JP4939158B2 - Brazing material, brazing composite material and brazing structure brazed and bonded using the same - Google Patents

Description

  The present invention relates to a brazing material, a brazing composite material, and a brazing structure brazed and bonded using the brazing material, and in particular, a brazing material and a brazing composite material that constitute a flow path of a heat exchanger such as a radiator and a gas cooler. The present invention also relates to a brazing structure that is brazed and joined using them.

  In recent years, interest in environmental issues has increased internationally, and as a part of this, a cogeneration system using a fuel cell and a micro gas turbine has been developed and widely spread. A high-temperature gas flows inside the heat exchanger constituting the cogeneration system, and the temperature of the gas tends to increase for the purpose of improving the heat generation efficiency. As a material for a heat exchanger that can withstand such a severe use environment at such a high temperature, conventionally, a material using stainless steel as a base material and nickel brazing (JIS BNi-1 to 7) as a brazing material is used. Are known. Nickel brazing is excellent in oxidation resistance and corrosion resistance, but is difficult to be plastically processed. Therefore, nickel brazing is generally manufactured in the form of powder or amorphous ribbon (amorphous metal foil strip) by liquid rapid solidification. . For this reason, there was an inconvenience of being expensive. In addition, since a paste made by mixing a binder with powdered nickel brazing is applied to the stainless steel substrate in the heat exchanger manufacturing process, a binder removal process is required after brazing and manufacturing. There was an inconvenience that the process was complicated. In addition, since the nickel brazing of the amorphous ribbon has a narrow width, it is necessary to dispose a plurality of nickel brazing, and the manufacturing process is complicated.

  Therefore, conventionally, a brazing clad material including a base material and a brazing material layer composed of a Ni layer, a Ti layer, and an Fe—Ni alloy layer has been proposed (see, for example, Patent Document 1). In the brazing material layer disclosed in Patent Document 1, a Ni layer, a Ti layer, and a Fe—Ni alloy layer are laminated in this order from the substrate side. In addition, by constituting this brazing material layer with a plate-like or foil-like Ni layer, Ti layer and Fe-Ni alloy layer, the manufacturing process is prevented from becoming complicated, and the corrosion resistance is prevented from being lowered. Is possible.

JP 2006-175506 A

However, since the conventional brazing material layer disclosed in Patent Document 1 does not contain Cr, an oxide film (passive film) of Cr ₂ O ₃ is not generated on the surface of the joint portion by brazing joining. For this reason, there is a problem that it is difficult to obtain high oxidation resistance.

  The present invention has been made to solve the above-described problems, and is capable of improving both oxidation resistance and corrosion resistance, a brazing composite material, and a brazing joint using the same. It is an object to provide a brazed structure.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, the brazing material according to the first aspect of the present invention is made of pure Ti, a Ti alloy composed of 85 mass% or more of Ti , Al and Sn, or 85 mass% or more of Ti and Al. One Ti brazing layer composed of a Ti layer composed of any one of Ti alloys composed of V, and 20% by mass or more and 40% by mass or less Cr arranged at a position in contact with the brazing target From a two- layer structure or a three-layer structure of 1 to 10% by mass of Mo and a 1-layer or 2-layer Cr—Mo—Ni brazing layer composed of a Cr—Mo—Ni alloy layer composed of Ni Do Ri, and Ti of Ti brazing layer, when the sum of the Cr-Mo-Ni Ni amount of the brazing layer is 100 mass%, Ni content of Cr-Mo-Ni brazing layer is 21.6 mass% or more and 37.1 mass% or less, or 59 .5 wt% or more 69.0 wt% Ru der less.

In the brazing material according to the first aspect, as described above, the brazing material is composed of the Ti brazing layer and the Cr—Mo—Ni brazing layer, so that Ti—Cr— Since the Mo—Ni alloy is formed, a Cr ₂ O ₃ oxide film (passive film) can be formed on the surface of the joint. Thereby, the oxidation resistance of the junction part by brazing joining can be improved. Further, by forming a brazing material with a Ti brazing layer and a Cr—Mo—Ni brazing layer, Ti, Cr, Mo and Ni having high corrosion resistance are contained in the joint portion by brazing joining, so that brazing It is possible to improve the corrosion resistance of the joined portion by the adhesive joining. In addition, by forming the brazing material with the Ti brazing layer and the Cr—Mo—Ni brazing layer, Mo is contained in the brazing layer, so that Ti—Cr— Since it is possible to suppress the formation of brittle TiCr ₂ due to the reaction between Ti and Cr of the Mo—Ni alloy, it is possible to suppress the joint portion due to brazing joining from becoming brittle and More oxide film (passive film) of Cr ₂ O ₃ can be formed on the surface of the part. Moreover, since Mo is contained in the brazing layer, the melting point during brazing joining of the brazing material can be lowered. Also, by forming a layered brazing material with a Ti brazing layer and a Cr—Mo—Ni brazing layer, unlike the powder and amorphous ribbon brazing materials, the manufacturing process of the brazing material becomes complicated. Can be suppressed. Moreover, since the brazing material is layered, a binder to be mixed is not necessary when using a powdered brazing material. Thereby, when brazing joining is performed using a layered brazing material, it is not necessary to remove the binder after the brazing joining, so that the manufacturing process can be simplified. Further, by constituting the brazing material by two layers of a Ti brazing layer and a Cr—Mo—Ni brazing layer, the brazing material is composed of two layers, unlike the case where the brazing material is composed of three brazing layers. Since it consists of a brazing layer, it can suppress that a manufacturing process becomes complicated. Further, by setting the Cr content of the Cr—Mo—Ni alloy layer to 20% by mass or more, an oxide film (passive film) made of Cr ₂ O ₃ having a sufficient thickness on the surface of the joint portion by brazing joining. Therefore, high oxidation resistance can be obtained. Moreover, since it can suppress that the ductility of a Cr-Mo-Ni alloy falls by making the Cr content rate of a Cr-Mo-Ni alloy layer 40 mass% or less, it is a board | substrate by cold welding etc. Can be easily joined. In addition, since the Ti in the Ti brazing layer and the Ni in the Cr—Mo—Ni brazing layer can be melted at a temperature of about 1220 ° C. or less, a special furnace that outputs a high temperature higher than about 1220 ° C. Ti in the Ti brazing layer and Ni in the Cr—Mo—Ni brazing layer can be melted. Moreover, by suppressing the amount of Ni in the Cr—Mo—Ni brazing layer to 37.1% by mass or less, it is possible to suppress the formation of an intermetallic compound composed of brittle Ti ₂ Ni at a joint portion by brazing joining. be able to. As a result, it can suppress that the junction part by brazing joining becomes weak.

  In the brazing material according to the first aspect, preferably, the Mo content of the Cr—Mo—Ni brazing layer made of the Cr—Mo—Ni alloy layer is 3% by mass or more and 10% by mass or less. If comprised in this way, the oxidation resistance of the junction part by brazing joining can be improved sufficiently and effectively.

  In the brazing material according to the first aspect, the ratio t1 / t2 between the thickness t1 of the Ti brazing layer and the thickness t2 of the Ti brazing layer and the Cr—Mo—Ni brazing layer is 0.36 or more and 0.46. Or 0.66 or more and 0.82 or less. According to this structure, when a Cr—Mo—Ni brazing layer having a Ni content of 64% by mass is used, the amount of Ti in the Ti brazing layer and the Ni in the Cr—Mo—Ni brazing layer are reduced. The amount of Ni in the Cr—Mo—Ni brazing layer is 21.6% by mass or more and 37.1% by mass or less, or 59.5% by mass or more and 69.0% when the total amount is 100% by mass. It can be made into mass% or less. As a result, the thickness ratio between the Ti brazing layer and the Cr—Mo—Ni brazing layer is set to 0.36 or more and 0.46 or less, or 0.68 or more and 0.82 or less. A composition (mass%) ratio of Ti and Ni that can melt Ti in the Ti brazing layer and Ni in the Cr—Mo—Ni brazing layer at a temperature of about 1220 ° C. or less without requiring a furnace. can do.

In the brazing material according to the first aspect, the brazing object includes a first brazing object and a second brazing object to be brazed to the first brazing object, and the Cr—Mo—Ni brazing layer is The first Cr-Mo-Ni brazing layer made of the first Cr-Mo-Ni alloy layer and the second Cr are arranged at a position in contact with the first brazing object . A Ti-brazing layer between the first Cr-Mo-Ni brazing layer and the second Cr-Mo-Ni brazing layer. It may be made of a three-layer structure in which are arranged. If comprised in this way, since it can suppress that a Ti brazing layer is exposed to atmosphere, hydrogen, nitrogen, etc. are contained in atmosphere at the time of high temperature, such as at the time of brazing material production or brazing. Even in the case where the Ti brazing layer is formed, the Ti brazing layer can be prevented from becoming fragile.

A brazing composite material according to a second aspect of the present invention includes a substrate formed of steel , a Ti alloy rolled and bonded to the surface of the substrate, and composed of pure Ti, 85% by mass or more of Ti , Al, and Sn, Or, it is disposed at a position in contact with the brazing object, one Ti brazing layer composed of a Ti layer composed of any one of Ti alloys composed of 85 mass% or more of Ti, Al and V , A Cr—Mo—Ni brazing layer composed of a Cr—Mo—Ni alloy layer composed of 20 mass% to 40 mass% Cr, 1 mass% to 10 mass% Mo, and Ni . A brazing material having a two- layer structure, and when the total amount of Ti in the Ti brazing layer and Ni in the Cr—Mo—Ni brazing layer is 100% by mass, Cr—Mo—Ni The amount of Ni in the brazing layer is 21.6% by mass or more 37 .1 wt% or less, or, Ru der 59.5 mass% or more 69.0% by mass or less.

