JPH06238468A - Joined structural body and its joining method - Google Patents

Abstract

PURPOSE:To provide a joined structural body which can be joined without inserting a brazing filler metal at the time of molding the joined structural body and without using a high vacuum furnace and does not generate thermal fatigue at joint points and its joining method. CONSTITUTION:The surfaces of metallic plates 1 and 3 consisting of stainless steels are coated with a self-fluxing alloy of an Ni-Cr-B-Si system, by an ion- plating method, by which self-fluxing alloy layers a, a' and b, b' are formed and flat plate materials 10, 20 and corrugated plate materials 30 are formed. The joined structural body 50 is formed by alternately laminating these materials and the self-fluxing alloy layers are fusion joined in the atmosphere, by which the integral joined structural body is constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joined structure formed by joining metal plates and a joining method thereof, and more particularly to a honeycomb-like joined structure and a joining method thereof.

[0002]

2. Description of the Related Art A conventional bonded structure is formed by alternately laminating a brazing material between a metal flat plate and a corrugated plate, or stacking the flat plate and the corrugated plate and winding them in a roll from the center to form a structure. Then, the brazing material is melted using a high vacuum furnace, and joining is performed at the contact portion of the plate materials. N for brazing material
An i-based brazing material was used, and a ferritic stainless steel material was used for the flat plate and the corrugated plate.

[0003]

In the above-mentioned conventional bonded structure, the brazing filler metal is sandwiched between the flat plate and the corrugated plate to form them by superposition, so that the molding process is difficult and the shape of the structure is inaccurate. In addition, in order to avoid oxidation due to heating in the brazing material joining process, it is necessary to perform joining in a non-oxidizing atmosphere using a high vacuum furnace. To avoid the use of a high-vacuum furnace, a Ni-based brazing material is used as the brazing material, and a joining structure using a ferrite material as the plate material is used in a high temperature environment because the brazing material and the plate material have different thermal expansion coefficients. In this case, there is a drawback that thermal fatigue is likely to occur at the joint and mechanical strength is lowered.

An object of the present invention is that the brazing material is not inserted in the molding process of the joint structure, and the shape after molding is accurate,
It is an object of the present invention to provide a bonded structure that can be bonded without using a high vacuum furnace and that does not cause thermal fatigue at a bonded portion, and a bonding method thereof.

[0005]

The joining structure of the present invention comprises:
The metal plate is made of a material having a self-fluxing alloy layer formed by a dry process on at least one of the surfaces to be joined, and the self-fluxing alloy layer at the contact portion of the metal plate temporarily becomes a liquid phase. After becoming a liquid phase at temperature, they are joined by isothermal solidification.

The joint structure is a corrugated sheet material made of a strip-shaped metal plate in which corrugated corrugations are continuously formed by bending.
A flat plate material made of a flat band-shaped metal plate is laminated and molded, or corrugated irregularities are continuously bent and formed, and a corrugated plate material made of a band-shaped metal plate and a flat band shape are formed. Desirably, a honeycomb body is formed by stacking a flat plate material made of a metal plate and rolling it into a roll shape, and the corrugated plate material and the flat plate material are Ni-based or Fe-based heat-resistant steel. It is desirable that the self-fluxing alloy layer contains a Ni-based self-fluxing alloy.

[0007]

[Function] By applying a self-fluxing alloy layer on the contact surfaces of both metal plates to be joined before joining, a structure is formed, and the structure is heated to the melting temperature of the self-fluxing alloy layer. , The layers melt, and bond at the contact portion to form a bonded structure. Since no separate brazing material is sandwiched between the metal plates, an accurate structure can be formed. Since the joint surface is covered with the Ni-based self-fluxing alloy layer, it is not necessary to use a high vacuum furnace because oxidation of the plate material can be avoided during the joint. In addition, since the self-fluxing alloy layer is applied by the ion plating method, the layer is thin, and therefore the joining layer formed at the joining portion after joining can also be made thin, resulting in a difference in thermal expansion coefficient between the joining layer and the plate material. The impact will be less.

[0008]

FIG. 1 is a schematic partial cross-sectional view of one embodiment of the bonded structure of the present invention, and FIG. 1 (A) is a diagram of a bonded structure in which flat plates and corrugated plates are alternately laminated. 1 (B) is a flat plate material in which a self-fluxing alloy layer is applied only to one surface of a metal plate, FIG. 1 (C)
Is a flat plate material having self-fluxing alloy layers on both sides of a metal plate, and FIG. 1D is a corrugated sheet material having self-fluxing alloy layers on both sides of a corrugated metal plate. FIG. 2 is a schematic cross-sectional view of another embodiment of the bonded structure of the present invention.

In FIG. 1 (B), the metal plate 1 has a flat thin strip shape, and the material thereof is Fe-based heat-resistant steel, that is, ferritic stainless steel, and Ni-C is formed on one surface.
The r-B-Si based self-fluxing alloy layer a is applied by the ion plating method to form the flat plate material 10. Figure 1 (C)
In, the flat plate member 20 is the same metal plate 1 as the flat plate member 10.
And self-fluxing alloy layers a and a ′ similar to the flat plate material 10 provided on both sides thereof. The thickness of these layers is much thinner than the plate thickness, for example 3 to 7 μm for a plate thickness of 50 μm. In FIG. 1 (C), the corrugated sheet material 30 is the same as the metal sheet 1 in the same manner as the strip-shaped metal sheet 3 which is continuously bent in an uneven shape and has a wavy shape, and the flat sheet materials 20 applied to both side surfaces thereof. Of the self-fluxing alloy layers b and b '.

