WO2020161817A1

WO2020161817A1 - Corrosion resistance diagnostic component, corrosion resistance diagnostic device, heat exchanger, air conditioner, method for manufacturing corrosion resistance diagnostic component and diagnosis method

Info

Publication number: WO2020161817A1
Application number: PCT/JP2019/004197
Authority: WO
Inventors: 栗木　宏徳
Original assignee: 三菱電機株式会社
Priority date: 2019-02-06
Filing date: 2019-02-06
Publication date: 2020-08-13
Also published as: JPWO2020161817A1

Abstract

This corrosion resistance diagnostic component is used for diagnosing the corrosion state of a material subjected to diagnosis, the material comprising an aluminum-containing core and a zinc-containing sacrificial layer formed on the surface of the core. This corrosion resistance diagnostic component comprises a first core that contains aluminum, and a first sacrificial layer formed on the surface of the first core and including zinc having lower corrosion resistance than the first core. The corrosion resistance diagnostic component is configured such that an exposed section where the first core is exposed is formed, at a location adjacent to the first sacrificial layer, by removing a portion starting from the surface of the first sacrificial layer, to the boundary between the first sacrificial layer and the first core, and further advancing into the inside of the first core.

Description

Corrosion resistance diagnostic component, corrosion resistance diagnostic device, heat exchanger, air conditioner, corrosion resistance diagnostic component manufacturing method, and diagnostic method

The present invention relates to a corrosion resistance diagnostic component used for diagnosing a corrosion state of a material to be diagnosed in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum, a corrosion resistance diagnostic device including the corrosion resistance diagnostic component, and the corrosion resistance diagnostic. The present invention relates to a heat exchanger including components, an air conditioner including the corrosion-resistant diagnostic component, a method for manufacturing the corrosion-resistant diagnostic component, and a diagnostic method using the corrosion-resistant diagnostic component.

Conventionally, there are products that use a material in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum. For example, in a heat exchanger of an air conditioner, a heat transfer tube in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum may be used. Hereinafter, the heat transfer tube in which the sacrificial layer containing zinc is formed on the surface of the core material containing aluminum may be simply referred to as an aluminum heat transfer tube. There is a concern that the aluminum heat transfer tube may have local corrosion, a through hole may be formed in the aluminum heat transfer tube, and a refrigerant leak may occur. For this reason, there is a demand for a technique for detecting corrosion leading to refrigerant leakage by grasping the progress of corrosion of the aluminum heat transfer tube.

Therefore, for example, Patent Document 1 discloses a technique for diagnosing the life of a heat exchanger using an aluminum heat transfer tube by using a corrosion resistance life diagnosis component. Specifically, the corrosion resistance life diagnosis component includes a plate-shaped base material having an aluminum layer on the surface. The corrosion-resistant life diagnostic component has a sacrificial anode layer made of a zinc-aluminum alloy formed on a part of the surface of the base material. That is, in the corrosion-resistant life diagnostic component, the base material exposed portion where the base material is exposed is formed on a part of the surface. Then, by observing the exposed part of the base metal of the corrosion resistance life diagnosis part, when local corrosion marks appeared within the specified distance from the place where the sacrificial anode layer was formed at the beginning of manufacturing, the heat generated using the aluminum heat transfer tube was used. It is diagnosed that the exchanger has reached the end of its life.

Japanese Patent No. 6058154

The corrosion resistance life diagnosis component described in Patent Document 1 is a zinc-aluminum alloy on the surface of the base material by spraying zinc on the surface of the base material or by applying a coating containing zinc on the surface of the base material. A sacrificial anode layer is formed. When forming the sacrificial anode layer, zinc diffuses to the base material side. That is, in the corrosion-resistant life diagnosis component described in Patent Document 1, diffused zinc is present in at least a part of the base material exposed portion observed when forming the sacrificial anode layer and performing life diagnosis. Therefore, in the corrosion resistance life diagnosis component described in Patent Document 1, local corrosion is suppressed by the zinc present in the exposed portion of the base metal, and the accuracy of diagnosing the corrosion state of the heat exchanger using the aluminum heat transfer tube decreases. There was a problem that it would end up.

The present invention has been made to solve the above-mentioned problems, and it is possible to more accurately diagnose the corrosion state of a material to be diagnosed in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum than in the past. A first object is to obtain a possible corrosion resistance diagnostic component. The present invention also provides a corrosion resistance diagnostic device including the corrosion resistance diagnostic component, a heat exchanger including the corrosion resistance diagnostic component, an air conditioner including the corrosion resistance diagnostic component, a method of manufacturing the corrosion resistance diagnostic component, and the corrosion resistance. A second object is to provide a diagnostic method using a diagnostic component.

The corrosion-resistant diagnostic component according to the present invention is a corrosion-resistant diagnostic component used for diagnosing a corrosion condition of a material to be diagnosed in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum, and the corrosion-resistant diagnostic component is A first core material containing aluminum and a first sacrificial layer formed on the surface of the first core material and containing zinc having a lower corrosion resistance than the first core material are provided, and the corrosion resistance diagnostic component includes At a position adjacent to the first sacrificial layer, the first sacrificial layer is removed from the surface to the inside of the first core material with respect to the boundary between the first sacrificial layer and the first core material, and the first core material is removed. It has a configuration in which an exposed portion where the core material is exposed is formed.

In addition, the corrosion resistance diagnostic device according to the present invention is a corrosion resistance diagnostic component according to the present invention, a photographing unit for photographing the surface of the exposed portion, and corrosion of the surface of the exposed portion from image data photographed by the photographing unit. And a detection unit that detects the situation.

Further, the heat exchanger according to the present invention includes the corrosion resistance diagnostic component according to the present invention, and a refrigerant pipe in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum, and a refrigerant flows, the corrosion resistance diagnosis The component is formed of the same member as the refrigerant pipe.

Further, an air conditioner according to the present invention is a corrosion resistance diagnostic component according to the present invention, a heat exchanger having a heat transfer tube in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum, and a core containing aluminum. A sacrificial layer containing zinc is formed on the surface of the material, and a refrigerant pipe in which the refrigerant flowing into the heat exchanger or the refrigerant flowing out of the heat exchanger flows is provided, and the corrosion-resistant diagnostic component is the same as the refrigerant pipe. It is formed of a member.

Further, the method for manufacturing a corrosion-resistant diagnostic component according to the present invention comprises a preparation step of preparing a material for a corrosion-resistant diagnostic component in which the first sacrificial layer is formed on the surface of the first core material, and a surface of the first sacrificial layer. From the boundary between the first sacrificial layer and the first core material to the inside of the first core material, and forming the exposed portion at a position adjacent to the first sacrificial layer. I have it.

Further, the diagnostic method according to the present invention is a diagnostic method for diagnosing a corrosion state of a material to be diagnosed in which a sacrificial layer containing zinc is formed on a surface of a core material containing aluminum using the corrosion resistance diagnostic component according to the present invention. Then, on the surface of the exposed portion, a range within a specified distance from the first sacrificial layer is defined as a first range, and when a local corrosion mark appears in the first range, the material to be diagnosed is used. Diagnose the product is at end of life.

In the corrosion resistance diagnostic component according to the present invention, the exposed portion is removed from the surface of the first sacrificial layer to the inside of the first core material with respect to the boundary between the first sacrificial layer and the first core material. The core material is exposed. That is, in the exposed portion of the corrosion-resistant diagnostic component according to the present invention, the boundary portion between the first sacrificial layer and the first core member is completely removed. In other words, in the exposed portion of the corrosion-resistant diagnostic component according to the present invention, zinc diffused in the first core material during the formation of the first sacrificial layer is completely removed. Therefore, in the corrosion-resistant diagnostic component according to the present invention, the corrosion status of the material to be diagnosed can be diagnosed more accurately than before based on the corrosion status of the surface of the exposed portion.

It is a refrigerant circuit diagram showing a schematic structure of an air conditioner concerning Embodiment 1 of the present invention. It is a functional block diagram of the corrosion-resistant diagnostic device which concerns on Embodiment 1 of this invention. It is a top view which shows the outline of the corrosion-resistant diagnostic component which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the outline of the corrosion-resistant diagnostic component which concerns on Embodiment 1 of this invention. It is a model figure for demonstrating the reaction which arises at the time of corrosion progress of the corrosion-resistant diagnostic component concerning Embodiment 1 of this invention. It is a figure which shows the changing process of the exposed part of the corrosion-resistant diagnostic component which concerns on Embodiment 1 of this invention. FIG. 4 is a vertical cross-sectional view of the corrosion resistance diagnostic component according to the first embodiment, showing a state in which general corrosion has occurred in the first sacrificial layer of the corrosion resistance diagnostic component. It is a figure which shows the changing process of the surface of the 1st sacrificial layer of the corrosion resistance diagnostic component which concerns on Embodiment 1 of this invention. 3 is a flowchart showing a manufacturing process of the corrosion resistance diagnostic component according to the first embodiment of the present invention. It is a figure which shows the formation process of the exposed part of the corrosion-resistant diagnostic component which concerns on Embodiment 1 of this invention. 3 is a flowchart showing a combined cycle test performed in the first embodiment of the present invention. It is a side view which shows a part of core part of the outdoor heat exchanger which concerns on Embodiment 4 of this invention.

An example of the present invention will be described in each of the following embodiments with reference to the drawings. In addition, the form of each configuration described in the following embodiments is merely an example. The present invention is not limited to the configurations described in the following embodiments. Further, in each of the following drawings, the relationship of the size of each component may be different from the actual product in which the present invention is implemented.

Embodiment 1.
[About the structure of the corrosion resistance diagnostic component, the structure of the corrosion resistance diagnostic device, and the purpose of providing these]
In the air conditioner 200 according to the first embodiment, a heat transfer tube made of a material containing aluminum is used as the heat transfer tube of the outdoor heat exchanger 100. This heat transfer tube has a structure in which a sacrificial layer containing zinc is formed on the surface and corrosion of the heat transfer tube is suppressed. That is, the heat transfer tube of the outdoor heat exchanger 100 has a structure in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum. In the following, the sacrificial layer containing zinc may be referred to as a zinc sacrificial layer. Further, hereinafter, a member having a zinc sacrificial layer formed on the surface of a core material containing aluminum may be referred to as an aluminum material with a zinc sacrificial layer. Moreover, below, the heat transfer tube using the core material containing aluminum may be called an aluminum heat transfer tube. Here, in the first embodiment, the core material of the aluminum heat transfer tube of the outdoor heat exchanger 100 is an aluminum alloy containing no zinc. The aluminum alloy is, for example, an aluminum-manganese alloy. The zinc sacrificial layer of the heat transfer tube of the outdoor heat exchanger 100 is an aluminum-zinc alloy layer.

The zinc sacrificial layer is lower in potential than the aluminum alloy as the core material. Therefore, in the heat transfer tube of the outdoor heat exchanger 100, the sacrificial layer is preferentially corroded, and the corrosion of the aluminum alloy of the core material can be suppressed. As described later, the corrosion mode of the zinc sacrificial layer is a general corrosion in which the surface layer is uniformly corroded from the surface side to the inside side. Moreover, the corrosion form of the core material which is an aluminum alloy becomes a local corrosion. Therefore, by forming a sacrificial layer containing zinc on the surface of the aluminum heat transfer tube of the outdoor heat exchanger 100, the corrosion resistance of the aluminum heat transfer tube of the outdoor heat exchanger 100 can be improved.

In an aluminum heat transfer tube in which the surface of the core material is covered with the zinc sacrificial layer, the zinc sacrificial layer may peel off at a part of the surface of the core material. Further, in the aluminum heat transfer tube in which the surface of the core material is covered with the zinc sacrificial layer, the aluminum alloy as the core material may be exposed on a part of the surface from the beginning of manufacturing. As described above, the exposed portion of the aluminum alloy as the core material on the surface of the aluminum heat transfer tube is also protected by the preferential corrosion of the zinc sacrificial layer. That is, the corrosion resistance of the aluminum heat transfer tube whose surface of the core material is covered with the zinc sacrificial layer greatly affects the product life of the outdoor heat exchanger 100 and the outdoor unit equipped with the outdoor heat exchanger 100. The corrosion resistance diagnostic component and the corrosion resistance diagnostic device according to the first embodiment are used for the purpose of diagnosing the corrosion state of the aluminum heat transfer tube in which the surface of the core material is covered with the zinc sacrificial layer. In other words, the corrosion-resistant diagnostic component and the corrosion-resistant diagnostic device according to the first embodiment include the outdoor heat exchanger 100 and the outdoor heat exchanger 100 that use the aluminum heat transfer tube whose surface of the core material is covered with the zinc sacrificial layer. It is used for the purpose of grasping the life of the installed outdoor unit. That is, in the first embodiment, the aluminum heat transfer tube whose surface is covered with the zinc sacrificial layer is the material to be diagnosed.

