Quenching apparatus

Abstract

To provide a quenching apparatus and a quenching method with which gas quenching employing hydrogen gas can be efficiently performed.MEANS FOR SOLVING THE PROBLEM: The present invention discloses a quenching apparatus having: a quenching chamber for air blast cooling a material using hydrogen gas; a heat exchanger for cooling the hydrogen gas; a first pipe for supplying the heat exchanger with hydrogen gas discharged from the quenching chamber; and a second pipe for supplying the quenching chamber with hydrogen gas cooled by means of the heat exchanger.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for quenching a material using hydrogen gas as a coolant. [Background technology]

[0002] Quenching is a process in which a material is cooled at a high temperature more quickly than in still air. Quenching is performed, for example, in the manufacturing process of ferrous materials (e.g., steel), to rapidly cool a heated metal structure with an austenitic structure to obtain a martensite structure, which has superior properties in terms of wear resistance, tensile strength, fatigue strength, etc. This process is particularly important for improving the properties of carburized ferrous materials, which tend to retain an austenitic structure on the surface.

[0003] Coolants used for quenching include oil, water, aqueous solutions (e.g., aqueous polymer solutions), gases, and the like. Quenching using oil as a coolant can cool materials quickly due to the high thermal conductivity of oil. However, quenching using oil as a coolant requires preheating the oil to an appropriate temperature to prevent it from boiling when first processing the hot material, which requires additional equipment. In addition, because oil adheres to the material, a cleaning process is required after quenching, and the cleaning liquid containing the oil must be disposed of.

[0004] Quenching using water or an aqueous solution (e.g., an aqueous polymer solution) as a coolant can also rapidly cool materials due to the high thermal conductivity of water or an aqueous solution. However, quenching using water as a coolant often poses the problem of cracks forming in materials such as steel. Furthermore, quenching using water or an aqueous solution (e.g., an aqueous polymer solution) as a coolant requires a post-quench process to wash away any coolant adhering to the material and to dry the material to prevent rust.

[0005] Quenching using gas as a coolant (gas quenching) is less advantageous than quenching using oil or water or aqueous solutions (e.g., polymer aqueous solutions) as coolants in terms of rapid cooling of materials because the thermal conductivity of gas is generally lower than that of oil, water, or aqueous solutions. Gas quenching, on the other hand, offers several advantages, including the ability to precisely adjust parameters such as the coolant temperature and pressure, the elimination of post-quenching material processing (e.g., cleaning and drying), minimal waste and a low environmental impact, and the reduced equipment required for easy integration into production lines. To improve cooling efficiency, gas quenching typically uses highly pressurized gas and is blast-cooled using a fan.

[0006] There is a need for an apparatus and method for effectively performing quenching. For example, JP 2007-502913 A reports an apparatus and method for efficiently performing gas quenching by efficiently pressurizing a high-pressure gas containing, among other things, helium. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2007-502913 Summary of the Invention [Problem to be solved by the invention]

[0008] In conventional gas quenching, nitrogen gas, helium gas, argon gas, and mixed gases including combinations of these have been mainly used as coolants. However, to perform gas quenching more effectively, it is desirable to use a gas with a higher thermal conductivity. In this regard, the use of hydrogen gas as a coolant is considered preferable from the viewpoint of cooling efficiency, considering that the thermal conductivity coefficient of hydrogen gas is approximately twice that of nitrogen gas and approximately 1.3 times that of helium gas. However, hydrogen gas is expensive compared to, for example, nitrogen gas, which is widely used because it is inexpensive, and therefore its use in industrial-scale quenching has not been easy from a cost perspective. Furthermore, unlike inert gases such as nitrogen gas, hydrogen gas is flammable and requires careful handling. In particular, it has been difficult to use highly pressurized hydrogen gas on an industrial scale. Therefore, an object of the present disclosure is to provide a quenching device and a quenching method that can effectively perform gas quenching using hydrogen gas, which has a high thermal conductivity coefficient. [Means for solving the problem]

[0009] In this disclosure, the following quenching equipment is used: a quenching chamber in which the material is blast-cooled using hydrogen gas; a fan unit for supplying the hydrogen gas to the quenching chamber; a heat exchanger for cooling the hydrogen gas; a first pipe for supplying hydrogen gas in the quenching chamber to the heat exchanger; a second pipe that supplies the hydrogen gas cooled by the heat exchanger to the fan unit; A quenching device comprising:

[0010] The quenching device of the present disclosure can effectively perform quenching using hydrogen gas, which has an excellent thermal conductivity coefficient. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows an example of the configuration of a gas quenching device according to the first embodiment. [Figure 2] FIG. 2 shows an example of the configuration of a gas quenching device according to the second embodiment. [Figure 3] FIG. 3 shows an example of the configuration of a gas quenching device according to the third embodiment. [Figure 4] FIG. 4 shows the relationship between the distance from the material surface and the Vickers hardness for materials quenched using oil, hydrogen, or nitrogen. DETAILED DESCRIPTION OF THE INVENTION

[0012] Exemplary embodiments of the present disclosure will be described in detail below. The embodiments may be implemented singly or in combination. The configurations shown in the drawings may not include some of the components, may include additional components, or may be modified to include other components, as long as the effects of the present invention are achieved. When a specific description given for one embodiment also applies to other embodiments, that description is omitted in the other embodiments.

