Metal material selection support device, metal material selection support method, and program

Abstract

The purpose is to support the selection of metal materials that will be exposed to hydrogen gas. [Solution] The metal material selection support device is a metal material selection support device that assists in the selection of metal materials to be used in a hydrogen-containing atmosphere, and comprises a storage unit that stores physical property information of candidate metal materials and usage condition information of candidate metal materials, and a processing unit. Based on the physical property information and usage condition information, the processing unit calculates the hydrogen fatigue crack propulsion force to evaluate the ease with which fatigue cracks propagate in the candidate metal material in a hydrogen-containing atmosphere.

Description

Technical Field

[0001] This disclosure relates to a technique for assisting in the selection of metal materials exposed to hydrogen gas.

Background Art

[0002] Patent Document 1 discloses a steel material fracture origin estimation device for estimating the fracture origin of steel materials due to hydrogen embrittlement.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In hydrogen equipment exposed to hydrogen gas, hydrogen embrittlement may occur. Hydrogen embrittlement is a phenomenon in which hydrogen penetrates into the material and reduces strength and ductility. For hydrogen equipment, material selection is made in consideration of hydrogen embrittlement.

[0005] It is understood that for steel materials widely used industrially, the strength level, hydrogen pressure, and stress level are the main influencing factors on hydrogen embrittlement. However, when considering a wide range of strength levels, hydrogen pressures, and stress levels, no specific findings for uniformly understanding hydrogen embrittlement are found. Therefore, it is difficult to select metal materials.

[0006]

Means for Solving the Problems

[0007] The metal material selection support device is a metal material selection support device that assists in the selection of metal materials to be used in a hydrogen-containing atmosphere, and comprises a storage unit that stores physical property information of candidate metal materials and usage condition information of the candidate metal materials, and a processing unit that calculates the hydrogen fatigue crack propulsion force, which evaluates the ease with which fatigue cracks propagate in the candidate metal materials in the hydrogen-containing atmosphere, based on the physical property information and the usage condition information.

[0008] This metal material selection support method is a metal material selection support method that supports the selection of metal materials to be used in a hydrogen-containing atmosphere, and includes identifying the physical property information of candidate metal materials, identifying the usage conditions information of the candidate metal materials, and calculating the hydrogen fatigue crack propulsion force to evaluate the ease with which fatigue cracks propagate in the candidate metal materials in the hydrogen-containing atmosphere based on the physical property information and the usage conditions information.

[0009] This program is for assisting in the selection of metal materials to be used in a hydrogen-containing atmosphere, and causes a computer to perform the following processes: receiving physical property information of candidate metal materials; receiving usage condition information of the candidate metal materials; and calculating the hydrogen fatigue crack propulsion force, which evaluates the ease with which fatigue cracks propagate in the candidate metal materials in the hydrogen-containing atmosphere, based on the physical property information and the usage condition information. [Effects of the Invention]

[0010] According to this disclosure, the selection of metal materials to be exposed to hydrogen gas will be supported. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram showing the electrical configuration of the metal material selection support device. [Figure 2] Figure 2 is a functional block diagram showing the metal material selection support device. [Figure 3] Figure 3 is an explanatory diagram illustrating the crack propagation mechanism. [Figure 4]Figure 4 shows the relationship between the distance from the crack tip and the hydrogen concentration. [Figure 5] Figure 5 is a graph showing the relationship between tensile strength and hydrogen concentration parameters. [Figure 6] Figure 6 is a graph showing the relationship between tensile strength and diffusion coefficient. [Figure 7] Figure 7 shows the relationship between fatigue crack propulsion force in hydrogen and the acceleration rate of fatigue crack propagation. [Figure 8] Figure 8 is a flowchart showing an example of processing by the processor. [Figure 9] Figure 9 shows an example of a display on a display device. [Modes for carrying out the invention]

[0012] The following describes the metal material selection support device, metal material selection support method, and program according to the embodiment.

[0013] Figure 1 is a block diagram showing the electrical configuration of the metal material selection support device. The metal material selection support device 20 is a device that assists in the selection of metal materials to be used in a hydrogen-containing atmosphere.