1 is a refrigerant circuit diagram showing a schematic configuration of an air conditioner according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioner 200 includes a compressor 201, a muffler 202, a four-way valve 203, an outdoor heat exchanger 100, a capillary tube 205, a strainer 206, an electronically controlled expansion valve 207, The refrigerant circuit is configured by connecting the stop valve 208a, the indoor heat exchanger 209, the stop valve 208b, and the auxiliary muffler 210 with the refrigerant pipe 204.

The indoor unit having the indoor heat exchanger 209 of the air conditioner 200 controls the actuators such as the compressor 201 and the electronically controlled expansion valve 207 based on the temperatures of the outside air, the indoor air, the refrigerant, and the like. A device 211 is provided. The four-way valve 203 is a valve that switches a refrigeration cycle for cooling and heating, and is controlled by the control device 211. As will be described later, the control device 211 also functions as a control device for the corrosion resistance diagnostic device 300. Of course, the control device of the air conditioner 200 and the control device of the corrosion resistance diagnostic device 300 may be separately configured.

The control device 211 is composed of dedicated hardware or a CPU (Central Processing Unit) that executes a program stored in a memory. Note that the CPU is also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a processor.

When the control device 211 is dedicated hardware, the control device 211 may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Applicable Each of the functional units realized by the control device 211 may be realized by individual hardware, or each functional unit may be realized by one piece of hardware.

When the control device 211 is a CPU, each function executed by the control device 211 is realized by software, firmware, or a combination of software and firmware. Software and firmware are described as programs and stored in memory. The CPU realizes each function of the control device 211 by reading and executing the program stored in the memory. Here, the memory is, for example, a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM.

A part of the functions of the control device 211 may be realized by dedicated hardware and a part thereof may be realized by software or firmware.

Next, an operation example of the air conditioner 200 during a cooling operation will be described with reference to FIG. When the four-way valve 203 is switched to the flow path during the cooling operation by the control device 211, the refrigerant is compressed by the compressor 201 to become a high-temperature and high-pressure gas refrigerant, and is transferred to the outdoor heat exchanger 100 via the four-way valve 203. Inflow. The high-temperature high-pressure gas refrigerant that has flowed into the outdoor heat exchanger 100 exchanges heat with the outdoor air passing through the outdoor heat exchanger 100, and flows out as a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flowing out of the outdoor heat exchanger 100 is decompressed by the capillary 205 and the electronically controlled expansion valve 207, becomes a low-pressure gas-liquid two-phase refrigerant, and flows into the indoor heat exchanger 209. The gas-liquid two-phase refrigerant flowing into the indoor heat exchanger 209 exchanges heat with the indoor air passing through the indoor heat exchanger 209, cools the indoor air, becomes a low-temperature low-pressure gas refrigerant, and is sucked into the compressor 201. To be done.

Next, an operation example of the air conditioner 200 during heating operation will be described with reference to FIG. When the four-way valve 203 is switched to the flow path of the heating operation by the control device 211, the refrigerant is compressed by the compressor 201 into a high-temperature and high-pressure gas refrigerant in the same manner as described above, and the indoor heat is transferred via the four-way valve 203. It flows into the exchanger 209. The high-temperature and high-pressure gas refrigerant flowing into the indoor heat exchanger 209 exchanges heat with the indoor air passing through the indoor heat exchanger 209 to warm the indoor air and become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flowing out from the indoor heat exchanger 209 is decompressed by the electronically controlled expansion valve 207 and the capillary tube 205, becomes a low-pressure gas-liquid two-phase refrigerant, and flows into the outdoor heat exchanger 100. The low-pressure gas-liquid two-phase refrigerant that has flowed into the outdoor heat exchanger 100 exchanges heat with the outdoor air that passes through the outdoor heat exchanger 100, becomes a low-temperature low-pressure gas refrigerant, and is sucked into the compressor 201.

FIG. 2 is a functional block diagram of the corrosion resistance diagnostic device according to the first embodiment of the present invention.
The corrosion resistance diagnostic device 300 includes a photographing unit 312, a detection unit 313, a storage unit 314, a comparison unit 315, a notification unit 316, a control device 211, and a corrosion resistance diagnosis component 1 described below. The imaging unit 312 is an imaging device such as a digital camera or a television camera, for example. Based on a control signal from the control device 211, the image capturing unit 312 captures an image of the surface of the corrosion resistance diagnostic component 1 described later. More specifically, the image capturing unit 312 captures at least the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 described below. The image data of the surface of the corrosion resistance diagnostic component 1 photographed by the photographing unit 312 is input to the detection unit 313. The detection unit 313 obtains a digital image signal by A/D (Analog/Digital) conversion of the image data output from the imaging unit 312 based on the control signal from the control device 211, and the corrosion resistance diagnostic component 1 The image data of the surface of is analyzed. That is, the detection unit 313 detects the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 from the image data captured by the imaging unit 312.

The image data analyzed by the detection unit 313 is output to the comparison unit 315 and the storage unit 314. The storage unit 314 is, for example, a memory, and stores a parameter indicating the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1. In the first embodiment, the storage unit 314 stores the image data output from the detection unit 313 as a parameter indicating the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1. The comparison unit 315 compares the detection result of the detection unit 313 with the parameter stored in the storage unit 314. In the case of the first embodiment, the comparison unit 315 compares the image data sent from the detection unit 313 with the image data stored in the storage unit 314. The notification unit 316 notifies the comparison result of the comparison unit 315. In the first embodiment, the operation panel or operation panel (not shown) of the air conditioner 200 is used as the notification unit 316. That is, in the first embodiment, the notification unit 316 notifies the comparison result of the comparison unit 315 by displaying the comparison result of the comparison unit 315.

Like the control device 211, the detection unit 313 and the comparison unit 315 are configured by dedicated hardware or a CPU that executes a program stored in a memory, for example. The detection unit 313 and the comparison unit 315 may be a part of the functional unit of the control device 211 or may be configured separately from the control device 211. Further, for example, the detection unit 313 can also be configured as hardware combined with the image capturing unit 312. The hardware in which the imaging unit 312 and the detection unit 313 are combined is, for example, a line scan camera, a three-dimensional image processing system, an image discrimination sensor, or the like.

The corrosion resistance diagnostic device 300 configured as described above is mounted on the air conditioner 200 described above. The corrosion resistance diagnostic device 300 may be sold together with the air conditioner 200, or may be sold together with the outdoor heat exchanger 100. That is, the corrosion resistance diagnostic device 300 may be treated as a configuration of the air conditioner 200 or may be treated as a configuration of the outdoor heat exchanger 100.

[Aluminum material with zinc sacrificial layer used for aluminum heat transfer tubes]
When manufacturing an aluminum material with a zinc sacrificial layer used for an aluminum heat transfer tube, first, a core material using a material containing aluminum is prepared. Then, by forming a zinc sacrificial layer having lower corrosion resistance than the core material on the surface of the core material, an aluminum material with a zinc sacrificial layer used for an aluminum heat transfer tube is manufactured. Specifically, for example, an aluminum alloy such as an aluminum-manganese alloy is used as a core material, a sacrificial layer of an aluminum-zinc alloy is formed on the surface of the core material, and an aluminum material with a zinc sacrificial layer used for an aluminum heat transfer tube. Is manufactured.

An aluminum clad material or a zinc sprayed aluminum material is used as the aluminum material with a zinc sacrificial layer. The aluminum clad material is manufactured by rolling and heat treating a material containing aluminum as a core material and an aluminum-zinc alloy material as a zinc sacrificial layer, and joining the both. The zinc-sprayed aluminum material is manufactured by spraying metallic zinc on the surface of a core material containing aluminum and diffusing the zinc into the core material by heat treatment.

When using a circular tube as the heat transfer tube of the heat exchanger, both aluminum clad material and zinc sprayed aluminum material can be used.

On the other hand, flat tubes may be used as the heat transfer tubes of the heat exchanger. The flat tube has a flat cross section, and has a pair of flat portions facing a part of the external shape. Further, the flat tube has a plurality of refrigerant flow paths formed therein. The flat tube thus configured is used as, for example, a fin tube type heat exchanger in which fin materials are combined. By using a flat tube as the heat transfer tube of the heat exchanger, there is an advantage that the internal area of the tube in contact with the refrigerant can be increased and the ventilation resistance can be reduced, as compared with the heat exchanger using a circular tube. .. Since the flat tube has a complicated shape and it is difficult to use an aluminum clad material, a zinc sprayed aluminum material is used.

When constructing a heat transfer tube with a zinc sprayed aluminum material, nozzles for spraying zinc are installed on both sides of a tubular member containing aluminum as a core material, and molten zinc is sprayed onto the surface of the tubular member from these nozzles. .. Therefore, on the surface of the tubular member, an unsprayed portion of zinc may be formed around the portion that is oriented in the direction perpendicular to the facing direction of the nozzle. That is, in the heat transfer tube made of zinc sprayed aluminum material, the core material may be exposed on a part of the surface. However, for the portion where the core material is exposed on the surface, the zinc sacrificial layer around the portion exhibits the anticorrosion function. Since the anticorrosion performance of the zinc sacrificial layer with respect to the core material is determined by the sprayed zinc basis weight and the degree of zinc diffusion by heat treatment, the zinc sacrificial layer is designed according to the product life.

The corrosion resistance diagnostic component 1 included in the corrosion resistance diagnostic device 300 according to the first embodiment is particularly effective in diagnosing the presence or absence of the anticorrosion function of the zinc sacrificial layer for the portion where the core material is exposed on the surface. Therefore, in the first embodiment, the case where a zinc sprayed aluminum material is used as the aluminum heat transfer tube of the outdoor heat exchanger 100 will be described below as an example.

[Outline of corrosion resistance diagnostic parts]
FIG. 3 is a plan view showing an outline of the corrosion resistance diagnostic component according to the first embodiment of the present invention. FIG. 4 is a vertical cross-sectional view showing an outline of the corrosion resistance diagnostic component according to the first embodiment of the present invention.
Here, in the following, in order to distinguish the core material of the corrosion resistance diagnostic component 1 from the core material of the material to be diagnosed, the core material of the corrosion resistance diagnostic component 1 is referred to as a first core material 3. Further, hereinafter, in order to distinguish the zinc sacrificial layer of the corrosion resistance diagnostic component 1 from the zinc sacrificial layer of the material to be diagnosed, the zinc sacrificial layer of the corrosion resistant diagnostic component 1 is referred to as a first sacrificial layer 2. 3 and 4, the concentration of zinc in the first sacrificial layer 2 is shown by hatching. Therefore, in the cross-sectional view of FIG. 4, hatching of the cross-section portion is omitted. The denser the hatching, the higher the zinc concentration. The two-dot chain line shown in FIG. 4 indicates the boundary between the first sacrificial layer 2 and the first core material 3.

The corrosion resistance diagnostic component 1 is used to diagnose the corrosion state of the material to be diagnosed. In the first embodiment, as a material of the corrosion resistance diagnostic component 1, an aluminum material with a zinc sacrificial layer used for an aluminum heat transfer tube of the outdoor heat exchanger 100, which is a material to be diagnosed, is used. This aluminum material with a zinc sacrificial layer is a zinc sprayed aluminum material. This zinc-sprayed aluminum material heat-treats metallic zinc that has been uniformly sprayed onto the surface of a core material containing aluminum, and diffuses zinc into the core material. By this diffusion of zinc, a zinc sacrificial layer which is an aluminum-zinc alloy is formed on the surface of the core material. During heat treatment, zinc diffuses from the surface layer of the core material toward the inside. Therefore, the zinc sacrificial layer is an aluminum-zinc alloy layer having a predetermined thickness with a highest concentration of zinc in the outermost layer and a concentration gradient in which the concentration decreases as it goes in the direction of the core material.