In the composite material for brazing according to the second aspect, as described above, a brazing joint composed of a Ti brazing layer and a Cr—Mo—Ni brazing layer is provided, so that a joint portion by brazing joining is provided. Since a Ti—Cr—Mo—Ni alloy is formed on the surface, an oxide film (passive film) of Cr ₂ O ₃ can be formed on the surface of the joint. Thereby, the oxidation resistance of the junction part by brazing joining can be improved. In addition, since a brazing material composed of a Ti brazing layer and a Cr—Mo—Ni brazing layer is provided, Ti, Cr, Mo and Ni having high corrosion resistance are included in the joint portion by brazing joining. Further, it is possible to improve the corrosion resistance of the joint portion by brazing joint. Further, by providing a brazing material composed of a Ti brazing layer and a Cr—Mo—Ni brazing layer, Mo is contained in the brazing layer, so that Ti— Since it is possible to suppress the formation of brittle TiCr ₂ due to the reaction between Ti and Cr in the Cr—Mo—Ni alloy, it is possible to suppress the joining portion due to brazing joining from becoming brittle. Thus, a larger amount of Cr ₂ O ₃ oxide film (passive film) can be formed on the surface of the joint. Moreover, since Mo is contained in the brazing layer, the melting point during brazing joining of the brazing material can be lowered.

In the second aspect, a brazing composite material is formed by rolling and bonding a layered brazing material having a two-layer structure of a Ti brazing layer and a Cr—Mo—Ni brazing layer to a substrate. Thus, unlike the case of using a brazing material in the form of powder or amorphous ribbon formed by the liquid rapid solidification method, it is possible to suppress the manufacturing process of the brazing material from becoming complicated. Thereby, it can suppress that the manufacturing process of the composite material for brazing is complicated. Moreover, since the brazing material is layered, a binder to be mixed is not necessary when using a powdered brazing material. Thereby, when brazing joining is performed using a layered brazing material, it is not necessary to remove the binder after the brazing joining, so that the manufacturing process can be simplified. Further, by forming a brazing composite material by rolling and bonding a layer brazing material having a two-layer structure of a Ti brazing layer and a Cr—Mo—Ni brazing layer to a substrate, the brazing material 3 Unlike the case where the brazing layer is composed of two layers, the brazing material is composed of two brazing layers, so that the manufacturing process can be prevented from becoming complicated. Further, by setting the Cr content of the Cr—Mo—Ni alloy layer to 20% by mass or more, an oxide film (passive film) made of Cr ₂ O ₃ having a sufficient thickness on the surface of the joint portion by brazing joining. Therefore, high oxidation resistance can be obtained. Moreover, since it can suppress that the ductility of a Cr-Mo-Ni alloy falls by making the Cr content rate of a Cr-Mo-Ni alloy layer 40 mass% or less, it is a board | substrate by cold welding etc. Can be easily joined. In addition, since the Ti in the Ti brazing layer and the Ni in the Cr—Mo—Ni brazing layer can be melted at a temperature of about 1220 ° C. or less, a special furnace that outputs a high temperature higher than about 1220 ° C. Ti in the Ti brazing layer and Ni in the Cr—Mo—Ni brazing layer can be melted. Moreover, by suppressing the amount of Ni in the Cr—Mo—Ni brazing layer to 37.1% by mass or less, it is possible to suppress the formation of an intermetallic compound composed of brittle Ti ₂ Ni at a joint portion by brazing joining. be able to. As a result, it can suppress that the junction part by brazing joining becomes weak.

  In the brazing composite material according to the second aspect, preferably, the Mo content in the Cr—Mo—Ni brazing layer made of the Cr—Mo—Ni alloy layer is 3% by mass or more and 10% by mass or less. . If comprised in this way, the oxidation resistance of the junction part by brazing joining can be improved sufficiently and effectively.

  In the brazing composite material according to the second aspect, the ratio t1 / t2 between the thickness t1 of the Ti brazing layer and the thickness t2 of the Ti brazing layer and the Cr—Mo—Ni brazing layer is 0.36 or more. 0.46 or less, or 0.68 or more and 0.82 or less. According to this structure, when a Cr—Mo—Ni brazing layer having a Ni content of 64% by mass is used, the amount of Ti in the Ti brazing layer and the Ni in the Cr—Mo—Ni brazing layer are reduced. The amount of Ni in the Cr-Mo-Ni brazing layer with respect to the amount of Ti in the Ti brazing layer is 21.6 mass% or more and 37.1 mass% or less when the total amount is 100 mass%, or It can be 59.5 mass% or more and 69.0 mass% or less. As a result, the thickness ratio between the Ti brazing layer and the Cr—Mo—Ni brazing layer is set to 0.36 or more and 0.46 or less, or 0.68 or more and 0.82 or less. A composition (mass%) ratio of Ti and Ni that can melt Ti in the Ti brazing layer and Ni in the Cr—Mo—Ni brazing layer at a temperature of about 1220 ° C. or less without requiring a furnace. can do.

The brazing structure according to the third aspect of the present invention includes a substrate formed of steel and a rolling alloy bonded to the surface of the substrate, pure Ti, a Ti alloy of 85% by mass or more of Ti , Al, and Sn, or 85% by mass or more of a Ti brazing layer composed of any one of Ti alloys composed of Ti, Al, and V, and a Ti brazing layer that is composed of any one of Ti alloys ; Two layers of a Cr—Mo—Ni brazing layer composed of a Cr—Mo—Ni alloy layer composed of Cr of not less than 40% by mass and not more than 40% by mass, Mo of not less than 1% by mass and not more than 10% by mass and Ni. A brazing material comprising a structure, and when the total amount of Ti in the Ti brazing layer and Ni in the Cr-Mo-Ni brazing layer is 100% by mass, Cr-Mo-Ni brazing The amount of Ni in the layer is 21.6% by mass or more 37 It is preferably formed by brazing and joining using a brazing composite material of 1 mass% or less, or 59.5 mass% or more and 69.0 mass% or less .

In the brazed structure according to the third aspect, a Ti—Cr—Mo—Ni alloy is preferably included at least in a brazed joint portion. If constituted in this way, since an oxide film (passive film) of Cr ₂ O ₃ can be formed on the surface of the brazed joint portion, the oxidation resistance of the brazed joint portion can be improved. Can do. In addition, by including a Ti—Cr—Mo—Ni alloy in the brazed joint portion, the brazed joint portion contains Ti, Cr, Mo and Ni having high corrosion resistance. The corrosion resistance of the part can be improved. In addition, by including Mo in the brazed joint portion, it is possible to suppress generation of brittle TiCr ₂ due to reaction between Ti and Cr of the Ti—Cr—Mo—Ni alloy during brazing joining of the brazing material. Therefore, the brazed joint portion can be prevented from becoming brittle, and a larger amount of Cr ₂ O ₃ oxide film (passive film) is formed on the surface of the brazed joint portion. can do. In addition, by including Mo in the brazed joint portion, the melting point at the time of brazing joining of the brazing material is lowered as compared with the case where the brazed joint portion is formed of a Ti—Cr—Ni alloy. be able to. In addition, when Mo is included in the brazed joint portion, the portion that is brazed from the substrate formed of steel when the brazing material is rolled and joined to the substrate formed of steel. It is possible to further diffuse Fe and Cr. As a result, the composition of the brazed joint is close to that of steel, so that the corrosion resistance and oxidation resistance of the brazed joint can be further improved, and the melting point of the brazed joint is brazed. It can be improved compared to the brazing material before being joined.

  In the brazing structure including the Ti—Cr—Mo—Ni alloy, the Mo content of the Ti—Cr—Mo—Ni alloy is preferably 1.1% by mass or more. If comprised in this way, the oxidation resistance of the part joined by brazing can fully be improved.

In the brazing structure containing the Ti—Cr—Mo—Ni alloy, the Ti content of the Ti—Cr—Mo—Ni alloy is preferably 6.6% by mass or more. With this configuration, since a sufficient amount of Cr is contained in the Ti—Cr—Mo—Ni alloy, a Cr ₂ O ₃ oxide film (passive state) having a sufficient thickness on the surface of the brazed joint portion. Film). Thereby, the oxidation resistance of the brazed joint portion can be further improved.

  In the brazing structure including the Ti—Cr—Mo—Ni alloy, preferably, when the total amount of Ti and Ni in the Ti—Cr—Mo—Ni alloy is 100% by mass, the Ti—Cr— The amount of Ni in the Mo-Ni alloy is 21.6 mass% or more and 37.1 mass% or less, or 59.5 mass% or more and 69.0 mass% or less. If comprised in this way, when forming the brazing structure of 3rd aspect, a Ti-Cr-Mo-Ni alloy can be fuse | melted at the temperature of about 1220 degrees C or less. Thereby, the brazing structure of the third aspect can be formed without using a special furnace that outputs a high temperature higher than about 1220 ° C.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a brazing material according to a first embodiment of the present invention. First, with reference to FIG. 1, the structure of the brazing material 1 by 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the brazing material 1 according to the first embodiment includes a Ti layer 2, a Cr—Mo—Ni alloy layer 3 a disposed on one side of the Ti layer 2, and the other side of the Ti layer 2. And a Cr—Mo—Ni alloy layer 3b disposed on the surface. Further, the Cr—Mo—Ni alloy layers 3 a and 3 b are roll-bonded to the Ti layer 2. Further, as the rolling joining, for example, hot welding, cold welding, vacuum welding, or the like can be used. The Ti layer 2 is an example of the “Ti brazing layer” in the present invention. The Cr—Mo—Ni alloy layer 3a is an example of the “Cr—Mo—Ni brazing layer” and the “first Cr—Mo—Ni brazing layer” of the present invention, and the Cr—Mo—Ni alloy layer 3b. These are examples of the “Cr—Mo—Ni brazing layer” and the “second Cr—Mo—Ni brazing layer” of the present invention.