[0013] Each numerical range in the present disclosure is intended to include the upper and lower limit values indicated by "to" or "from." For example, the description "A to B" or "A to B" using numerical values A and B means A or more and B or less. Furthermore, the descriptions "A to B," "A to B," or "A or more and B or less" in the numerical ranges described in stages in the present disclosure independently include both "A or more is preferred" and "B or less is preferred," and these lower or upper limit values may be replaced with the upper or lower limit value of another numerical range. Furthermore, the lower or upper limit value of a numerical range described in the present disclosure may be replaced with a numerical value within that numerical range and shown in the examples.

[0014] <Embodiment 1> An example of the configuration of a quenching device according to one embodiment is shown in FIG. The quenching apparatus shown in FIG. 1 includes a quenching chamber 102 that uses hydrogen gas to blast-cool a material 101, a heat exchanger 104 that cools the hydrogen gas, a first pipe (pipe L101) that supplies the hydrogen gas discharged from the quenching chamber to the heat exchanger 104, and a second pipe (pipe L102) that supplies the hydrogen gas cooled by the heat exchanger 104 to the quenching chamber 102. In the quenching apparatus shown in Figure 1, the hydrogen gas used for quenching circulates within the apparatus and is used repeatedly during quenching, so that the apparatus can effectively perform quenching using hydrogen gas.

[0015] (Quenching room) The quenching chamber 102 is a space (preferably an enclosed space) for quenching the material 101, and is provided with an openable and closable material entrance / exit (not shown) and an installation table 103 on which the material 101 can be placed. The material 101 placed on the installation table 103 is cooled by blast using hydrogen gas supplied from a fan unit 105 connected to the quenching chamber 102.

[0016] (material) The material 101 is any material that can be hardened. The material may be a metal material or a glass material. The metal material may be, for example, a ferrous material, and the ferrous material may be, for example, steel. The ferrous material may be a carburized ferrous material, and the steel may be a carburized steel. The material 101 can be placed on a placement table 103 in the quenching chamber 102 through a material inlet / outlet provided in the quenching chamber 102 . The material 101 is preferably a material that has been heated in a heating furnace before being subjected to the apparatus of the present disclosure. The material that has been heated in a heating furnace may be, for example, a material that has been heated to 800 to 1000°C in a heating furnace.

[0017] (hydrogen gas) Hydrogen gas refers to a gas containing H2 as a major component. Hydrogen gas may contain 50% by volume or more, 60% by volume or more, 70% by volume or more, 80% by volume or more, 85% by volume or more, 90% by volume or more, 95% by volume or more, 98% by volume or more, 99% by volume or more, 99.9% by volume or more, or 100% by volume of H2 relative to the total volume of the gas. Hydrogen gas may contain unavoidable impurities derived from the raw materials. Non-limiting examples of such impurities include water, hydrocarbons, carbon monoxide, carbon dioxide, etc. The impurities may be in the form of a solid, liquid, or gas. Hydrogen gas may also be free of, or substantially free of, inert gases. Examples of inert gases include helium gas, neon gas, argon gas, nitrogen gas, carbon dioxide gas, and mixed gases containing any combination thereof. The hydrogen gas may contain impurities such as fine particles derived from the material that were mixed in when the material was quenched. When the composition of the hydrogen gas varies within the quenching apparatus, the hydrogen gas may be hydrogen gas having the above-mentioned composition at the time when the hydrogen gas is supplied from the outside to the inside of the quenching apparatus. Hydrogen gas is supplied from the outside of the apparatus to the inside of the apparatus through a supply port provided in an appropriate location of the apparatus. Non-limiting examples of appropriate locations of the apparatus where the supply port may be provided include the high-pressure hydrogen gas tank 108, the low-pressure hydrogen gas tank 109, the hydrogen gas tanks 207 and 307, the pipes L102, L203, and L302, and the quenching chambers 102, 202, and 302. The supply port can be closed when hydrogen gas is not being supplied to the inside of the apparatus.