When using the zinc sprayed aluminum material manufactured in this way as the material of the corrosion resistance diagnostic component 1, the core material portion where the zinc has not diffused by the heat treatment becomes the first core material 3. Further, the portion where zinc is diffused becomes the first sacrificial layer 2. That is, the corrosion resistance diagnostic component 1 includes a first core material 3 containing aluminum and a first sacrificial layer 2 formed on the surface of the first core material 3 and containing zinc having a lower corrosion resistance than the first core material 3. It will be equipped.

Further, in the corrosion resistance diagnostic component 1, a part of the surface is removed by cutting in the depth direction, and an exposed portion 3a is formed at a position adjacent to the first sacrificial layer 2. The exposed portion 3a is removed, for example, by cutting from the surface of the first sacrificial layer 2 to the inside of the first core material 3 with respect to the boundary between the first sacrificial layer 2 and the first core material 3, and the first core material 3 is removed. Is exposed. By forming the exposed portion 3a in this manner, zinc is completely removed from the surface of the exposed portion 3a. That is, in the portion where the first sacrificial layer 2 is formed in the corrosion resistance diagnostic component 1, a state in which the first sacrificial layer 2 in which zinc is diffused and the first core material 3 in which zinc is not diffused are laminated. Has become. The exposed portion 3a of the corrosion resistance diagnostic component 1 is in a state where the first sacrificial layer 2 is not laminated on the first core material 3.

The corrosion resistance diagnostic component 1 is provided in an outdoor unit having the outdoor heat exchanger 100 together with the outdoor heat exchanger 100. For example, the corrosion resistance diagnostic component 1 is attached to the outdoor heat exchanger 100.

The corrosion resistance diagnostic component 1 may be sold together with the air conditioner 200 or may be sold together with the outdoor heat exchanger 100. That is, the corrosion resistance diagnostic component 1 may be treated as a configuration of the air conditioner 200 or as a configuration of the outdoor heat exchanger 100.

[Progress of corrosion in corrosion resistance diagnostic parts]
FIG. 5 is a model diagram for explaining a reaction that occurs when corrosion progresses in the corrosion resistance diagnostic component according to the first embodiment of the present invention.
As described above, the corrosion resistance diagnostic component 1 according to the first embodiment uses the aluminum material with the zinc sacrificial layer used for the aluminum heat transfer tube of the outdoor heat exchanger 100. Therefore, FIG. 5 can also be regarded as a model diagram for explaining the reaction that occurs when corrosion of the aluminum heat transfer tube of the outdoor heat exchanger 100 progresses.

The corrosion resistance diagnostic component 1 can be regarded as a structure in which two metals having different electric potentials are electrically connected. Specifically, it can be considered that the first core material 3 which is an aluminum alloy such as an aluminum-manganese alloy and the first sacrificial layer 2 which is an aluminum-zinc alloy are electrically connected. Therefore, when the liquid junction 4 extending over the first core material 3 and the first sacrificial layer 2 is formed, the first sacrificial layer 2 that is an aluminum-zinc alloy is the first core material 3 that is an aluminum alloy. Since it has a lower potential than that, it functions as an anode in which the oxidation reaction proceeds. In addition, when the liquid junction 4 extending over the first core material 3 and the first sacrificial layer 2 is formed, the first core material 3 which is an aluminum alloy is more than the first sacrificial layer 2 which is an aluminum-zinc alloy. Since it also has a high potential, it functions as a cathode in which the reduction reaction proceeds.

Specifically, the oxidation reaction of the aluminum-zinc alloy represented by the formulas (1) and (2) proceeds on the anode side.
^{^{Al → Al 3+ + 3e - ···}} (1)
^{^{Zn → Zn 2+ + 2e - ···}} (2)

On the other hand, on the cathode side, the oxygen reduction reaction represented by the formulas (3) and (4) proceeds.
_{_{O 2 + 2H 2 O + 4e}} - → 4OH - ··· (3)
2H ⁺ +2e ⁻ →H ₂ (4)

As shown in FIG. 5, the oxidation reaction shown in Formula (1) and Formula (2) and the reduction reaction shown in Formula (3) and Formula (4) proceed with electron transfer. These oxidation reaction and reduction reaction proceed even if the surface of the first core material 3 which is an aluminum alloy is not covered with the first sacrificial layer 2 as long as the movement of electrons can reach the surface. On the other hand, in the region where the movement of electrons does not reach, the reduction reaction of oxygen does not proceed, and the corrosion reaction of the single first core material 3 proceeds. The range where the movement of the electrons reaches is referred to as "corrosion prevention range of the zinc sacrificial layer with respect to the core material" or simply "corrosion prevention range". This anticorrosion range has a great influence on the diagnosis of the product life of the corrosion resistance diagnostic component 1. The correlation between the product life and the corrosion protection range will be described later.

The first sacrificial layer 2, which is an aluminum-zinc alloy, and the first core material 3, which is an aluminum alloy, have features in their respective corrosion forms. Corrosion of the first sacrificial layer 2 that is a zinc sacrificial layer suppresses corrosion of the first core material 3 that is within the corrosion protection range. On the other hand, the corrosion of the first core material 3 outside the anticorrosion range proceeds.

Corrosion that occurs in the first sacrificial layer 2, which is a zinc sacrificial layer, is caused by the addition of zinc to aluminum, which weakens the corrosion resistance of the passivation film, which is the feature of aluminum alloys, and thus the corrosion resistance of the overall surface. Take a form. This general corrosion proceeds at a rate corresponding to the zinc concentration. For this reason, in the first sacrificial layer 2 in which the zinc concentration decreases uniformly from the surface to the inside, general corrosion progresses uniformly from the surface in the depth direction at a predetermined rate. How much the general corrosion progresses in the depth direction in a predetermined time can be grasped by observing the cross section of the first sacrificial layer 2 in the predetermined time.

On the other hand, in the first core material 3, in the anticorrosion range, the corrosion is performed as described above and the corrosion does not proceed, but the corrosion progresses outside the anticorrosion range. In the first core material 3, which is an aluminum alloy, so-called "local corrosion" in which the film is locally destroyed due to the influence of the surface passive film, which is a feature of the aluminum alloy, progresses. The appearance of this local corrosion can be grasped as a local corrosion mark by observing the surface.

[Product life of heat exchanger and outdoor unit using aluminum material with zinc sacrificial layer as heat transfer tube]
Also in the aluminum material with a zinc sacrificial layer that constitutes the aluminum heat transfer tube of the outdoor heat exchanger 100, a place outside the corrosion protection range on the surface of the core material containing aluminum is outside the corrosion protection range of the first core material 3 described above. Similar to the localized corrosion that occurs, localized corrosion occurs. When the passivation film is destroyed due to adhesion of a corrosion factor or the like and local corrosion occurs in the core material, the local corrosion arbitrarily progresses inside the core material. In particular, since the passivation film is composed of aluminum oxide, it has a higher potential than the core material containing aluminum. Therefore, a local battery is formed by the passivation film and the core material, and corrosion to the core material side having a low potential is promoted. Further, oxygen is present on the surface of the passivation film, and oxygen is deficient inside the core material. Therefore, a so-called oxygen concentration battery is formed between the passivation film and the inside of the core material, and corrosion to the core material side is also promoted. Therefore, in the aluminum heat transfer tube, when local corrosion occurs, the progress of the corrosion cannot be controlled, and the formation of the through hole leads to refrigerant leakage, resulting in failure of the outdoor heat exchanger 100. Therefore, setting the occurrence of local corrosion as the product life point is considered to be a safe design for ensuring the reliability of the outdoor heat exchanger 100 and the outdoor unit.

Therefore, in the corrosion resistance diagnostic component 1 according to the first embodiment, the “time point when local corrosion appears in the region within the corrosion protection range of the first sacrificial layer 2 with respect to the first core material 3” is defined as the outdoor heat exchanger 100 and It is the life point of the outdoor unit. Specifically, when the aluminum heat transfer tube of the outdoor heat exchanger 100 is a flat tube of zinc-sprayed aluminum material, zinc is sprayed on the pair of flat portions that form a part of the external shape. Therefore, in the flat tube of the zinc sprayed aluminum material, the exposed portion of the core material is formed on the side surface portion connecting the pair of flat surface portions from the beginning of manufacturing. That is, this side surface portion is the most unfavorable portion for corrosion resistance, and it is considered that when the zinc sacrificial layer gradually disappears with the lapse of time, local corrosion first appears in the exposed portion of the core material on the side surface portion. Therefore, the time when the local corrosion appears on the side surface is the life point of the outdoor heat exchanger 100.

[Achieving product life due to reduced corrosion protection range and detection by corrosion resistance diagnostic parts]
An outdoor heat exchanger 100 in which an aluminum material with a zinc sacrificial layer is applied to a heat transfer tube, and an outdoor unit having the outdoor heat exchanger 100, the operating time after the air conditioner 200 is installed increases, in other words, the outdoor heat exchanger. With the lapse of time since the installation of 100 and the outdoor unit, product deterioration due to the progress of corrosion progresses. The outdoor heat exchanger 100 in which the aluminum material with the zinc sacrificial layer is applied to the heat transfer tube and the outdoor unit including the outdoor heat exchanger 100 finally reach the product life. When corrosion progresses in the aluminum material with the zinc sacrificial layer, the aluminum-zinc alloy disappears from the surface layer of the zinc sacrificial layer due to corrosion, and the zinc concentration of the zinc sacrificial layer gradually decreases. Since the zinc sacrificial layer having a reduced zinc concentration has a higher potential, the potential difference from the core material becomes smaller. That is, the movement of electrons between the anode and the cathode is attenuated, and the corrosion protection range of the zinc sacrificial layer in the core material is reduced.

When a predetermined period has passed since the outdoor heat exchanger 100 and the outdoor unit were installed and the zinc sacrificial layer disappears due to corrosion, the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material. Some of them are outside the corrosion protection range of the zinc sacrificial layer. Then, at the location where the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material, local corrosion occurs in the area outside the corrosion protection range of the zinc sacrificial layer, and the life of the outdoor heat exchanger 100 and the outdoor unit. Becomes Therefore, the anticorrosion range of the zinc sacrificial layer in the initially manufactured flat tube of zinc sprayed aluminum material is larger than the range in which the core material is exposed on the surface of the initially manufactured flat tube of zinc sprayed aluminum material. Needs to be set so that

FIG. 6 is a diagram showing a changing process of the exposed portion of the corrosion resistance diagnostic component according to the first embodiment of the present invention. FIG. 6 is a plan view of the corrosion resistance diagnostic component 1. Further, in FIG. 6, the concentration of zinc in the first sacrificial layer 2, which is a zinc sacrificial layer, is indicated by hatching, and the denser the hatching, the higher the zinc concentration. Further, the black dots shown in FIG. 6 are local corrosion marks 5. Further, FIG. 6A shows the corrosion resistance diagnostic component 1 in a state before the operation of the outdoor unit having the outdoor heat exchanger 100 to which the corrosion resistance diagnostic component 1 is attached is started. In other words, FIG. 6A shows the corrosion resistance diagnostic component 1 in a state before the outdoor unit is installed. In other words, FIG. 6(a) shows the corrosion resistance diagnostic component 1 at the beginning of manufacture. FIG. 6B shows the corrosion resistance diagnostic component 1 after a predetermined time has elapsed since the outdoor unit was installed. FIG. 6C shows the corrosion resistance diagnostic component 1 after a predetermined time has elapsed from the state of FIG. 6B. FIG. 6(d) shows the corrosion resistance diagnostic component 1 after a predetermined time has elapsed from the state of FIG. 6(c). The corrosion resistance diagnostic component 1 indicates that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives. It is a figure of the state shown.

