butting surfaces) is used for bonding. Solid phase diffusion bonding is simple, but
Insufficient smoothing and cleaning of the joint surface tend to cause joint defects, and there is a drawback that it takes a long time to obtain a sufficient diffusion joint state.

On the other hand, in the liquid phase diffusion bonding method, an insert material having a melting point lower than that of a base material to be bonded is formed into a sheet shape (foil shape, scale shape, etc.) or a powder shape in the form of a joint surface of the base material ( It is interposed between the abutting surfaces) and heated above the melting point of the insert material and below the melting point of the bonding base material to melt the insert material and generate a liquid phase, and at the same time diffuse the components contained in the insert material into the base material. This is a joining method for joining the base materials together. In this method, defects such as voids are less likely to remain because the liquid phase permeates the irregularities of the joint surface, and the effect of cleaning the joint surface by liquid phase contact can be expected,
There is an advantage that a bonding structure with few defects can be obtained without performing the end face treatment precisely as in the solid phase diffusion bonding method. Also,
Since it passes through the liquid phase, the component diffusion rate is high, and it is convenient that the processing can be completed in a short time.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An example of the apparatus for joining long metal strips according to the present invention will be described below. FIG. 1 is a front sectional view showing a liquid phase diffusion bonding apparatus 100 for pipeline piping as an example of a long metal material. The liquid phase diffusion bonding apparatus 100 includes a base material holding unit 4, a heating unit 5, a moving unit 6, and a position changing unit 7.
And are provided.

The base material holding portion 4 is an end face (abutting surface 1a) of the first and second long metal pipes 1 and 2 (first and second long metal members to be joined; hereinafter referred to as a base metal). , 2a; FIG. 3
The chucks 4a, 4a for holding the parts (a) and (b) butted against each other via the insert material 3 are located on the end side opposite to the butted end. This chuck 4
a and 4a are inserted and arranged in through holes 4c and 4c on both side walls of a holding frame 4b having a U-shaped cross section.

The heating section 5 includes an induction heating coil 5a for rapidly heating the insert material 3 by high frequency induction heating so as to raise the temperature of the insert material 3 to a liquid phase diffusion bonding temperature, and an induction heating coil 5a.
And a heating chamber 5b containing therein. After the liquid phase diffusion bonding of the base materials 1 and 2, the moving section 6 moves the heating section 5 continuously or intermittently along the axial direction of the base materials 1 and 2 in order to move the heating section 5 at the bottom outer surface of the heating chamber 5b. Wheels 6b, 6b (moving section rotors) rotatably attached to the vehicle and moving section motors 6a, 6a for driving and rotating the wheels 6b, 6b.
(Moving portion drive actuator).

When the moving part 6 moves in the heating part 5, the heat-affected parts 1A and 2A are formed in the base materials 1 and 2 in a predetermined range at the abutting ends with the joining interface therebetween.
Reheats the heat-affected zones 1A and 2A to a heat treatment temperature (specifically, quenching temperature) lower than the liquid phase diffusion bonding temperature. The wheels 6b, 6b of the moving unit 6 roll while being guided by grooves or rails (not shown) formed on the inner surface of the bottom of the holding frame 4b of the base material holding unit 4.

The liquid phase diffusion bonding apparatus 100 sequentially changes the position on the ground and performs the liquid phase diffusion bonding process and the subsequent heat treatment process on the base materials 1 and 2. Therefore, the position changing unit 7 includes position changing unit wheels 7b, 7b (position changing unit rotating bodies) rotatably attached to the outer surface of the bottom of the holding frame 4b and a position changing unit motor 7a for driving and rotating the wheels 7b, 7b. , 7a (position changer drive actuator).

The outline of the liquid phase diffusion bonding process and the heat treatment process in this embodiment will be described below.

<Liquid Phase Diffusion Bonding Step ...> See FIGS. 2 and 3 As described above, the base materials 1 and 2 are made of a pipe material, and as shown in FIG. The end faces are butted against each other with 3 being sandwiched. Then, as shown in FIG. 2, while the end face is used as a surface to be joined and pressure is applied in the axial direction, the butt portion is heated to the liquid phase diffusion joining temperature by the induction heating coil 5a arranged around the butt portion, and then air-cooled. By doing so, the joining is performed. In the joining step, the base materials 1 and 2 are held at their ends on the side opposite to the butt side by chucks 4a and 4a of a pressurizing device, and both chucks 4a and 4a are urged toward each other by a hydraulic cylinder (not shown) or the like. It is being pressurized.