[0018] (Fan Club) The fan unit 105 has a supply port that supplies hydrogen gas to the fan unit 105 through the pipe L102, and a discharge port that discharges the hydrogen gas from the fan unit 105. The discharge port is connected to the quenching chamber 102 and supplies hydrogen gas to the quenching chamber 102 for air blast cooling of the material 101. The fan unit 105 supplies hydrogen gas to the quenching chamber 102 at a wind speed appropriate for blast cooling the material 101. The fan unit 105 also creates a flow of hydrogen gas that is supplied to the quenching chamber 102, passes through the pipe L101, the heat exchanger 104, and the pipe L102, and is then introduced back into the fan unit 105.

[0019] (heat exchanger) The heat exchanger 104 cools the hydrogen gas supplied from the quenching chamber 102 through the pipe L101 to the quenching temperature, and discharges the cooled hydrogen gas through the pipe L102.

[0020] The quenching apparatus shown in FIG. 1 further includes a branch pipe branching off from the second pipe (pipe L102), a low-pressure hydrogen gas tank 109 for storing hydrogen gas supplied through the branch pipe, a hydrogen gas compressor 107 for pressurizing the hydrogen gas supplied from the low-pressure hydrogen gas tank 109, a high-pressure hydrogen gas tank 108 for storing the hydrogen gas pressurized by the hydrogen gas compressor 107, and a supply pipe for supplying the hydrogen gas in the high-pressure hydrogen gas tank 108 to the second pipe. By providing these configurations, the quenching device shown in FIG. 1 can repressurize and store the hydrogen gas used in quenching, allowing it to be used in the next quenching.

[0021] (Hydrogen gas compressor) The hydrogen gas compressor 107 is a hydrogen gas compressor that can pressurize hydrogen gas preferably to 2 to 10 bar, more preferably to 5 to 10 bar. By using pressurized hydrogen gas, it becomes possible to cool the material more quickly. Any known hydrogen gas processor can be used as the hydrogen gas compressor 107 as long as the effects of the present invention can be obtained. Non-limiting examples of such known hydrogen gas processors include piston compressors (including oil-free and highly lubricated types). Furthermore, a hydrogen gas compressor using a metal hydride, which will be described later, can be used as the hydrogen gas compressor.

[0022] In the quenching apparatus shown in Fig. 1, hydrogen gas in pipe L102 is supplied to a low-pressure hydrogen gas tank 109 through a branch pipe branching off from pipe L102 and stored therein. The hydrogen gas in the low-pressure hydrogen gas tank 109 is supplied through pipe L104 to a hydrogen gas regeneration unit 106, which removes impurities from the hydrogen gas. The hydrogen gas from which the impurities have been removed is supplied from the hydrogen gas regeneration unit 106 to a hydrogen gas compressor 107 through pipe L105. The hydrogen gas pressurized by the hydrogen gas compressor 107 is supplied to a high-pressure hydrogen gas tank 108 through pipe L106 and stored therein.

[0023] In conventional gas quenching, from the viewpoint of quenching efficiency, it has been considered desirable to use high-pressure gas, typically pressurized to 20 to 30 bar, as the coolant. However, to generate such high-pressure gas, the quenching device must be equipped with an expensive gas compressor (e.g., a piston compressor). Furthermore, when using high-pressure gas exceeding 10 bar, it is not easy to satisfy the safety standards specified by many countries (e.g., quantity restrictions on high-pressure gas, the existence of facilities that meet the standards, the presence of a qualified manager at all times, etc.), and therefore it has not been easy to operate a gas quenching device equipped with a gas compressor that generates such high-pressure gas. On the other hand, hydrogen gas used as a coolant in the quenching apparatus shown in FIG. 1 has a high thermal conductivity, so quenching can be effectively performed even when the hydrogen gas pressure is relatively low (e.g., 2 to 10 bar or 5 to 10 bar). Therefore, in the quenching apparatus shown in FIG. 1, the hydrogen gas compressor 107 may be an inexpensive gas compressor that pressurizes hydrogen gas to a relatively low pressure (e.g., 2 to 10 bar or 5 to 10 bar). Therefore, the quenching apparatus shown in FIG. 1 can be operated more safely and at a lower cost than conventional apparatuses.

