Bonding material for reinforcing corrosion resistance, bonding method for reinforcing corrosion resistance, heat exchanger with reinforced corrosion resistance, and manufacturing method therefor

Abstract

Provided is a method for manufacturing a heat exchanger with reinforced corrosion resistance, comprising the steps of: preparing an alloy material including aluminum; processing the alloy material into a component including a tube, a fin, and a header, and a bonding material; and manufacturing a heat exchanger by bonding the component with the bonding material, wherein the bonding is performed at more than 590 ℃ and less than 610 ℃.

Description

Bonding material for enhancing corrosion resistance, bonding method for enhancing corrosion resistance, heat exchanger with enhanced corrosion resistance, and manufacturing method thereof

[0001] The present application relates to a bonding material for enhancing corrosion resistance, a bonding method for enhancing corrosion resistance, a heat exchanger with enhanced corrosion resistance, and a method for manufacturing the same, and more particularly, to a bonding material for enhancing corrosion resistance, a bonding method for enhancing corrosion resistance, a heat exchanger with enhanced corrosion resistance, and a method for manufacturing the same, wherein the temperature and time at which tubes and fins of a heat exchanger are bonded are controlled.

[0002]

[0003] In the manufacture of heat exchangers, the tubes and fins constituting the heat exchanger can be brazed using a filler metal.

[0004] For this purpose, various technologies related to filler materials have been disclosed in the past. For example, Korean Patent Laid-Open Publication No. 10-2016-0142667 discloses a filler material for a fusion welding process, wherein the filler material is in the form of a bundle in which a plurality of wires are twisted together or in the form of a bundle of bundles in which a plurality of the wires are twisted together, and the material of the wire is carbon steel, low alloy steel, high-strength steel, case-hardening steel, heat-resistant steel, corrosion-resistant steel, austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, precipitation-hardening martensitic stainless steel, duplex stainless steel, nickel, nickel alloy, aluminum, aluminum alloy, magnesium, or magnesium alloy, and each of the wires has a circular cross section and the diameter of the circle is 0.22 mm or less.

[0005] For another example, Korean Patent Publication No. 10-1644019 discloses a welding filler metal in which an electrode is positioned on the top of a base material, energy is continuously supplied from the electrode to the top of the base material, and the filler metal is melted by the energy, wherein the cross-section of the filler metal is concavely bent in the direction toward the electrode, the cross-section of the filler metal is a flat plate expressed in width and thickness that is concavely bent toward the electrode, and the thickness of the cross-section of the concavely bent shape is thicker in the central portion than at both ends that are concavely bent, and the corner portion of the cross-section of the filler metal is removed by deburring.

[0006] However, most heat exchangers are experiencing problems related to corrosion.

[0007] Accordingly, there is a need for a method to improve the corrosion resistance of heat exchangers.

[0008]

[0009] The technical problem to be solved by the present application is to provide a bonding material for enhancing corrosion resistance, which minimizes corrosion and improves corrosion resistance, a bonding method for enhancing corrosion resistance, a heat exchanger with enhanced corrosion resistance, and a method for manufacturing the same.

[0010] Another technical problem that the present application seeks to solve is to provide a bonding material for enhancing corrosion resistance, in which the corrosion potential of the bonding material is lower than the corrosion potential of the tubes of the heat exchanger, a bonding method for enhancing corrosion resistance, a heat exchanger with enhanced corrosion resistance, and a method for manufacturing the same.

[0011] The technical problems that this application seeks to solve are not limited to those described above.

[0012]

[0013] To solve the above technical problem, the present application provides a method for manufacturing a heat exchanger with enhanced corrosion resistance.

[0014] According to one embodiment, the method for manufacturing a heat exchanger with enhanced corrosion resistance includes the steps of preparing an alloy material including aluminum, processing the alloy material into components including tubes, fins, and headers and a bonding material, and manufacturing a heat exchanger by bonding the components with the bonding material, wherein the bonding can be performed at a temperature exceeding 590°C and less than 610°C.

[0015] In one embodiment, the bonding may be performed in a time period of more than 5 minutes and less than 15 minutes.

[0016] According to one embodiment, the joining material includes a first filler metal for joining the tube and the fin, and a second filler metal for joining the tube and the header, and the method for manufacturing a heat exchanger with enhanced corrosion resistance may further include a first joining step of joining the tube and the fin with the first filler metal, and a second joining step of joining the tube and the header with the second filler metal.

[0017] In one embodiment, the corrosion potential of the bonding material may be higher than the corrosion potential of the pin and lower than the corrosion potential of the tube.

