Ammonia permeation evaluation method, method for determining superiority or inferiority of material, and ammonia permeation evaluation system

Abstract

To provide an ammonia permeation evaluation method that can easily evaluate ammonia resistance of a material.SOLUTION: An ammonia permeation evaluation method according to one aspect of the present disclosure includes: a step of bringing a medium including any one of liquid ammonia, an ammonia gas, and an ammonia-containing solution, into contact with a surface of a specimen; a step of exposing the internal area of the specimen after the contact step; a step of performing color development processing on the internal area exposed in the exposure step by using a color developer; and a step of evaluating permeation of ammonia into the specimen on the basis of the color of the internal area after the color development processing step.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an ammonia penetration evaluation method, a method for determining the superiority and inferiority of materials, and an ammonia penetration evaluation system.

Background Art

[0002] Ammonia has been attracting attention as a fuel that does not emit carbon dioxide during combustion and as a hydrogen energy carrier. In order for the use of ammonia to become widespread, technologies for storing and transporting ammonia in large quantities are required. In order to store and transport ammonia, the selection and development of materials with high ammonia resistance are required (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The ammonia resistance of a material is closely related to the permeability of liquid ammonia, ammonia gas, or a solution containing ammonia. On the other hand, since ammonia is a colorless gas or liquid, it is difficult to determine whether or not there is penetration into the material.

[0005] Based on such circumstances, the present disclosure has been made, and an object thereof is to provide an ammonia penetration evaluation method capable of easily evaluating the ammonia resistance of a material.

Means for Solving the Problems

[0006] The ammonia penetration evaluation method according to one aspect of the present disclosure includes a step of bringing a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into contact with the surface of a test body, a step of exposing an internal region of the test body after the contacting step, a step of performing a coloring treatment on the internal region exposed in the exposing step using a coloring agent, and a step of evaluating the penetration of ammonia into the test body based on the color of the internal region after the coloring treatment step.

Effect of the Invention

[0007] The ammonia penetration evaluation method according to one aspect of the present disclosure can easily evaluate the ammonia resistance of a material.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described.

[0010] (1) The ammonia penetration evaluation method according to one aspect of the present disclosure includes a step of bringing a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into contact with the surface of a test body, a step of exposing an internal region of the test body after the contacting step, a step of performing a coloring treatment on the internal region exposed in the exposing step using a coloring agent, and a step of evaluating the penetration of ammonia into the test body based on the color of the internal region after the coloring treatment step.

[0011] By performing the coloring treatment step in the ammonia penetration evaluation method, it is possible to color the region where ammonia has penetrated in the test body. Therefore, by performing the evaluation step, the ammonia resistance of the test body can be easily evaluated based on the colored region colored in the coloring treatment step.

[0012] (2) In the above (1), in the contacting step, it is preferable to bring a factor that promotes or suppresses the reaction between the test body and the medium into contact with the test body. According to this configuration, the ammonia resistance according to the actual use environment can be easily evaluated.

[0013] (3) In the above (1) or (2), in the exposing step, it is preferable to divide the test body in a direction perpendicular to the surface. According to this configuration, the penetration depth of ammonia in the test body can be measured more accurately. As a result, the ammonia resistance of the test body can be easily and surely evaluated based on the penetration depth of ammonia.

[0014] (4) In any one of the above (1) to (3), in the evaluating step, it is preferable to evaluate the penetration of ammonia into the test body based on the contact time of the medium with the test body and the depth of the colored region with respect to the surface of the test body. According to this configuration, the ammonia resistance of the test body can be evaluated more surely.

[0015] (5) In any of (1) to (4) above, the color former preferably contains metal ions that undergo a chelation reaction with ammonia. According to this configuration, the penetration depth of ammonia in the test body can be easily measured.

[0016] (6) In (5) above, the metal ions are preferably copper ions. According to this configuration, the penetration depth of ammonia in the test body can be more easily measured.