[0024] (Hydrogen gas compressor using metal hydride) Metal hydrides, also known as hydrogen storage alloys, are alloys that have the property of releasing hydrogen at high temperatures and absorbing hydrogen at low temperatures. A hydrogen compressor using metal hydrides is a gas compressor that uses this property of metal hydrides to compress hydrogen gas. In the method and apparatus of this embodiment, the hydrogen compressor using metal hydride can effectively pressurize hydrogen gas to a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar). Hydrogen compressors using metal hydrides can generally be introduced and operated at lower cost and are easier to integrate into production lines than compressors that have been primarily used in conventional gas quenching, such as piston compressors (including oil-free and high-lubrication types). Furthermore, hydrogen gas is flammable and combustible, so care must be taken when handling it. However, hydrogen compressors using metal hydride are able to pressurize hydrogen gas more safely than conventional compressors. Furthermore, hydrogen compressors using metal hydride specifically adsorb and discharge hydrogen using the metal hydride, and therefore can improve and maintain the purity of hydrogen gas during the process of pressurizing the hydrogen gas. Examples of metal hydrides include iron-titanium, titanium-nickel, lanthanum-nickel, and magnesium alloys.

[0025] (High-pressure hydrogen gas tank) The high-pressure hydrogen gas tank 108 can store hydrogen gas pressurized by a hydrogen gas compressor 107 and supplied through a pipe L106. The hydrogen gas stored in the high-pressure hydrogen gas tank 108 is supplied to a second pipe (pipe L102) through a supply pipe (pipe L107) equipped with an on-off valve V101 by opening the on-off valve V101. The hydrogen gas supplied to the pipe L102 is supplied to the quenching chamber 102 via a fan unit 105. The on-off valve V101 can be opened when the pressure of the hydrogen gas in the quenching chamber 102 drops below a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar), and can be closed when the pressure of the hydrogen gas in the quenching chamber 102 rises above the desired pressure. This allows the on-off valve V101 to adjust the pressure of the hydrogen gas in the quenching chamber 102 so as to maintain the desired pressure.

[0026] (Low-pressure hydrogen gas tank) The low-pressure hydrogen gas tank 109 stores the hydrogen gas used in gas quenching, which is supplied through a supply pipe (pipe L103). The hydrogen gas in the low-pressure hydrogen gas tank 109 is supplied to a hydrogen gas compressor 107 through pipes L104 and L105, which have a hydrogen gas regeneration unit 106 interposed therebetween. An on-off valve V102 is provided in the pipe L103. The on-off valve V102 can be closed while the material 101 is being quenched. After the quenching of the material 101 is completed, the on-off valve V102 is opened, and the hydrogen gas used for quenching is supplied to the low-pressure hydrogen gas tank 109 through the pipe L103.

[0027] (Hydrogen gas regeneration unit) 1 includes a hydrogen gas regeneration unit 106 installed in the pipes L104 and L105. The hydrogen gas regeneration unit 106 is a unit that can regenerate hydrogen gas so that it can be used again for quenching by removing components such as fine particles originating from the material 101 that are contained in the hydrogen gas used for quenching. Any known hydrogen gas regeneration unit can be used as the hydrogen gas regeneration unit 106 as long as the effects of the present invention can be obtained. The hydrogen gas regeneration unit 106 is preferably a filter. The filter may have, for example, a pore size that prevents solid impurities of a certain size or larger from passing through and / or may have the property of adsorbing impurities.

[0028] 1 may also include any other optional additional components. Non-limiting examples of optional additional components include a supply port for supplying hydrogen gas from the outside of the apparatus to the inside of the apparatus, a pressure gauge for measuring the pressure of hydrogen gas at a desired location within the apparatus, a pressure relief valve (safety valve), an exhaust port, a temperature measurement port for measuring the temperature inside the quenching chamber, etc.

[0029] (Operation of the gas quenching device shown in Figure 1) The quenching of material using the gas quenching apparatus shown in FIG. 1 is carried out as follows. By opening the on-off valve V101 and closing the on-off valve V102, the high-pressure hydrogen gas stored in the high-pressure hydrogen gas tank 108 is supplied to the second pipe (pipe L102) through the supply pipe (pipe L107). The on-off valve V101 can then be closed when the pressure of the high-pressure hydrogen gas supplied to pipe L102 reaches a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar), and can be opened again when the pressure of the high-pressure hydrogen gas in pipe L102 drops below the desired pressure. The hydrogen gas supplied to the pipe L102 is supplied to the quenching chamber 102. Furthermore, the fan unit 105 is operated to cool the material 101 placed on the placement table 103 by air blast, and the material 101 is quenched. During quenching, the temperature of the hydrogen gas increases as the material 101 is cooled. The hydrogen gas with increased temperature is sent from the quenching chamber 102 to the heat exchanger 104 through the first pipe (pipe L101), and is cooled by the heat exchanger 104. The cooled hydrogen gas is supplied again to the quenching chamber 102 by the fan unit 105 through a second pipe (pipe L102). That is, until the quenching of the material 101 is completed, the high-pressure hydrogen gas circulates from the quenching chamber 102 through the first pipe (pipe L101), the heat exchanger 104, the second pipe (pipe L102), and back to the quenching chamber 102. Therefore, the device shown in Fig. 1 can reduce the amount of hydrogen gas used by repeatedly reusing the hydrogen gas during quenching.

