Material testing apparatus and material testing method

Abstract

The present invention provides a material testing apparatus and a material testing method, and may include a chamber having an internal space and accommodating a specimen and a test solution, an electrode unit having a first electrode and a second electrode immersed in the test solution, and a test unit that performs a characteristic test to evaluate the corrosion characteristics of the specimen by applying a second potential to the specimen after applying a first potential to the specimen immersed in the test solution.

Description

Technology Field

[0001] The present invention relates to a material testing apparatus and a material testing method. Background Technology

[0002] With the recent rise in demand for measures against global warming, ammonia, which does not emit carbon dioxide during combustion, is attracting attention as a next-generation energy source. Furthermore, as ammonia can function as a carrier for hydrogen, which is difficult to transport and store, demand for it is increasing. Accordingly, research and development on ammonia storage and transport technologies, particularly regarding the construction of large ammonia tanks made of high-strength steel, is being continuously conducted.

[0003] Meanwhile, since ammonia is corrosive to steel, stress corrosion cracking (SCC) can occur in steel in liquid or gaseous ammonia. To elucidate the mechanism of such ammonia SCC, it is essential to verify the ammonia corrosion behavior of steel. The problem to be solved

[0004] The present invention aims to provide a material testing apparatus and a material testing method capable of performing a corrosion characteristic test after cleaning the surface of a specimen. means of solving the problem

[0005] One aspect of the present invention provides a material testing apparatus comprising: a chamber having an internal space and accommodating a specimen and a test solution; an electrode section having a first electrode and a second electrode immersed in the test solution; and a test unit that performs a characteristic test to evaluate the corrosion characteristics of the specimen by applying a second potential to the specimen after applying a first potential to the specimen immersed in the test solution.

[0006] In addition, the test unit can reduce oxides on the surface of the specimen by applying a first potential to the specimen for a preset time.

[0007] In addition, the test unit can sense the change in current of the specimen while applying the second potential, which is a potential that changes over time within a preset range, to the specimen.

[0008] In addition, the distance between the specimen and the first electrode may be smaller than or equal to the distance between the specimen and the second electrode.

[0009] Additionally, the internal space of the chamber is sealed, and each of the specimen, the first electrode, and the second electrode may be electrically connected to the test unit while having at least a portion disposed in the internal space.

[0010] Additionally, the chamber may comprise a chamber body forming the internal space, a chamber cover coupled to the chamber body to cover the internal space, and an electrode insertion module disposed in the chamber cover and having an opening communicating with the internal space.

[0011] In addition, the electrode insertion module may be provided in multiple numbers so that the specimen, the first electrode, and the second electrode are each inserted.

[0012] Additionally, the electrode insertion module may include a first body connected to the chamber cover, a second body coupled to one side of the first body, and an auxiliary sealing member disposed on the first body or the second body to maintain a sealed state of the internal space.

[0013] Another aspect of the present invention may comprise the steps of: placing a test solution, a specimen, a first electrode, and a second electrode in a chamber; applying a first potential to a specimen immersed in the test solution in the chamber to clean the surface of the specimen; and applying a second potential to a specimen immersed in the test solution in the chamber to perform a characteristic test to evaluate the corrosion characteristics of the specimen.

[0014] Additionally, at least a portion of the specimen, the first electrode, and the second electrode are disposed in the sealed internal space of the chamber, and the distance between the specimen and the first electrode may be smaller than or equal to the distance between the specimen and the second electrode. Effects of the invention

[0015] A material testing apparatus and a material testing method according to one embodiment of the present invention can improve the reliability of test data by cleaning the surface of a specimen before testing the corrosion characteristics of the specimen, and can quickly and efficiently verify the corrosion characteristics of the specimen by performing both surface cleaning and corrosion characteristic testing of the specimen in a single apparatus. Brief explanation of the drawing

[0016] FIG. 1 is a conceptual drawing illustrating a material testing apparatus according to one embodiment of the present invention. Figure 2 is a diagram conceptually showing the arrangement of the specimen, the first electrode, and the second electrode of Figure 1. FIG. 3 is a perspective view exemplarily showing the chamber of FIG. 1. Figure 4 is a cross-sectional view taken along the line A-A' of Figure 3. Figure 5 is a drawing showing an enlarged view of a part of Figure 3. Figure 6 is a cross-sectional view of the first insertion module of Figure 5. FIG. 7 is a flowchart illustrating a material testing method according to one embodiment of the present invention. Specific details for implementing the invention

[0017] The structure and operation of the present invention will be described in detail below with reference to embodiments of the present invention illustrated in the attached drawings.