[0018] In one embodiment, the bonding material has a voltage of -900 mV according to Equation 1 below. SCE Ideal to -730 mV SCE The following corrosion potentials may be included:

[0019] <Formula 1>

[0020] E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%)

[0021] According to one embodiment, the alloy material includes aluminum, silicon, copper, and iron, and may further include at least one of zirconium, manganese, and zinc.

[0022] In one embodiment, the component and the bonding material may include aluminum, silicon, copper, and iron, the tube may further include zirconium and manganese, the pin may further include manganese and zinc, and the bonding material may further include zinc.

[0023] In one embodiment, the second filler metal may contain more silicon than the first filler metal.

[0024]

[0025] To solve the above technical problem, the present application provides a heat exchanger with enhanced corrosion resistance.

[0026] According to one embodiment, the heat exchanger having enhanced corrosion resistance comprises a tube through which a heat-exchanged fluid flows, fins mounted within the tube to provide an area through which the heat is transferred, and a header coupled to both ends of the tube, the tube having the fins mounted therebetween, the header further comprising a first joint joined to connect the tube and the fins, and a second joint joined to connect the tube and the header, wherein the second joint may comprise more silicon than the first joint.

[0027] In one embodiment, the tube, the fin, the header, the first joint, and the second joint may comprise aluminum, silicon, copper, and iron, the tube may further comprise zirconium and manganese, the fin may further comprise manganese and zinc, and the first joint and the second joint may further comprise zinc.

[0028] In one embodiment, the first joint has a corrosion potential higher than the corrosion potential of the pin and lower than the corrosion potential of the tube, but -900 mV according to Equation 1 below. SCE Ideal to -730 mV SCE The following corrosion potentials may be included:

[0029] <Formula 1>

[0030] E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%)

[0031]

[0032] To solve the above technical problem, the present application provides a joining method for enhancing corrosion resistance.

[0033] According to one embodiment, a method of joining used in the manufacture of a heat exchanger comprising a tube through which a heat-exchanged fluid flows, fins mounted inside the tube to provide an area through which the heat is transferred, and headers joined to both ends of the tube, the tube having the fins mounted therebetween, wherein the tube and the fins can be joined at a temperature of more than 590°C and less than 610°C for more than 5 minutes and less than 15 minutes.

[0034]

[0035] To solve the above technical problem, the present application provides a bonding material for enhancing corrosion resistance.

[0036] According to one embodiment, a heat exchanger is provided comprising a tube through which a heat-exchanged fluid flows, fins mounted inside the tube to provide an area through which the heat is transferred, and headers joined to opposite ends of the tube, the heat exchanger comprising a first filler material for joining the tube and the fins, and a second filler material for joining the tube and the header, wherein the second filler material may contain more silicon than the first filler material.

[0037] According to one embodiment, the bonding material for enhancing the corrosion resistance has a corrosion potential higher than the corrosion potential of the pin and lower than the corrosion potential of the tube, but -900 mV according to Equation 1 below. SCE Ideal to -730 mV SCE The following corrosion potentials may be included:

[0038] <Formula 1>

[0039] E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%)

[0040]

[0041] According to an embodiment of the present application, a method for manufacturing a heat exchanger with enhanced corrosion resistance may be provided, including the steps of preparing an alloy material including aluminum, processing the alloy material into parts including a tube, a fin, and a header, and a bonding material, and manufacturing a heat exchanger by bonding the parts with the bonding material, wherein the bonding is performed at a temperature exceeding 590°C and less than 610°C.

[0042] Additionally, according to an embodiment of the present application, the method for manufacturing a heat exchanger with enhanced corrosion resistance may include performing the bonding for more than 5 minutes and less than 15 minutes.

[0043] Due to this, corrosion can be minimized and corrosion resistance can be improved in the heat exchanger manufactured according to the present application.

[0044] Additionally, according to an embodiment of the present application, the corrosion potential of the bonding material may be higher than the corrosion potential of the pin and lower than the corrosion potential of the tube.

[0045] Accordingly, corrosion of the tube in the heat exchanger can be minimized.

[0046]

[0047] FIG. 1 is a drawing for explaining a method for manufacturing a heat exchanger with enhanced corrosion resistance according to an embodiment of the present application.

[0048] Figure 2 is a drawing for explaining a bonding method according to an embodiment of the present application.

[0049] FIGS. 3 and 4 are drawings for explaining a heat exchanger with enhanced corrosion resistance according to an embodiment of the present application.

[0050] Fig. 5 is a graph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-1 to 1-5 of the present application.

[0051] Fig. 6 is a graph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-3, 1-6, and 1-9 of the present application.

[0052] FIG. 7 is a photograph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-1, 1-3, and 1-5 of the present application.

[0053] Fig. 8 is a graph evaluating the standard deviation of corrosion potential in the tubes of the heat exchanger according to Experimental Examples 1-1 to 1-5 of the present application.