[0030] After the hardening of the material 101 is completed, the on-off valve V101 is closed and the on-off valve V102 is opened, whereby the hydrogen gas used for hardening is supplied to the low-pressure hydrogen gas tank 109 through the pipe L102 and the pipe L103. The hydrogen gas in the low-pressure hydrogen gas tank 109 is sent to the hydrogen gas regeneration unit 106 through pipe L104, where fine particles and other contaminants that may have been mixed in during quenching are removed, and the hydrogen gas is then supplied to the hydrogen gas compressor 107 through pipe L105. The hydrogen gas is pressurized in the hydrogen gas compressor 107. The pressurized hydrogen gas is supplied to the high-pressure hydrogen gas tank 108 through the pipe L106 and stored in the high-pressure hydrogen gas tank 108. The high-pressure hydrogen gas stored in the high-pressure hydrogen gas tank 108 can be supplied again to the pipe L102 through a supply pipe (pipe L107) equipped with an on-off valve V101 by opening the on-off valve V101. Therefore, the device shown in FIG. 1 repressurizes and stores the used gas after quenching is completed, and can reuse it for the next quenching, thereby reducing the amount of hydrogen gas used.

[0031] <Embodiment 2> An example of the configuration of a quenching device according to the second embodiment is shown in FIG. The quenching apparatus shown in FIG. 2 includes a quenching chamber 202 that uses hydrogen gas to blast-cool the material, a heat exchanger 204 that cools the hydrogen gas, a first pipe (pipes L201 and L202 that have a hydrogen gas compressor 206 using metal hydride installed) that supplies the hydrogen gas discharged from the quenching chamber 202 to the heat exchanger 204, and a second pipe L203 that supplies the hydrogen gas cooled by the heat exchanger 204 to the quenching chamber 202. In the quenching apparatus shown in Figure 2, the hydrogen gas used for quenching circulates within the apparatus and is repeatedly used during quenching, so the apparatus can effectively perform quenching using hydrogen gas.

[0032] The quenching apparatus shown in FIG. 2 further includes a hydrogen gas compressor 206 using metal hydride, which is interposed between the pipes L201 and L202 and pressurizes the hydrogen gas supplied from the quenching chamber 202, and a hydrogen gas tank 207 which stores the hydrogen gas supplied through a branch pipe L204 branching from the pipe L203. By providing these configurations, the quenching device shown in FIG. 2 can repressurize and store the hydrogen gas used in quenching, allowing it to be used in the next quenching.

[0033] (Hydrogen gas tank 207) The hydrogen gas tank 207 can store hydrogen gas supplied from the pipe L203 through the pipe L204. The hydrogen gas tank 207 can also supply the stored hydrogen gas to the pipe L203 through the pipe L204. The pipe L204 is equipped with an on-off valve V201. The on-off valve V201 is opened when hydrogen gas is supplied from the pipe L203 to the hydrogen gas tank 207 and when hydrogen gas is discharged from the hydrogen gas tank 207 to the pipe L203, and can be closed at other times.

[0034] (Other configurations) As each component of the quenching device shown in FIG. 2, the same components as those of the quenching device shown in FIG. 1 can be used.

[0035] (Operation of the gas quenching device shown in Figure 2) Quenching of material by the gas quenching apparatus shown in Fig. 2 is carried out in the same manner as quenching of material by the gas quenching apparatus shown in Fig. 1. That is, during quenching of material 201, hydrogen gas circulates from quenching chamber 202 through pipe L201, hydrogen gas compressor 206 using metal hydride, pipe L202, heat exchanger 204, pipe L203, and back to quenching chamber 202. Therefore, the gas quenching apparatus shown in Fig. 2 can reduce the amount of hydrogen gas used by circulating and reusing the hydrogen gas during quenching.

[0036] The hydrogen gas used for blast cooling of the material 201 can be introduced into the quenching chamber 202 from the hydrogen gas tank 207 via the pipes L204, L203, and the fan section 205 by opening the opening / closing valve V201 at the start of quenching.

[0037] The hydrogen gas in the quenching chamber 202 used for quenching the material 201 is supplied to a hydrogen gas compressor 206 using metal hydride through a pipe L201. Here, the material 201 is preferably a material that has been heated to a high temperature (e.g., 800 to 1000°C) in a heating furnace (e.g., a carburizing furnace) before being introduced into the quenching chamber. Therefore, the hydrogen gas used for quenching is preferably hydrogen gas that has been heated by contact with the heated material. As heated hydrogen gas is supplied, the temperature of the metal hydride-based hydrogen gas compressor 206 rises, causing the metal hydride-based hydrogen gas compressor 206 to release the hydrogen adsorbed in the metal hydride, and the pressure of the hydrogen gas discharged from the hydrogen gas compressor 206 through the pipe L202 is increased to a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar).