[0018] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0020] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0021] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0022] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0023] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the following embodiments are not necessarily limited to those illustrated.

[0024] The present invention relates to a material testing apparatus and a material testing method for testing the characteristics of a specimen by applying a potential to a specimen immersed in a test solution. The material testing apparatus and the material testing method of the present invention may have various specimens and test solutions depending on the test purpose and conditions.

[0025] In the following, the characteristic test may be a test to verify the characteristics of the specimen. In particular, the characteristic test may be an electrochemical test to verify corrosion characteristics such as corrosion resistance, passivation, and corrosion rate of the specimen. For example, the characteristic test may be a potentiodynamic polarization test. Alternatively, the characteristic test may be a potentiodynamic polarization test, a constant current polarization test, an open-circuit potential measurement test, etc.

[0026] In the following, the specimen may be a test subject material for verifying characteristics. The specimen may be a material that corrodes when subjected to stress while exposed to a specific corrosive environment. The material testing apparatus and material testing method of the present invention can verify the characteristics of the specimen by performing a characteristic test while the specimen is immersed in a test solution.

[0027] For example, the specimen may be a sample of carbon steel or other metal or alloy material. The type, size, shape, etc. of the specimen are not particularly limited and may be selected in a suitable state where a potential can be applied and corrosion characteristics can be verified.

[0028] In the following, the test solution may be a substance capable of causing corrosion to the specimen. For example, the test solution may be liquid ammonia, gaseous ammonia, liquid argon, liquid oxygen, liquid hydrogen, liquid nitrogen, etc., or a mixture thereof. That is, the test solution may be various substances capable of corroding the immersed specimen.

[0029] In addition, the test solution can function as an electrolyte used for characteristic testing of a specimen. The material testing apparatus and material testing method of the present invention perform electrochemical characteristic testing with the specimen immersed in the test solution, and the test solution can function as an electrolyte in the characteristic testing.

[0030] In one embodiment, the specimen may be selected according to the test solution. For example, the specimen may be a sample taken from steel to be used in equipment or facilities exposed to the test solution environment. That is, the specimen and the test solution may be appropriately selected according to the test purpose and environment.

[0031] For convenience of explanation, the following description focuses on examples of a material testing apparatus and a material testing method for performing a potentiodynamic polarization test on steel exposed to a liquid ammonia environment. The following description focuses on examples where the test solution is liquid ammonia and the specimen is carbon steel, and the characteristic test may be a potentiodynamic polarization test. However, it is not limited thereto, and the characteristic test, specimen, and test solution may be set in various ways.

[0032] FIG. 1 is a conceptual drawing showing a material testing device (1) according to one embodiment of the present invention.

[0033] Referring to FIG. 1, the material testing device (1) may be equipped with a chamber (10), an electrode section (EP), and a test unit (20).

[0034] The chamber (10) may have an internal space. A test solution (TS) may be injected into the internal space of the chamber (10). Additionally, a specimen (SP) may be introduced into the internal space of the chamber (10) and immersed in the test solution (TS). A characteristic test may be performed in the internal space of the chamber (10).

[0035] The electrode section (EP) may have a first electrode (RE) and a second electrode (CE). The electrode section (EP) may be used for electrochemical characteristic testing. The first electrode (RE) and the second electrode (CE) may be placed in the internal space of the chamber (10) and immersed in a test solution (TS).

[0036] The first electrode (RE) can provide a reference potential in a characteristic test. The first electrode (RE) may be a reference electrode that serves as a standard for applying potential to a specimen (SP). The first electrode (RE) may be equipped with various types of electrodes capable of stably maintaining potential, such as a calomel electrode (SCE) or an AgCl electrode.

[0037] The second electrode (CE) can provide a flow of current in a characteristic test. The second electrode (CE) may be a counter electrode positioned to apply a predetermined potential to the specimen (SP) or to allow current to flow. The second electrode (CE) may be provided with various types of electrochemically stable materials, such as platinum or carbon rods.

[0038] That is, the first electrode (RE) can function as a reference electrode used for electrochemical characteristic testing, and the second electrode (CE) can function as an auxiliary electrode. In addition, the specimen (SP) can function as an operating electrode in electrochemical characteristic testing by receiving a potential from the test unit (20). The material testing device of the present invention can perform electrochemical characteristic testing using the specimen (SP) and the electrode part (EP), and evaluate the corrosion characteristics of the specimen (SP) through the test data.