[0017] (7) In any of (1) to (4) above, the color former preferably contains an ultraviolet light-emitting agent. According to this configuration, the penetration depth of ammonia in the test body can be easily measured.

[0018] (8) In (7) above, the color former preferably contains ions of a Group 8 metal in the periodic table. According to this configuration, the time from the color-forming treatment to the color development of the test body can be shortened. As a result, the penetration depth of ammonia in the test body can be more easily measured.

[0019] (9) In any of (1) to (4) above, the color former is preferably a pH indicator. According to this configuration, the penetration depth of ammonia in the test body can be easily measured.

[0020] (10) A method for determining the superiority or inferiority of a material according to another aspect of the present disclosure is a determination method using any of the ammonia penetration evaluation methods of (1) to (9) above, and includes a step of determining the ammonia resistance of the material based on the evaluation result of the evaluation step.

[0021] Since the method for determining the superiority or inferiority of the material uses the ammonia penetration evaluation method, the ammonia resistance of the test body can be easily determined. As a result, the method for determining the superiority or inferiority of the material can easily perform the determination of the material using ammonia resistance as an evaluation criterion.

[0022] (11) Another ammonia penetration evaluation system according to an aspect of the present disclosure includes a container in which a test piece is disposed, a supply unit that replaces and supplies a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into the container, an exposure unit that exposes an internal region of the test piece taken out from the container after contact with the medium, and a color developing agent applied to the internal region exposed by the exposure unit.

[0023] The ammonia penetration evaluation system can cause a color developing agent to develop a color in a region where ammonia has penetrated in the test piece. Therefore, the ammonia penetration evaluation system can easily evaluate the ammonia resistance of the test piece based on the color developing region colored by the color developing agent.

[0024] In the present disclosure, "color" means a wavelength range of a specific wavelength of energy reflected from a substance, and includes a color visible by the naked eye and a color that can be quantified using an instrument analysis device. "Replacing and supplying" a medium into the container by the supply unit includes a configuration in which the medium (or the medium and a factor) is supplied into a container controlled to a vacuum or an inert gas atmosphere, and a configuration in which the inside of the container is replaced with the medium (or the medium and a factor).

[0025] [Details of Embodiments of the Present Disclosure] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate.

[0026] <Ammonia Penetration Evaluation Method>[ As shown in FIG. 1, the ammonia penetration evaluation method includes a step S1 of bringing a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into contact with the surface of a test piece, a step S2 of exposing an internal region of the test piece after the contacting step S1, a step S3 of performing a color developing treatment on the internal region exposed in the exposing step S2 using a color developing agent, and a step S4 of evaluating the penetration of ammonia into the test piece based on the color of the internal region after the color developing treatment step S3.

[0027] In the ammonia permeation evaluation method, the region of the test specimen into which ammonia has permeated can be colored by performing the color development step S3. Therefore, in the ammonia permeation evaluation method, by performing the evaluation step S4, the ammonia resistance of the test specimen can be easily evaluated based on the colored region colored in the color development step S3.

[0028] [Test specimen] The ammonia permeation evaluation method can evaluate the ammonia resistance of the test specimen, thereby determining the suitability (usability) of the test specimen for a specific application or a specific environment. The test specimen may be, for example, a sample of a member (insulation material, strength member, sealing material for airtightness, insulating material for instrumentation wires, etc.) used in a tank or container for storing or transporting liquid ammonia. The ammonia permeation evaluation method is suitable for easily evaluating ammonia resistance in a short time using a relatively small test specimen.

[0029] The material of the test specimen is not particularly limited, and examples thereof include resin, mortar, concrete, ceramics, etc. The resin may be colorless or colored. The test specimen may contain a reinforcing member, a pigment, etc., and may be, for example, a resin to which carbon fiber has been added. The shape of the test specimen is not particularly limited, and may be, for example, a plate, a column, a cylinder, a block, etc.

[0030] (Contacting step) In the contacting step S1, the medium is brought into contact with the surface of the test piece and maintained in this state, thereby allowing the ammonia contained in the medium to permeate the test piece.