  The Ti layer 2 is composed of pure Ti only. The Ti layer 2 has a thickness of t1. Further, the Cr—Mo—Ni alloy layers 3a and 3b are composed only of Cr, Mo and Ni. The Cr—Mo—Ni alloy layers 3a and 3b have a Cr content of about 20% by mass or more and about 40% by mass or less, and preferably about 30% by mass. The Cr—Mo—Ni alloy layers 3a and 3b have a Mo content of about 3 mass% or more and about 10 mass% or less, preferably about 6 mass%. The brazing material 1 (Ti layer 2, Cr—Mo—Ni alloy layers 3a and 3b) has a thickness of t2.

  Here, in the first embodiment, when the total amount of Ti in the Ti layer 2 and the amount of Ni in the Cr—Mo—Ni alloy layers 3a and 3b is 100% by mass, the Cr—Mo—Ni alloy is used. The amount of Ni in the layers 3a and 3b is about 21.6 mass% or more and about 37.1 mass% or less, or about 59.5 mass% or more and about 69.0 mass% or less, preferably about 28.3 mass%. % By mass or about 65.2% by mass. Further, the ratio t1 / t2 between the thickness t1 of the Ti layer 2 and the thickness t2 of the brazing material 1 is about 0.36 or more and about 0.46 or less, or about 0.68 or more and about 0.82 or less, Preferably, it is about 0.40 or about 0.76.

  2 and 3 are sectional views partially showing a heat exchanger formed using the brazing material according to the first embodiment shown in FIG. Next, with reference to FIG. 2 and FIG. 3, the structure of the heat exchanger 100 formed using the brazing material 1 by 1st Embodiment of this invention is demonstrated. In the first embodiment, an example in which the brazing structure of the present invention is applied to the heat exchanger 100 will be described.

  As shown in FIGS. 2 and 3, the heat exchanger 100 formed using the brazing material 1 according to the first embodiment includes a pair of plates 11 made of stainless steel and six pieces made of stainless steel. A wave-shaped fin 12 and five plates 13 formed of stainless steel are provided. The plates 11 and 13 are examples of the “substrate” in the present invention. Further, as stainless steel, SUS410 and SUS430 which are ferritic stainless steels, SUS304 and SUS316 which are austenitic stainless steels, and the like can be used. The pair of plates 11 constitutes an outer frame of the heat exchanger 100. In addition, the six fins 12 and the five plates 13 are arranged so as to be alternately stacked between the pair of plates 11. The inside of the heat exchanger 100 is divided into six layers by five plates 13, and exhaust gas and water are alternately flowed through the six layers every other layer. Moreover, the fin 12 is provided in order to slow down the flow velocity of the exhaust gas and water which flow through the six layers.

  Here, in 1st Embodiment, as shown in FIG. 2, the heat exchanger 100 is Ti-Cr-Mo-Ni formed by the brazing joining mentioned later between the fin 12 and the plates 13 and 11. As shown in FIG. Alloy 1a is included. That is, a plate 13 and a pair of Ti—Cr—Mo—Ni alloy 1 a are formed between adjacent fins 12, and a Ti—Cr—Mo—Ni alloy is formed between the plate 11 and the fins 12. 1a is formed. This Ti—Cr—Mo—Ni alloy 1 a has a function for joining the outer peripheral surface of the bent portion of the fin 12 and the plates 13 and 11 as shown in FIG. 3. In addition, the content rate of Cr of the Ti-Cr-Mo-Ni alloy 1a is about 6.6 mass% or more, Preferably, it is about 11.5 mass% or about 22.4 mass%. Further, the content of Mo in the Ti—Cr—Mo—Ni alloy 1a is about 1.1% by mass or more, and preferably about 2.3% by mass or about 4.5% by mass. Further, when the total amount of Ti and Ni in the Ti—Cr—Mo—Ni alloy 1a is 100% by mass, the amount of Ni in the Ti—Cr—Mo—Ni alloy 1a is about 21.6 mass. % Or more and about 37.1% by mass or less, or about 59.5% by mass or more and about 69.0% by mass or less, and preferably about 28.3% by mass or about 65.2% by mass. Moreover, in 1st Embodiment, the temperature of the waste gas which flows through the inside of the heat exchanger 100 is about 700 degreeC. Then, the exhaust gas and water that alternately flow through the six layers formed in the heat exchanger 100 alternately exchange heat through the plate 13 and the pair of Ti—Cr—Mo—Ni alloys 1a. By doing so, the heat of the exhaust gas is transferred to the water, so that the water is warmed to become hot water.

  4 and 5 are cross-sectional views for explaining the brazing and joining process when forming the heat exchanger according to the first embodiment shown in FIG. With reference to FIGS. 1-5, the brazing joining performed using the brazing material 1 by 1st Embodiment of this invention is demonstrated.

  First, the brazing material 1 (see FIG. 1) is disposed between the plate 11 (see FIG. 2) and the fins 12 (see FIG. 2), and as shown in FIG. The brazing material 1 is disposed. At this time, the outer peripheral surface of the bent portion of the fin 12 is in contact with the Cr—Mo—Ni alloy layer 3 a constituting the brazing material 1, and the plate 13 and the Cr—Mo—Ni constituting the brazing material 1 are in contact. The alloy layer 3b is in contact. From this state, it is heated for about 10 minutes in an inert gas or in vacuum. When the total amount of Ti in the Ti layer 2 and the amount of Ni in the Cr—Mo—Ni alloy layers 3a and 3b is 100% by mass, the Ni in the Cr—Mo—Ni alloy layers 3a and 3b When the brazing filler metal 1 having an amount of about 21.6 mass% or more and about 37.1 mass% or less is used, it is heated to about 960 ° C. or more and about 1150 ° C. or less. Further, when the total amount of Ti in the Ti layer 2 and the amount of Ni in the Cr—Mo—Ni alloy layers 3a and 3b is 100% by mass, the Ni in the Cr—Mo—Ni alloy layers 3a and 3b When the brazing filler metal 1 having an amount of about 59.5 mass% or more and about 69.0 mass% or less is used, it is heated to about 1100 ° C. or more and about 1220 ° C. or less.

  At this time, as shown in FIG. 5, the Ti layer 2 constituting the brazing material 1 (see FIGS. 1 and 4) and the Cr—Mo—Ni alloy layer 3a (Cr—Mo—Ni alloy layer 3b) are solidified. By changing from the phase state to the liquid phase state, the Ti—Cr—Mo—Ni liquid phase 1b is formed. At this time, Fe and Cr diffuse from the fins 12 and the plates 13 and 11 into the Ti—Cr—Mo—Ni liquid phase 1b due to the fins 12 and the plates 13 and 11 being formed of stainless steel. When the temperature of the Ti—Cr—Mo—Ni liquid phase 1b decreases due to the decrease in temperature after brazing, the Ti—Cr—Mo—Ni liquid phase 1b is in a solid phase state from the liquid phase state. It changes into the Cr-Mo-Ni alloy 1a (refer FIG. 2 and FIG. 3). As a result, the outer peripheral surface of the bent portion of the fin 12 and the plates 13 and 11 are brazed and joined by the Ti—Cr—Mo—Ni alloy 1a, so that the heat exchanger 100 shown in FIG. 2 is formed.

In the first embodiment, as described above, the brazing material 1 is composed of the Ti layer 2 and the Cr—Mo—Ni alloy layers 3a and 3b, so that Ti—Cr—Mo— is formed at the joint portion by brazing joining. Since the Ni alloy 1a is formed, an oxide film (passive film) of Cr ₂ O ₃ can be formed on the surface of the joint. Thereby, the oxidation resistance of the junction part by brazing joining can be improved.

  In the first embodiment, the brazing material 1 is composed of the Ti layer 2 and the Cr—Mo—Ni alloy layers 3a and 3b, so that Ti, Cr, Mo having high corrosion resistance in the joint portion by brazing joining. Since Ni and Ni are contained, the corrosion resistance of the joint part by brazing joint can be improved.

Further, in the first embodiment, by constituting the brazing material 1 with the Ti layer 2 and the Cr—Mo—Ni alloy layers 3a and 3b, Mo is contained in the joint portion by brazing, Since it is possible to suppress the formation of brittle TiCr ₂ due to the reaction between Ti and Cr of the Ti—Cr—Mo—Ni alloy 1a during brazing joining of the brazing material 1, the joint portion by brazing joining is reduced. While being able to suppress becoming weak, more oxide films (passive film) of Cr ₂ O ₃ can be formed on the surface of the joint. Moreover, since Mo is contained in the joint part by brazing joining, compared with the case where the joining part by brazing joining is formed of a Ti—Cr—Ni alloy, the brazing material 1 can be used at the time of brazing joining. The melting point can be lowered. In addition, since Mo is contained in the joint portion by brazing joining, when brazing joining is performed, Fe and Cr are added to the parts to be brazed from the fins 12 and the plates 13 and 11 formed of stainless steel. Can be more diffused. As a result, the composition of the brazed joint is close to that of stainless steel, so that the corrosion resistance and oxidation resistance of the brazed joint can be further improved, and the melting point of the brazed joint is brazed. This can be improved as compared with the brazing material 1 before being joined.