[0014] When selecting a metal material, information regarding the usage conditions of that metal material is set. In addition, information regarding the physical properties of candidate metal materials is identified. Based on the usage conditions information and physical property information, this metal material selection support device 20 calculates information useful for supporting the selection of metal materials.

[0015] The metal material selection support device 20 includes a storage unit 22 and an arithmetic unit 21 which includes a processor 24 as a processing unit.

[0016] The storage unit 22 is composed of a non-volatile storage device that stores data. The storage unit 22 is, for example, an HDD (hard disk drive) or an SSD (solid-state drive). Usage condition information 22a and physical property information 22b are stored in this storage unit 22.

[0017] The memory unit 22 may store program 22e. Program 22e describes the processing procedures for the processor 24 to perform its functions as a processing unit.

[0018] The processor 24 includes a circuit. The processor 24 is, for example, a CPU (Central Processing Unit). By executing the processing described in program 22e, the processor 24 performs processing as a processing unit that calculates the hydrogen fatigue crack propulsion force based on the material property information 22b and the usage condition information 22a. The hydrogen fatigue crack propulsion force is a value that evaluates the ease with which fatigue cracks propagate in a candidate metal material in a hydrogen-containing atmosphere. The hydrogen fatigue crack propulsion force may include an evaluation concept called the propulsive force or driving force of hydrogen fatigue crack propagation.

[0019] The calculated hydrogen fatigue crack propulsion force or information based on said propulsion force is provided to the selector of the candidate metal material.

[0020] The above-mentioned computing device 21 may be implemented by a single computer or a dedicated system in which multiple computers cooperate. Alternatively, it may be implemented by a virtual computer provided by a cloud system.

[0021] The metal material selection support device 20 may include an input interface 30. The input interface 30 is a device that receives various information or instructions to the arithmetic unit 21. The input interface 30 may be, for example, a keyboard including multiple switches, a pointing device such as a mouse that receives operation input to a screen, or a touch panel.

[0022] The metal material selection support device 20 may also include a display device 32. The display device 32 may be a liquid crystal display device, an organic EL (electro-luminescence) display device, or the like.

[0023] The computing device 21 may control the display device 32 to display the hydrogen fatigue crack propulsion force according to the set physical property information 22b and usage condition information 22a.

[0024] The memory unit 22 may store an evaluation criterion value 22c. The evaluation criterion value 22c is a criterion value for determining the suitability of a candidate metal material for use. The evaluation criterion value 22c is a value that has been set in advance for determining whether or not a candidate metal material is suitable for use.

[0025] The processor 24 may determine the suitability of the candidate metal material by comparing the calculated value based on the hydrogen fatigue crack propulsion force with the evaluation criterion value 22c.

[0026] The memory unit 22 may store acceleration rate relationship information 22d. The acceleration rate relationship information 22d is information relating the fatigue crack propulsion force in hydrogen to the acceleration rate of fatigue crack propagation due to hydrogen. The acceleration rate of fatigue crack propagation due to hydrogen is an acceleration rate that indicates how much the crack propagation rate of the candidate metal material in a hydrogen atmosphere is accelerated compared to the crack propagation rate of the candidate metal material in air. The smaller this acceleration rate is, the more the candidate metal material can be used under the same conditions as in air. The larger this acceleration is, the less suitable it is to use the candidate metal material in a hydrogen atmosphere.

[0027] The acceleration rate relationship information 22d may be a data table that correlates the fatigue crack thrust force in hydrogen with the acceleration rate of fatigue crack propagation due to hydrogen. Alternatively, the acceleration rate relationship information 22d may be an equation that can calculate the acceleration rate of fatigue crack propagation due to hydrogen, with the fatigue crack thrust force in hydrogen as a variable.

[0028] The memory unit 22 may store surface concentration-related information 22f and diffusion coefficient-related information 22g, which will be described later.

[0029] Figure 2 is a functional block diagram of the metal material selection support device 20. Each block shown in Figure 2 represents an example of a processing module executed by the metal material selection support device 20, as well as examples of input and output data for each processing module.

[0030] As shown in the figure, the intermediate evaluation value calculation process is performed based on the physical property information and usage condition information. This calculates the first intermediate evaluation value and the second intermediate evaluation value. The first intermediate evaluation value is a value corresponding to the amount of hydrogen at the tip of the crack expected to occur in the candidate metal material. The second intermediate evaluation value is a value corresponding to the hydrogen concentration gradient at the tip of the crack.