[0038] The pressurized hydrogen gas is supplied to the heat exchanger 204 through the pipe L202, cooled in the heat exchanger 204, and then supplied again to the quenching chamber 202 through the pipe L203 and the fan unit 205. Therefore, as the quenching progresses, the pressure of the hydrogen gas supplied to the heat exchanger 204 increases from the start of the quenching, and reaches a steady state at a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar). The temperature of the material 201 and the temperature of the hydrogen gas used to quench the material 201 decrease as the quenching progresses, and typically reaches room temperature by the end of the quenching. As a result, the temperature of the metal hydride-based hydrogen gas compressor 206 also decreases, causing hydrogen to be adsorbed into the metal hydride-based hydrogen gas compressor 206. Note that since the adsorption of hydrogen into the metal hydride generates heat, the temperature of the metal hydride-based hydrogen gas compressor 206 tends to be slightly higher than room temperature during hydrogen adsorption, even if the temperature of the supplied hydrogen gas is room temperature. At the end of the quenching, the pressure of the hydrogen gas is reduced, for example, to 2 to 5 bar due to adsorption of the hydrogen gas into the metal hydride.

[0039] The on-off valve V201 is opened when the pressure of the hydrogen gas in the quenching chamber 202 rises to a predetermined pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar) or when it rises to a higher pressure, thereby supplying hydrogen gas to the hydrogen gas tank 207 and maintaining the pressure of the hydrogen gas in the quenching chamber 202 at the predetermined pressure. The hydrogen gas supplied to the hydrogen gas tank 207 is stored in a sealed state in the hydrogen gas tank 207 by closing the on-off valve V201.

[0040] After quenching is completed, the material 201 is removed from the quenching chamber 202. Subsequently, another material to be quenched next is placed in the quenching chamber 202. After the other material is placed, the open / close valve V201 is opened and hydrogen gas stored in the hydrogen gas tank 207 is introduced into the pipe L203, thereby making it possible to quench the other material. Therefore, the apparatus shown in FIG. 2 can reduce the amount of hydrogen gas used by reusing the hydrogen gas used in quenching for the next quenching. The quenching apparatus shown in Fig. 2 uses a hydrogen gas compressor 206 that uses metal hydride as the hydrogen gas compressor. This quenching apparatus uses the thermal change of the material that accompanies quenching to adsorb and release hydrogen into the metal hydride. Therefore, the quenching apparatus shown in Fig. 2 can effectively pressurize hydrogen gas without using an external cold or heat source.

[0041] <Embodiment 3> An example of the configuration of a quenching device according to the third embodiment is shown in FIG. The quenching apparatus shown in FIG. 3 includes a quenching chamber 302 that uses hydrogen gas to blast-cool material 301, a heat exchanger 304 that cools the hydrogen gas, a first pipe (pipe L301) that supplies the hydrogen gas discharged from the quenching chamber 302 to the heat exchanger 304, and a second pipe (pipe L302) that supplies the hydrogen gas cooled by the heat exchanger 304 to the quenching chamber 302. In the quenching apparatus shown in Figure 3, the hydrogen gas used for quenching circulates within the apparatus and is repeatedly used during quenching, so the apparatus can effectively perform quenching using hydrogen gas.

[0042] The quenching apparatus shown in FIG. 3 further includes a hydrogen gas compressor 306 using metal hydride that pressurizes hydrogen gas supplied through a branch pipe (pipe L305) branching off from pipe L301, a hydrogen gas tank 307 that stores the hydrogen gas pressurized by the hydrogen gas compressor 306, and a supply pipe that supplies the hydrogen gas in the hydrogen gas tank to the second pipe. The hydrogen gas compressor 306 and the hydrogen gas tank 307 are connected by a connecting pipe (pipe L304). An on-off valve V303 is provided on the pipe L305, an on-off valve V302 on the pipe L304, and an on-off valve V301 on the pipe L303. By providing these configurations, the quenching device shown in FIG. 3 can repressurize and store the hydrogen gas used in quenching, allowing it to be used in the next quenching.

[0043] (Hydrogen gas tank 307) Hydrogen gas pressurized by a metal hydride-based hydrogen gas compressor 306 is supplied to the hydrogen gas tank 307 through a pipe L304, and this hydrogen gas can be stored in the hydrogen gas tank 307. The hydrogen gas stored in the hydrogen gas tank 307 can be sealed within the hydrogen gas tank 307 by closing the on-off valve V302 and the on-off valve V301.