In the first embodiment, when the total amount of Ti in the Ti layer 2 and the amount of Ni in the Cr—Mo—Ni alloy layers 3a and 3b is 100% by mass, the Cr—Mo—Ni alloy layer 3a And 3b at a temperature of about 1220 ° C. or less by adjusting the amount of Ni in the range of about 21.6% by mass to about 37.1% by mass, or about 59.5% by mass to about 69.0% by mass. Ti layer 2 and Cr—Mo—Ni alloy layers 3a and 3b can be melted. Thereby, Ti in the Ti layer 2 and Ni in the Cr—Mo—Ni alloy layers 3 a and 3 b can be melted without using a special furnace that outputs a high temperature higher than about 1220 ° C. Also, by more than about 37.1 wt% of Ni amount, it is possible to prevent the intermetallic compound made of fragile Ti 2 _Ni in the portions bonded by brazing is produced. As a result, it is possible to suppress the strength of the joint portion from being lowered by brazing joint.

(Second Embodiment)
FIG. 6 is a cross-sectional view showing a configuration of a brazing composite material according to a second embodiment of the present invention. FIG. 7 is a cross-sectional view for explaining a brazing joint process using the brazing composite material according to the second embodiment shown in FIG. Referring to FIGS. 2, 3, and 5 to 7, in the second embodiment, unlike the first embodiment, a brazing composite in which a brazing material 51 having a two-layer structure is roll-bonded to plate 13. The material 50 will be described.

  A brazing composite material 50 according to the second embodiment of the present invention includes a plate 13 made of stainless steel and a pair of brazing materials rolled and joined to one side and the other side of the plate 13 as shown in FIG. 51.

  Here, in the second embodiment, the pair of brazing materials 51 are each configured by a two-layer structure of a Ti layer 2 and a Cr—Mo—Ni alloy layer 3 that are roll-bonded to the plate 13. Further, when the total amount of Ti in the Ti layer 2 and Ni in the Cr—Mo—Ni alloy layer 3 is 100 mass%, the amount of Ni in the Cr—Mo—Ni alloy layer 3 is about 21. From 6 mass% to about 37.1 mass%, or from about 59.5 mass% to about 69.0 mass%, preferably from about 28.3 mass% or about 65.2 mass%. It is. Here, when the total amount of Ti in the Ti layer 2 and the amount of Ni in the Cr—Mo—Ni alloy layer 3 is 100% by mass, the amount of Ni in the Cr—Mo—Ni alloy layer 3 is about In the case of using the brazing material 51 that is 21.6 mass% or more and about 37.1 mass% or less, the melting point of the brazing material 51 is about 960 ° C. to about 1150 ° C., and the Ti amount in the Ti layer 2 and Cr -When the total amount of Ni in the Mo-Ni alloy layer 3 is 100 mass%, the amount of Ni in the Cr-Mo-Ni alloy layer 3 is about 59.5 mass% or more and about 69.0 mass% or less. When the brazing material 51 is used, the melting point of the brazing material 51 is about 1100 ° C. to about 1220 ° C. Further, when the brazing material 51 is rolled and joined to the SUS304 or SUS316 plate 13 which is an austenitic stainless steel, the temperature is about 1050 ° C. or higher so that sigma brittleness (embrittlement phenomenon) does not occur in the austenitic stainless steel. It needs to be annealed. Therefore, when austenitic stainless steel is used as the plate 13, when the total amount of Ti in the Ti layer 2 and Ni in the Cr—Mo—Ni alloy layer 3 is 100% by mass, Cr— It is preferable to use a brazing material 51 in which the amount of Ni in the Mo—Ni alloy layer 3 is about 59.5 mass% or more and about 69.0 mass% or less.

  And in order to form the heat exchanger 100 (refer FIG. 2) using the brazing material 51 by 2nd Embodiment, as shown in FIG. 7, the brazing composite material 50 so that the bending part of fin 12 may be contact | connected. Place. And brazing joining is performed on the conditions similar to the brazing joining performed in the said 1st Embodiment. At this time, as shown in FIG. 5, the Ti layer 2 and the Cr—Mo—Ni alloy layer 3 constituting the brazing material 51 change from the solid phase state to the liquid phase state to form a Ti—Cr—Mo—Ni liquid phase. 1b is formed. At this time, Fe and Cr diffuse from the fins 12 and the plates 13 and 11 into the Ti—Cr—Mo—Ni liquid phase 1b due to the fins 12 and the plates 13 and 11 being formed of stainless steel. When the temperature of the Ti—Cr—Mo—Ni liquid phase 1b decreases due to the decrease in temperature after brazing, the Ti—Cr—Mo—Ni liquid phase 1b is in a solid phase state from the liquid phase state. It changes into the Cr-Mo-Ni alloy 1a (refer FIG. 2 and FIG. 3). As a result, the outer peripheral surface of the bent portion of the fin 12 and the plates 13 and 11 are brazed and joined by the Ti—Cr—Mo—Ni alloy 1a, so that the heat exchanger 100 shown in FIG. 2 is formed.

  The effect of the second embodiment is the same as that of the first embodiment described above.

  Next, a comparative experiment conducted for confirming the effect of the first embodiment of the present invention (the effect of improving the oxidation resistance of the joint portion by brazing joint) will be described. In this comparative experiment, the first embodiment was formed using a brazing material having a three-layer structure composed of a pure Ti layer and a Cr—Mo—Ni alloy layer roll-bonded to one side and the other side of the pure Ti layer. According to Comparative Examples 1 and 2 formed by using a reaction layer of the clad material according to Examples 1 to 16 (joint part by brazing joining) and a brazing material containing no Mo unlike the above Examples 1 to 16 The composition of the clad material was compared with the reaction layer (joint part by brazing joint). Moreover, Examples 1-16 and Comparative Examples 1 and 2 were obtained by calculating and comparing the oxidation increase of the reaction layers of the clad material according to Examples 1 to 16 and Comparative Examples 1 and 2 (joint portions by brazing joining). The oxidation resistance of the reaction layer of the clad material (bonded part by brazing) was evaluated. Details will be described below.

[Preparation of brazing material]
Example 1
As a brazing material, a pure Ti layer and a 30Cr-6Mo-Ni alloy layer containing 30 mass% Cr, 6 mass% Mo, and 64 mass% Ni were used. Then, 30Cr-6Mo-Ni alloy layers were rolled and joined to one side and the other side of the pure Ti layer, respectively, and then subjected to diffusion annealing at a temperature of 800 ° C. for 1 minute in an argon atmosphere. Then, finish rolling and annealing were performed to adjust the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer to 0.036 mm and 0.032 mm, respectively. This produced the brazing material according to Example 1 having a three-layer structure of 30Cr-6Mo-Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.36.

(Example 2)
30Cr-6Mo was performed in the same manner as in Example 1 except that the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer were adjusted to 0.040 mm and 0.030 mm, respectively, by performing finish rolling and annealing. A brazing material according to Example 2 having a three-layer structure of -Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.40.

(Example 3)
30Cr-6Mo was performed in the same manner as in Example 1 except that the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer were adjusted to 0.046 mm and 0.027 mm, respectively, by performing finish rolling and annealing. A brazing material according to Example 3 having a three-layer structure of -Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.46.

Example 4
30Cr-6Mo was performed in the same manner as in Example 1 except that the plate thicknesses of the pure Ti layer and 30Cr-6Mo-Ni alloy layer were adjusted to 0.068 mm and 0.016 mm, respectively, by performing finish rolling and annealing. A brazing material according to Example 4 having a three-layer structure of -Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.68.

(Example 5)
30Cr-6Mo was performed in the same manner as in Example 1 except that the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer were adjusted to 0.076 mm and 0.012 mm, respectively, by performing finish rolling and annealing. A brazing material according to Example 5 having a three-layer structure of -Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.76.

(Example 6)
30Cr-6Mo was performed in the same manner as in Example 1 except that the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer were adjusted to 0.082 mm and 0.009 mm, respectively, by performing finish rolling and annealing. A brazing material according to Example 6 having a three-layer structure of -Ni alloy layer / pure Ti layer / 30Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.82.

(Example 7)
Example 2 except that a pure Ti layer and a 30Cr-1Mo-Ni alloy layer containing 30% by mass of Cr, 1% by mass of Mo and 69% by mass of Ni are used as raw materials for the brazing filler metal. Similarly, a brazing material according to Example 7 having a three-layer structure of 30Cr-1Mo-Ni alloy layer / pure Ti layer / 30Cr-1Mo-Ni alloy layer was produced.

(Example 8)
Example 5 except that a pure Ti layer and a 30Cr-1Mo-Ni alloy layer containing 30% Cr, 1% Mo and 69% Ni by weight are used as the brazing material. Similarly, a brazing material according to Example 8 having a three-layer structure of 30Cr-1Mo-Ni alloy layer / pure Ti layer / 30Cr-1Mo-Ni alloy layer was produced.

Example 9
As Example 2 except that a pure Ti layer and a 30Cr-3Mo-Ni alloy layer containing 30 mass% Cr, 3 mass% Mo, and 67 mass% Ni are used as the brazing material. Similarly, a brazing material according to Example 9 having a three-layer structure of 30Cr-3Mo—Ni alloy layer / pure Ti layer / 30Cr-3Mo—Ni alloy layer was produced.

(Example 10)
Example 5 except that a pure Ti layer and a 30Cr-3Mo-Ni alloy layer containing 30 mass% Cr, 3 mass% Mo, and 67 mass% Ni are used as the brazing material. Similarly, a brazing material according to Example 10 having a three-layer structure of 30Cr-3Mo—Ni alloy layer / pure Ti layer / 30Cr-3Mo—Ni alloy layer was produced.

(Example 11)
Example 2 except that a pure Ti layer and a 30Cr-10Mo-Ni alloy layer containing 30 mass% Cr, 10 mass% Mo, and 60 mass% Ni are used as the brazing material. Similarly, a brazing material according to Example 11 having a three-layer structure of 30Cr-10Mo-Ni alloy layer / pure Ti layer / 30Cr-10Mo-Ni alloy layer was produced.