[0039] The test unit (20) can perform a characteristic test on the specimen (SP). The test unit (20) can be electrically connected to the specimen (SP), the first electrode (RE), and the second electrode (CE). The test unit (20) can apply a potential to the specimen (SP) under preset conditions, and the test unit (20) can also sense potential and current changes of the specimen (SP), the first electrode (RE), and the second electrode (CE).

[0040] The test unit (20) can apply a first potential to the specimen (SP) for a preset time. The test unit (20) can clean the specimen (SP) by applying a reduction potential to the specimen (SP) for a predetermined time to remove oxides or other impurities from the surface of the specimen (SP).

[0041] In detail, in an embodiment where the test solution (TS) is liquid ammonia and the potentiodynamic polarization test is performed as a characteristic test, since liquid ammonia has relatively low electrical conductivity, it is necessary to reduce the surface resistance of the specimen (SP) to perform the potentiodynamic polarization test. The material testing apparatus (1) of the present invention can effectively perform the potentiodynamic polarization test by first cleaning the surface of the specimen (SP) before performing the potentiodynamic polarization test.

[0042] The test unit (20) can apply a first potential, which is pre-set, to the specimen (SP) by considering a standard reduction potential. That is, the first potential can be defined as a potential applied to the specimen (SP) for surface cleaning of the specimen (SP). When the first potential is applied to the specimen (SP), oxides or other impurities on the surface of the specimen (SP) can be reduced. As the material on the surface of the specimen (SP) is reduced and removed, the surface of the specimen (SP) can be cleaned. At this time, the first potential may be a potential of a constant value or may be set as a potential that changes over time.

[0043] In one embodiment, the test unit (20) can apply a first potential to the specimen (SP) for 10 seconds to 30 seconds in the range of -2.0V to -1.5V. Meanwhile, the magnitude of the first potential and the time for applying the first potential can be set differently depending on the type and shape of the specimen (SP), the type and conditions of the characteristic test, etc.

[0044] The test unit (20) can apply a second potential to the specimen (SP). That is, the second potential can be defined as the potential applied to the specimen (SP) to perform a characteristic test.

[0045] Specifically, in an embodiment where the characteristic test is a potentiodynamic polarization test, the second potential can be set to have a predetermined range. The test unit (20) can apply the potential to the specimen (SP) while changing the potential at a preset speed. That is, the second potential applied to the specimen (SP) is defined as a potential that changes over time within a predetermined range, and the test unit (20) can perform a characteristic test, which is a potentiodynamic polarization test, by applying the second potential to the specimen (SP).

[0046] The test unit (20) can be electrically connected to the specimen (SP), the first electrode (RE), and the second electrode (CE), respectively. The test unit (20) can sense changes in current according to changes in potential applied to the specimen (SP). Depending on the corrosion characteristics of the specimen (SP), the change in current when potential is applied to the specimen (SP) may vary. Therefore, data on the change in current of the specimen (SP) sensed by the test unit (20) can be used to evaluate the corrosion characteristics of the specimen (SP).

[0047] Additionally, the test unit (20) can sense the potential of the first electrode (RE) and adjust the potential applied to the specimen (SP). Additionally, the test unit (20) can be connected to the second electrode (CE) to supply or adjust the current. That is, the test unit (20) is electrically connected to the specimen (SP), the first electrode (RE), and the second electrode (CE), respectively, and can stably perform electrochemical characteristic tests by applying or adjusting the potential and current.

[0048] FIG. 2 is a conceptual diagram showing the arrangement of the specimen (SP), the first electrode (RE), and the second electrode (CE) of FIG. 1.

[0049] Referring to FIG. 2, the specimen (SP), the first electrode (RE), and the second electrode (CE) can be spaced apart from each other. The distance between the specimen (SP), the first electrode (RE), and the second electrode (CE) can each be selected within a predetermined range.

[0050] The distance (L1) between the specimen and the first electrode may be smaller than or equal to the distance (L2) between the specimen and the second electrode. For example, the distance (L1) between the specimen and the first electrode may be 1 / 3 to 1 times the distance (L2) between the specimen and the second electrode. The second electrode (CE) is positioned at a point relatively far from the specimen (SP) compared to the first electrode (RE) to maintain a stable electrochemical environment, thereby allowing surface cleaning and characteristic testing of the specimen (SP) to be performed smoothly.