A method for joining a joined structure having a honeycomb structure by using these flat plate material and corrugated plate material will be described.
Ni-C was previously formed on a ferritic stainless steel metal plate 1 by an ion plating method of a dry process.
A flat plate material 10 or 20 is prepared by applying a r-B-Si based self-fluxing alloy layer a or a, a '. Further, a flat plate of ferritic stainless steel is continuously bent into irregularities to form a corrugated metal plate 3, and the self-fluxing alloy layers b and b ′ are applied to both sides of the metal plate 3 in the same manner as the flat plate material 20 to form a corrugated plate material. Make 30 The flat plate member 10 or 20 thus produced and the corrugated plate member 30 are laminated to form a honeycomb-shaped bonded structure 50. The formed joint structure has self-fluxing alloy layers a, a ′,
The b and b'are heated and melted in the atmosphere to a temperature at which they can be melted, and the flat plate member and the corrugated plate member are joined at the contact portion 4 to be integrally formed.

FIG. 2 shows an embodiment of a honeycomb-like bonded structure 60 formed by laminating a flat plate member 20 and a corrugated plate member 30 and winding them in a roll shape, which is similar to the embodiment shown in FIG. After being superposed, the self-fluxing alloy layers a, a ′, b,
b ′ is melted and the flat plate member 20 and the corrugated plate member 30 are joined at the contact portion 4.

[0012]

As described above, according to the present invention, a flat plate material and a corrugated plate material of a metal plate having a self-fluxing alloy layer formed in advance by a dry process are laminated or superposed and wound in a roll shape to form a honeycomb. Molded into a body and melt-bonding the self-fluxing alloy layer in the atmosphere to form a bonded structure, so that a brazing material is not sandwiched between plate materials, and a bonded structure with an accurate shape is molded. Since the joining surface of the plate material is covered with the self-fluxing alloy layer,
Oxidation of the plate material is avoided at the time of bonding, so there is an effect that it can be bonded in the atmosphere without using a high vacuum furnace and can be bonded without being restricted by the shape and area of the bonding surface or the material of the metal plate that constitutes the plate material. Since the thickness of the joining layer at the joining portion can be further reduced, even if there is a difference in the coefficient of thermal expansion between the joining layer and the plate material, the effect is reduced, so that thermal fatigue does not occur at the joining portion. Play.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view of a bonded structure and a flat plate / corrugated plate material of the present invention, FIG. 1 (A) is a bonded structure in which a flat plate material and a corrugated plate material are laminated, and FIG. ) And (C) are flat plate materials, and FIG. 1 (D) is a corrugated plate material.

FIG. 2 is a schematic cross-sectional view of another embodiment of the bonded structure of the present invention, which is a bonded structure in which a flat plate material and a corrugated plate material are superposed and wound in a roll shape.

[Explanation of symbols]

 1 metal plate (flat plate) 3 metal plate (corrugated plate) 4 contact part / joint point 10 flat plate material (single-sided self-fluxing alloy layer) 20 〃 (double-sided self-fluxing alloy layer) 30 corrugated sheet material (double-sided self-fluxing alloy layer) a, a ', b, b'self-fluxing alloy layer 50 bonded structure (laminated honeycomb body) 60 bonded structure (rolled honeycomb body)

Claims (8)

[Claims] 1. A bonded structure formed by bonding a plurality of metal plates at their contact portions, wherein the metal plates have a self-fluxing alloy layer formed by a dry process on at least one surface to be bonded before bonding. A joining structure, which is made of a material having, and is joined by isothermal solidification after the self-fluxing alloy layer of a contact portion of the metal plate becomes a liquid phase at a temperature that temporarily becomes a liquid phase. 2. The corrugated irregularities are continuously bent and formed,
The joined structure according to claim 1, wherein a corrugated sheet material made of a strip-shaped metal plate and a flat sheet material made of a flat strip-shaped metal plate are laminated. 3. The corrugated irregularities are continuously bent and formed,
The bonded structure according to claim 1, wherein a corrugated sheet material made of a strip-shaped metal plate and a flat sheet material made of a flat strip-shaped metal plate are stacked and wound in a roll shape to form a honeycomb body. 4. The material of the corrugated plate material and the flat plate material is Ni
The joined structure according to claim 2 or 3, wherein the joined structure is a heat-resistant steel based on Fe or Fe. 5. The bonded structure according to claim 1, wherein the self-fluxing alloy layer contains a Ni-based self-fluxing alloy. 6. A joining method of a joining structure comprising a plurality of metal plates joined at their contact portions, wherein a self-fluxing alloy layer by a dry process is formed on at least one of the surfaces of the metal plates to be joined by a dry process before joining. In the contact portion of the metal plate to be applied and joined, at least one metal plate is disposed so as to have a self-fluxing alloy layer,
A joint structure formed into a predetermined joint structure, the joint structure being heated to a temperature at which the self-fluxing alloy layer can be melted, joined at the contact portion, and integrally formed. Joining method. 7. The method for joining a joined structure according to claim 6, wherein a self-fluxing alloy layer containing a Ni-based self-fluxing alloy is applied to the surfaces to be joined of the metal plates before joining. 8. The joining method for a joining structure according to claim 6, wherein the self-fluxing alloy layer applied to the metal plate before joining is applied by an ion plating method.