(Example 12)
Example 5 except that a pure Ti layer and a 30Cr-10Mo-Ni alloy layer containing 30% Cr, 10% Mo and 60% Ni by weight are used as the brazing material. Similarly, a brazing material according to Example 12 having a three-layer structure of 30Cr-10Mo-Ni alloy layer / pure Ti layer / 30Cr-10Mo-Ni alloy layer was produced.

(Example 13)
Example 2 except that a pure Ti layer and a 20Cr-6Mo-Ni alloy layer containing 20 mass% Cr, 6 mass% Mo, and 74 mass% Ni are used as the brazing material. Similarly, a brazing material according to Example 13 having a three-layer structure of 20Cr-6Mo-Ni alloy layer / pure Ti layer / 20Cr-6Mo-Ni alloy layer was produced.

(Example 14)
By using a pure Ti layer, a 20Cr-6Mo-Ni alloy layer containing 20% by mass of Cr, 6% by mass of Mo and 74% by mass of Ni as a raw material for the brazing material, and performing finish rolling and annealing. 20Cr-6Mo-Ni alloy layer / pure in the same manner as in Example 1 except that the thicknesses of the pure Ti layer and the 20Cr-6Mo-Ni alloy layer were adjusted to 0.080 mm and 0.010 mm. A brazing material according to Example 14 having a three-layer structure of Ti layer / 20Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.80.

(Example 15)
Example 2 except that a pure Ti layer and a 40Cr-6Mo-Ni alloy layer containing 40% by mass of Cr, 6% by mass of Mo, and 54% by mass of Ni are used as raw materials for the brazing material. Similarly, a brazing material according to Example 15 having a three-layer structure of 40Cr-6Mo-Ni alloy layer / pure Ti layer / 40Cr-6Mo-Ni alloy layer was produced.

(Example 16)
By using a pure Ti layer, a 40Cr-6Mo-Ni alloy layer containing 40% by mass of Cr, 6% by mass of Mo and 54% by mass of Ni as a raw material for the brazing material, and performing finish rolling and annealing 40Cr-6Mo-Ni alloy layer / pure in the same manner as in Example 1 except that the thicknesses of the pure Ti layer and 40Cr-6Mo-Ni alloy layer were adjusted to 0.078 mm and 0.011 mm, respectively. A brazing material according to Example 16 having a three-layer structure of Ti layer / 40Cr-6Mo-Ni alloy layer was produced. In this way, the thickness ratio of the pure Ti layer to the brazing material was set to 0.78.

(Comparative Example 1)
Except for using a pure Ti layer and a 30Cr—Ni alloy layer containing 30% by mass of Cr and 70% by mass of Ni as raw materials for the brazing material, the same as in Example 2 above. A brazing material according to Comparative Example 1 having a three-layer structure of 30Cr—Ni alloy layer / pure Ti layer / 30Cr—Ni alloy layer was produced.

(Comparative Example 2)
Except for using a pure Ti layer and a 30Cr—Ni alloy layer containing 30% by mass of Cr and 70% by mass of Ni as the raw material for the brazing material, the same as in Example 5 above. A brazing material according to Comparative Example 2 having a three-layer structure of 30Cr—Ni alloy layer / pure Ti layer / 30Cr—Ni alloy layer was produced.

  Here, the correspondence relationship between the thickness (mm) of each layer of the brazing material and the thickness ratio of the pure Ti layer to the brazing material is shown in Tables 1 to 7 below. In Examples 1 to 6 shown in Table 1, a 30Cr-6Mo-Ni alloy layer was used. Further, in Examples 7 and 8 shown in Table 2, in the 30Cr-1Mo—Ni alloy layer, in Examples 9 and 10 shown in Table 3, in the 30Cr-3Mo—Ni alloy layer, in Examples 11 and 12 shown in Table 4. A 30Cr-10Mo-Ni alloy layer was used. In Examples 13 and 14 shown in Table 5, a 20Cr-6Mo-Ni alloy layer was used, and in Examples 15 and 16 shown in Table 6, a 40Cr-6Mo-Ni alloy layer was used. In Comparative Examples 1 and 2 in Table 7, a 30Cr—Ni alloy layer not containing Mo was used.

［クラッド材の反応層の組成分析］
（実施例１〜１６、比較例１および２に共通）
次に、上記のようにして作製した実施例１〜１６、比較例１および２によるろう材を反応させて得られたクラッド材の反応層の組成およびろう材の融点を分析した。具体的には、実施例１〜１６、比較例１および２によるろう材を所定の条件（温度：約１２２０℃、時間：１０分）で反応させた。そして、上記反応により得られたクラッド材の反応層を上記第１実施形態によるろう付け接合による接合部と見なし、その反応層の断面を樹脂で埋め込んだ後、研磨を行った。そして、反応層の断面におけるＮｉ、Ｃｒ、ＭｏおよびＴｉの含有率（質量％）を、ＥＰＭＡ（電子線マイクロアナリシス）を用いて分析した。さらに、実験によって得られたクラッド材の反応層のＮｉとＴｉとの組成（質量％）比を分析した。その結果を以下の表８に示す。

[Composition analysis of reaction layer of clad material]
(Common to Examples 1 to 16 and Comparative Examples 1 and 2)
Next, the composition of the reaction layer of the clad material obtained by reacting the brazing materials according to Examples 1 to 16 and Comparative Examples 1 and 2 produced as described above and the melting point of the brazing material were analyzed. Specifically, the brazing materials according to Examples 1 to 16 and Comparative Examples 1 and 2 were reacted under predetermined conditions (temperature: about 1220 ° C., time: 10 minutes). Then, the reaction layer of the clad material obtained by the above reaction was regarded as a joint portion by brazing joint according to the first embodiment, and after polishing the cross section of the reaction layer with resin, polishing was performed. And the content rate (mass%) of Ni, Cr, Mo, and Ti in the cross section of the reaction layer was analyzed using EPMA (electron beam microanalysis). Further, the composition (mass%) ratio of Ni and Ti in the reaction layer of the clad material obtained by the experiment was analyzed. The results are shown in Table 8 below.

上記表８に示すように、実施例１によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが４９．７質量％、Ｃｒが２３．３質量％、Ｍｏが４．７質量％、Ｔｉが２２．３質量％であった。また、実施例１による反応層のＮｉとＴｉとの組成比は、６９．０質量％：３１．０質量％であり、融点は、１２２０℃であった。また、実施例２によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが４７．７質量％、Ｃｒが２２．４質量％、Ｍｏが４．５質量％、Ｔｉが２５．４質量％であった。また、実施例２による反応層のＮｉとＴｉとの組成比は、６５．２質量％：３４．８質量％であり、融点は、１１００℃であった。また、実施例３によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが４４．６質量％、Ｃｒが２０．９質量％、Ｍｏが４．２質量％、Ｔｉが３０．３質量％であった。また、実施例３による反応層のＮｉとＴｉとの組成比は、５９．５質量％：４０．５質量％であり、融点は、１１５０℃であった。また、実施例４によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが３０．７質量％、Ｃｒが１４．３質量％、Ｍｏが２．９質量％、Ｔｉが５２．１質量％であった。また、実施例４による反応層のＮｉとＴｉとの組成比は、３７．１質量％：６２．９質量％であり、融点は約１１５０℃であった。また、実施例５によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが２４．４質量％、Ｃｒが１１．５質量％、Ｍｏが２．３質量％、Ｔｉが６１．８質量％であった。また、実施例５による反応層のＮｉとＴｉとの組成比は、２８．３質量％：７１．７質量％であり、融点は、９６０℃であった。また、実施例６によるろう材を反応させて得られた反応層の組成（質量％）比は、Ｎｉが１９．２質量％、Ｃｒが９．０質量％、Ｍｏが１．８質量％、Ｔｉが７０．０質量％であった。また、実施例６による反応層のＮｉとＴｉとの組成比は、２１．６質量％：７８．４質量％であり、融点は、１１００℃であった。

As shown in Table 8 above, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 1 was 49.7 mass% for Ni, 23.3 mass% for Cr, and Mo for Mo. The content was 4.7% by mass and Ti was 22.3% by mass. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Example 1 was 69.0% by mass: 31.0% by mass, and the melting point was 1220 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 2 was 47.7 mass% for Ni, 22.4 mass% for Cr, 4.5 mass% for Mo, Ti was 25.4% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 2 was 65.2% by mass: 34.8% by mass, and the melting point was 1100 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 3 was 44.6 mass% for Ni, 20.9 mass% for Cr, 4.2 mass% for Mo, Ti was 30.3% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 3 was 59.5% by mass: 40.5% by mass, and the melting point was 1150 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 4 was as follows: Ni was 30.7 mass%, Cr was 14.3 mass%, Mo was 2.9 mass%, Ti was 52.1% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 4 was 37.1% by mass: 62.9% by mass, and the melting point was about 1150 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 5 was 24.4 mass% for Ni, 11.5 mass% for Cr, 2.3 mass% for Mo, Ti was 61.8% by mass. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Example 5 was 28.3 mass%: 71.7 mass%, and the melting point was 960 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 6 was 19.2 mass% for Ni, 9.0 mass% for Cr, 1.8 mass% for Mo, Ti was 70.0% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 6 was 21.6% by mass: 78.4% by mass, and the melting point was 1100 ° C.

  Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 7 was 51.5 mass% for Ni, 22.4 mass% for Cr, 0.7 mass% for Mo, Ti was 25.4% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 7 was 66.9% by mass: 33.1% by mass, and the melting point was 1125 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 8 was 26.3% by mass of Ni, 11.5% by mass of Cr, 0.4% by mass of Mo, Ti was 61.8% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 8 was 29.9% by mass: 70.1% by mass, and the melting point was 985 ° C.