[0051] In one embodiment, the distance (L1) between the specimen and the first electrode can be selected within a preset range. For example, the distance (L1) between the specimen and the first electrode can be selected within a range of 5 mm to 10 mm.

[0052] Specifically, if the specimen (SP) and the first electrode (RE) are too close, the flow of the test solution (TS) becomes unstable, which may cause uneven diffusion of reactants and products during the electrochemical reaction, or cause the current to be locally biased, leading to excessive oxidation or reduction reactions. Conversely, if the specimen (SP) and the first electrode (RE) are too far apart, the resistance increases, which may increase noise caused by voltage reduction.

[0053] Accordingly, the material testing device (1) places the first electrode (RE) within a preset distance range from the specimen (SP) to effectively perform both surface cleaning and characteristic testing of the specimen (SP), and can obtain more accurate data on the corrosion characteristics of the specimen (SP).

[0054] In one embodiment, the distance (L2) between the specimen and the second electrode and the distance (L3) between the first electrode and the second electrode can each be selected within a preset range. For example, the distance (L2) between the specimen and the second electrode can be selected within a range of 10 mm to 15 mm. Additionally, the distance (L3) between the first electrode and the second electrode can be selected within a range of 10 mm to 15 mm.

[0055] Specifically, if the second electrode (CE) is too close to the specimen (SP) and / or the first electrode (RE), gas generated from the second electrode (CE) may flow into the first electrode (RE), and the potential applied to the specimen (SP) may be distorted or the specimen (SP) may be damaged depending on changes in the chemical environment. Conversely, if the second electrode (CE) is too far from the specimen (SP) and / or the first electrode (RE), resistance may increase, and noise caused by voltage reduction may increase.

[0056] Accordingly, the material testing device (1) places the second electrode (CE) within a predetermined distance range from the specimen (SP) and the first electrode (RE), respectively, thereby effectively performing both surface cleaning and characteristic testing of the specimen (SP) and obtaining more accurate data on the corrosion characteristics of the specimen (SP).

[0057] Below, the detailed structure of the chamber (10) of FIG. 1 and the arrangement of the specimen (SP), the first electrode (RE), and the second electrode (CE) according thereto will be described in detail.

[0058] FIG. 3 is an exemplary perspective view of the chamber (10) of FIG. 1, and FIG. 4 is a cross-sectional view taken along the line A-A' of FIG. 3. FIG. 5 is an enlarged view of a portion of FIG. 3.

[0059] Referring to FIGS. 3 to 5, the chamber (10) may be equipped with a chamber body (100) and a chamber cover (200).

[0060] The chamber body (100) may have an internal space (S) that accommodates a specimen (SP) and a test solution (TS). The internal space (S) may be a space enclosed by the inner circumference of the chamber body (100).

[0061] One side of the chamber body (100) may be open so that the internal space (S) and the outside are in communication. The open side of the chamber body (100) may be closed by a chamber cover (200).

[0062] The chamber body (100) may have a predetermined thickness to ensure sufficient pressure resistance. The test solution (TS) contained in the internal space of the chamber (10) may be in a liquid state at cryogenic temperatures. Therefore, when the test solution (TS) vaporizes in the internal space, an excess amount of gas may be generated, and accordingly, the chamber body (100) may have a predetermined thickness to improve pressure resistance performance.

[0063] For example, the chamber body (100) may have a thickness of 20 mm to 50 mm. Additionally, the thickness of the chamber body (100) may be selected in consideration of the size of the internal space. For example, the ratio of the thickness to the diameter of the chamber body (100) may be 0.15 to 0.25.

[0064] The chamber body (100) may include a metal material with excellent chemical resistance. For example, the chamber body (100) may include austenitic stainless steel.

[0065] The shape of the chamber body (100) is not particularly limited. The chamber body (100) may be formed in a cylindrical shape as shown in FIG. 3, or may have various shapes such as a cube, a rectangular prism, a sphere, or a truncated pyramid.

[0066] The chamber body (100) may have an extension (110), a first flange (120), and a second flange (130).

[0067] The extension portion (110) may extend from one end of the chamber body (100) in a direction away from the chamber body (100). The extension portion (110) may be provided integrally by extending from the chamber body (100), or it may be provided as a separate part and combined with the chamber body (100).

[0068] In one embodiment, the inner surface of the extension (110) may be continuously connected to the inner surface of the chamber body (100).