As shown in FIG. 6, a first range 6a is arranged on the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 at a position adjacent to the first sacrificial layer 2 which is a zinc sacrificial layer. Specifically, on the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1, the range within the specified distance L from the first sacrificial layer 2 is the first range 6a. Further, on the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1, a second range 6b is arranged at a position opposite to the first sacrificial layer 2 with respect to the first range 6a. The prescribed distance L of the first range 6a is the most distant part from the zinc sacrificial layer within the range where the core material is exposed on the surface of the flat tube of the initially manufactured zinc sprayed aluminum material, and the zinc sacrificial layer. It is the same as the distance between. In other words, the specified distance L of the first range 6a is the position farthest from the zinc sacrificial layer within the range where the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material before the outdoor unit is installed. And the distance between the zinc sacrificial layer and.

When the operation of the outdoor unit is started, in other words, when the operation of the air conditioner 200 is started, the local corrosion mark 5 appears in the second range 6b before the first range 6a. After that, the local corrosion mark 5 is generated in the first range 6a. When the local corrosion mark 5 appears in the first range 6a, the outdoor heat exchanger 100 using the flat tube of the zinc sprayed aluminum material as the material to be diagnosed, in other words, the outdoor heat exchanger 100 having the outdoor heat exchanger 100 is used. Can be diagnosed as lifespan. In addition, by estimating the safety factor, the specified distance L of the first range 6a from the zinc sacrificial layer within the range in which the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material before the outdoor unit is installed. It may be longer than the distance between the most distant part and the zinc sacrificial layer.

Specifically, the corrosion resistance diagnostic component 1 shown in FIG. 6A is in a state before the outdoor unit starts to operate, and in any of the first range 6a and the second range 6b of the exposed portion 3a, No corrosion mark 5 appears. When the outdoor unit is installed and the operation is started, the corrosion of the first sacrificial layer 2, which is the zinc sacrificial layer, proceeds. Then, the anticorrosion range of the first sacrificial layer 2 gradually decreases. Therefore, when the operation of the outdoor unit is started and a predetermined time elapses, as shown in FIG. 6( b ), the surface of the exposed portion 3 a of the corrosion-resistant diagnostic component 1 is outside the anticorrosion range of the first sacrificial layer 2. The local corrosion mark 5 appears in the second range 6b. Further, when time further elapses from the state of FIG. 6(b) and the corrosion of the first sacrificial layer 2 further progresses, as shown in FIG. 6(c), the first surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 is exposed. The local corrosion marks 5 increase in the second range 6b, and the local corrosion marks 5 also appear at a position closer to the first range 6a than in FIG. 6B.

When the time further elapses from the state of FIG. 6C and the corrosion of the first sacrificial layer 2 further progresses, as shown in FIG. 6D, the surface of the exposed portion 3a of the corrosion-resistant diagnostic component 1 may have a The local corrosion marks 5 appear not only in the second range 6b but also in the first range 6a. It is considered that even in the flat tube made of the zinc sprayed aluminum material of the outdoor heat exchanger 100, which is the material to be diagnosed, local corrosion appeared at the portion where the core material was exposed on the surface. Then, after that, the localized corrosion rapidly progresses into the core material, and a through hole is formed in the flat tube of the zinc sprayed aluminum material. As described above, the method of detecting the appearance of the local corrosion traces 5 in the first range 6a includes the outdoor heat exchanger 100 and the outdoor heat exchanger 100 using the flat tube of the zinc sprayed aluminum material as the material to be diagnosed. This is a method for diagnosing the life of an outdoor unit that the user has.

Note that this life diagnosis method can be performed by a person or the corrosion resistance diagnostic device 300 described above. A detailed example of the life diagnosis method will be described later in the fifth embodiment.

[Diagnosis of remaining product life with corrosion resistance diagnostic parts]
As the corrosion of the first sacrificial layer 2 which is a zinc sacrificial layer progresses, the corrosion prevention range of the first sacrificial layer 2 with respect to the first core material 3 decreases. Along with this, local corrosion that has occurred outside the first range 6a of the exposed portion 3a also occurs within the first range 6a over time. As described above, when the corrosion resistance diagnostic component 1 is in such a state, it is determined that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives. That is, the state where local corrosion occurs in the first area 6a of the exposed portion 3a of the corrosion resistance diagnostic component 1 is the point at which the product life is reached. By utilizing the corrosion progressing process of the corrosion resistance diagnostic component 1, it becomes possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit. Specifically, by grasping the correlation between the appearance of the local corrosion mark 5 on the exposed portion 3a of the corrosion resistance diagnostic component 1 up to the reaching point of the product life and the progress of corrosion of the first sacrificial layer 2, By observing the corrosion resistance diagnostic component 1, it is possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit. Hereinafter, the diagnosis of the remaining life of the outdoor heat exchanger 100 and the outdoor unit using the corrosion resistance diagnostic component 1 will be described.

Of the progress of the corrosion of the corrosion resistance diagnostic component 1, the progress of the first core material 3 is as described in [Achieving the product life due to the reduction of the corrosion prevention range and detection by the corrosion resistance diagnostic component]. The surface of the exposed portion 3a of 3 may be observed. Although the first sacrificial layer 2 undergoes general corrosion in the depth direction from the surface, corrosion products may remain on the surface or fall off, which makes it difficult to measure the corrosion depth of the first sacrificial layer 2. Many. Therefore, in the first embodiment, the corrosion depth of the first sacrificial layer 2 is measured as follows.

FIG. 7 is a vertical cross-sectional view of the corrosion resistance diagnostic component according to the first embodiment, showing a state in which general corrosion occurs in the first sacrificial layer of the corrosion resistance diagnostic component. Note that, in FIG. 7, the shape of the corrosion resistance diagnostic component 1 in a state before the general corrosion occurs in the first sacrificial layer 2 is also indicated by a chain double-dashed line.

When measuring the corrosion depth of the first sacrificial layer 2, the surface of the exposed portion 3a is used as the height standard. In other words, the height of the surface of the exposed portion 3a is set to 0. When the height reference is defined in this way, the height from the surface of the exposed portion 3a to the surface of the first sacrificial layer 2 is d1 at the beginning of manufacture. When the corrosion resistance diagnostic component 1 is manufactured as described above, this d1 is the cutting depth when the exposed portion 3a is formed.

Also, when measuring the corrosion depth of the first sacrificial layer 2, a reference point 7a and a reference line 7 are defined as shown in FIG. The reference point 7a is defined on the surface of the exposed portion 3a. That is, the height from the surface of the exposed portion 3a to the reference point 7a is 0. The reference point 7a is defined as a position within the corrosion prevention range of the first sacrificial layer 2 until the end point of the product life is reached so that the corrosion resistance diagnostic component 1 does not corrode until the end point of the product life. Therefore, it is preferable to set the reference point 7a at a position as close as possible to the boundary 2a between the first sacrificial layer 2 and the exposed portion 3a. By defining the reference point 7a at such a position, the height of the reference point 7a does not change until the corrosion resistance diagnostic component 1 reaches the end point of the product life, and the corrosion depth of the first sacrificial layer 2 is reduced. Can be measured accurately. The reference line 7 is an imaginary straight line extending parallel to the surface of the first first sacrificial layer 2 manufactured from the reference point 7a. That is, the height from the surface of the exposed portion 3a to the reference line 7 is also 0, like the reference point 7a.

The corroded portion 8 shown in FIG. 7 is the portion of the first sacrificial layer 2 that disappears due to corrosion over time. The remaining portion 9 shown in FIG. 7 is the portion of the first sacrificial layer 2 remaining at that time. In a vertical cross section at an arbitrary distance L1 from the boundary 2a, the height from the reference line 7 to the surface of the remaining portion 9 is d2. Therefore, the height d of the corroded portion 8 in the cross section, in other words, the corrosion depth d of the first sacrificial layer 2 in the cross section is given by the following equation (5).
d=d1-d2 (5)
Therefore, by changing the distance L1 from the boundary 2a and measuring the corrosion depth d of the first sacrificial layer 2 at each position by the formula (5), the first sacrificial layer 2 at the time of measurement is measured. It is possible to grasp the corrosion depth.

FIG. 8 is a diagram showing a process of changing the surface of the first sacrificial layer of the corrosion resistance diagnostic component according to the first embodiment of the present invention. The horizontal axis of FIG. 8 indicates the distance L1 from the boundary 2a. The vertical axis of FIG. 8 indicates the corrosion depth d of the first sacrificial layer 2. Further, the line (a) shown in FIG. 8 shows the measurement result of the corrosion depth d of the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 in the state of FIG. 6(a). The line (b) shown in FIG. 8 shows the measurement result of the corrosion depth d of the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 in the state of FIG. 6(b). The line (c) shown in FIG. 8 shows the measurement result of the corrosion depth d of the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 in the state of FIG. 6(c). The line (d) shown in FIG. 8 shows the measurement result of the corrosion depth d of the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 in the state of FIG. 6(d).

As shown by the line (a) in FIG. 8, in the state before the outdoor heat exchanger 100 starts to operate, the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 has no corrosion. When the outdoor unit is installed and the operation is started, the corrosion of the first sacrificial layer 2, which is the zinc sacrificial layer, progresses as shown by the line (b) in FIG. 8. Then, the anticorrosion range of the first sacrificial layer 2 gradually decreases. Therefore, as shown in FIG. 6B, the local corrosion mark 5 appears on the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 in the second range 6b which is outside the corrosion protection range of the first sacrificial layer 2. .. When time further elapses from the state of FIG. 6B, the corrosion of the first sacrificial layer 2, which is a zinc sacrificial layer, progresses and the corrosion depth d becomes deeper, as indicated by the line (c) of FIG. Become. Then, the anticorrosion range of the first sacrificial layer 2 is further reduced as compared with the state of FIG. Therefore, as shown in FIG. 6C, the local corrosion mark 5 is increased in the second range 6b on the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1, and the first range 6a is larger than that in FIG. 6B. Local corrosion marks 5 also appear at a close position.

When time further elapses from the state of FIG. 6C, as shown by the line (d) of FIG. 8, the corrosion of the first sacrificial layer 2 that is the zinc sacrificial layer further progresses, and the corrosion depth d becomes deeper. Become. Then, the anticorrosion range of the first sacrificial layer 2 is further reduced as compared with the state of FIG. Therefore, as shown in FIG. 6D, not only the second range 6b but also the local corrosion mark 5 appears on the surface of the exposed part 3a of the corrosion resistance diagnostic component 1 not only in the second range 6b.

Thus, there is a correlation between the appearance of the local corrosion mark 5 on the exposed portion 3a over time and the corrosion depth d of the first sacrificial layer 2. Therefore, data such as a table showing the relationship between the appearance of the local corrosion mark 5 on the exposed portion 3a and the corrosion depth d of the first sacrificial layer 2 may be created. The appearance of the local corrosion traces 5 is, for example, the number of local corrosion traces 5, the distance between the local corrosion traces 5 and the first sacrificial layer 2, and the like. By creating such data, the parameters indicating the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 stored in the storage unit 314 of the corrosion resistance diagnostic device 300, and the corrosion depth of the first sacrificial layer 2 Can be associated with.

Then, by creating such data, the corrosion depth d of the first sacrificial layer 2 can be diagnosed by comparing the appearance of the local corrosion mark 5 in the exposed portion 3a with the data, and the outdoor heat The remaining life of the exchanger 100 and the outdoor unit can be diagnosed. In other words, the residual life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by the local corrosion marks 5 appearing in the second range 6b of the exposed portion 3a. Moreover, the corrosion depth d of the first sacrificial layer 2 is measured by creating data indicating the relationship between the elapsed time and the corrosion depth d of the first sacrificial layer 2, and the measured first sacrificial layer 2 is measured. The remaining life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by comparing the corrosion depth d of Eq.

For example, the corrosion depth d of the first sacrificial layer 2 is observed in the corrosion resistance diagnostic component 1 in a state where the local corrosion does not occur in the first range 6a of the exposed portion 3a. It is assumed that the corrosion depth d at this time is in the state indicated by the line c1 in FIG. In this case, the time until the corrosion depth d indicated by the line c1 reaches the state of the line (d) in FIG. 8 can be predicted based on the above data. That is, the remaining life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed. Therefore, by measuring the corrosion resistance diagnostic component 1 as many times as possible between the state shown in FIG. 6(a) and the state shown in FIG. 6(d), the remaining life of the outdoor heat exchanger 100 and the outdoor unit is reduced. Data for more accurate diagnosis can be created.