  The composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 9 was 50.0 mass% for Ni, 22.4 mass% for Cr, 2.2 mass% for Mo, Ti was 25.4% by mass. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Example 9 was 66.3 mass%: 33.7 mass%, and the melting point was 1120 ° C. The composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 10 was as follows: Ni was 25.6 mass%, Cr was 11.5 mass%, Mo was 1.1 mass%, Ti was 61.8% by mass. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Example 10 was 29.3 mass%: 70.7 mass%, and the melting point was 980 ° C.

  Moreover, as shown in the said Table 8, composition (mass%) ratio of the reaction layer obtained by making the brazing material by Example 11 react is 44.7 mass% of Ni, 22.4 mass% of Cr, Mo was 7.5% by mass and Ti was 25.4% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 11 was 63.8% by mass: 36.2% by mass, and the melting point was 1125 ° C. The composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 12 was as follows: Ni was 22.9 mass%, Cr was 11.5 mass%, Mo was 3.8 mass%, Ti was 61.8% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 12 was 27.0% by mass: 73.0% by mass, and the melting point was 990 ° C.

  Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 13 was 55.2 mass% for Ni, 14.9 mass% for Cr, 4.5 mass% for Mo, Ti was 25.4% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 13 was 68.5% by mass: 31.5% by mass, and the melting point was 1110 ° C. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 14 was 24.3% by mass of Ni, 6.5% by mass of Cr, 2.0% by mass of Mo, Ti was 67.2 mass%. The composition ratio of Ni and Ti in the reaction layer according to Example 14 was 26.6% by mass: 73.4% by mass, and the melting point was 970 ° C.

  The composition (mass%) ratio of the reaction layer obtained by reacting the brazing material according to Example 15 was 40.3% by mass of Ni, 29.8% by mass of Cr, 4.5% by mass of Mo, Ti was 25.4% by mass. The composition ratio of Ni and Ti in the reaction layer according to Example 15 was 61.3% by mass: 38.7% by mass, and the melting point was 1120.degree. Further, the composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Example 16 was 18.5 mass% for Ni, 13.7 mass% for Cr, 2.0 mass% for Mo, Ti was 65.8 mass%. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Example 16 was 21.9% by mass: 78.1% by mass, and the melting point was 980 ° C.

  As described above, it was found from the composition of the reaction layer obtained by reacting the brazing material according to Examples 1 to 16 that the reaction layer was made of a Ni—Cr—Mo—Ti alloy.

  Moreover, as shown in the said Table 8, composition (mass%) ratio of the reaction layer obtained by making the brazing material by the comparative example 1 react is 52.2 mass% for Ni, 22.4 mass% for Cr, Mo was 0.0 mass% and Ti was 25.4 mass%. Moreover, the composition ratio of Ni and Ti in the reaction layer according to Comparative Example 1 was 67.2% by mass: 32.8% by mass, and the melting point was 1130 ° C. The composition (mass%) ratio of the reaction layer obtained by reacting the brazing filler metal according to Comparative Example 2 was as follows: Ni was 26.7 mass%, Cr was 11.5 mass%, Mo was 0.0 mass%, Ti was 61.8% by mass. The composition ratio of Ni and Ti in the reaction layer according to Comparative Example 2 was 30.2% by mass: 69.8% by mass, and the melting point was 990 ° C. As described above, it was found that the reaction layer obtained by reacting the brazing material according to Comparative Examples 1 and 2 was made of a Ni—Cr—Ti alloy.

  Further, from the above results, Examples 2 and 7 in which the composition ratio of Ni and Ti is in the vicinity of the composition ratio of the eutectic point of Ni—Ti alloy (64.4 (Ni): 35.6 (Ti)). , 9 and the melting point of the brazing material according to Comparative Example 1, and the composition ratio of Ni and Ti is close to the composition ratio of the eutectic point of the Ni—Ti alloy (28.3 (Ni): 71.7 (Ti)) When the melting points of the brazing materials according to Examples 5, 8, 10 and Comparative Example 2 were compared, it was found that the melting point of the brazing material decreased as the amount of Mo added to the reaction layer was increased. Note that the melting point of the brazing material according to Examples 11 and 12 is high because the Ni content decreases due to the large amount of Mo added, so the composition ratio of Ni and Ti is that of the Ni-Ti alloy. This is considered to be because it is far from the eutectic point composition ratio (64.4 (Ni): 35.6 (Ti) and 28.3 (Ni): 71.7 (Ti)). Further, when the melting points of the brazing materials according to Examples 1 to 3 were compared, it was found that the melting points of the brazing materials according to Examples 1 and 3 were higher than the melting point of the brazing material according to Example 2. This is because the composition ratio of Ni and Ti of the brazing material according to Examples 1 and 3 is higher than the composition ratio of Ni and Ti of the brazing material according to Example 2 (the eutectic point composition ratio ( 64.4 (Ni): 35.6 (Ti)). Further, when the melting points of the brazing materials according to Examples 4 to 6 were compared, it was found that the melting point of the brazing material according to Examples 4 and 6 was higher than the melting point of the brazing material according to Example 5. This is because the composition ratio of Ni and Ti of the brazing material according to Examples 4 and 6 is higher than the composition ratio of Ni and Ti of the brazing material according to Example 5 (the eutectic point composition ratio ( 64.4 (Ni): 35.6 (Ti)).

[Oxidation resistance evaluation test]
(Common to Examples 1 to 16 and Comparative Examples 1 and 2)
Moreover, the oxidation test for evaluating the oxidation resistance of the reaction layer (joint part by brazing joining) obtained by making the brazing material by the said Examples 1-16 and the comparative examples 1 and 2 react was done. Specifically, the reaction layers obtained by reacting the brazing materials according to Examples 1 to 16 and Comparative Examples 1 and 2 were cut into 50 mm × 50 mm squares, and the weight of the reaction layer before the oxidation test was measured. It was heated at a temperature of 900 ° C. for 100 hours. Then, the weight of the reaction layer after the oxidation test was measured, the oxidation increase of the reaction layer was calculated from the change in the weight of the reaction layer before and after the oxidation test, and the oxidation resistance of the reaction layer was evaluated. The results are shown in Table 9 below.

上記表９を参照して、実施例１によるろう材を反応させて得られたＮｉを４９．７質量％、Ｃｒを２３．３質量％、Ｍｏを４．７質量％、Ｔｉを２２．３質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．０９ｍｇ／ｍｍ^２であった。また、実施例２によるろう材を反応させて得られたＮｉを４７．７質量％、Ｃｒを２２．４質量％、Ｍｏを４．５質量％、Ｔｉを２５．４質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．０９ｍｇ／ｍｍ^２であった。また、実施例３によるろう材を反応させて得られたＮｉを４４．６質量％、Ｃｒを２０．９質量％、Ｍｏを４．２質量％、Ｔｉを３０．３質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．１０ｍｇ／ｍｍ^２であった。また、実施例４によるろう材を反応させて得られたＮｉを３０．７質量％、Ｃｒを１４．３質量％、Ｍｏを２．９質量％、Ｔｉを５２．１質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．２０ｍｇ／ｍｍ^２であった。また、実施例５によるろう材を反応させて得られたＮｉを２４．４質量％、Ｃｒを１１．５質量％、Ｍｏを２．３質量％、Ｔｉを６１．８質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．２１ｍｇ／ｍｍ^２であった。また、実施例６によるろう材を反応させて得られたＮｉを１９．２質量％、Ｃｒを９．０質量％、Ｍｏを１．８質量％、Ｔｉを７０．０質量％の割合で含有する反応層の酸化試験前後における酸化増量は、０．２２ｍｇ／ｍｍ^２であった。

Referring to Table 9 above, Ni obtained by reacting the brazing material according to Example 1 was 49.7% by mass, Cr was 23.3% by mass, Mo was 4.7% by mass, and Ti was 22.3%. The amount of increase in oxidation before and after the oxidation test of the reaction layer contained at a ratio of mass% was 0.09 mg / mm ² . Further, Ni obtained by reacting the brazing filler metal according to Example 2 was 47.7 mass%, Cr was 22.4 mass%, Mo was 4.5 mass%, and Ti was contained in a proportion of 25.4 mass%. The increase in oxidation of the reaction layer before and after the oxidation test was 0.09 mg / mm ² . Moreover, 44.6 mass% of Ni obtained by making the brazing material by Example 3 react, 20.9 mass% of Cr, 4.2 mass% of Mo, and 30.3 mass% of Ti are contained. The oxidation increase of the reaction layer before and after the oxidation test was 0.10 mg / mm ² . Further, Ni obtained by reacting the brazing filler metal according to Example 4 was 30.7% by mass, Cr was 14.3% by mass, Mo was 2.9% by mass, and Ti was contained at a ratio of 52.1% by mass. The increase in oxidation before and after the oxidation test of the reaction layer was 0.20 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 5 was contained in a ratio of 24.4% by mass, Cr 11.5% by mass, Mo 2.3% by mass, and Ti 61.8% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.21 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 6 was contained in a proportion of 19.2 mass%, Cr 9.0 mass%, Mo 1.8 mass%, and Ti 70.0 mass%. The increase in oxidation of the reaction layer before and after the oxidation test was 0.22 mg / mm ² .