In the liquid phase diffusion bonding step, the above-mentioned pressurization is
As shown in FIG. 3 (b), a part of the liquid phase (melting part) 3 ′ based on the insert material 3 is abutted with the abutting surfaces 1 a of the base materials 1 and 2.
In 2a, adjusting to the extent that it is extruded outward in the in-plane direction enhances the permeation effect of the liquid phase 3 ′ into the joint interface due to pressurization, and thus improves the bending strength or impact resistance of the joint. It is more desirable for the purpose. Note that FIG.
As shown in (c), the joining metal part 3 ″ obtained by the above-mentioned pressurization is accompanied by the extrusion of the liquid phase 3 ′,
The projecting ridges 3 "a are formed on the outer peripheral surface of the ridges. The ridges 3" a may be removed by grinder grinding or the like, if necessary. The joined body may be left for use.

Here, for example, SUS4 is used as the base materials 1 and 2.
20J2 (Martensitic stainless steel; JIS G
4303) and BNi-2 (nickel braze; JIS Z3265) as the insert material 3, various parameters in the liquid phase diffusion bonding process are adjusted and set as follows.・ Pressure force of base materials 1 and 2: 5 to 25 MPa ・ Liquid phase diffusion bonding temperature: 1150 to 1250 ° C ・ Heating maintenance time at liquid phase diffusion bonding temperature: 30 seconds or more ・ Atmosphere in heating chamber 5b: Non-oxidizing atmosphere (Ar gas filling; oxygen partial pressure is 50 kPa or less) -Thickness of insert material 3: 20 to 100 μm (foil-like or scale-like)

<Heat treatment step> ... See FIG. 4. The heat-affected zone 1 formed at the butt ends of the base materials 1 and 2 by liquid-phase diffusion bonding (heating to the liquid-phase diffusion bonding temperature).
As described above, A and 2A are in a quenched state due to the properties of the base materials 1 and 2 (Fig. 4 (a)). Therefore, the heat-affected zones 1A and 2A are reheated by the induction heating coil 5a,
Tempering temperature lower than liquid phase diffusion bonding temperature (heat treatment temperature)
The temperature rises to. At this time, the induction heating coil 5a (heating unit 5) is moved by the moving unit 6 (see FIG. 1) by the heat-affected unit 1.
The outer sides of A and 2A are continuously moved along the axial direction of the base materials 1 and 2 (FIG. 4B). The base materials 1 and 2 are S
US420J2 (Martensitic stainless steel; JI
S G4303), the heat treatment temperature is 700
It is adjusted and set in the range of ~ 800 ° C.

In such a heat treatment process, in order to achieve a wide range of homogenization of the structure by tempering, when the length of the induction heating coil 5a in the moving direction is L, the induction heating coil 5a (heating unit 5) is used. It is desirable that the reheating range W is set to 2 L or more with the bonding interface interposed.

Next, in the heating section 5, the heat-affected zones 1A and 2A of the base materials 1 and 2 are reheated to be tempered (heat treatment temperature).
It is adjusted so as to maintain the heat treatment temperature for at least 10 seconds after reaching (1) (this time is referred to as heat treatment temperature maintaining time). As a result, the heat-affected zone 1 of the base materials 1 and 2
A and 2A can be sufficiently tempered to achieve homogenization of the structure.

Further, when the heat treatment temperature maintenance time is determined, the moving speed of the heating portion also has an influence. For example, the heating unit 5
Moves continuously in the reheating range W = 2L over 10 seconds, the heating part moving speed v is v = W / 10 = 2L / 10.
= 0.2 L (mm / sec). Therefore, v ≦ 0.2 L (mm / sec) is desirable in order to maintain the heat treatment temperature maintenance time of 10 seconds or more. As a result, the heat-affected zones 1A and 2A can be sufficiently tempered to further homogenize the structure. Note that v>
At 0.2 L (mm / sec), heat treatment temperature maintenance time is 1
It may be less than 0 seconds, and temperature unevenness (heating unevenness) easily occurs as the moving speed of the heating unit increases. Further, in order to make the homogenization of the tissue more complete, v ≦ 0.1 L (mm / sec) can be set.

Example 1 After performing the liquid phase diffusion bonding process and the heat treatment process in accordance with the above description, the hardness of the heat-affected zone and the adjacent non-heat-affected zone are measured to measure the heat-affected zone. It was determined whether tempering (heat treatment) was sufficient.