Here, in order to create data indicating the relationship between the appearance of the local corrosion mark 5 on the exposed portion 3a and the corrosion depth d of the first sacrificial layer 2, the distance of the exposed portion 3a from the first sacrificial layer 2 is used. Is preferably as long as possible. The distance of the exposed portion 3a from the first sacrificial layer 2 is the distance in the juxtaposed direction of the first sacrificial layer 2 and the exposed portion 3a in the exposed portion 3a. For example, in FIG. 6, it is the lateral distance of the exposed portion 3a. is there. This is because, when the distance of the exposed portion 3a from the first sacrificial layer 2 is short, the zinc sacrificial layer is exposed in the range where the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material before the outdoor unit is installed. This is because the distance between the exposed portion 3a and the first sacrificial layer 2 may be shorter than the distance between the zinc sacrificial layer and the most distant portion. In such a case, when the local corrosion mark 5 appears on the exposed portion 3a, the lives of the outdoor heat exchanger 100 and the outdoor unit have already passed. Therefore, it is not possible to grasp the appearance of the local corrosion mark 5 on the exposed portion 3a until the outdoor heat exchanger 100 and the outdoor unit reach the end of their lives. Therefore, in order to create data indicating the relationship between the appearance of the local corrosion marks 5 on the exposed portion 3a and the corrosion depth d of the first sacrificial layer 2, the distance of the exposed portion 3a from the first sacrificial layer 2 is calculated. Is more than the distance between the zinc sacrificial layer and the part farthest from the zinc sacrificial layer within the range where the core material is exposed on the surface of the flat tube of the zinc sprayed aluminum material before the outdoor unit is installed. , Need to be long.

Note that the method of diagnosing the remaining life of the outdoor heat exchanger 100 and the outdoor unit can be performed by a person, or can be performed by the above-described corrosion resistance diagnostic device 300. A detailed example of this remaining life diagnosis method will be described later in the fifth embodiment.

[Example of product life evaluation using corrosion resistance diagnostic parts]
The corrosion resistance diagnostic component 1 according to the first embodiment was mounted on an outdoor unit, and the performance of the corrosion resistance diagnostic component 1 was verified. As described above, the material to be diagnosed according to the first embodiment is the flat tube of zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100. In this example, the corrosion resistance diagnostic component 1 was formed of the same member as the flat tube of zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100. Hereinafter, a method of manufacturing the corrosion resistance diagnostic component 1 will be specifically described.

FIG. 9 is a flowchart showing a manufacturing process of the corrosion resistance diagnostic component according to the first embodiment of the present invention. FIG. 10 is a diagram showing a process of forming an exposed portion of the corrosion resistance diagnostic component according to the first embodiment of the present invention. Note that FIG. 10 is a view of the material 500 for the corrosion-resistant diagnostic component, which is the corrosion-resistant diagnostic component 1, observed in the direction of the arrow Z shown in FIG. 4, and is a diagram showing an end surface of the material 500 for the corrosion-resistant diagnostic component.

When manufacturing the corrosion resistance diagnostic component 1, first, in step S10, which is a preparatory step, the material 500 for the corrosion resistance diagnostic component that becomes the corrosion resistance diagnostic component 1 is prepared. That is, the corrosion-resistant diagnostic component material 500 in which the first sacrificial layer 2 is formed on the surface of the first core material 3 is prepared. In the first embodiment, the same member as the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 is cut to a length of 50 mm to obtain the corrosion resistance diagnostic component material 500. Note that the length of 50 mm is the length in the direction orthogonal to the paper surface in FIG. That is, the core material of the flat tube of the zinc sprayed aluminum material becomes the first core material 3 of the corrosion resistance diagnostic component 1 formed from the material 500 for corrosion resistance diagnostic component. Further, the zinc sacrificial layer of the flat tube of the zinc sprayed aluminum material becomes the first sacrificial layer 2 of the corrosion resistance diagnostic component 1 formed of the material 500 for corrosion resistance diagnostic component. As shown in FIG. 10( a ), this corrosion resistance diagnostic component material 500 is plate-shaped and has a width of 10 mm, a thickness of 4 mm, a wall thickness of 500 μm, and a thickness of the first sacrificial layer 2 of 50 μm. ing. Further, in the corrosion resistance diagnostic component material 500, the zinc concentration in the surface portion of the first sacrificial layer 2 is 10 wt %.

The flat tube made of zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 may be purchased or may be manufactured by itself. In the case of manufacturing itself, step S10, which is a preparation step, includes step S11 and step S12. Step S11 is a core material preparing step of preparing the first core material 3. In other words, step S11 is a step of preparing the same core material as the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100. Step S12 is a sacrificial layer forming step of forming the first sacrificial layer 2 on the surface of the first core material 3. In other words, in step S12, the zinc spraying used as the heat transfer tube of the outdoor heat exchanger 100 is formed on the surface of the same core material as the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100. This is a step of forming the same zinc sacrificial layer as the zinc sacrificial layer of an aluminum material. As a result, a flat tube of zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 can be manufactured.

When manufacturing the corrosion resistance diagnostic component 1, after step S10 which is a preparatory step, step S20 which is a forming step for forming the exposed portion 3a is performed. In step S20, the first sacrificial layer 2 is removed from the surface thereof to the inside of the first sacrificial layer 3 beyond the boundary between the first sacrificial layer 2 and the first sacrificial layer 3, and is located at a position adjacent to the first sacrificial layer 2. The exposed portion 3a is formed. In the first embodiment, the exposed portion 3a is formed by removing a part of the plate-shaped material 500 for corrosion-resistant diagnostic parts by cutting. In this case, step S20, which is a forming step of forming the exposed portion 3a, includes steps S21 and S22.

Step S21 is, as shown in FIG. 10(b), a first cutting step of cutting the flat surface portion of the corrosion-resistant diagnostic component material 500 and exposing the first core material 3 at the flat surface portion. In the first embodiment, the range from the end surface of the material 500 for corrosion-resistant diagnostic parts to 25 mm in the depth direction of the paper surface of FIG. 10 is cut by 120 μm from the surface of the first sacrificial layer 2 in the first core material 3 direction to expose the exposed portion. 3a is formed. This cutting process is performed, for example, by milling. As described above, the thickness of the first sacrificial layer 2 is 50 μm. Therefore, the flat portion of the exposed portion 3a is formed by cutting the flat portion of the corrosion-resistant diagnostic component material 500 by 120 μm from the surface of the first sacrificial layer 2 in the first core 3 direction. In the range, zinc can be completely removed.

As described above, in the case of a flat tube made of zinc-sprayed aluminum material, zinc is sprayed on the pair of flat parts that form a part of the external shape. The zinc sprayed onto the flat surface portion also diffuses into a part of the side surface portion during the heat treatment. Therefore, as shown in FIG. 10B, after cutting the flat surface portion of the material 500 for corrosion-resistant diagnostic parts, the zinc residual region 10 where zinc remains is present in a part of the side surface portion. .. Therefore, as shown in FIG. 10C, the zinc remaining region 10 is removed in step S22 which is the second cutting process. Specifically, in step S22, which is the second cutting step, both side surface portions of the corrosion-resistant diagnostic component material 500 are cut so as to be continuous with the exposed portion of the first core material 3 in the flat surface portion. The first core material 3 is exposed. As a result, zinc can be completely removed from the surface of the exposed portion 3a, and the corrosion resistance diagnostic component 1 is completed.

In the corrosion resistance diagnostic component 1 manufactured in this way, the first range 6a was determined as follows. In other words, the specified distance L from the first sacrificial layer 2 in the exposed portion 3a of the corrosion resistance diagnostic component 1 shown in FIG. 6 was determined as follows. As described above, in the case of the flat tube made of zinc-sprayed aluminum material, zinc is sprayed on the pair of flat surface portions that form a part of the external shape. Therefore, in the initially manufactured flat tube of zinc sprayed aluminum material, the core material may be exposed on the entire surface of the side surface portion.

Here, as described above, the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 has a thickness of 4 mm. In other words, the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 has a surface distance between the pair of flat surfaces of 4 mm. Further, as can be seen from FIG. 10, in the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100, the cross-sectional shape of the side surface portion connecting the pair of flat surface portions is an arc shape. .. Therefore, the cross-sectional shape of the side surface of the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 is an arc shape with a radius of 2 mm. The arc length of the side surface portion is 6.28 mm.

Also, local corrosion is suppressed at the part where the core material is exposed on the surface of the side surface while it is within the corrosion protection range of the zinc sacrificial layer formed on the flat part. Therefore, the center of the side surface portion in the cross-sectional shape is the farthest position from both of the flat surface portions on the side surface portion, so that it is the earliest outside the anticorrosion range and local corrosion occurs. That is, the local corrosion occurs earliest at a position on the side surface where the distance on the surface from the flat surface is 3.14 mm. Therefore, in the first embodiment, the specified distance L from the first sacrificial layer 2 in the exposed portion 3a of the corrosion resistance diagnostic component 1 shown in FIG. 6 is set to 3.14 mm.

Unlike the conventional component that diagnoses the product life of a heat exchanger using an aluminum heat transfer tube, the corrosion resistance diagnostic component 1 configured in this way has zinc completely removed from the exposed portion 3a. Therefore, in the corrosion resistance diagnostic component 1 according to the first embodiment, the corrosion status of the material to be diagnosed can be diagnosed more accurately than before based on the corrosion status of the surface of the exposed portion 3a. Therefore, by using the corrosion resistance diagnostic component 1 according to the first embodiment, it is possible to accurately diagnose the service life and the remaining service life of the outdoor heat exchanger 100 and the outdoor unit having the outdoor heat exchanger 100. Further, the conventional component for diagnosing the product life of the heat exchanger using the aluminum heat transfer tube is manufactured by a member different from the material to be diagnosed. For this reason, in order to accurately diagnose the corrosion state of the material to be diagnosed, the conventional component requires a complicated design, which increases the manufacturing cost. On the other hand, since the corrosion resistance diagnostic component 1 according to the first embodiment is formed of the same member as the flat tube of the zinc sprayed aluminum material used as the heat transfer tube of the outdoor heat exchanger 100 which is the material to be diagnosed, The life of the outdoor heat exchanger 100 and the outdoor unit having the outdoor heat exchanger 100 can be diagnosed more accurately while suppressing the manufacturing cost.

FIG. 11 is a flowchart showing the combined cycle test performed in the first embodiment of the present invention.
The corrosion resistance diagnostic component 1 manufactured as described above was provided in the outdoor unit of the air conditioner 200 together with the outdoor heat exchanger 100, and the combined cycle test shown in FIG. 11 was performed as an accelerated test for reproducing the corrosion pattern in the salt damage area. ..

First, in step S31, a spray process of salt water was performed. Specifically, the installation environment of the outdoor unit was set to an environment of a temperature of 35° C. and a relative humidity of 100%. Then, in this state, the outdoor unit was operated for 2 hours while spraying an aqueous solution having a salt concentration of 5% by weight on the outdoor unit. In step S32 after step S31, a drying process was performed. Specifically, the installation environment of the outdoor unit was set to an environment of a temperature of 60° C. and a relative humidity of 30%. Then, in this state, the outdoor unit was operated for 4 hours. In step S33 after step S32, a wetting process was performed. Specifically, the installation environment of the outdoor unit was set to an environment of a temperature of 50° C. and a relative humidity of 95%. Then, in this state, the outdoor unit was operated for 2 hours.

In step S34 after step S33, it is determined whether the operating time of the outdoor unit has reached the specified time. When the operating time of the outdoor unit has not reached the specified time, the process returns to step S31. On the other hand, when the operating time of the outdoor unit has reached the specified time, the combined cycle test ends. That is, in the combined cycle test performed in the first embodiment, the processes of steps S31 to S33 are repeated until the operating time of the outdoor unit reaches the specified time. In addition, in the first embodiment, the specified time is set to 2000 hours.