[0054] Figure 9 is a corrosion potential contour line according to the joining temperature and zinc content when the first filler metal according to the experimental example of the present application contains 7.5 wt% of silicon.

[0055] Figure 10 is a corrosion potential contour line according to the joining temperature and zinc content when the first filler metal according to the experimental example of the present application contains 10 wt% of silicon.

[0056] Figure 11 is a corrosion potential contour line according to the silicon and zinc contents when the first filler metal according to the experimental example of the present application is joined at 600°C.

[0057] Fig. 12 is a photograph of the first joint of the heat exchanger according to Experimental Example 1-3 of the present application.

[0058] Figure 13 is a photograph of a joint of a heat exchanger joined through conventional brazing fastening according to a comparative example.

[0059]

[0060] Hereinafter, preferred embodiments of the present application will be described in detail with reference to the attached drawings. However, the technical concepts of the present application are not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the concepts of the present application to those skilled in the art.

[0061] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. Furthermore, in the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical content.

[0062] Additionally, although terms such as first, second, and third have been used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. Additionally, the term "and / or" has been used herein to mean including at least one of the components listed before and after.

[0063] In the specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof described in the specification, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, the term "connection" is used in the present specification to mean both indirectly connecting multiple components and directly connecting them.

[0064] Additionally, the term "bonding" in this specification may be used to mean brazing, which joins components of a heat exchanger containing alloy materials using a bonding agent containing the alloy material. More specifically, the term "bonding" in this specification may be used to mean brazing, which joins components of a heat exchanger using an alloy material having a lower melting point than the components of the heat exchanger as a bonding agent.

[0065] In addition, when describing the present application below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present application, the detailed description will be omitted.

[0066]

[0067] FIG. 1 is a drawing for explaining a method for manufacturing a heat exchanger with enhanced corrosion resistance according to an embodiment of the present application, FIG. 2 is a drawing for explaining a joining method according to an embodiment of the present application, and FIGS. 3 and 4 are drawings for explaining a heat exchanger with enhanced corrosion resistance according to an embodiment of the present application.

[0068] Referring to Fig. 1, an alloy material including aluminum can be prepared (S100).

[0069] According to one embodiment, the alloy material may be used as a raw material for manufacturing a heat exchanger (100). More specifically, the alloy material may include a main material and an additional material for manufacturing the heat exchanger (100). The alloy material may include, for example, aluminum, silicon, copper, and iron as the main material. The alloy material may further include, for example, at least one of zirconium, manganese, and zinc as the additional material.

[0070] According to one embodiment, the heat exchanger (100) may include a tube (10) through which a fluid to be heat-exchanged flows, as shown in FIGS. 3 and 4, fins (20) mounted inside the tube (10) to provide an area through which the heat is transferred, and headers (30) coupled to both ends of the tube (10) with the tube (10) having the fins (20) mounted therebetween.

[0071] According to one embodiment, the alloy material may optionally include the additional material depending on the components of the heat exchanger (100), that is, the tube (10), the fin (20), and the header (30). For example, the alloy material may include aluminum, silicon, copper, and iron as the main material. When the component of the heat exchanger (100) is the tube (10), the alloy material may include the main material, and further include, for example, zirconium and manganese as the additional material. When the component of the heat exchanger (100) is the fin (20), the alloy material may include the main material, and further include, for example, manganese and zinc as the additional material. Specifically, for example, when the component is the tube (10), the alloy material may include silicon of 0.001 wt% or more and 0.15 wt% or less, copper of 0.001 wt% or more and 0.01 wt% or less, iron of 0.001 wt% or more and 0.1 wt% or less, zirconium of 0.05 wt% or more and 0.2 wt% or less, manganese of 0.001 wt% or more and 1.5 wt% or less, and aluminum of the remaining content so that the total sum is 100 wt%. More specifically, for example, when the component is the tube (10), the alloy material may include 0.15 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.2 wt% of zirconium, 1.5 wt% of manganese, and the remainder of aluminum so that the total amount is 100 wt%. However, the present invention is not limited thereto. In addition, specifically, for example, when the component is the fin (20), the alloy material may include 0.001 wt% to 1.2 wt% of silicon, 0.001 wt% to 0.6 wt% of copper, 0.001 wt% to 1.4 wt% of iron, 0.001 wt% to 3 wt% of manganese, and 0.2 wt% to 3.It may include 5 wt% or less of zinc, and the remainder of aluminum so that the total sum is 100 wt%. More specifically, for example, when the component is the pin (20), the alloy material may include 0.6 wt% of silicon, 0.3 wt% of copper, 0.7 wt% of iron, 1.5 wt% of manganese, 2.5 wt% of zinc, and the remainder of aluminum so that the total sum is 100 wt%. However, the present invention is not limited thereto.