The liquid phase diffusion bonding conditions in Example 1 are as follows (see FIGS. 2 and 3). (Liquid phase diffusion bonding conditions) -Heating method: high frequency induction heating method-Length L of induction heating coil 5a (in moving direction): 40 m
m ・ Material of base materials 1 and 2: SUS420J2 (JIS G4
303) ・ Shape of butting surfaces 1a, 2a: outer diameter 140 mm, inner diameter 1
24 mm (pipe wall thickness 8 mm) annular material of insert material 3: BNi-2 (JIS Z32
65) ・ Shape of insert material 3: Same shape as butt surfaces 1a, 2a ・ Thickness of insert material 3: 40 μm (foil shape) ・ Pressure force of base materials 1 and 5: 5 MPa ・ Liquid phase diffusion bonding temperature: 1200 ° C・ Heat maintenance time at liquid phase diffusion bonding temperature: 60 seconds ・ Atmosphere in heating chamber 5b: Non-oxidizing atmosphere (Ar gas filling; oxygen partial pressure is 50 kPa or less)

Next, the heat treatment conditions in Example 1 are as follows (see FIG. 4). (Heat treatment conditions) -Heating method: high frequency induction heating method-Length L of the induction heating coil 5a in the moving direction: 40 mm
(Use the same one used in the liquid phase diffusion bonding process) ・ Heat treatment temperature: 750 ° C ・ Reheat range W: 80 mm = 2 L ・ Heat treatment temperature maintenance time: 10 seconds ・ Heating part moving speed v: 8 mm / sec = 0. 2 L mm / sec

Further, the Vickers hardness of the heat-affected zones 1A and 1B and the adjacent non-heat-affected zone is determined according to JIS Z2244.
-Measured based on 1998. The measurement conditions are as follows.・ Test force: 2.97N ・ Measurement position: Outer peripheral surfaces of the base materials 1 and 2 ・ Measurement pitch: Zero point at the joint interface, and 1mm intervals along the moving direction of the heating part

The Vickers hardness measurement diagram thus obtained is shown in FIG. 5 (a). According to FIG. 5A, the hardness (about 280 HV) in the region of ± 40 mm considered to be the heat-affected zones 1A and 1B is ± 40 m considered to be the non-heat-affected zone.
The hardness is almost equal to that of the area outside m,
It was confirmed that tempering (heat treatment) in A and 1B was sufficiently performed.

Example 2 In Example 2, the heat treatment conditions of Example 1 were partially changed, and hardness measurement and heat treatment determination were performed.

The liquid phase diffusion bonding conditions in Example 2 are the same as in Example 1. However, of the heat treatment conditions in Example 1, only the heat treatment temperature maintenance time was changed as follows. (Heat Treatment Conditions Changed from Example 1) Heat treatment temperature maintenance time: 8 seconds The measurement conditions of Vickers hardness in Example 2 are the same as those in Example 1.

The Vickers hardness measurement diagram thus obtained is shown in FIG. 5 (b). According to FIG. 5B, the hardness (about 360 HV) in the region of ± 40 mm considered to be the heat-affected zones 1A and 1B is ± 40 m considered to be the non-heat-affected zone.
80 than the hardness (approx. 280 HV) of the area outside m
It appeared as large as HV. However, it has a hardness reduction effect of about 180 HV as compared with the case where the heat treatment process is not performed (see Comparative Example described later), and cracks and cracks are less likely to occur in the heat-affected zones 1A and 1B in the pipe expanding process of the next process. It was confirmed that it could be put to practical use.

(Example 3) In Example 3, the heat treatment conditions of Example 1 were partially changed, and hardness measurement and heat treatment determination were performed.

The liquid phase diffusion bonding conditions in Example 3 are the same as in Example 1. However, only the reheating range W of the heat treatment conditions in Example 1 was changed as follows. (Heat Treatment Conditions Changed from Example 1) Reheating Range W: 60 mm The Vickers hardness measurement conditions in Example 3 are the same as in Example 1.

The Vickers hardness measurement diagram thus obtained is shown in FIG. 6 (a). According to FIG. 6 (a), the hardness (about 450 HV) at both ends of the ± 40 mm region considered to be the heat-affected zones 1 A and 1 B is in the region outside the ± 40 mm region considered to be the non-heat-affected zone. Hardness (about 280HV)
About 170 HV. However, compared with the case where the heat treatment step is not performed (see Comparative Example described later),
There is a hardness reduction effect of about 90 HV at the peak, and the hardness of the heat-affected zone 1A, 1B inside the peak is almost the same as the hardness of the non-heat-affected zone. It was confirmed that the portions 1A and 1B were less likely to have defects such as cracks and cracks and could be practically used.

(Comparative Example) In order to compare the hardness measurement results with those of Examples 1 to 3 described above, only the liquid phase diffusion bonding process similar to that of Example 1 was carried out (the heat treatment process was not carried out),
Hardness was measured. The Vickers hardness measurement conditions in the comparative example are the same as in Example 1.