While performing the above-mentioned combined cycle test, the corrosion state of the corrosion resistance diagnostic component 1 was periodically observed. In the first embodiment, the corrosion state of the corrosion resistance diagnostic component 1 was observed every 250 hours. In addition, the periodic observation of the corrosion state of the corrosion resistance diagnostic component 1 was repeated until the local corrosion mark 5 was generated in the first area 6a of the exposed portion 3a of the corrosion resistance diagnostic component 1.

As a result of observing the corrosion state of the corrosion resistance diagnostic component 1 with the elapsed time of operation, 250 hours after the start of the operation of the outdoor unit, a local corrosion mark 5 was found in the second range 6b of the exposed portion 3a of the corrosion resistance diagnostic component 1. I confirmed the appearance. In addition, in this corrosion resistance diagnostic component 1, the corrosion depth of the first sacrificial layer 2, which is a zinc sacrificial layer, was measured. As a result of observing the corrosion resistance diagnostic component 1 after 500 hours, 750 hours, 1000 hours, and 1250 hours from the start of operation of the outdoor unit, local corrosion marks 5 were found in the second range 6b of the exposed portion 3a. I confirmed how it is occurring. In addition, it was confirmed that the appearance range of the local corrosion mark 5 spreads toward the first range 6a of the exposed portion 3a in the second range 6b of the exposed portion 3a as the operating time increases. It was also confirmed that the corrosion of the first sacrificial layer 2 progressed in the depth direction as the operating time increased.

As a result of observing the corrosion resistance diagnostic component 1 1500 hours after the start of operation of the outdoor unit, it was confirmed that the local corrosion mark 5 appeared in the first range 6a of the exposed portion 3a. Further, when the first sacrificial layer 2 was observed in the corrosion resistance diagnostic component 1, it was confirmed that the first sacrificial layer 2 disappeared over almost the entire surface due to corrosion. Since the first sacrificial layer 2 disappeared and the anticorrosion function for the exposed portion 3a disappeared, it is considered that the local corrosion proceeded within the first range 6a of the exposed portion 3a. Similarly, as a result of observing the heat transfer tube of the outdoor heat exchanger 100 1500 hours after the start of operation of the outdoor unit, local corrosion appears at the portion where the core material is exposed on the surface, and the corrosion resistance diagnostic component 1 is not covered. It was verified that the product life using the diagnostic material can be accurately diagnosed.

From the above, it is determined that 1500 hours from the start of operation of the outdoor unit is the life of the outdoor heat exchanger 100 and the outdoor unit in this combined cycle test. Then, for example, when it is known that the present combined cycle test proceeds at a predetermined acceleration rate for corrosion of the outdoor heat exchanger 100 and the outdoor unit in a certain environment, the outdoor heat exchange is performed based on the acceleration rate. The life of the unit 100 and the outdoor unit can be estimated. In addition, based on the test results of the present combined cycle test, data indicating the relationship between the appearance of the local corrosion mark 5 on the exposed portion 3a and the corrosion depth d of the first sacrificial layer 2 is created in advance. The remaining life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed based on the data.

Embodiment 2.
The members used for the corrosion resistance diagnostic component 1 are not limited to the members shown in the first embodiment. Further, the manufacturing method of the corrosion resistance diagnostic component 1 is not limited to the manufacturing method shown in the first embodiment. In the second embodiment, another example of members that can be used for the corrosion resistance diagnostic component 1 will be introduced. In addition, in the second embodiment, an example of another method of manufacturing the corrosion resistance diagnostic component 1 will be described. In the second embodiment, items not particularly described are the same as those in the first embodiment, and the same functions and configurations as those in the first embodiment will be described using the same reference numerals.

The outdoor unit is equipped with a refrigerant pipe through which the refrigerant flowing into the outdoor heat exchanger 100 or the refrigerant flowing out of the outdoor heat exchanger 100 flows. A part of this refrigerant pipe may be formed of an aluminum material with a zinc sacrificial layer. For example, the refrigerant distributor may form a part of the refrigerant pipe of the outdoor unit. The refrigerant distributor includes a main pipe and a plurality of branch pipes connected to the main pipe. Since the refrigerant distributor has a complicated shape, it is difficult to form the sacrificial layer by spraying zinc. Therefore, in the refrigerant distributor, the zinc-containing paint is applied to the surface of the core material containing aluminum, and the zinc sacrificial layer is formed on the surface of the core material.

The heat transfer tubes are a part of the refrigerant pipes of the outdoor heat exchanger 100, and the outdoor heat exchanger 100 also includes refrigerant pipes other than the heat transfer tubes, such as the refrigerant pipes connecting the heat transfer tubes. An aluminum material with a zinc sacrificial layer may be used for the refrigerant pipe other than the heat transfer pipe. As the refrigerant pipes other than the heat transfer pipe, a circular pipe having a simple shape may be used even when a flat pipe made of zinc sprayed aluminum material is used as the heat transfer pipe for improving the performance of the outdoor heat exchanger 100. .. When the refrigerant pipes other than the heat transfer pipes are circular pipes of aluminum material with a zinc sacrificial layer, zinc sprayed aluminum material or aluminum clad material can be used.

It is also possible to manufacture the corrosion resistance diagnostic component 1 using the same member as the refrigerant pipe of the outdoor unit, which is formed of an aluminum material with a zinc sacrificial layer. In this case, the refrigerant pipe of the outdoor unit formed of the aluminum material with the zinc sacrificial layer serves as the material to be diagnosed. Further, the corrosion resistance diagnostic component 1 can be manufactured using the same member as the refrigerant pipe other than the heat transfer pipe of the outdoor heat exchanger 100 formed of the aluminum material with the zinc sacrificial layer. In this case, the refrigerant pipes other than the heat transfer pipes of the outdoor heat exchanger 100 formed of the aluminum material with the zinc sacrificial layer serve as the material to be diagnosed. In the second embodiment, a method of manufacturing the corrosion resistance diagnostic component 1 using the same member as the refrigerant pipe formed of such an aluminum material with a zinc sacrificial layer will be described.

When the corrosion-resistant diagnostic component 1 is manufactured using the same member as the flat tube made of an aluminum material with a zinc sacrificial layer, the zinc sacrificial layer is formed on the flat surface portion, so the zinc sacrificial layer is removed by cutting and the exposed portion 3a is removed. Can be formed. On the other hand, when manufacturing the corrosion-resistant diagnostic component 1 using the same member as the refrigerant pipe formed of the aluminum material with the zinc sacrificial layer described in the second embodiment, it is difficult to remove the zinc sacrificial layer by cutting. There is. In this case, a method of removing the zinc sacrificial layer by chemical etching and forming the exposed portion 3a is effective. In chemical etching, a chemical solution is brought into contact with an aluminum material and both react with each other, whereby the aluminum material is dissolved. If this chemical etching is applied to an aluminum material with a zinc sacrificial layer, the corrosion resistance diagnostic component 1 can be manufactured. That is, the core material can be exposed on the surface of the same member as the refrigerant pipe formed of the aluminum material with a zinc sacrificial layer by bringing the surface of the member into contact with the chemical solution. Then, zinc can be completely removed from the exposed surface of the core material, and the exposed portion 3a can be formed.

If the same member as the refrigerant pipe made of an aluminum material with a zinc sacrificial layer has a uniform shape such as a circular pipe, the member may be immersed in a chemical solution to expose the core material on the surface. On the other hand, when the same member as the refrigerant pipe formed of the aluminum material with a zinc sacrificial layer has a complicated shape like a refrigerant distributor, the member is simply immersed in a chemical solution to expose the core material on the surface. Is difficult. In such a case, for example, the core material may be exposed on the surface by applying gauze impregnated with a chemical solution to the place where the exposed portion 3a is to be formed and chemically etching the place where the gauze or the like is applied. In addition, for example, when the same member as the refrigerant pipe formed of an aluminum material with a zinc sacrificial layer has a complicated shape, masking is applied to a portion where the zinc sacrificial layer is to be left, and the chemical solution is contacted with other portions, The core material may be exposed on the surface.

The chemical solution used for chemical etching may be any material that dissolves an aluminum material, and an acidic chemical solution having a pH of 5 or less or an alkaline chemical solution having a pH of 10 or more is preferable. Further, the time until the core material is exposed by bringing the zinc sacrificial layer-provided aluminum material into contact with the chemical solution may be appropriately determined depending on the chemical solution used and the zinc sacrificial layer-provided aluminum material.

As described above, since the corrosion resistance diagnostic component 1 according to the second embodiment is also formed of the same material as the material to be diagnosed, the life of the outdoor heat exchanger 100 and the outdoor unit is accurately diagnosed while suppressing the manufacturing cost. be able to.

Whether the exposed portion 3a is formed by cutting or the exposed portion 3a is formed by chemical etching, if the surface roughness of the exposed portion 3a is large, the local corrosion mark 5 cannot be detected. It can be difficult. For this reason, it is preferable to reduce the surface roughness of the exposed portion 3a by performing electrolytic polishing, chemical polishing, buffing, or the like on the exposed portion 3a after forming the exposed portion 3a by cutting or chemical etching. Thereby, the local corrosion mark 5 appearing on the exposed portion 3a can be accurately confirmed, and the accuracy of diagnosing the corrosion state of the product using the material to be diagnosed can be improved.

Embodiment 3.
In the first embodiment, the corrosion depth of the first sacrificial layer 2 which is the zinc sacrificial layer was measured in the cross section, and the progress of corrosion of the first sacrificial layer 2 with the passage of time was grasped. However, the method of ascertaining the progress of corrosion of the first sacrificial layer 2 over time is not limited to this method. In the third embodiment, some other examples for grasping the progress of corrosion of the first sacrificial layer 2 over time will be introduced. In the third embodiment, items not particularly described are the same as those in the first or second embodiment, and the same reference numerals are used for the same functions and configurations as those in the first or second embodiment. Will be described.

[Understanding the progress of corrosion of the first sacrificial layer based on the amount of corrosion]
For example, based on the amount of corrosion of the first sacrificial layer 2, it is possible to grasp the progress of corrosion of the first sacrificial layer 2 over time. In the following, two methods for grasping the progress of corrosion of the first sacrificial layer 2 over time based on the amount of corrosion of the first sacrificial layer 2 will be introduced.

The first method is a method of grasping the amount of corrosion of the first sacrificial layer 2 by measuring the area of the region where the first sacrificial layer 2 has corroded in a predetermined cross section of the first sacrificial layer 2. Regarding the corrosion of the first sacrificial layer 2, general corrosion progresses in the depth direction. Therefore, by setting a predetermined cross section and measuring the corroded area of the first sacrificial layer 2 in this cross section, it is considered possible to convert it into the corrosion amount of the entire first sacrificial layer 2. If the ratio between the corroded portion 8 and the remaining portion 9 is grasped by binarization or the like in the predetermined cross section, the corroded portion 8 of the entire first sacrificial layer 2 can be derived. Therefore, as a result, it is possible to grasp the progress of corrosion of the first sacrificial layer 2 over time.

Then, by creating data such as a table showing the relationship between the appearance of the local corrosion marks 5 on the exposed portion 3a and the corrosion area of the first sacrificial layer 2 in a predetermined cross section, the storage unit 314 of the corrosion resistance diagnostic device 300 stores the data. The stored parameter indicating the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 can be associated with the corrosion area of the first sacrificial layer 2 in the predetermined cross section. Then, by creating such data, it is possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit by comparing the appearance of the local corrosion mark 5 on the exposed portion 3a with the data. it can. In other words, the residual life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by the local corrosion marks 5 appearing in the second range 6b of the exposed portion 3a.

In addition, by creating data indicating the relationship between the passage of time and the corroded area of the first sacrificial layer 2 in the predetermined cross section, the corroded area of the first sacrificial layer 2 in the predetermined cross section is measured, and the measured first sacrificial layer 2 is measured. The remaining life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by comparing the corroded area in the predetermined cross section of the layer 2 with the data.