[0044] (Other configurations) As each component of the quenching device shown in FIG. 3, the same components as those of the quenching device shown in FIGS. 1 and 2 can be used.

[0045] (Operation of the gas quenching device shown in Figure 3) Quenching of material by the gas quenching apparatus shown in Fig. 3 is carried out in the same manner as quenching of material by the gas quenching apparatus shown in Fig. 1 or 2. That is, during quenching of material 301, high-pressure hydrogen gas circulates in a cycle from quenching chamber 302 through pipe L301, heat exchanger 304, pipe L302, and back to quenching chamber 302. Therefore, the apparatus shown in Fig. 3 circulates and reuses hydrogen gas during quenching, thereby reducing the amount of hydrogen gas used.

[0046] At the start of quenching, the hydrogen gas used for air blast cooling of the material 301 can be introduced from the hydrogen gas tank 307 through the pipes L303, L302, and fan unit 305 into the quenching chamber 302 by opening the on-off valve V301 and closing the on-off valves V302 and V303. After the introduction of the hydrogen gas, the pressure rises to a predetermined level, and then the on-off valve V301 is closed. After quenching of the material 301 is completed, the open / close valve V303 is opened, and the hydrogen gas used for quenching flows through the hydrogen gas compressor 306, which uses metal hydride. Here, the metal hydride is kept at a temperature below room temperature by an external cold heat source, so that the hydrogen in the hydrogen gas is adsorbed by the metal hydride. The hydrogen adsorbed to the metal hydride is released from the metal hydride by heating the metal hydride with an external heat source. At this time, the pressure of the hydrogen gas in the hydrogen gas tank 307 can be increased to a desired pressure (preferably 2 to 10 bar, more preferably 5 to 10 bar) by closing the on-off valves V303 and V301 and opening the on-off valve V302. After the quenching is completed, the material 301 is removed from the quenching chamber 302. Thereafter, by placing another material in the quenching chamber 302, the above-described quenching process can be repeated for another material. Therefore, the device shown in FIG. 3 can reduce the amount of hydrogen gas used by reusing the hydrogen gas used in quenching for the next quenching. The quenching apparatus shown in Fig. 3 uses a hydrogen gas compressor 306 that uses metal hydride as the hydrogen gas compressor. The quenching apparatus uses an external cooling and heating source to adsorb and discharge hydrogen into the metal hydride. Therefore, the quenching apparatus shown in Fig. 3 can efficiently reuse hydrogen gas.

[0047] <Gas quenching method and manufacturing method for quenched parts or products equipped with parts> In one embodiment, a method for producing a quenched material and a method for producing a product comprising the quenched material are disclosed, including quenching the material with hydrogen gas in the quenching apparatus described above, including, but not limited to, any product that can be produced by the method, including, but not limited to, gears, shafts, and bearings.

[0048] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure are disclosed below. [1] a quenching chamber in which the material is blast-cooled using hydrogen gas; a heat exchanger for cooling the hydrogen gas; a first pipe for supplying hydrogen gas discharged from the quenching chamber to the heat exchanger; a second pipe for supplying the hydrogen gas cooled by the heat exchanger to the quenching chamber; A quenching device comprising: [2] a branch pipe branching from the second pipe; a low-pressure hydrogen gas tank that stores hydrogen gas supplied through the branch pipe; a hydrogen gas compressor that pressurizes the hydrogen gas supplied from the low-pressure hydrogen gas tank; a high-pressure hydrogen gas tank that stores hydrogen gas pressurized by the hydrogen gas compressor; a supply pipe that supplies hydrogen gas in the high-pressure hydrogen gas tank to the second pipe; The quenching device according to [1], further comprising: [3] The quenching device according to [2], wherein the piping connecting the low-pressure hydrogen gas tank and the hydrogen gas compressor is provided with a hydrogen gas regeneration unit that removes impurities from the hydrogen gas. [4] The quenching device according to [2], wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride. [5] a hydrogen gas compressor that is installed in the first pipe and that pressurizes the hydrogen gas supplied from the quenching chamber; a hydrogen gas tank communicating with the second pipe through a branch pipe branching from the second pipe; Furthermore, The quenching device according to [1], wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride. [6] a hydrogen gas compressor that compresses hydrogen gas supplied through a branch pipe branching from the first pipe; a hydrogen gas tank for storing hydrogen gas pressurized by the hydrogen gas compressor; a supply pipe that supplies hydrogen gas in the hydrogen gas tank to the second pipe; Furthermore, The quenching device according to [1], wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride. [7] A method for producing a quenched material, comprising quenching a material with hydrogen gas in a quenching apparatus according to any one of [1] to [6]. [8] A method for manufacturing a product having a quenched material, comprising quenching the material with hydrogen gas in a quenching device according to any one of [1] to [6]. [9] The manufacturing method according to [8], wherein the product is a gear, a shaft, or a bearing. [Example]

[0049] The present invention will be described below with reference to examples, but is not limited to these examples. Commercially available reagents and equipment referred to in the examples were used according to the manufacturer's instructions or standard procedures, unless otherwise specified.