The Vickers hardness measurement diagram thus obtained is shown in FIG. 6 (b). According to FIG. 6B, the hardness (about 540 HV) in the region of ± 40 mm considered to be the heat-affected zones 1A and 1B is ± 40 m considered to be the non-heat-affected zone.
26 than the hardness (approx. 280 HV) of the area outside m
It appeared as large as 0 HV. Then, it was confirmed that defects such as cracks and cracks occur in the heat-affected zones 1A and 1B in the pipe expanding step of the next step.

Although the above description has been made with respect to the liquid phase diffusion bonding apparatus for pipelines, the present invention is not limited to this. For example, the present invention can be applied to gas and water pipes and the like, and can also be applied to a welding device having a butt welding process and the like.

[Brief description of drawings]

FIG. 1 is a front cross-sectional view of a liquid phase diffusion bonding apparatus for pipelines that is an example of the present invention.

FIG. 2 is an explanatory diagram of a liquid phase diffusion bonding process.

FIG. 3 is a schematic diagram showing the concept of a liquid phase diffusion bonding method.

FIG. 4 is an explanatory diagram of a heat treatment process.

5 is a Vickers hardness measurement diagram of Example 1 and Example 2. FIG.

FIG. 6 is a Vickers hardness measurement diagram of Example 3 and a comparative example.

[Explanation of symbols]

100 Liquid Phase Diffusion Bonding Device for Pipeline 1 First Metal Long Tube (First Long Metal Member to be Joined; Base Material) 1A Heat Affected Zone 2 Second Metal Long Tube (Second Long metal member to be joined; base material) 2A Heat-affected zone 3 Insert material 4 Base material holding section 5 Heating section 6 Moving section

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeyuki Inagaki             2-30, Daido-cho, Minami-ku, Nagoya-shi, Aichi             Daido Steel Co., Ltd. Technology Development Laboratory F term (reference) 3K059 AA08 AB19 AB23 AB24 AC72                       AD03 AD05 AD35 AD40                 4E067 AA02 AA03 AB05 AB06 AD03                       BA05 CA03 DA17 DC05 DD01                       EA08 EC06                 4K042 AA06 BA02 DA02 DB01 DE04

Claims (7)

[Claims] 1. A base material holding part for holding the end surfaces of the first and second elongated metal members to be joined (hereinafter referred to as base materials) directly or indirectly with each other through an insert material. A butt end of the base material or a heating unit that rapidly heats the insert material to raise the temperature to the joining temperature; and, after joining the base materials, a thermal effect over a predetermined range on the butt end across the joining interface. The base material in which the portion is formed and the heating portion that reheats the heat affected zone to raise the heat treatment temperature to a heat treatment temperature lower than the joining temperature, continuously or intermittently along the axial direction of the base material. A device for joining a long metal material, comprising: a moving part that relatively moves relative to each other. 2. A base material holding part for holding the end surfaces of the first and second elongated metal members to be joined (hereinafter referred to as base materials) in a state of directly or indirectly abutting each other via an insert material. In order to raise the butt end of the base material or the insert material to the joining temperature, a heating unit that rapidly heats by high frequency induction heating, and, after joining the base material, at the butt end with a joining interface sandwiched therebetween. With respect to the base material in which the heat-affected zone is formed over a predetermined range, the heating section that reheats the heat-affected zone to raise the heat-affected zone to a heat treatment temperature lower than the bonding temperature is provided in the axial direction of the base material. A joining device for a long metal material, comprising: a moving unit that moves continuously or intermittently along. 3. A base material holding part for holding the end surfaces of the first and second long metal pipes (hereinafter, referred to as base materials) in a state of abutting each other via an insert material, and a liquid phase diffusion of the insert material. To raise the temperature to the bonding temperature,
A heating part that rapidly heats by high-frequency induction heating, and, after the base material is joined, the heat-affected zone for the base material having a heat-affected zone formed over a predetermined range at the butt end across the joining interface. A moving part that moves the heating part, which reheats to heat-treat to a heat treatment temperature lower than the liquid phase diffusion bonding temperature, continuously or intermittently along the axial direction of the base material. An apparatus for joining long metal materials, characterized by: 4. The reheating range W by the heating unit is set to be 2 L or more across the bonding interface, where L is the length of the induction heating coil in the moving direction. The apparatus for joining long metal members according to Item 3. 5. The heating unit is at least 10 after the heat-affected zone of the base material reaches the heat treatment temperature by reheating.
The apparatus for joining a long metal material according to claim 1, wherein the heat treatment temperature is adjusted for a second. 6. The apparatus for joining a long metal material according to claim 1, wherein the heating unit is adjusted so that the heat treatment temperature becomes a tempering temperature of the base material. 7. The joining of the base material is performed by heating the butt end of the base material or the insert material to the joining temperature and then air-cooling, and during the air-cooling period, the heat-affected zone is The apparatus for joining long metal members according to claim 1, which is in a quenched state.