[0031] The step S1 of bringing into contact can be carried out, for example, using the test apparatus 10 shown in FIG. 2. The test apparatus 10 has a container 1 in which a test piece P is disposed, and a supply unit 3 that replaces and supplies a medium A containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into the container 1. Further, the test apparatus 10 has a heat-insulating unit 4 that controls the temperature inside the container 1 to a constant temperature, a thermometer 5 that measures the temperature inside the container 1, a discharge unit 6 that discharges the medium A and other gases existing inside the container 1, and a storage unit (not shown) that stores the temperature measured by the thermometer 5, the contact time between the test piece P and the medium A, and the like. Furthermore, the test apparatus 10 has a control unit 2 that controls the inside of the container 1 to a vacuum or an inert gas atmosphere. In the test apparatus 10, for example, the supply unit 3 may be provided so as to replace the inside of the container 1 with the medium A. In this case, the test apparatus 10 may be configured not to have the control unit 2.

[0032] Container 1 is, for example, a pressure vessel. The upper limit of the volume of Container 1 can be, for example, 4L. The control unit 2 has, for example, a vacuum pump 11 and a pipe 12 connecting the vacuum pump 11 and Container 1. A valve 12a is provided in the pipe 12. The control unit 2 is provided so that the inside of Container 1 can be controlled to a vacuum by the vacuum pump 11. The supply unit 3 has a tank 13 for storing the medium A and a pipe 14 connecting the tank 13 and Container 1. Valves 14a, 14b, and 14c are provided in the pipe 14. The valves 14a and 14b are provided so that the inside of Container 1 can be sealed. The valve 14c is provided so that the presence or absence and the supply amount of the medium A from the tank 13 can be controlled. The specific configuration of the heat preservation unit 4 can be set according to the type of the sample A. For example, when the medium A contains liquid ammonia, it is required that the inside of Container 1 be controlled to -33 degrees or less. In this case, the heat preservation unit 4 can have, for example, a sealed container for housing Container 1 and dry ice filled in this sealed container. As the thermometer 5, a known one can be used, for example, a thermocouple can be used. The discharge unit 6 is configured to be able to discharge the medium A and other gases existing inside Container 1 to the outside of Container 1, and has a first discharge pipe 15 connected to Container 1 and a second discharge pipe 16 branched from the first discharge pipe 15. Valves 15a and 15b are provided on both sides of the first discharge pipe 15 sandwiching the portion where the second discharge pipe 16 branches. A pressure gauge 16a and a safety valve 16b are provided in the second discharge pipe 16.

[0033] In the contacting step S1, for example, the test piece P is placed inside Container 1, and after sealing Container 1, it is evacuated by the vacuum pump 11. Also, in the contacting step S1, instead of making the inside of Container 1 a vacuum, the inside of Container 1 may be controlled to an inert gas atmosphere. Next, in the contacting step S1, the medium A is supplied from the supply unit 3 into Container 1. When the medium A stored inside Container 1 contains liquid ammonia or a solution containing ammonia, the test piece P is immersed in the medium A inside Container 1. When the medium A stored inside Container 1 contains ammonia gas, the test piece P is placed in an ammonia gas atmosphere inside Container 1.

[0034] Next, in the contacting step S1, the state where the medium A is in contact with the surface of the test piece P is maintained. Specifically, the test piece P is immersed in the medium A in the container 1, or the state where the test piece P is placed in the atmosphere of the medium A is maintained. At this time, the inside of the container 1 may be kept under a constant temperature and a constant pressure. The time for bringing the medium A into contact with the surface of the test piece P in the contacting step S1 can be set according to the assumed use of the test piece P and the test environment (such as the concentration of ammonia in the medium A).

[0035] Next, in the contacting step S1, the medium A is discharged from the inside of the container 1. The discharge of the medium A can be performed by the discharge unit 6. In the contacting step S1, after the discharge of the medium A, the test piece P is taken out from the container 1. The test piece P taken out from the container 1 is subjected to the exposing step S2.