Further, Ni obtained by reacting the brazing material according to Example 7 was contained in a ratio of 51.5% by mass, Cr 22.4% by mass, Mo 0.7% by mass, and Ti 25.4% by mass. The increase in oxidation before and after the oxidation test of the reaction layer was 0.31 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 8 was contained in a ratio of 26.3% by mass, Cr 11.5% by mass, Mo 0.4% by mass, and Ti 61.8% by mass. The oxidation increase of the reaction layer before and after the oxidation test was 0.32 mg / mm ² . Further, Ni obtained by reacting the brazing filler metal according to Example 9 was contained in a proportion of 50.0% by mass, Cr 22.4% by mass, Mo 2.2% by mass, and Ti 25.4% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.09 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 10 was contained in a ratio of 25.6% by mass, Cr 11.5% by mass, Mo 1.1% by mass, and Ti 61.8% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.22 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 11 was 44.7% by mass, Cr was 22.4% by mass, Mo was 7.5% by mass, and Ti was contained at a rate of 25.4% by mass. The oxidation increase of the reaction layer before and after the oxidation test was 0.08 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 12 was contained in a ratio of 22.9 mass%, Cr 11.5 mass%, Mo 3.8 mass%, and Ti 61.8 mass%. The increase in oxidation before and after the oxidation test of the reaction layer was 0.20 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 13 was contained in a ratio of 55.2% by mass, Cr 14.9% by mass, Mo 4.5% by mass, and Ti 25.4% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.19 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 14 was contained at a ratio of 24.3% by mass, Cr by 6.5% by mass, Mo by 2.0% by mass, and Ti by 67.2% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.24 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 15 was contained at a ratio of 40.3% by mass, Cr at 29.8% by mass, Mo at 4.5% by mass, and Ti at a rate of 25.4% by mass. The oxidation increase of the reaction layer before and after the oxidation test was 0.08 mg / mm ² . Further, Ni obtained by reacting the brazing material according to Example 16 was contained in a ratio of 18.5% by mass, Cr 13.7% by mass, Mo 2.0% by mass, and Ti 65.8% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.21 mg / mm ² .

Further, Ni obtained by reacting the brazing filler metal according to Comparative Example 1 was contained at a ratio of 52.2 mass%, Cr 22.4 mass%, Mo 0.0 mass%, and Ti 25.4 mass%. The oxidation increase of the reaction layer before and after the oxidation test was 0.33 mg / mm ² . Further, Ni obtained by reacting the brazing filler metal according to Comparative Example 2 was 26.7% by mass, Cr was 11.5% by mass, Mo was 0.0% by mass, and Ti was contained at a ratio of 61.8% by mass. The increase in oxidation of the reaction layer before and after the oxidation test was 0.38 mg / mm ² .

From the above results, when comparing the oxidation increase of the reaction layers obtained by reacting the brazing materials according to Examples 1 to 16 and Comparative Examples 1 and 2, it was obtained by reacting the brazing materials according to Examples 1 to 16. the reaction oxidation weight gain of layer ^{(0.09mg / mm 2, 0.09mg /} mm 2, 0.10mg / mm 2, 0.20mg / mm 2, 0.21mg / mm 2, 0.22mg / mm 2, 0. ^{31mg / mm 2, 0.32mg / mm} 2, 0.09mg / mm 2, 0.22mg / mm 2, 0.08mg / mm 2, 0.20mg / mm 2, 0.19mg / mm 2, 0.24mg / ^{mm 2,} 0.08mg / ^mm 2 and 0.21 mg / mm ^2), the oxidized amounts of the reaction layer obtained by reacting the brazing filler metal according to Comparative example 1 and ² (0.33mg / mm 2 and 0. 38mg / mm ) Smaller than, it has been found that a high oxidation resistance. This is because the reaction layer obtained by reacting the brazing material according to Comparative Examples 1 and 2 does not contain Mo, whereas the reaction layer obtained by reacting the brazing material according to Examples 1-16. Since Mo contains Mo, it is considered that an oxide film of Cr ₂ O ₃ was sufficiently formed on the surface of the reaction layer obtained by reacting the brazing material according to Examples 1 to 16.

  Further, a Cr—Mo—Ni alloy layer containing 30% by mass of Cr is formed, and the composition ratio of Ni and Ti is the eutectic point composition ratio of Ni—Ti alloy (64.4 (Ni): 35. 6 (Ti)) in the vicinity of Examples 1 to 3, 7, 9, 11 and Comparative Example 1, the increase in oxidation of the reaction layers obtained by reacting the brazing material, and Cr- containing 30% by mass of Cr An embodiment in which the Mo—Ni alloy layer is used and the composition ratio of Ni and Ti is in the vicinity of the eutectic point composition ratio (28.3 (Ni): 71.7 (Ti)) of the Ni—Ti alloy. When comparing the amount of increase in oxidation of the reaction layers obtained by reacting the brazing filler metals according to Examples 4 to 6, 8, 10, 12 and Comparative Example 2, respectively, the reaction layer increases as the amount of Mo added to the reaction layer increases. It has been found that the increase in oxidation of is reduced. That is, it was found that the oxidation resistance of the reaction layer can be improved as the amount of Mo added to the reaction layer is increased.

  In addition, a Cr—Mo—Ni alloy layer containing 6 mass% of Mo is formed, and the composition ratio of Ni and Ti is the composition ratio of the eutectic point of the Ni—Ti alloy (64.4 (Ni): 35. 6 (Ti)), an increase in oxidation of the reaction layer obtained by reacting the brazing material according to Examples 1-3, 13 and 15 and a Cr—Mo—Ni alloy layer containing 6% by mass of Mo. Examples 4-6, 14 in which the composition ratio of Ni and Ti is in the vicinity of the eutectic point composition ratio (28.3 (Ni): 71.7 (Ti)) of the Ni—Ti alloy. When the amount of increase in oxidation in the reaction layer obtained by reacting the brazing filler metals according to No. 16 and No. 16 was compared, it was found that the amount of increase in oxidation in the reaction layer decreased as the amount of Cr added to the reaction layer was increased. That is, it was found that the oxidation resistance of the reaction layer can be improved as the amount of Cr added to the reaction layer is increased.

  Next, a comparative experiment conducted to confirm the diffusion of Fe and Cr from stainless steel due to the above-described addition of Mo will be described. In this comparative experiment, a brazing material having a three-layer structure composed of a pure Ti layer and a Cr—Mo—Ni alloy layer rolled and bonded to one surface and the other surface of the pure Ti layer was rolled and bonded to a substrate made of SUS304. Brazing of the brazing composite material according to Examples 17 to 22 and the brazing composite material according to Comparative Examples 3 to 5 formed using the brazing filler metal layer of the brazing composite material according to Examples 17 to 22 and the brazing material not containing Mo unlike the above Examples 17 to 22 The diffusion of Fe with the material layer was compared. Details will be described below.

[Preparation of brazing composites]
(Examples 17 to 19)
As a brazing material, a pure Ti layer and a 30Cr-6Mo-Ni alloy layer containing 30 mass% Cr, 6 mass% Mo, and 64 mass% Ni were used. Then, 30Cr-6Mo-Ni alloy layers were rolled and joined to one side and the other side of the pure Ti layer, respectively, and then subjected to diffusion annealing at a temperature of 800 ° C. for 1 minute in an argon atmosphere. Then, finish rolling and annealing were performed to adjust the plate thicknesses of the pure Ti layer and the 30Cr-6Mo-Ni alloy layer to 0.040 mm and 0.030 mm, respectively. Thereafter, the brazing material was roll-bonded to a substrate made of SUS304, and then subjected to diffusion annealing at a temperature of 800 ° C. for 1 minute in an argon atmosphere. And the finish rolling and annealing were performed and the composite material for brazing by Examples 17-19 was produced.

(Examples 20 to 22)
Each of the above implementations was performed except that a pure Ti layer and a 30Cr-3Mo-Ni alloy layer containing 30 mass% Cr, 3 mass% Mo, and 67 mass% Ni were used as the brazing material. In the same manner as in Examples 17 to 19, composite materials for brazing according to Examples 20 to 22 were produced.

(Comparative Examples 3-5)
Except for using a pure Ti layer and a 30Cr—Ni alloy layer containing 30% by mass of Cr and 70% by mass of Ni as the raw material for the brazing material, the same as in Examples 17 to 19, respectively. Composite materials for brazing according to Comparative Examples 3 to 5 were produced.

[Fe diffusion evaluation]
(Common to Examples 17 and 20 and Comparative Example 3)
Next, the diffusion evaluation of Fe in the brazing material layer obtained by reacting the composite materials for brazing according to Examples 17 and 20 and Comparative Example 3 produced as described above was performed. Specifically, the brazing composite materials according to Examples 17 and 20 and Comparative Example 3 were reacted under predetermined conditions (temperature: about 1120 ° C., time: 10 minutes). The results are shown in FIGS.

  The Fe concentration in the brazing filler metal layer of the composite material for brazing according to Comparative Example 3 shown in FIG. 8 was about 10% by mass. On the other hand, the concentration of Fe in the brazing filler metal layer of the brazing composite material according to Example 20 shown in FIG. 9 is about 15% by mass, and the brazing composite material according to Example 17 shown in FIG. The concentration of Fe in the brazing filler metal layer was about 20% by mass.

(Common to Examples 18 and 21 and Comparative Example 4)
Next, Fe diffusion evaluation of the brazing material layer obtained by reacting the composite materials for brazing according to Examples 18 and 21 and Comparative Example 4 produced as described above was performed. Specifically, the brazing composite materials according to Examples 18 and 21 and Comparative Example 4 were reacted under predetermined conditions (temperature: about 1150 ° C., time: 10 minutes). The results are shown in FIGS.

  The Fe concentration in the brazing filler metal layer of the composite material for brazing according to Comparative Example 4 shown in FIG. 11 was about 20% by mass. On the other hand, the Fe concentration in the brazing material layer of the brazing composite material according to Example 21 shown in FIG. 12 is about 40% by mass, and the brazing composite material according to Example 18 shown in FIG. The concentration of Fe in the brazing filler metal layer was about 42% by mass.

(Common to Examples 19 and 22 and Comparative Example 5)
Next, the diffusion evaluation of Fe in the brazing material layer obtained by reacting the composite materials for brazing according to Examples 19 and 22 and Comparative Example 5 produced as described above was performed. Specifically, the brazing composite materials according to Examples 19 and 22 and Comparative Example 4 were reacted under predetermined conditions (temperature: about 1180 ° C., time: 10 minutes). The results are shown in FIGS.