[0069] The first flange (120) may be disposed at one end of the chamber body (100). The first flange (120) may be formed along the outer periphery at one end of the extension (110). Additionally, the first flange (120) may extend outward from the extension (110) along the radial direction of the chamber body (100). The chamber body (100) and the chamber cover (200) can be joined more airtightly by the first flange (120), and the internal pressure performance of the chamber (10) can be improved.

[0070] The second flange (130) may be disposed at the other end of the chamber body (100). The second flange (130) may be formed along the outer periphery of the other end of the chamber body (100). Additionally, the second flange (130) may extend outward along the radial direction of the chamber body (100). The second flange (130) may be provided as a single member extending in the circumferential direction of the chamber body (100) as shown in FIG. 3, or it may be provided in the form of a plurality of protruding members spaced apart along the circumferential direction.

[0071] Although not shown in the drawing, bolt holes may be formed in the second flange (130) to allow fastening members (B), such as stud bolts, to be coupled. Multiple bolt holes may be formed and spaced apart at predetermined intervals along the circumferential direction of the second flange (130).

[0072] The chamber cover (200) can be coupled to the chamber body (100) to seal the internal space (S). The chamber cover (200) can be connected to the first flange (120) and the second flange (130), respectively, so that the internal space (S) is sealed.

[0073] A coupling hole may be formed in the chamber cover (200) at a position corresponding to the bolt hole of the second flange (130). A fastening member (B) may penetrate the chamber cover (200) through the coupling hole and be inserted into the bolt hole. Although not shown in the drawing, a screw thread (311A) may be formed on one end of the fastening member (B), and the fastening member (B) and the bolt hole may be screw-coupled to each other. Additionally, the other end of the fastening member (B) may protrude outward from the chamber cover (200) and be coupled with a separate fixing member (N), such as a nut. Through this, the chamber cover (200) is stably coupled with the chamber body (100), and the internal space (S) can be completely sealed.

[0074] The chamber (10) may further include a chamber sealing member (150). The chamber sealing member (150) may be disposed between the chamber body (100) and the chamber cover (200).

[0075] The chamber sealing member (150) may be positioned between the first flange (120) and the chamber body (100). Additionally, the chamber sealing member (150) may be positioned between the extension (110) and the chamber cover (200). Through this, the internal space (S) of the chamber (10) can be kept more airtight and watertight, and the heat resistance, corrosion resistance, and mechanical strength of the chamber (10) can be improved.

[0076] For example, the chamber sealing member (150) may be an O-ring, a V-ring, etc. Additionally, the chamber sealing member (150) may be made of a rubber material. For example, the chamber sealing member (150) may include any one of EPDM (Ethylene Propylene Diene Monomer), FFKM (Perfluoroelastomer), or a polymer thereof. The type, shape, and material of the chamber sealing member (150) are not particularly limited and can be selected in any form that can be placed between the chamber body (100) and the chamber cover (200) to effectively seal the bonding area.

[0077] The chamber (10) may further include an electrode insertion module (300). The electrode insertion module (300) provides a path for inserting a specimen (SP), a first electrode (RE), and a second electrode (CE) into the internal space (S) of the chamber (10).

[0078] As described above, the material testing device (1) can clean the surface of the specimen (SP) and perform a characteristic test by applying a potential to the specimen (SP) through the test unit (20) while the specimen (SP), the first electrode (RE), and the second electrode (CE) are each immersed in the test solution (TS) contained in the internal space of the chamber (10).

[0079] Meanwhile, the chamber (10) can have its internal space (S) sealed by the combination of the chamber body (100) and the chamber cover (200). Accordingly, the chamber (10) is equipped with an electrode insertion module (300) into which a specimen (SP), a first electrode (RE), and a second electrode (CE) are respectively inserted, so that the specimen (SP), the first electrode (RE), and the second electrode (CE) can be immersed in a test solution (TS) while maintaining the sealed state of the internal space (S). In addition, the specimen (SP), the first electrode (RE), and the second electrode (CE) can be connected to a test unit (20) respectively by the electrode insertion module (300).

[0080] The electrode insertion module (300) can be placed on the chamber cover (200). The electrode insertion module (300) is connected to the chamber cover (200) and may have an opening that communicates with the internal space (S). Through the opening of the electrode insertion module (300), a specimen (SP), a first electrode (RE), and a second electrode (CE) can each be introduced into the internal space.