[0050] [Example 1] Relationship between distance from the surface and Vickers hardness for hardened materials The steel material SCr420H was quenched by air blast cooling using oil or 100% hydrogen gas or 100% nitrogen gas pressurized to 7-8 bar as a coolant. Figure 4 shows the results of measuring the relationship between the distance from the surface and the Vickers hardness of hardened steel material. As shown in Figure 4, quenching using hydrogen gas as a coolant effectively improved the Vickers hardness of the surface of the steel material, similar to quenching using oil as a coolant. On the other hand, when nitrogen gas was used as a coolant, the Vickers hardness of the surface of the steel material was not as good as when hydrogen gas was used as a coolant. These results show that the quenching device of the present invention can efficiently perform quenching even when the hydrogen gas pressure is relatively low. Also, these results show that the quenching efficiency using the quenching device of the present invention is better than that using quenching devices that use other gases as coolants and is comparable to that using oil as a coolant. Therefore, the quenching device of the present invention can effectively perform quenching. Furthermore, since the quenching device of the present invention reuses hydrogen gas, effective quenching using hydrogen gas can be performed at low cost. [Explanation of symbols]

[0051] 101 Material 102 Quenching Room 103 Installation stand 104 Heat exchanger 105 Fan Club 106 Hydrogen gas regeneration unit 107 Hydrogen Gas Compressor 108 High-pressure hydrogen gas tank 109 Low-pressure hydrogen gas tank L101-L107 piping V101, V102 shut-off valve 201 Material 202 Quenching Room 203 Installation stand 204 Heat exchanger 205 Fan Club 206 Hydrogen Gas Compressor Using Metal Hydride 207 Hydrogen gas tank L201-L204 piping V201 Opening and Closing Valve 301 Material 302 Quenching Room 303 Installation stand 304 Heat exchanger 305 Fan Club 306 Hydrogen Gas Compressor Using Metal Hydride 307 Hydrogen Gas Tank L301-L305 piping V301-V303 Opening and Closing Valves

Claims

1. a quenching chamber in which the material is blast-cooled using hydrogen gas; a heat exchanger for cooling the hydrogen gas; a first pipe for supplying hydrogen gas discharged from the quenching chamber to the heat exchanger; a second pipe for supplying the hydrogen gas cooled by the heat exchanger to the quenching chamber; A quenching device comprising:

2. a branch pipe branching from the second pipe; a low-pressure hydrogen gas tank that stores hydrogen gas supplied through the branch pipe; a hydrogen gas compressor that pressurizes the hydrogen gas supplied from the low-pressure hydrogen gas tank; a high-pressure hydrogen gas tank that stores hydrogen gas pressurized by the hydrogen gas compressor; a supply pipe that supplies hydrogen gas in the high-pressure hydrogen gas tank to the second pipe; The quenching apparatus of claim 1 further comprising:

3. 3. The quenching device according to claim 2, wherein a hydrogen gas regeneration unit that removes impurities from the hydrogen gas is installed in a pipe that connects the low-pressure hydrogen gas tank and the hydrogen gas compressor.

4. 3. The quenching device according to claim 2, wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride.

5. a hydrogen gas compressor that is installed in the first pipe and that pressurizes the hydrogen gas supplied from the quenching chamber; a hydrogen gas tank communicating with the second pipe through a branch pipe branching from the second pipe; Furthermore, 2. The quenching device according to claim 1, wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride.

6. a hydrogen gas compressor that compresses hydrogen gas supplied through a branch pipe branching from the first pipe; a hydrogen gas tank for storing hydrogen gas pressurized by the hydrogen gas compressor; a supply pipe that supplies hydrogen gas in the hydrogen gas tank to the second pipe; Furthermore, 2. The quenching device according to claim 1, wherein the hydrogen gas compressor is a hydrogen gas compressor using metal hydride.

7. 7. A method for producing a hardened material, comprising quenching the material with hydrogen gas in a quenching apparatus according to any one of claims 1 to 6.

8. A method for producing a product comprising a quenched material, the method comprising quenching the material with hydrogen gas in a quenching apparatus according to any one of claims 1 to 6.

9. The method of claim 8 , wherein the product is a gear, a shaft, or a bearing.

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