The second method is to measure the corrosion amount of the first sacrificial layer 2 by measuring the weight of the corrosion resistance diagnostic component 1. The weight of the corrosion resistance diagnostic component 1 before the outdoor unit starts to operate and the weight of the corrosion resistance diagnostic component 1 after the outdoor unit has operated for a predetermined time are measured, and the weight change of the corrosion resistance diagnostic component 1 indicates the first sacrificial layer 2 Understand the amount of corrosion of. The amount of corrosion of the first core material 3 is on the order of μm in terms of the amount of corrosion itself, which is smaller than the amount of corrosion of the first sacrificial layer 2. Therefore, the change in weight of the corrosion resistance diagnostic component 1 may be regarded as the amount of corrosion of the first sacrificial layer 2. Therefore, the amount of corrosion of the first sacrificial layer 2 can be grasped from the weight change of the corrosion resistance diagnostic component 1. Therefore, as a result, it is possible to grasp the progress of corrosion of the first sacrificial layer 2 over time.

When the first sacrificial layer 2 corrodes, corrosive organisms accumulate on the corrosion resistance diagnostic component 1. Therefore, when measuring the weight of the corrosion resistance diagnostic component 1, it is necessary to remove corrosive organisms. As the removal method, the “chemical corrosion product removal method” in JIS Z2371 standard or mechanical removal with a brush or the like is suitable. After starting the operation of the outdoor unit, the corrosion products are removed from the corrosion resistance diagnostic component 1 by these methods, and the weight of the corrosion resistance diagnostic component is measured. Then, by comparing this weight with the weight of the corrosion resistance diagnostic component 1 before the operation of the outdoor unit, it is possible to grasp the progress of corrosion of the first sacrificial layer 2 over time.

Then, by creating data such as a table showing the relationship between the appearance of the local corrosion marks 5 on the exposed portion 3a and the weight change of the corrosion resistance diagnostic component 1, the data is stored in the storage unit 314 of the corrosion resistance diagnostic device 300. The parameter indicating the corrosion state of the surface of the exposed portion 3a of the corrosion resistance diagnostic component 1 can be associated with the weight change of the corrosion resistance diagnostic component 1. Then, by creating such data, it is possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit by comparing the appearance of the local corrosion mark 5 on the exposed portion 3a with the data. it can. In other words, the residual life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by the local corrosion marks 5 appearing in the second range 6b of the exposed portion 3a.

In addition, by creating data indicating the relationship between the passage of time and the weight change of the corrosion resistance diagnostic component 1, the weight change of the corrosion resistance diagnostic component 1 is measured, and the measured weight change of the corrosion resistance diagnostic component 1 and the data By comparing, it is possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit.

[Corrosion depth measurement by depth of focus method]
In the first embodiment, the corrosion depth of the first sacrificial layer 2, which is a zinc sacrificial layer, was measured in the cross section. The method for measuring the corrosion depth of the first sacrificial layer 2 is not limited to this method, and the corrosion depth of the first sacrificial layer 2 may be measured by, for example, the depth of focus method. When measuring the corrosion depth of the first sacrificial layer 2 by the depth of focus method, first, as described above, the corrosive organisms are removed from the corrosion resistance diagnostic component 1. Then, the corrosion depth of the first sacrificial layer 2 is measured by the depth of focus method for the corrosion resistance diagnostic component 1 from which the corrosion product has been removed. This method can continuously measure the corrosion depth at each position from the boundary between the first sacrificial layer 2 and the exposed portion 3a, and can easily measure the corrosion depth of the first sacrificial layer 2. Therefore, it is a useful method for measuring the corrosion depth of the first sacrificial layer 2.

Fourth Embodiment
In the refrigerant pipe made of an aluminum material with a zinc sacrificial layer, which is provided in the outdoor unit, corrosion is more likely to occur at a portion where the amount of adhering salt that is a corrosion factor of atmospheric corrosion is greater. Therefore, in order to make a reliable life diagnosis, in other words, in order to make sure that the product life is diagnosed before the through hole is formed in the refrigerant pipe of the aluminum material with the zinc sacrificial layer, it is most important. It is preferable to install the corrosion resistance diagnostic component 1 at a position where corrosion easily progresses. In the fourth embodiment, an example of a suitable installation position of the corrosion resistance diagnostic component 1 will be introduced. In the fourth embodiment, items that are not particularly described are the same as those in the first to third embodiments, and the same functions and configurations as those in the first to third embodiments are the same. Will be described using the reference sign.

For example, when an aluminum material with a zinc sacrificial layer is used for at least a part of the refrigerant pipe of the outdoor heat exchanger 100, a portion of the refrigerant pipe of the aluminum material with a zinc sacrificial layer where fly salt is most likely to adhere It is advisable to install the corrosion resistance diagnostic component 1. For example, when the corrosion resistance diagnostic component 1 is formed of a zinc sprayed aluminum material used as a heat transfer tube of the outdoor heat exchanger 100, the corrosion resistance diagnostic component 1 may be installed at the following position.

FIG. 12: is a side view which shows a part of core part of the outdoor heat exchanger which concerns on Embodiment 4 of this invention.
The core section 400 of the outdoor heat exchanger 100 according to the fourth embodiment includes the heat transfer tube 411. The heat transfer tube 411 is a flat tube of zinc sprayed aluminum material. Further, a plurality of fins 412 made of, for example, a material containing aluminum is attached to the surface of a part of the heat transfer tube 411 in order to improve the amount of heat exchange between the refrigerant flowing in the heat transfer tube 411 and the outside air. ing. That is, the heat transfer tube 411 has the exposed surface portion 413 where the fin 412 is not attached to the surface and the fin contact portion 414 where the surface is covered with the fin 412.

In the exposed surface portion 413, the surface of the heat transfer tube 411 is not covered with the fins 412. Therefore, flying salt is more likely to adhere to the exposed surface 413 of the heat transfer tube 411 than the fin contact portion 414. Therefore, the exposed surface portion 413 of the heat transfer tube 411 is more likely to corrode than the fin contact portion 414. Therefore, when the corrosion resistance diagnostic component 1 is formed of the zinc sprayed aluminum material used as the heat transfer pipe of the outdoor heat exchanger 100, the corrosion resistance diagnostic component 1 may be attached to the exposed surface portion 413 of the heat transfer pipe 411. As a result, it can be reliably diagnosed that the outdoor heat exchanger 100 has reached the end of its life before the through hole is formed in the heat transfer tube 411, and the reliability of the product life diagnosis using the corrosion resistance diagnosis component 1 is improved.

Also, paying attention to the wind flow inside the outdoor unit when operating the outdoor unit, you may consider the installation position of the corrosion resistance diagnostic component 1. It can be considered that the portion with the highest wind speed in the outdoor unit during operation of the outdoor unit is the portion where the flying salt is most likely to adhere in the outdoor unit during operation of the outdoor unit. Therefore, when the corrosion resistance diagnostic component 1 is installed in the portion of the outdoor unit having the highest wind speed during operation of the outdoor unit, the corrosion resistance diagnostic component 1 is less likely to corrode than the refrigerant pipe made of aluminum material with a zinc sacrificial layer provided in the outdoor unit. It will progress faster. Therefore, even if the corrosion resistance diagnostic component 1 is installed at such a position, it can be reliably diagnosed that the outdoor unit has reached the end of life before the through hole is formed in the refrigerant pipe of the aluminum material with the zinc sacrificial layer, Reliability of product life diagnosis using the corrosion resistance diagnosis component 1 is improved.

Embodiment 5.
As described above, the life and the remaining life of the outdoor heat exchanger 100 and the outdoor unit can be diagnosed by a person or the corrosion resistance diagnosing device 300. In the fifth embodiment, an example of the life and remaining life diagnosis of the outdoor heat exchanger 100 and the outdoor unit performed by a person, and the life and remaining life diagnosis of the outdoor heat exchanger 100 and the outdoor unit performed by the corrosion resistance diagnosing device 300. I will introduce an example. In the fifth embodiment, items not particularly described are the same as those in any of the first to fourth embodiments, and the same functions and configurations as those in any of the first to fourth embodiments are the same. Will be described using the reference sign.

When a person diagnoses the life of the outdoor heat exchanger 100 and the outdoor unit, a person such as a maintenance maker checks the local corrosion mark 5 that appears on the exposed portion of the corrosion resistance diagnostic component 1. The local corrosion mark 5 that appears on the exposed portion 3a of the corrosion resistance diagnostic component 1 is visually confirmed, for example. When visually confirming the local corrosion traces 5 appearing on the exposed portion 3a, for example, a person temporarily removes the corrosion resistance diagnostic component 1 and confirms the local corrosion traces 5 appearing on the exposed portion 3a of the corrosion resistance diagnostic component 1. Further, for example, when the corrosion resistance diagnostic component 1 is installed at a position where the local corrosion mark 5 appearing on the exposed portion 3a can be directly viewed, a person does not remove the corrosion resistance diagnostic component 1 and the local corrosion appearing on the exposed portion 3a is removed. The mark 5 may be confirmed. Further, for example, even by installing a mirror or the like, a person can confirm the local corrosion marks 5 appearing on the exposed portion 3a without removing the corrosion resistance diagnostic component 1. In addition, for example, when the corrosion resistance diagnostic device 300 including at least the imaging unit 312 and the detection unit 313 is provided, a person can visually check the image data of the detection unit 313 to see the local corrosion mark appearing on the exposed portion 3a. 5 can be confirmed. Then, when confirming the local corrosion mark 5 in the first range 6a of the exposed portion 3a, the person diagnoses that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives.

Note that if it is diagnosed that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives, maintenance of the outdoor unit may be executed. The maintenance of the outdoor unit includes replacement of the refrigerant pipe of the aluminum material with the zinc sacrificial layer, repair of a local corrosion portion generated in the refrigerant pipe of the aluminum material with the zinc sacrificial layer, replacement of the outdoor heat exchanger 100, and the like.

When a person diagnoses the remaining life of the outdoor heat exchanger 100 and the outdoor unit, the corrosion resistance diagnostic component 1 is once brought back to the environment where the progress of corrosion of the first sacrificial layer 2 can be measured. Then, for example, when the data indicating the relationship between the elapsed time and the corrosion depth d of the first sacrificial layer 2 is created, a person measures the corrosion depth d of the first sacrificial layer 2. Then, by comparing the measured corrosion depth d of the first sacrificial layer 2 with the data, the remaining life of the outdoor heat exchanger 100 and the outdoor unit is diagnosed. Further, for example, when data indicating the relationship between the elapsed time and the corroded area of the first sacrificial layer 2 in the predetermined cross section is created, a person measures the corroded area of the first sacrificial layer 2 in the predetermined cross section. Then, the remaining area of the outdoor heat exchanger 100 and the outdoor unit is diagnosed by comparing the measured corrosion area in the predetermined cross section of the first sacrificial layer 2 with the data. Further, for example, when data indicating the relationship between the passage of time and the weight change of the corrosion resistance diagnostic component 1 is created, a person measures the weight change of the corrosion resistance diagnostic component 1. Then, the remaining weight of the outdoor heat exchanger 100 and the outdoor unit is diagnosed by comparing the measured weight change of the corrosion resistance diagnostic component 1 with the data.

The case where the corrosion resistance diagnostic device 300 diagnoses the life of the outdoor heat exchanger 100 and the outdoor unit will be described. The local corrosion mark 5 that appears on the exposed portion 3 a of the corrosion resistance diagnostic component 1 is different in color and shape from the first core material 3. Therefore, the detection unit 313 converts the image data of the exposed portion 3a photographed by the photographing unit 312 into image data composed of at least one of color and shape, and the local corrosion appearing on the exposed portion 3a. The trace 5 is used as discriminable data.

The image data generated by the detection unit 313 is sent to the storage unit 314 and the comparison unit 315 at predetermined time intervals, for example. The comparing unit 315 compares with the image data stored in the storage unit 314 every time the image data is sent from the detecting unit 313. When the comparison unit 315 confirms that the local corrosion mark 5 appears in the first range 6a of the exposed portion 3a, the comparison unit 315 diagnoses that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives. In addition, the notification unit 316 notifies that the outdoor heat exchanger 100 and the outdoor unit have reached the end of their lives.