[0036] The medium A may be either liquid ammonia or ammonia gas, or a solution containing ammonia. Note that liquid ammonia means a liquid in which ammonia is liquefied, ammonia gas means a gas species containing ammonia, and a solution containing ammonia means aqueous ammonia, ammonium salts, etc.

[0037] In the contacting step S1, a factor that promotes the reaction between the test piece P and the medium A (hereinafter also referred to as "reaction promoting factor") or a factor that suppresses the reaction (hereinafter also referred to as "reaction suppressing factor") may be brought into contact with the test piece P. By bringing the above factors into contact with the test piece P in the contacting step S1, the ammonia resistance according to the actual use environment can be easily evaluated.

[0038] Examples of the above reaction accelerator include nitrogen, carbon dioxide gas (CO, CO2), etc. For example, when it is assumed that the test body P is used in a transport container for liquid ammonia, this transport container may be used to transport another liquid such as liquefied CO2 after discharging the liquid ammonia. Therefore, by adding possible reaction accelerators to the medium A and evaluating the ammonia resistance, the resistance of the test body P to the actual use environment can be evaluated more accurately.

[0039] Examples of the above reaction inhibitor include water, oxygen, etc. For example, when it is assumed that the test body P is used in a storage container for liquid ammonia, it may involve air or moisture when replacing the liquid ammonia. Also, liquid ammonia may be stored with water or oxygen intentionally added. Therefore, by adding possible reaction inhibitors in the medium A and evaluating the ammonia resistance, the resistance of the test body P to the actual use environment can be evaluated more accurately. For example, when adding water as the above reaction inhibitor to liquid ammonia, the addition amount of water relative to 100 parts by mass of liquid ammonia can be 0.2 parts by mass or less.

[0040] (Exposing step) In the exposing step S2, the test piece P is halved or cut along a single cutting surface. The cutting direction of the test piece P in the exposing step S2 is not particularly limited. For example, the cutting surface of the test piece P may be inclined at an angle of 45° or the like with respect to the surface S that was in contact with the medium A in the contacting step S1. In this case, the depth in the direction perpendicular to the surface S can be calculated using the inclination angle. On the other hand, in the exposing step S2, as shown in FIG. 3, it is preferable to divide the test piece P in a direction perpendicular to the surface S. That is, in the exposing step S2, it is preferable to cut the test piece P along a cutting surface C that is perpendicular to the surface S that was in contact with the medium A in the contacting step S1. The cutting surface C exposed by the exposing step S2 is preferably a flat surface. According to this configuration, the penetration depth of ammonia in the test piece P can be measured more accurately. As a result, in the evaluating step S4, the ammonia resistance of the test piece P can be easily and surely evaluated based on the penetration depth of ammonia.

[0041] In the exposing step S2, the exposing means for exposing the internal region of the test piece P is not particularly limited, and examples thereof include a cutter, a chisel, a minus driver, a hammer, and an anvil.

[0042] (Coloring treatment step) In the coloring treatment step S3, as shown in FIG. 4, a coloring agent is used to perform a coloring treatment on the internal region of the test piece P (the cutting surface C in FIG. 4). In the coloring treatment step S3, for example, the above-mentioned coloring agent is applied to the internal region of the test piece P. The method of applying the coloring agent is not particularly limited, but for example, spraying with a spray may be used from the viewpoint of being able to quickly apply the coloring agent. By performing the coloring treatment step S3, among the above-mentioned internal regions, the portion where ammonia has penetrated in the contacting step S1 becomes visible as a colored region X. Note that the coloring treatment step S3 may be performed, for example, with the test piece P placed in a draft.

[0043] The coloring agent can be selected, for example, based on the properties of the test body P. The coloring agent may contain metal ions that cause a chelation reaction with ammonia, and more specifically, may contain metal ions that generate a colored chelation product with ammonia. According to this configuration, the penetration depth of ammonia in the test body P can be easily measured.