[0072] According to one embodiment, the heat exchanger (100) may further include a first joint (25) and a second joint (35), as illustrated in FIGS. 3 and 4. The first joint (25) and the second joint (35) may be formed by a jointing material. Specifically, the jointing material may include a first filler metal and a second filler metal. More specifically, the first filler metal may form the first joint (25) connecting the tube (10) and the fin (20). The second filler metal may form the second joint (35) connecting the tube (10) and the header (30).

[0073] According to one embodiment, the alloy material may optionally include the additional material according to the joining material, which includes a first filler metal forming the first joint (25) of the heat exchanger (100) and a second filler metal forming the second joint (35). For example, the alloy material may include aluminum, silicon, copper, and iron as the main materials, and may further include, for example, zinc as the additional material. Specifically, for example, in the case of the first joint (25), the alloy material may include silicon in an amount of 6 wt% or more to 9 wt% or less, copper in an amount of 0.001 wt% or more to 0.01 wt% or less, iron in an amount of 0.001 wt% or more to 0.1 wt% or less, zinc in an amount of 0.2 wt% or more to 1 wt% or less, and aluminum in a remainder such that the total amount is 100 wt%. More specifically, for example, in the case of the first joint (25), the alloy material may include 7.5 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.7 wt% of zinc, and the remainder of aluminum so that the total sum is 100 wt%. However, it is not limited thereto. In addition, specifically, for example, in the case of the second joint (35), the alloy material may include 10 wt% or more to 20 wt% of silicon, 0.001 wt% or more to 0.01 wt% or less of copper, 0.001 wt% or more to 0.1 wt% or less of iron, 0.2 wt% or more to 0.8 wt% or less of zinc, and the remainder of aluminum so that the total sum is 100 wt%. More specifically, for example, in the case of the second joint (35), the alloy material may include 15 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.5 wt% of zinc, and the remainder of aluminum so that the total amount is 100 wt%. However, the present invention is not limited thereto.

[0074] Continuing with reference to FIG. 1, the alloy material can be processed into the component including the tube (10), the pin (20), and the header (30), and the bonding material (S200).

[0075] According to one embodiment, the alloy material can be processed into a tube (10) having a tubular shape including a hollow space therein so that a heat-exchanged fluid can flow, as shown in FIGS. 3 and 4.

[0076] According to one embodiment, the alloy material can be processed into the fin (20) having a plurality of alternating convex and concave portions protruding to provide an area through which heat is transferred, as illustrated in FIGS. 3 and 4.

[0077] According to one embodiment, the alloy material, when combined with the tube (10), as illustrated in FIG. 3, can be processed into the header (30) that allows a fluid to pass through the inside of the tube (10) to be heat exchanged.

[0078] According to one embodiment, the alloy material can be processed into the bonding material for bonding the components of the heat exchanger (100), i.e., the tube (10), the fin (20), and the header (30), as shown in FIGS. 3 and 4. More specifically, the alloy material can be processed into the bonding material, which includes the first filler material for bonding the tube (10) and the fin (20), and the second filler material for bonding the tube (10) and the header (30).

[0079] In one embodiment, the second filler metal may contain more silicon than the first filler metal. Specifically, for example, the first filler metal may contain 6 wt% or more and 9 wt% or less of silicon, and the second filler metal may contain 10 wt% or more and 20 wt% or less of silicon. More specifically, for example, the first filler metal may contain 7.5 wt% of silicon, and the second filler metal may contain 15 wt% of silicon. However, the present invention is not limited thereto.

[0080] Due to this, the joining of the tube (10) and the pin (20) by the first filler material and the joining of the tube (10) and the header (30) by the second filler material can be facilitated.

[0081] Continuing with reference to FIG. 1, the heat exchanger (100) may be manufactured by bonding the components with the bonding material (S300). More specifically, referring to FIGS. 2 to 4, the tube (10) and the fin (20) may be bonded for the first time with the first filler material (S310). Continuing with reference to FIGS. 2 and 3, the tube and the header may be bonded for the second time with the second filler material (S320). The first bonding may be performed, for example, at a temperature exceeding 590°C and less than 610°C. More specifically, for example, the first bonding may be performed at 600°C. In addition, the first bonding may be performed for, for example, more than 5 minutes and less than 15 minutes. More specifically, for example, the first bonding may be performed for 10 minutes.

[0082] Due to this, corrosion can be minimized and corrosion resistance can be improved in the heat exchanger (100) manufactured according to the present application.

[0083] On the other hand, unlike the embodiment of the present application, when the tube and the fin are joined at 610° C. or higher and / or for 15 minutes or longer, diffusion, precipitation, for example, precipitation, recrystallization, and / or grain growth of alloy components in the tube may occur. In addition, silicon included in the filler metal joining the tube and the fin may penetrate into the tube.