When the corrosion resistance diagnosing device 300 diagnoses the remaining life of the outdoor heat exchanger 100 and the outdoor unit, the storage unit 314 stores data for guiding the remaining life of the outdoor heat exchanger 100 and the outdoor unit in advance. The data that indicates the remaining life of the outdoor heat exchanger 100 and the outdoor unit is, for example, data indicating the relationship between the appearance of the local corrosion trace 5 on the exposed portion 3a and the corrosion depth d of the first sacrificial layer 2 described above. , Data showing the relationship between the appearance of the local corrosion marks 5 on the exposed portion 3a and the corrosion area of the first sacrificial layer 2 in a predetermined cross section, or the appearance of the local corrosion marks 5 on the exposed portion 3a. 2 is data showing the relationship between the weight change of the corrosion resistance diagnostic component 1 and. Further, for example, data indicating the relationship between the appearance of the local corrosion mark 5 on the exposed portion 3a and the remaining life of the outdoor heat exchanger 100 and the outdoor unit is used as data for guiding the remaining life of the outdoor heat exchanger 100 and the outdoor unit. It may be stored in the storage unit 314.

When the image data is sent from the detection unit 313, the comparison unit 315 determines how the local corrosion mark 5 appears in the exposed portion 3 a in the data and the outdoor heat exchanger 100 and the outdoor stored in the storage unit 314. The remaining lifespan of the outdoor heat exchanger 100 and the outdoor unit are diagnosed by comparing with the data that guides the remaining lifespan of the machine. In addition, the notification unit 316 notifies the remaining life of the outdoor heat exchanger 100 and the outdoor unit.

As described above, by using the corrosion resistance diagnosing device 300, it is possible to diagnose the remaining life of the outdoor heat exchanger 100 and the outdoor unit without human work and judgment.

Sixth Embodiment
By using the corrosion resistance diagnostic component 1, the presence or absence of corrosive substances in the atmosphere in the installation environment of the outdoor unit and the degree of influence of the corrosive substances in the atmosphere on the members including aluminum provided in the outdoor unit are grasped. It is also possible. In the sixth embodiment, a method of diagnosing the corrosiveness of the installation environment of the outdoor unit will be introduced. In the sixth embodiment, items not particularly described are the same as those in any of the first to fifth embodiments, and the same functions and configurations as those in any of the first to fifth embodiments are the same. Will be described using the reference sign.

Conventionally, when installing an outdoor unit in an area where the effect on the aluminum-containing components installed in the outdoor unit is not known, the corrosiveness of the installation environment may be affected by the presence or absence of corrosive substances that have already been identified in environmental surveys. Therefore, the aluminum material with the zinc sacrificial layer was used according to the environment. By installing the corrosion resistance diagnosing device 300 or the corrosion resistance diagnosing component 1 alone together with the outdoor unit in the above-mentioned region, it is possible to grasp the influence on the member including aluminum provided in the outdoor unit.

Specifically, the corrosion resistance diagnostic device 300 or the corrosion resistance diagnostic component 1 alone is installed inside the outdoor unit when the outdoor unit is installed. Then, after the operation of the air conditioner is started, the corrosion state of the corrosion resistance diagnostic component 1 is regularly investigated.

Specifically, one of the areas where the corrosiveness of the aluminum-containing members installed in the outdoor unit is known is set as the standard area. Then, data indicating the relationship between the passage of time from the start of operation of the air conditioner in the standard area and the degree of occurrence of the local corrosion mark 5 on the exposed portion 3a of the corrosion resistance diagnostic component 1 is created. Then, when the outdoor unit is installed in a new area and the operation of the air conditioner is started, the degree of occurrence of the local corrosion marks 5 on the exposed portion 3a of the corrosion resistance diagnostic component 1 installed inside the outdoor unit and the above-mentioned data. Compare with. This makes it possible to diagnose whether the corrosiveness of the new area where the outdoor unit is installed is larger or smaller than that of the standard area.

In addition, when the corrosion resistance diagnostic device 300 is installed inside the outdoor unit, the time elapsed from the start of operation of the air conditioner in the standard area and the occurrence of the local corrosion mark 5 on the exposed portion 3a of the corrosion resistance diagnostic component 1 Data indicating the relationship is stored in the storage unit 314. Then, the comparison unit 315 compares the image data sent from the detection unit 313 with the data stored in the storage unit 314, so that the corrosiveness of the new area where the outdoor unit is installed is the standard area. Diagnose whether it is larger or smaller than.

Further, it is possible to create data indicating the relationship between the elapsed time from the start of operation of the air conditioner in the standard area and the degree of progress of corrosion of the first sacrificial layer 2 of the corrosion resistance diagnostic component 1. Then, when the outdoor unit is installed in a new area and the operation of the air conditioner is started, the corrosion resistance diagnostic component 1 installed inside the outdoor unit is brought back and the degree of corrosion progress of the first sacrificial layer 2 is measured. Good. By comparing the measured degree of corrosion progress of the first sacrificial layer 2 with the above data, the corrosiveness of the environment in which the outdoor unit is installed can be diagnosed with higher accuracy. The degree of progress of corrosion of the first sacrificial layer 2 can be measured by the above-described corrosion depth of the first sacrificial layer 2 or the like.

As described above, the present invention may appropriately combine the configurations shown in the above embodiments. Further, the configurations shown in the above-described respective embodiments are merely examples, and do not limit the configurations of the present invention. The scope of the present invention is defined by the scope of the claims, and includes meanings equivalent to the scope of the claims and all modifications within the scope.

1 Corrosion resistance diagnostic part, 2 1st sacrifice layer, 2a boundary, 3 1st core material, 3a exposed part, 4 liquid junction, 5 local corrosion mark, 6a 1st range, 6b 2nd range, 7 reference line, 7a reference point , 8 corroded parts, 9 remaining parts, 10 zinc remaining areas, 100 outdoor heat exchanger, 200 air conditioner, 201 compressor, 202 muffler, 203 four-way valve, 204 refrigerant pipe, 205 capillary tube, 206 strainer, 207 electronically controlled Expansion valve, 208a stop valve, 208b stop valve, 209 indoor heat exchanger, 210 auxiliary muffler, 211 control device, 300 corrosion resistance diagnostic device, 312 imaging unit, 313 detection unit, 314 storage unit, 315 comparison unit, 316 notification unit, 400 core part, 411 heat transfer tube, 412 fin, 413 surface exposed part, 414 fin contact part, 500 material for corrosion resistance diagnostic parts.

Claims

A corrosion resistance diagnostic component used for diagnosing a corrosion state of a material to be diagnosed, wherein a sacrificial layer containing zinc is formed on a surface of a core material containing aluminum,
The corrosion resistance diagnostic parts are
A first core material containing aluminum;
A first sacrificial layer formed on the surface of the first core material and containing zinc having a lower corrosion resistance than the first core material;
Equipped with
In the corrosion resistance diagnostic component, at a position adjacent to the first sacrificial layer, the inner side of the first core material is more than the boundary between the first sacrificial layer and the first core material from the surface of the first sacrificial layer. The corrosion-resistant diagnostic component, wherein the exposed portion is formed by removing the first core material.
On the surface of the exposed portion,
When a local corrosion mark appears at a position adjacent to the first sacrificial layer, a first range in which the product using the material to be diagnosed is diagnosed as a life is arranged,
The corrosion resistance diagnosis according to claim 1, wherein a second range in which a local corrosion mark appears before the first range is arranged at a position opposite to the first sacrificial layer with respect to the first range. parts.
The first sacrificial layer is an aluminum-zinc alloy,
The corrosion resistance diagnostic component according to claim 1, wherein the first core material is an aluminum alloy that does not contain zinc.
A corrosion-resistant diagnostic component according to any one of claims 1 to 3,
A photographing unit for photographing the surface of the exposed portion,
From the image data taken by the imaging unit, a detection unit that detects a corrosion state of the surface of the exposed portion,
Corrosion resistance diagnostic device equipped with.
A storage unit that stores a parameter indicating the corrosion state of the surface of the exposed portion,
A comparison unit that compares the detection result of the detection unit and the parameter stored in the storage unit,
An informing section for informing the comparison result in the comparing section,
The corrosion resistance diagnostic device according to claim 4, further comprising:
The corrosion resistance diagnostic device according to claim 5, wherein the parameter is associated with a corrosion area of the first sacrificial layer in a cross section of the first sacrificial layer.
The corrosion resistance diagnosing device according to claim 5, wherein the parameter is associated with a corrosion depth of the first sacrificial layer in a cross section of the first sacrificial layer.
The corrosion resistance diagnostic device according to claim 5, wherein the parameter is associated with a weight change of the corrosion resistance diagnostic component.
A corrosion-resistant diagnostic component according to any one of claims 1 to 3,
A sacrificial layer containing zinc is formed on the surface of the core material containing aluminum, and a refrigerant pipe through which the refrigerant flows,
Equipped with
The said corrosion-resistant diagnostic component is a heat exchanger formed with the same member as the said refrigerant pipe.
A heat transfer tube forming a part of the refrigerant pipe,
The heat exchanger according to claim 9, wherein the corrosion resistance diagnostic component is formed of the same member as the heat transfer tube.
A corrosion resistance diagnostic device according to any one of claims 4 to 8,
A sacrificial layer containing zinc is formed on the surface of the core material containing aluminum, and a refrigerant pipe through which the refrigerant flows,
Equipped with
The said corrosion-resistant diagnostic component is a heat exchanger formed with the same member as the said refrigerant pipe.
A heat transfer tube forming a part of the refrigerant pipe,
The heat exchanger according to claim 11, wherein the corrosion resistance diagnostic component is formed of the same member as the heat transfer tube.
A corrosion-resistant diagnostic component according to any one of claims 1 to 3,
A heat exchanger having a heat transfer tube in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum;
A sacrificial layer containing zinc is formed on the surface of the core material containing aluminum, and a refrigerant pipe in which the refrigerant flowing into the heat exchanger or the refrigerant flowing out from the heat exchanger flows.
Equipped with
An air conditioner in which the corrosion resistance diagnostic component is formed of the same member as the refrigerant pipe.
A corrosion resistance diagnostic device according to any one of claims 4 to 8,
A heat exchanger having a heat transfer tube in which a sacrificial layer containing zinc is formed on the surface of a core material containing aluminum;
A sacrificial layer containing zinc is formed on the surface of the core material containing aluminum, and a refrigerant pipe in which the refrigerant flowing into the heat exchanger or the refrigerant flowing out from the heat exchanger flows.
Equipped with
An air conditioner in which the corrosion resistance diagnostic component is formed of the same member as the refrigerant pipe.
A method of manufacturing a corrosion-resistant diagnostic component according to any one of claims 1 to 3,
A preparatory step of preparing a material for a corrosion-resistant diagnostic component in which the first sacrificial layer is formed on the surface of the first core material;
The exposed portion is removed from the surface of the first sacrificial layer to the inside of the first core material with respect to the boundary between the first sacrificial layer and the first core material, and the exposed portion is provided at a position adjacent to the first sacrificial layer. A forming process for forming,
And a method for manufacturing a corrosion-resistant diagnostic component.
The preparation step is
A core material preparing step of preparing the first core material,
A sacrificial layer forming step of forming the first sacrificial layer on the surface of the first core material;
The method for manufacturing a corrosion-resistant diagnostic component according to claim 15, further comprising:
The material for corrosion-resistant diagnostic parts is plate-shaped,
The forming step includes
A first cutting step of cutting a flat surface portion of the material for corrosion-resistant diagnostic parts and exposing the first core material in the flat surface portion;
A second cutting step in which both side surface portions of the material for a corrosion-resistant diagnostic component are cut and the first core material is exposed at both side surface portions so as to be continuous with the exposed portion of the first core material in the flat surface portion; ,
The method for manufacturing a corrosion-resistant diagnostic component according to claim 15 or 16, further comprising:
A diagnostic method for diagnosing a corrosion state of a material to be diagnosed, wherein the corrosion-resistant diagnostic component according to any one of claims 1 to 3 is used, and a sacrificial layer containing zinc is formed on a surface of a core material containing aluminum. There
On the surface of the exposed portion, a range within a specified distance from the first sacrificial layer is defined as a first range,
A diagnostic method for diagnosing that the product using the material to be diagnosed has reached the end of its life when a local corrosion mark appears in the first range.
On the surface of the exposed portion, a range farther than a specified distance from the first sacrificial layer is defined as a second range,
The diagnostic method according to claim 18, wherein the residual life of the product is diagnosed by a local corrosion mark appearing in the second range.