[0081] As illustrated in FIG. 3, the electrode insertion module (300) may be provided in three parts. A specimen (SP), a first electrode (RE), and a second electrode (CE) may be inserted into each of the three electrode insertion modules (300). Hereinafter, the electrode insertion module (300) into which the specimen (SP) is inserted will be defined as the first insertion module (300A), the electrode insertion module (300) into which the first electrode (RE) is inserted will be defined as the second insertion module (300B), and the electrode insertion module (300) into which the second electrode (CE) is inserted will be defined as the third insertion module (300C).

[0082] The first insertion module (300A), the second insertion module (300B), and the third insertion module (300C) may be spaced apart from each other. As previously described regarding the distance between the specimen (SP), the first electrode (RE), and the second electrode (CE), the first insertion module (300A), the second insertion module (300B), and the third insertion module (300C) are spaced apart within an appropriate distance range so that both surface cleaning and characteristic testing of the specimen (SP) can be effectively performed. Regarding the placement range of the first insertion module (300A), the second insertion module (300B), and the third insertion module (300C), the details previously described regarding the distance between the specimen (SP), the first electrode (RE), and the second electrode (CE) will be referenced.

[0083] The detailed structures of the first insertion module (300A) to the third insertion module (300C) can be substantially identical. Therefore, for the convenience of explanation, the following description will focus on the structure of the first insertion module (300A) into which the specimen (SP) is inserted, and regarding the structures of the second insertion module (300B) and the third insertion module (300C), the description of the first insertion module (300A) will be referenced.

[0084] FIG. 6 is a cross-sectional view of the first insertion module (300A) of FIG. 5.

[0085] Referring to FIG. 6, the first insertion module (300A) may have a first body (310A) and a second body (320A).

[0086] The first body (310A) is positioned on one side of the chamber cover (200) and may have an opening that communicates with the internal space. As shown in FIG. 6, the first body (310A) may be formed integrally with the chamber cover (200) by extending from the chamber cover (200), or it may be formed as a separate member and coupled to communicate with the opening formed in the chamber cover (200).

[0087] In one embodiment, the first body (310A) may have screw threads (311A) on its outer surface. Through this, the first body (310A) and the second body (320A) can be screw-coupled.

[0088] The second body (320A) can be coupled to the first body (310A). The second body (320A) is formed in the shape of a cap that is coupled to the first body (310A), and may have an opening that communicates with the opening of the first body (310A). As the first body (310A) and the second body (320A) are coupled, an opening that communicates with the internal space (S) may be formed in the first insertion module (300A).

[0089] The first insertion module (300A) may further include one or more auxiliary sealing members (330A). The first insertion module (300A) has a combined structure of a first body (310A) and a second body (320A) into which a specimen (SP) can be inserted. Accordingly, the first insertion module (300A) may include auxiliary sealing members (330A) so that the specimen (SP), the first body (310A), and the second body (320A) each come into close contact with one another to maintain a sealed state of the internal space (S).

[0090] The auxiliary sealing member (330A) may be an O-ring, a V-ring, etc. Additionally, the auxiliary sealing member (330A) may be made of a rubber material. For example, the auxiliary sealing member (330A) may include any one of EPDM (Ethylene Propylene Diene Monomer), FFKM (Perfluoroelastomer), or a polymer thereof. The type, shape, and material of the auxiliary sealing member (330A) are not particularly limited and may be selected in any form that can effectively seal the bonding area of ​​each of the specimen (SP), the first body (310A), and the second body (320A).

[0091] Specifically, the first insertion module (300A) may have a first auxiliary sealing member (331A) disposed between the first body (310A) and the specimen (SP), a second auxiliary sealing member (332A) disposed between the second body (320A) and the specimen (SP), and a third auxiliary sealing member (333A) disposed between the first body (310A) and the second body (320A).

[0092] The first auxiliary sealing member (331A) may be placed in the first seating portion (312A) formed on the inner circumference of the first body (310A). The first auxiliary sealing member (331A) may be placed in the first seating portion (312A) between the first body (310A) and the specimen (SP) to seal the bonding area between the first body (310A) and the specimen (SP).

[0093] The second auxiliary sealing member (332A) may be placed in the second seating portion (321A) formed on the inner circumference of the second body (320A). The second auxiliary sealing member (332A) may be placed in the second seating portion (321A) between the second body (320A) and the specimen (SP) to seal the bonding area between the second body (320A) and the specimen (SP).

[0094] The third auxiliary sealing member (333A) may be placed in the third seating portion (313A) formed on one side of the first body (310A). A groove-shaped third seating portion (313A) may be formed on the side of the first body (310A) that is coupled with the second body (320A), and the third auxiliary sealing member (333A) may be placed in the third seating portion (313A) to seal the coupling area between the first body (310A) and the second body (320A).