[0084] Heat exchangers manufactured accordingly may have high corrosiveness but low corrosion resistance.

[0085] On the other hand, unlike the embodiment of the present application, when the tube and the fin are joined at 590°C or less and / or for 5 minutes or less, the joining area connecting the tube and the fin may be small, and the bonding strength may be reduced in the joining area.

[0086] Heat exchangers manufactured accordingly may have high corrosiveness but low corrosion resistance.

[0087] However, according to an embodiment of the present application, the first bonding in which the tube (10) and the fin (20) are bonded can be performed, for example, at a temperature exceeding 590°C and less than 610°C and / or exceeding 5 minutes and less than 15 minutes.

[0088] Due to this, corrosion can be minimized and corrosion resistance can be improved in the heat exchanger (100) manufactured according to the present application.

[0089] According to one embodiment, the corrosion potential of the bonding material may be higher than the corrosion potential of the pin (20) and lower than the corrosion potential of the tube (10). More specifically, the bonding material may have a corrosion potential of -900 mV according to Equation 1 below. SCE Ideal to -730 mV SCE The following corrosion potentials may be included:

[0090] <Formula 1>

[0091] E corr (mVSCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%)

[0092]

[0093] Due to this, the bonding material can act as a sacrificial anode for the tube (10).

[0094] Accordingly, corrosion of the tube (10) in the heat exchanger (100) can be minimized.

[0095] On the other hand, unlike the embodiments of the present application, if the corrosion potential of the bonding material is higher than the corrosion potential of the tube, the tube can act as a sacrificial anode for the bonding material.

[0096] Accordingly, corrosion of the tubes in the heat exchanger may be accelerated.

[0097] However, according to an embodiment of the present application, the corrosion potential of the bonding material may be lower than the corrosion potential of the tube (10).

[0098] Due to this, the bonding material can act as a sacrificial anode for the tube (10), and thus, corrosion of the tube (10) in the heat exchanger (100) can be minimized.

[0099] According to the method for manufacturing a heat exchanger with enhanced corrosion resistance according to the embodiment of the present application described above, a heat exchanger (100) with enhanced corrosion resistance can be provided.

[0100] According to one embodiment, the heat exchanger (100) may include the tube (10) through which a heat-exchanged fluid flows, fins (20) mounted inside the tube (10) to provide an area through which the heat is transferred, and headers (30) coupled to both ends of the tube (10) with the tube (10) having the fins (20) mounted therebetween. In addition, the heat exchanger (100) may further include the first joint (25) joined so that the tube (10) and the fins (20) are connected, and the second joint (35) joined so that the tube (10) and the header (30) are connected. The tube (10), the fins (20), the header (30), the first joint (25), and the second joint (35) may include, for example, aluminum, silicon, copper, and iron. In addition, the tube (10) may further include, for example, zirconium and manganese. In addition, the pin (20) may further include, for example, manganese and zinc. In addition, the first joint (25) and the second joint (35) may further include, for example, zinc. In addition, the second joint (35) may further include, for example, more silicon than the first joint (25).

[0101] Due to this, the first joint (25) can have a corrosion potential that is higher than the corrosion potential of the pin (20) and lower than the corrosion potential of the tube (10). More specifically, the first joint (25) can have a corrosion potential of -900 mV according to the above formula 1. SCE Ideal to -730 mV SCE The following corrosion potentials may be included:

[0102] Due to this, the first joint (25) can serve as a sacrificial anode for the tube (10).

[0103] Accordingly, corrosion of the tube (10) in the heat exchanger (100) can be minimized.

[0104] On the other hand, unlike the embodiment of the present application, if the corrosion potential of the joint is higher than the corrosion potential of the tube, the tube can act as a sacrificial anode for the joint.

[0105] Accordingly, corrosion of the tubes in the heat exchanger may be accelerated.

[0106] However, according to an embodiment of the present application, the corrosion potential of the first joint (25) may be lower than the corrosion potential of the tube (10).

[0107] Due to this, the first joint (25) can serve as a sacrificial anode for the tube (10), and thus, corrosion of the tube (10) in the heat exchanger (100) can be minimized.

[0108]

[0109] Hereinafter, specific experimental examples and characteristic evaluation results according to embodiments of the present application are described.

[0110]

[0111] Manufacturing of a heat exchanger (ex1-1) according to Experimental Example 1-1

[0112] The tube (10) was manufactured using the alloy material containing 0.15 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.2 wt% of zirconium, 1.5 wt% of manganese, and the remainder of aluminum so that the total amount is 100 wt%.