[0044] The coloring agent is configured to contain metal ions that cause a chelation reaction with ammonia, and has the advantage of being usable regardless of the pH of the test body P. That is, when the coloring agent has such a configuration, as the test body P, both non-alkaline members and alkaline members can be used. Examples of non-alkaline members include those mainly composed of resins such as polyurethane, polyethylene, and fluororesin. Examples of alkaline members include mortar, concrete, and ceramics.

[0045] The coloring agent desirably has low environmental toxicity. From such a viewpoint, examples of the metal ions include divalent cations such as copper ions (Cu 2+ ), nickel ions (Ni 2+ ), zinc ions (Zn 2+ ), cobalt ions (Co 2+ ), iron ions (Fe 2+ ), manganese ions (Mn 2+ ), magnesium ions (Mg 2+ ), calcium ions (Ca 2+ ), strontium ions (Sr 2+ ), and barium ions (Ba 2+ ). Among them, as the metal ions, copper ions (Cu 2+) is preferred. Copper ions are rich in reactivity with ammonia and easily form tetraamine copper (II), which is a chelate reaction product with ammonia. Also, copper ions become soluble in excess ammonia, and this reaction changes from light blue to dark blue, which is preferred because the color development becomes clearer. Therefore, according to this configuration, the penetration depth of ammonia in the test piece P can be measured more easily. Specific examples of the color former containing the above copper ions include, for example, aqueous copper (II) hydroxide solution, aqueous copper (II) sulfate solution, aqueous copper (II) nitrate solution, aqueous copper (II) chloride solution, and the like.

[0046] In addition, the above color former may contain an ultraviolet light-emitting agent. Since the ultraviolet light-emitting agent emits light when irradiated with ultraviolet light, the visual recognition of the color development region X becomes easier. Therefore, according to this configuration, the penetration depth of ammonia in the test piece P can be easily measured.

[0047] The above color former has the advantage that the visual recognition of the color development region X for the colored test piece P becomes easy by including an ultraviolet light-emitting agent. Therefore, when the above color former contains an ultraviolet light-emitting agent, the test piece P is not particularly limited, but carbon, resins added with colored substances, members with difficult-to-discriminate chelate reaction colors, and the like can be used.

[0048] Examples of the above ultraviolet light-emitting agent include ethanethiol (C2H6S), o-phthalaldehyde (C6H4(CHO)2), dithiothreitol (C4H 10 O2S2), 2-mercaptoethanol (C2H6OS), and the like.

[0049] When the coloring agent contains an ultraviolet light-emitting agent, this coloring agent preferably further contains a metal ion of Group 8 of the periodic table. Since ammonia is easy to vaporize, it may be desirable to color the internal region of the test body P in a short time after the exposing step S2. In this regard, by including a metal ion of Group 8 of the periodic table in the coloring agent, the time from the coloring treatment to the coloring of the test body P can be shortened. As a result, the penetration depth of ammonia in the test body P can be more easily measured. For example, it was confirmed that by adding iron (Fe) or ruthenium (Ru) to o-phthalaldehyde and dithiothreitol, coloring can be achieved in a short time. For example, when it took one hour or more to develop color using a coloring agent composed of o-phthalaldehyde or dithiothreitol, the time to develop color could be shortened to 7 minutes by adding Fe to o-phthalaldehyde. Also, by adding Fe to dithiothreitol, the time to develop color could be shortened to 4 minutes. This is considered to be due to acceleration by a catalytic reaction.

[0050] Further, the coloring agent may be a pH indicator. As the pH indicator, for example, an indicator that reacts with alkalinity such as bromothymol blue (BTB) can be used. Since the pH indicator reacts with alkalinity, the penetration region of ammonia can be colored. Therefore, according to this configuration, the penetration depth of ammonia in the test body P can be easily measured.

[0051] When the coloring agent is a pH indicator, it is desirable that the test body P itself does not react with the pH indicator. Therefore, the test body P is preferably a non-alkaline member. Examples of non-alkaline members include those mainly composed of resins such as polyurethane, polyethylene, and fluororesin.