[0095] In one embodiment, the first auxiliary sealing member (331A) and the second auxiliary sealing member (332A) may be provided as V-rings. Since the specimen (SP) is inserted into the opening communicating with the internal space (S) in the first body (310A) and the second body (320A), it is necessary to seal the inner surface area where the specimen (SP) contacts each of the first body (310A) and the second body (320A).

[0096] Accordingly, the first auxiliary sealing member (331A) and the second auxiliary sealing member (332A) are provided in a shape such that, as shown in FIG. 6, a V-ring, particularly a portion extending at an angle, can be elastically deformed, thereby allowing the inner surface of each of the first body (310A) and the second body (320A) to be closely coupled with the specimen (SP). At this time, when the specimen (SP) is inserted into the opening, the portion extending at an angle is pushed toward the inner surface of the first body (310A) and the second body (320A) by the specimen (SP), respectively, and comes into contact with the specimen (SP). As a result, the internal space (S) can be sealed as the specimen (SP) is inserted into the chamber (10).

[0097] In one embodiment, the third auxiliary sealing member (333A) may be provided as an O-ring. The third auxiliary sealing member (333A) may be placed in a third seating portion (313A) formed in a groove shape on one side (upper side based on the drawing) of the first body (310A) that is coupled with the second body (320A). Accordingly, the third auxiliary sealing member (333A) may be provided and placed in the form of an O-ring between the first body (310A) and the second body (320A) so that the first body (310A) and the second body (320A) are coupled tightly and stably.

[0098] In this way, the material testing device (1) of the present invention allows a specimen (SP), a first electrode (RE), and a second electrode (CE) to be immersed in a test solution (TS) within a chamber (10) having a structure with improved pressure resistance performance, thereby enabling surface cleaning and characteristic testing. At this time, the specimen (SP), the first electrode (RE), and the second electrode (CE) are each inserted into an electrode insertion module (300), and a portion of them are placed in an internal space (S) in a sealed state, while being electrically connected to a test unit (20). Additionally, the chamber (10) may provide an internal space (S) in which surface cleaning and characteristic testing are performed while effectively maintaining a sealed state by placing an auxiliary sealing member (330A) in the area where the specimen (SP), the first electrode (RE), and the second electrode (CE) are each inserted.

[0099] FIG. 7 is a flowchart illustrating a material testing method according to one embodiment of the present invention.

[0100] Referring to FIG. 7, the material testing method may comprise the steps of: placing a test solution, a specimen, a first electrode, and a second electrode in a chamber (S100); applying a first potential to a specimen immersed in the test solution to clean the surface of the specimen (S200); and applying a second potential to a specimen immersed in the test solution to perform a characteristic test to evaluate the corrosion characteristics of the specimen (S300).

[0101] The step (S100) of placing a test solution, a specimen, a first electrode, and a second electrode in a chamber may involve injecting the test solution into the internal space of the chamber and inserting each of the specimen, the first electrode, and the second electrode such that at least a portion thereof is placed in the internal space. At this time, the specimen, the first electrode, and the second electrode are each inserted into the electrode insertion module of the chamber, and connected to a test unit outside the chamber while maintaining the sealing of the internal space of the chamber so that a potential may be applied or an electrical state may be sensed.

[0102] The specimen, the first electrode, and the second electrode may be spaced apart from each other in the chamber and each may be positioned within a predetermined distance range. For this, refer to the above description regarding the material testing apparatus.

[0103] The step (S200) of cleaning the surface of a specimen by applying a first potential to a specimen immersed in a test solution can be performed by applying a first potential to the specimen immersed in the test solution for a preset time to clean the surface of the specimen. As a first potential, which is a predetermined reduction potential, is applied to the specimen immersed in the test solution for a preset time, oxides formed on the surface of the specimen can be reduced and removed. In this way, the material testing method can obtain more accurate test data by reducing the surface resistance of the specimen prior to the characteristic test of the specimen.

[0104] The step (S300) of performing a characteristic test to evaluate the corrosion characteristics of a specimen by applying a second potential to a specimen immersed in a test solution can be performed by applying a second potential to a specimen immersed in a test solution. In an embodiment where the characteristic test is a potentiodynamic polarization test, the second potential applied to the specimen can change over time within a preset range. After the surface of the specimen is cleaned by applying a first potential, a characteristic test to evaluate the corrosion characteristics can be performed by applying a second potential.