[0113] The pin (20) was manufactured using the alloy material containing 0.6 wt% of silicon, 0.3 wt% of copper, 0.7 wt% of iron, 1.5 wt% of manganese, 2.5 wt% of zinc, and the remainder of aluminum so that the total amount is 100 wt%.

[0114] The first filler metal was manufactured from the alloy material containing 7.5 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.7 wt% of zinc, and the remainder being aluminum so that the total amount is 100 wt%.

[0115] With the above first filler material, the tube (10) and the fin (20) were joined at 580°C for 10 minutes to form the first joint (25) connecting the tube (10) and the fin (20), and a heat exchanger (ex1-1) according to Experimental Example 1-1 was manufactured.

[0116] The composition of the alloy material for manufacturing the heat exchanger according to the above experimental example 1-1 can be summarized as shown in Table 1 below.

[0117]

[0118] Classification Alloy Material (wt%) Silicon Copper Iron Zirconium Manganese Zinc Aluminum Tube (10) 0.15 0.01 0.10 2 1.50 9 8.04 Pin (20) 0.6 0.30 70 1.52 59 4.4 First joint (25) 7.5 0.01 0.10 0 0.79 1.69

[0119]

[0120] Manufacturing of a heat exchanger (ex1-2) according to Experimental Example 1-2

[0121] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 590°C for 10 minutes to manufacture a heat exchanger (ex1-2) according to experimental example 1-2.

[0122]

[0123] Manufacturing of a heat exchanger (ex1-3) according to Experimental Example 1-3

[0124] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 600°C for 10 minutes to manufacture a heat exchanger (ex1-3) according to experimental example 1-3.

[0125]

[0126] Manufacturing of a heat exchanger (ex1-4) according to Experimental Example 1-4

[0127] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 610°C for 10 minutes to manufacture a heat exchanger (ex1-4) according to experimental example 1-4.

[0128]

[0129] Manufacturing of a heat exchanger (ex1-5) according to Experimental Example 1-5

[0130] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were bonded at 620°C for 10 minutes to manufacture a heat exchanger (ex1-5) according to experimental example 1-5.

[0131]

[0132] Manufacturing of a heat exchanger (ex1-6) according to Experimental Example 1-6

[0133] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were bonded at 600°C for 3 minutes to manufacture a heat exchanger (ex1-6) according to experimental example 1-6.

[0134]

[0135] Manufacturing of a heat exchanger (ex1-7) according to Experimental Example 1-7

[0136] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 600°C for 5 minutes to manufacture a heat exchanger (ex1-7) according to experimental example 1-7.

[0137]

[0138] Manufacturing of a heat exchanger (ex1-8) according to Experimental Example 1-8

[0139] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 600°C for 15 minutes to manufacture a heat exchanger (ex1-8) according to experimental example 1-8.

[0140]

[0141] Manufacturing of a heat exchanger (ex1-9) according to Experimental Example 1-9

[0142] In the above-described experimental example 1-1 (ex1-1), the tube (10) and the fin (20) were joined at 600°C for 20 minutes to manufacture a heat exchanger (ex1-9) according to experimental example 1-9.

[0143]

[0144] The experimental examples 1-1 to 1-9 described above can be summarized as shown in Table 2 below.

[0145] Classification Bonding temperature (℃) Bonding time (min) Heat exchanger according to Experimental Example 1-1 (ex1-1) 580 10 Heat exchanger according to Experimental Example 1-2 (ex1-2) 590 10 Heat exchanger according to Experimental Example 1-3 (ex1-3) 600 10 Heat exchanger according to Experimental Example 1-4 (ex1-4) 610 10 Heat exchanger according to Experimental Example 1-5 (ex1-5) 620 10 Heat exchanger according to Experimental Example 1-6 (ex1-6) 600 3 Heat exchanger according to Experimental Example 1-7 (ex1-7) 600 5 Heat exchanger according to Experimental Example 1-8 (ex1-8) 600 15 Heat exchanger according to Experimental Example 1-9 (ex1-9) 600 20

[0146]

[0147] Fig. 5 is a graph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-1 to 1-5 of the present application.

[0148] Referring to Fig. 5, the brazing success rate in the first joint (25) of the heat exchanger (ex1-3) according to the experimental example 1-3, which has the highest brazing success rate among the experimental examples, was evaluated as 100%.

[0149] Accordingly, when the first bonding is performed at 600°C, an excellent brazing success rate can be demonstrated.

[0150]

[0151] Fig. 6 is a graph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-3, 1-6, and 1-9 of the present application.

[0152] Referring to Fig. 6, the brazing success rate in the first joint (25) of the heat exchanger (ex1-3) according to the experimental example 1-3, which has the highest brazing success rate among the experimental examples, was evaluated as 100%.

[0153] Accordingly, when the first bonding is performed for 10 minutes, an excellent brazing success rate can be demonstrated.