[0052] (Step of evaluating) In the evaluating step S4, the colored region X colored in the coloring step S3 is evaluated as the penetration region of ammonia. At this time, the penetration depth of ammonia can be evaluated by measuring the depth D (see FIG. 4) of the colored region X with respect to the surface S of the test body P.

[0053] The depth D of the coloring region X may be measured, for example, using a ruler. Further, the coloring region X may be defined based on the color difference, color tone, etc. of the captured image, or the change point may be defined as the boundary line of the coloring region X after binarization image processing. Further, when the test body P is small, etc., the depth D of the coloring region X may be obtained using a microscope or the like.

[0054] In the evaluation step S4, it is preferable to evaluate the penetration of ammonia into the test body P based on the contact time of the medium A with the test body P and the depth D of the coloring region X with respect to the surface S of the test body P. According to this configuration, the ammonia resistance of the test body P can be evaluated more reliably.

[0055] <Ammonia Penetration Evaluation System> Next, with reference to FIGS. 2 to 4, an embodiment of an ammonia penetration evaluation system capable of implementing the ammonia penetration evaluation method will be described. The ammonia penetration evaluation system can be configured using the test apparatus 10 of FIG. 2. The ammonia penetration evaluation system includes a container 1 in which a test body P is disposed, a supply unit 3 that replaces and supplies a medium A including any one of liquid ammonia, ammonia gas, and a solution containing ammonia into the container 1, an exposing means for exposing the internal region of the test body P taken out from the container 1 after contact with the medium A, and a coloring agent applied to the internal region exposed by the exposing means. The ammonia penetration evaluation system may include a control unit 2 that controls the inside of the container 1 to a vacuum or an inert gas atmosphere.

[0056] The ammonia penetration evaluation system can color the region where ammonia has penetrated in the test body P with the coloring agent. Therefore, the ammonia penetration evaluation system can easily evaluate the ammonia resistance of the test body P based on the coloring region X colored by the coloring agent.

[0057] In the ammonia penetration evaluation system, the medium A is brought into contact with the surface S of the test piece P using the test apparatus 10 shown in FIG. 2. Therefore, the ammonia penetration evaluation system can easily evaluate the ammonia resistance of the test piece P under a desired environment. Further, by using the ammonia penetration evaluation system, the ammonia resistance of the test piece P can be easily evaluated at the laboratory level.

[0058] Examples of the exposure means in the ammonia penetration evaluation system include a cutter, a chisel, a Phillips screwdriver, a hammer, a anvil, etc. As the color former in the ammonia penetration evaluation system, the color former described above in the ammonia penetration evaluation method can be used.

[0059] <Method for determining the quality of materials> The method for determining the quality of the material is a determination method using the ammonia penetration evaluation method described above. As shown in FIG. 5, the method for determining the quality of the material includes a step S1 of bringing a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into contact with the surface of the test piece, a step S2 of exposing the internal region of the test piece after the contact step S1, a step S3 of performing a color development treatment on the internal region exposed in the exposure step S2 using a color former, a step S4 of evaluating the penetration of ammonia into the test piece based on the color of the internal region after the color development treatment step S3, and a step S5 of determining the ammonia resistance of the material based on the evaluation result of the evaluation step S4.

[0060] Since the method for determining the quality of the material uses the ammonia penetration evaluation method, the ammonia resistance of the test piece P can be easily determined. As a result, the method for determining the quality of the material can easily perform the determination of the material using ammonia resistance as an evaluation criterion. The method for determining the quality of the material can be performed for both existing materials and new materials.

[0061] In the method for determining the quality of the material, the contacting step S1, the exposing step S2, the coloring process step S3, and the evaluating step S4 can be performed in the same procedures as the contacting step S1, the exposing step S2, the coloring process step S3, and the evaluating step S4 in FIG. 1, respectively.