  The Fe concentration in the brazing filler metal layer of the composite material for brazing according to Comparative Example 5 shown in FIG. 14 was about 17% by mass. On the other hand, the concentration of Fe in the brazing material layer of the brazing composite material according to Example 22 shown in FIG. 15 is about 55% by mass, and the brazing composite material according to Example 19 shown in FIG. The concentration of Fe in the brazing filler metal layer was about 60% by mass.

  From the above results, the amount of diffusion of Fe in the brazing material layer obtained by reacting the brazing composite materials according to Examples 17 and 20 and Comparative Example 3 reacted at a temperature of about 1120 ° C., at a temperature of about 1150 ° C. The amount of diffusion of Fe in the brazing material layer obtained by reacting the reacted brazing composites according to Examples 18 and 21 and Comparative Example 4, and Examples 19 and 22 reacted at a temperature of about 1180 ° C. When the amount of Fe diffusion in the brazing filler metal layer obtained by reacting the brazing composite material according to Comparative Example 5 was compared, the amount of Fe diffusion into the brazing filler metal layer was increased as the amount of Mo added to the brazing filler metal was increased. The amount was found to be large.

  The embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments and examples but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first and second embodiments, the example in which the brazing structure of the present invention is applied to a heat exchanger has been described. However, the present invention is not limited to this, and the brazing structure of the present invention is heated with exhaust gas at a high temperature. It can also be applied to brazed structures other than heat exchangers that require high oxidation resistance by flowing.

  Moreover, in the said 2nd Embodiment, although the example which uses stainless steel as a plate which comprises the composite material for brazing was shown, this invention is not restricted to this, Stainless steel is used as a plate which comprises the composite material for brazing. Steels containing Ni-base heat-resistant alloys such as Hastelloy (registered trademark) and Inconel (registered trademark) may be used.

  In the first and second embodiments, an example in which a Ti layer made of only pure Ti is used as a brazing material has been shown. However, the present invention is not limited to this, and pure Ti is used as a brazing material in a proportion of 85% or more. You may use the Ti alloy layer to contain. As such a Ti alloy containing pure Ti as a main component, for example, an α alloy having an α phase (close-packed hexagonal phase) such as Ti-5Al-2.5Sn, or an α phase such as Ti-6Al-4V (most An α + β alloy having a dense hexagonal phase) and a β phase (body-centered cubic phase) may be mentioned.

  Further, in the second embodiment, as shown in FIG. 6, the two-layer brazing material 51 in a state where the Cr—Mo—Ni alloy layer 3 is rolled and joined to the surface of the Ti layer 2 is rolled onto the plate 13. Although the example which braze-joins using the joined composite material for brazing was shown, this invention is not restricted to this, As shown in FIG. 17, the clad | crud which joined Ti layer 20a to one side of the plate 13 by rolling You may make it prepare separately the material and the clad material which rolled-joined the Cr-Mo-Ni alloy layer 30a to the other side of the plate 13. FIG.

It is sectional drawing which showed the structure of the brazing material by 1st Embodiment of this invention. It is sectional drawing which showed partially the heat exchanger formed using the brazing material by 1st Embodiment shown in FIG. It is the expanded sectional view which showed the junction part of the heat exchanger by 1st Embodiment shown in FIG. It is sectional drawing for demonstrating the process of brazing joining at the time of forming the heat exchanger by 1st Embodiment shown in FIG. It is sectional drawing for demonstrating the process of brazing joining at the time of forming the heat exchanger by 1st Embodiment shown in FIG. It is sectional drawing which showed the structure of the composite material for brazing by 2nd Embodiment of this invention. It is sectional drawing for demonstrating the process of the brazing joining using the composite material for brazing by 2nd Embodiment shown in FIG. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is the line profile which showed the density | concentration of Fe of SUS304, a diffusion layer, and a brazing material layer. It is sectional drawing which showed the structure of the composite material for brazing by the modification of 2nd Embodiment of this invention.

Explanation of symbols

1, 51 Brazing material 2, 20a Ti layer (Ti brazing layer)
3, 30a Cr-Mo-Ni alloy layer (Cr-Mo-Ni brazing layer)
3a Cr—Mo—Ni alloy layer (Cr—Mo—Ni brazing layer, first Cr—Mo—Ni brazing layer)
3b Cr—Mo—Ni alloy layer (Cr—Mo—Ni brazing layer, second Cr—Mo—Ni brazing layer)
11, 13 Plate (substrate)
50 Brazing composite 100 Heat exchanger (brazing structure)

Claims (12)

Ti alloy consisting of pure Ti, 85 mass% or more of Ti and Al and Sn, or made of a Ti layer composed of any one of Ti alloy consisting of 85 wt% or more of Ti, Al and V 1 A layer of Ti brazing layer;
One layer composed of a Cr—Mo—Ni alloy layer which is arranged at a position in contact with the brazing object and which is composed of 20 mass% to 40 mass% of Cr, 1 mass% to 10 mass% of Mo, and Ni. or are two-layered or three-layered structure of a two-layer Cr-Mo-Ni brazing layer of Tona,
When the total amount of Ti in the Ti brazing layer and the amount of Ni in the Cr—Mo—Ni brazing layer is 100% by mass, the amount of Ni in the Cr—Mo—Ni brazing layer is 21.6 wt% or more 37.1% by mass or less, or, Ru der 69.0 mass% or more 59.5 wt%, the brazing material.   The brazing filler metal according to claim 1, wherein the content of Mo in the Cr-Mo-Ni brazing layer made of the Cr-Mo-Ni alloy layer is 3 mass% or more and 10 mass% or less. The ratio t1 / t2 between the thickness t1 of the Ti brazing layer and the thickness t2 of the Ti brazing layer and the Cr—Mo—Ni brazing layer is 0.36 or more and 0.46 or less, or 0.68. The brazing material according to claim 1 or 2 , which is 0.82 or less. The brazing object includes a first brazing object and a second brazing object to be brazed to the first brazing object,
The Cr—Mo—Ni brazing layer is disposed at a position in contact with the first brazing object, and includes a first Cr—Mo—Ni brazing layer made of a first Cr—Mo—Ni alloy layer, and the second brazing. A second Cr-Mo-Ni brazing layer that is disposed at a position in contact with the object to be soldered and is made of a second Cr-Mo-Ni alloy layer;
Said first 1Cr-Mo-Ni brazing layer, between the first 2Cr-Mo-Ni brazing layer, a three-layer structure in which the Ti brazing layer is arranged, claim 1-3 The brazing material according to item 1. A substrate formed of steel;
One of pure Ti, a Ti alloy composed of 85% by mass or more of Ti , Al, and Sn, or a Ti alloy composed of 85% by mass or more of Ti, Al, and V, which is roll-bonded to the surface of the substrate. A Ti brazing layer composed of a Ti layer composed of the following: a Ti brazing layer disposed at a position in contact with an object to be brazed; 20 mass% to 40 mass% Cr; and 1 mass% to 10 mass% Mo. And a brazing material having a two- layer structure of a Cr—Mo—Ni brazing layer composed of a Cr—Mo—Ni alloy layer composed of Ni ,
When the total amount of Ti in the Ti brazing layer and the amount of Ni in the Cr—Mo—Ni brazing layer is 100% by mass, the amount of Ni in the Cr—Mo—Ni brazing layer is 21.6 wt% or more 37.1% by mass or less, or, Ru der 69.0 mass% or more 59.5% by mass, brazing composite material. The brazing composite material according to claim 5 , wherein a content of Mo in the Cr—Mo—Ni brazing layer made of the Cr—Mo—Ni alloy layer is 3% by mass or more and 10% by mass or less. The ratio t1 / t2 between the thickness t1 of the Ti brazing layer and the thickness t2 of the Ti brazing layer and the Cr—Mo—Ni brazing layer is 0.36 or more and 0.46 or less, or 0.68. The brazing composite material according to claim 5 or 6 , wherein the composite material is 0.82 or less. From a substrate formed of steel and rolled and bonded to the surface of the substrate, pure Ti, a Ti alloy of 85% by mass or more of Ti , Al and Sn, or 85% by mass or more of Ti, Al and V One Ti brazing layer composed of a Ti layer composed of any one of the Ti alloys to be formed , and 20 wt% to 40 wt% Cr, A brazing material comprising a two- layer structure of a Cr—Mo—Ni brazing layer composed of a Cr—Mo—Ni alloy layer composed of Mo and 10% by mass or less of Mo, and the Ti brazing When the total amount of Ti in the brazing layer and the amount of Ni in the Cr—Mo—Ni brazing layer is 100 mass%, the amount of Ni in the Cr—Mo—Ni brazing layer is 21.6. % By mass or more and 37.1% by mass or less, or 5 A brazing structure formed by brazing and joining using a brazing composite material of 9.5 mass% or more and 69.0 mass% or less . The brazing structure according to claim 8 , comprising at least a brazed joint portion including a Ti—Cr—Mo—Ni alloy. The brazing structure according to claim 9 , wherein the Mo content of the Ti-Cr-Mo-Ni alloy is 1.1 mass% or more. The brazing structure according to claim 9 or 10 , wherein a Cr content of the Ti-Cr-Mo-Ni alloy is 6.6 mass% or more. When the total amount of Ti and Ni in the Ti—Cr—Mo—Ni alloy is 100 mass%, the Ni content in the Ti—Cr—Mo—Ni alloy is 21.6 mass% or more. The brazing structure according to any one of claims 9 to 11 , which is 1% by mass or less, or 59.5% by mass or more and 69.0% by mass or less.

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