[0154]

[0155] FIG. 7 is a photograph evaluating the brazing success rate at the first joint of the heat exchanger according to Experimental Examples 1-1, 1-3, and 1-5 of the present application.

[0156] Referring to Fig. 7, the brazing success rate at the first joint (25) of the heat exchanger (ex1-3) according to the experimental example 1-3 was evaluated as 100%.

[0157] Accordingly, when the first bonding is performed at 600°C for 10 minutes, an excellent brazing success rate can be demonstrated.

[0158]

[0159] Fig. 8 is a graph evaluating the standard deviation of corrosion potential in the tubes of the heat exchanger according to Experimental Examples 1-1 to 1-5 of the present application.

[0160] In order to evaluate the above corrosion potential standard deviation, the tube (10) was cut from the heat exchanger (ex1-1 to ex1-5) according to the above experimental examples 1-1 to 1-5, and the corrosion potential of the tube (10) was measured for 48 hours in a salt water acetic acid test (SWAAT) solution environment according to the ASTM G85 standard. At this time, a saturated calomel electrode (SCE) was used as the reference electrode.

[0161] Referring to Fig. 8, the average value and standard deviation of the corrosion potential over time of the tubes (ex1-1 to ex1-5) according to the above experimental examples 1-1 to 1-5 can be observed.

[0162] Through Fig. 8, it can be seen that the standard deviation is stably maintained at 0.01 or less at a temperature exceeding the experimental example 1-2 (ex1-2), that is, at 592 ℃ or higher.

[0163] Accordingly, it can be proven that when the first bonding is performed at a temperature exceeding 590°C, more specifically, at a temperature exceeding 592°C, corrosion can be minimized and corrosion resistance can be improved in the manufactured heat exchanger (100).

[0164]

[0165] FIG. 9 is a corrosion potential contour line according to the joining temperature and zinc content when the first filler metal according to the experimental example of the present application contains 7.5 wt% of silicon, FIG. 10 is a corrosion potential contour line according to the joining temperature and zinc content when the first filler metal according to the experimental example of the present application contains 10 wt% of silicon, and FIG. 11 is a corrosion potential contour line according to the silicon and zinc content when the first filler metal according to the experimental example of the present application is joined at 600°C.

[0166] The above corrosion potential contour line can be applied to the above equation 1.

[0167] Referring to FIGS. 9 to 11, considering that the corrosion potential of the first filler metal must be higher than the corrosion potential of the pin (20) and lower than the corrosion potential of the tube (10), the silicon and zinc contents can be determined in the first filler metal used at a maximum joining temperature of 590° C. or higher and 605° C. or lower.

[0168] Through FIGS. 9 to 11, it can be seen that the maximum temperature of the bonding, i.e., the brazing, is preferably controlled to be 590°C or more and 605°C or less, and the exposure time at the maximum temperature is preferably controlled to be 7 minutes or more and 12 minutes or less.

[0169]

[0170] Fig. 12 is a photograph of the first joint of a heat exchanger according to Experimental Example 1-3 of the present application, and Fig. 13 is a photograph of the joint of a heat exchanger joined through conventional brazing fixation according to a comparative example.

[0171] To evaluate the above corrosion potential standard deviation, the heat exchangers (ex1-3, cf) according to the above experimental examples 1-3 and the above comparative examples were immersed in a salt water acetic acid test (SWAAT) solution environment of the ASTM G85 standard for 12 weeks, then taken out and cross-sections were photographed.

[0172] Referring to Fig. 12, it can be observed that no corrosion occurred at all in the heat exchanger (ex1-3) according to the experimental example 1-3.

[0173] On the other hand, referring to Fig. 13, in the heat exchanger (cf) according to the comparative example, it can be observed that a lot of corrosion (cr) has occurred around the joint.

[0174] Accordingly, the tube (10) comprises 0.15 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.2 wt% of zirconium, 1.5 wt% of manganese, and the remainder of aluminum so that the total sum is 100 wt%, the pin (20) comprises 0.6 wt% of silicon, 0.3 wt% of copper, 0.7 wt% of iron, 1.5 wt% of manganese, 2.5 wt% of zinc, and the remainder of aluminum so that the total sum is 100 wt%, and the first filler metal comprises 7.5 wt% of silicon, 0.01 wt% of copper, 0.1 wt% of iron, 0.7 wt% of zinc, and the remainder of aluminum so that the total sum is 100 wt%, and as the first filler metal, When the tube (10) and the fin (20) are joined at 600°C for 10 minutes, and the first joint (25) connecting the tube (10) and the fin (20) is formed, it can be proven that corrosion can be minimized and corrosion resistance can be improved in the heat exchanger (100) manufactured.