[0062] (Determining step) In the determining step S5, based on the ammonia resistance of the test piece P, the ammonia resistance of the material is determined. That is, in the method for determining the quality of the material, the test piece P is configured as a sample of the material. In the determining step S5, for example, the ammonia resistance of the material may be determined by comparing the ammonia resistance of an existing material with the ammonia resistance of the test piece P, or the ammonia resistance of the material may be determined based on whether the ammonia resistance of the test piece P meets a predetermined requirement. It is also possible to determine the ammonia resistance of the material based on the change in the physical property value of the test piece P that depends on the penetration depth.

[0063] [Other embodiments] The above embodiments do not limit the configuration of the present invention. Therefore, based on the description in this specification and common technical knowledge, components of each part of the above embodiments can be omitted, replaced, or added, and all of them should be construed as belonging to the scope of the present invention.

[0064] The cutting direction of the test piece in the above exposing step is not limited to the configuration described in the above embodiment. Also, in the above exposing step, it is not necessary to cut the test piece into two pieces, and it may be cut into three or more pieces.

[0065] In the above embodiment, in the above evaluating step, the procedure for evaluating the penetration of ammonia based on the measured value of the depth of the colored area with reference to the surface of the test piece was described. At this time, the entire internal area of the test piece may be colored. Even when the entire internal area of the test piece is colored, the penetration of ammonia into the test piece can be evaluated based on the contact time of the medium with the test piece and the like.

Explanation of reference numerals

[0066] 1 Container 2 Control Unit 3 Supply Unit 4 Heat Preservation Unit 5 Thermometer 6 Discharge Unit 10 Test Device 11 Vacuum Pump 12, 14 Pipes 12a, 14a, 14b, 14c, 15a, 15b Valves 13 Tank 15 First Discharge Pipe 16 Second Discharge Pipe 16a Pressure Gauge 16b Safety Valve A Medium C Cutting Plane P Test Specimen S Surface X Color Development Region D Depth of the Color Development Region with Respect to the Surface of the Test Specimen

Claims

1. A step of bringing a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into contact with the surface of a test body; A step of exposing the internal region of the test body after the contacting step; A step of performing a color development treatment on the internal region exposed in the exposing step using a color developer; A step of evaluating the penetration of ammonia into the test body based on the color of the internal region after the color development treatment An ammonia penetration evaluation method comprising:

2. The ammonia penetration evaluation method according to claim 1, wherein, in the contacting step, a factor that promotes or suppresses the reaction between the test body and the medium is brought into contact with the test body.

3. The ammonia penetration evaluation method according to claim 1, wherein, in the exposing step, the test body is divided in a direction perpendicular to the surface.

4. The ammonia penetration evaluation method according to claim 1, wherein, in the evaluating step, the penetration of ammonia into the test body is evaluated based on the contact time of the medium with the test body and the depth of the color development region with respect to the surface of the test body.

5. The ammonia penetration evaluation method according to claim 1, wherein the color developer contains metal ions that cause a chelation reaction with ammonia.

6. The ammonia penetration evaluation method according to claim 5, wherein the metal ions are copper ions.

7. The ammonia penetration evaluation method according to claim 1, wherein the color developer contains an ultraviolet light-emitting agent.

8. The ammonia penetration evaluation method according to claim 7, wherein the color developer contains ions of a metal in Group 8 of the periodic table.

9. The ammonia penetration evaluation method according to claim 1, wherein the color developer is a pH indicator.

10. A method for determining the superiority or inferiority of a material using the ammonia penetration evaluation method according to any one of claims 1 to 9, The determination method comprising a step of determining the ammonia resistance of the material based on the evaluation result of the evaluating step.

11. A container in which a test body is disposed; A supply unit that replaces and supplies a medium containing any one of liquid ammonia, ammonia gas, and a solution containing ammonia into the container; An exposing means for exposing the internal region of the test body taken out of the container after contact with the medium; A color developer applied to the internal region exposed by the exposing means An ammonia penetration evaluation system comprising:

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