[0105] In this way, the material testing method can obtain more accurate test data by reducing the surface resistance of the specimen prior to the characteristic test of the specimen. Specific embodiments regarding the structure of the chamber, the specimen, the arrangement of the first electrode and the second electrode in the material testing method will be described by referring to the above description of the material testing apparatus with reference to FIGS. 1 to 6.

[0106] The material testing apparatus and material testing method of the present invention can effectively perform characteristic testing without being affected by the low electrical conductivity of the test solution and improve the reliability of the test data by cleaning the surface of the specimen prior to the characteristic test for evaluating the corrosion characteristics of the specimen.

[0107] The material testing apparatus and material testing method of the present invention can perform both surface cleaning and characteristic testing of a specimen within a single chamber. In addition, the material testing apparatus and material testing method of the present invention can effectively perform both surface cleaning and characteristic testing in a stable electrochemical environment by positioning the specimen, the first electrode, and the second electrode within a predetermined distance range from each other.

[0108] As such, the present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

[0109] The specific practices described in the embodiments are examples and do not limit the scope of the embodiments in any way. Furthermore, unless specifically stated as "essential," "importantly," etc., components may not be strictly necessary for the application of the present invention.

[0110] In the specification of the embodiments (particularly the claims), the use of the term "the above" and similar descriptive terms may be in both singular and plural. Furthermore, where a range is described in the embodiments, it is considered to include the invention with respect to individual values ​​within said range (unless otherwise stated), and is equivalent to describing each individual value constituting said range in the detailed description. Finally, regarding the steps constituting the method according to the embodiments, unless explicitly stated in order or otherwise stated, said steps may be performed in a suitable order. The embodiments are not necessarily limited by the order in which said steps are described. The use of all examples or exemplary terms (e.g., etc.) in the embodiments is merely for the purpose of describing the embodiments in detail, and the scope of the embodiments is not limited by said examples or exemplary terms unless limited by the claims. Furthermore, those skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents to which they are added. Explanation of the symbols

[0111] 1: Material testing device 10: Chamber 20: Test Unit SP: Psalms TS: Test solution EP: Electrode part RE: First electrode CE: Second electrode

Claims

Claim 1 A material testing apparatus comprising: a chamber having an internal space and accommodating a specimen and a test solution; an electrode section having a first electrode and a second electrode immersed in the test solution; and a test unit that performs a characteristic test to evaluate the corrosion characteristics of the specimen by applying a second potential to the specimen after applying a first potential to the specimen immersed in the test solution. Claim 2 In claim 1, the test unit is a material testing device that applies a first potential to the specimen for a preset time to reduce oxides on the surface of the specimen. Claim 3 In claim 1, the test unit is a material testing device that senses a change in current of a specimen while applying a second potential, which is a potential that changes over time within a preset range, to the specimen. Claim 4 A material testing device according to claim 1, wherein the distance between the specimen and the first electrode is less than or equal to the distance between the specimen and the second electrode. Claim 5 A material testing device according to claim 1, wherein the internal space of the chamber is sealed, and each of the specimen, the first electrode, and the second electrode has at least a portion disposed in the internal space and is electrically connected to the test unit. Claim 6 A material testing device according to claim 1, wherein the chamber comprises: a chamber body forming the internal space; a chamber cover coupled to the chamber body to cover the internal space; and an electrode insertion module disposed in the chamber cover and having an opening communicating with the internal space. Claim 7 In claim 6, the electrode insertion module is provided in a plurality of such modules so that the specimen, the first electrode, and the second electrode are each inserted therein, in a material testing device. Claim 8 In claim 6, the electrode insertion module comprises: a first body connected to the chamber cover; a second body coupled to one side of the first body; and an auxiliary sealing member disposed on the first body or the second body to maintain a sealed state of the internal space; a material testing device. Claim 9 A material testing method comprising: a step of placing a test solution, a specimen, a first electrode, and a second electrode in a chamber; a step of applying a first potential to a specimen immersed in the test solution in the chamber to clean the surface of the specimen; and a step of applying a second potential to a specimen immersed in the test solution in the chamber to perform a characteristic test to evaluate the corrosion characteristics of the specimen. Claim 10 A material testing method according to claim 9, wherein at least a portion of the specimen, the first electrode, and the second electrode are disposed in a sealed internal space of the chamber, and the distance between the specimen and the first electrode is less than or equal to the distance between the specimen and the second electrode.

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