[0175]

[0176] While the present application has been described in detail using preferred embodiments, the scope of the present application is not limited to the specific embodiments and should be interpreted in accordance with the appended claims. Furthermore, those skilled in the art will appreciate that numerous modifications and variations are possible without departing from the scope of the present application.

Claims

1. A step of preparing an alloy material containing aluminum; A step of processing the above alloy material into parts including tubes, fins, and headers, and a joining material; and Including a step of manufacturing a heat exchanger by bonding the above components with the above bonding material, A method for manufacturing a heat exchanger with enhanced corrosion resistance, wherein the bonding is performed at a temperature exceeding 590°C and less than 610°C.

2. In paragraph 1, A method for manufacturing a heat exchanger with enhanced corrosion resistance, wherein the bonding is performed for more than 5 minutes and less than 15 minutes.

3. In paragraph 1, The above-mentioned joining material comprises a first filler material for joining the tube and the pin, and a second filler material for joining the tube and the header. A first joining step of joining the tube and the pin with the first filler material; and A method for manufacturing a heat exchanger with enhanced corrosion resistance, further comprising a second joining step of joining the tube and the header with the second filler metal.

4. In paragraph 1, A method for manufacturing a heat exchanger with enhanced corrosion resistance, wherein the corrosion potential of the bonding material is higher than the corrosion potential of the fin and lower than the corrosion potential of the tube.

5. In paragraph 1, The above bonding material is -900 mV according to Equation 1 below. SCE Above -730 mV SCE A method for manufacturing a heat exchanger having enhanced corrosion resistance, comprising the following corrosion potentials: <Formula 1> E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%) 6. In paragraph 1, The above alloy material is, Contains aluminum, silicon, copper, and iron; A method for manufacturing a heat exchanger having enhanced corrosion resistance, the method further comprising at least one of zirconium, manganese, and zinc.

7. In paragraph 1, The above components and the bonding material include aluminum, silicon, copper, and iron, The above tube further comprises zirconium and manganese, The above pin further comprises manganese and zinc, A method for manufacturing a heat exchanger with enhanced corrosion resistance, wherein the above bonding material further contains zinc.

8. In paragraph 3, A method for manufacturing a heat exchanger with enhanced corrosion resistance, wherein the second filler metal contains more silicon than the first filler metal.

9. A tube through which a heat-exchanging fluid flows; Fins mounted inside the tube to provide an area through which the heat is transferred; and A tube having the above pins mounted thereon, and a header coupled to both ends of the tube, A first joint joined so that the above tube and the above pin are connected; and Further comprising a second joint joined so that the above tube and the above header are connected, A heat exchanger having enhanced corrosion resistance, wherein the second joint comprises more silicon than the first joint.

10. In paragraph 9, The above tube, the above pin, the above header, the above first joint, and the above second joint comprise aluminum, silicon, copper, and iron, The above tube further comprises zirconium and manganese, The above pin further comprises manganese and zinc, A heat exchanger having enhanced corrosion resistance, wherein the first joint and the second joint further comprise zinc.

11. In paragraph 9, The above first joint is, Having a corrosion potential higher than the corrosion potential of the above pin and lower than the corrosion potential of the above tube, -900 mV according to Equation 1 below SCE Above -730 mV SCE A heat exchanger having enhanced corrosion resistance, comprising the following corrosion potentials: <Formula 1> E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%) 12. A joining method used in the manufacture of a heat exchanger including a tube through which a fluid to be heat-exchanged flows, fins mounted inside the tube to provide an area through which the heat is transferred, and a header connected to both ends of the tube, with the tube having the fins mounted therebetween, A joining method for enhancing corrosion resistance, wherein the tube and the fin are joined at a temperature of more than 590°C and less than 610°C for more than 5 minutes and less than 15 minutes.

13. A joint material used in the manufacture of a heat exchanger, which comprises a tube through which a fluid to be heat-exchanged flows, fins mounted inside the tube to provide an area through which the heat is transferred, and headers connected to both ends of the tube, with the tube having the fins mounted therebetween, A first filler material for joining the above tube and the above pin; and Including a second filler metal for joining the above tube and the above header, The second filler metal is a bonding material for enhancing corrosion resistance, which contains more silicon than the first filler metal.

14. In paragraph 13, Having a corrosion potential higher than the corrosion potential of the above pin and lower than the corrosion potential of the above tube, -900 mV according to Equation 1 below SCE Above -730 mV SCE A bonding agent for enhancing corrosion resistance, comprising the following corrosion potentials: <Formula 1> E corr (mV SCE ) = -82 - 0.8 X Temperature - 687 X Zn% - 39 X Si% + 0.82 X (Temperature X Zn%) + 0.035 X (Temperature X Si%)

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