[0031] Based on the first and second intermediate evaluation values, the fatigue crack thrust calculation process in hydrogen is performed. This determines the fatigue crack thrust in hydrogen. For example, the fatigue crack thrust in hydrogen is calculated by multiplying the first and second intermediate evaluation values ​​as factors.

[0032] A suitability assessment process is performed to determine the suitability of a candidate metal material by comparing a value based on the fatigue crack propulsion force in hydrogen with an evaluation standard value. This results in the output of a suitability assessment result. The suitability assessment result may be, for example, "Recommended" (recommended to use the candidate metal material), "Approved" (approved to use the candidate metal material), or "Review" (recommends reviewing the specifications of the candidate metal material).

[0033] The value based on the fatigue crack thrust force in hydrogen may be the calculated value of the fatigue crack thrust force in hydrogen itself, or it may be a value further calculated from the calculated value of the fatigue crack thrust force in hydrogen. For example, the suitability of the candidate metal material may be determined by comparing the acceleration rate estimated from the value of the fatigue crack thrust force in hydrogen with an evaluation standard value.

[0034] A process is executed to estimate the acceleration rate of candidate metal materials based on the fatigue crack thrust force in hydrogen and the acceleration rate relationship information. The estimated acceleration rate is then output.

[0035] This section explains the approach to determining the fatigue crack propulsion force in hydrogen based on physical property information and usage conditions.

[0036] First, we will explain the mechanism of crack propagation in metal materials in a hydrogen-containing atmosphere.

[0037] As shown in Figure 3(a), the metal material 40 has a crack 42, and an oxide film is formed on the surface of the crack 42. When the metal material 40 is exposed to a hydrogen-containing atmosphere, the hydrogen-containing gas enters the crack 42.

[0038] When a tensile load is applied to the metal material 40, the crack 42 opens wide, as shown in Figure 2(b). This causes the oxide film at the tip of the crack 42 to break. Additionally, a plastic region PE is formed at the tip of the crack 42.

[0039] As shown in Figure 2(c), hydrogen diffuses to the tip of the crack 42. Furthermore, as shown in Figure 2(d), hydrogen dissociates and adsorbs onto the tip surface of the crack 42, and penetrates into the interior of the metal material 40, particularly into the plastic region PE.

[0040] The portion of the metal material 40 that absorbs hydrogen becomes brittle due to hydrogen embrittlement. As shown in Figure 3(e), a crack forms in the portion of the metal material 40 closer to the tip of the crack 42, resulting in a deeper crack 42a.

[0041] As the above process is repeated, cracks 42 and 42a propagate.

[0042] Based on the crack propagation mechanism described above, the ease with which fatigue cracks propagate in metal materials, i.e., the hydrogen-induced fatigue crack propulsion force, can be evaluated by the ease with which hydrogen penetrates the tip of crack 42. Therefore, we consider evaluating the ease with which hydrogen penetrates the tip of crack 42.

[0043] Figure 4 shows the relationship between the distance from the crack tip (x) and the hydrogen concentration inside the crack tip of the metal material 42. In Figure 4, the distance from the crack tip (x) corresponds to the crack 42 and the plastic region PE.

[0044] First, let the hydrogen concentration on the tip surface of the crack 42 be C S ·P H2 1 / 2 and

[0045] Here, C S is a parameter indicating the ratio of the hydrogen concentration when the tensile strength is changed, based on the hydrogen concentration in steel with a tensile strength of 800 MPa. C S may also be referred to as the hydrogen content parameter.

[0046] FIG. 5 is a graph showing the relationship between the tensile strength (Tensile Strength) TS (MPa) and the hydrogen content parameter C S As shown in the figure, as the tensile strength TS increases, the hydrogen content parameter C S tends to increase. That is, the higher the strength of the high-strength steel, the higher the surface hydrogen concentration. Such a relationship between the tensile strength TS and the hydrogen content parameter C S can be known information, for example, by experiments. The relationship between the tensile strength TS and the hydrogen content parameter C S may be specified in the form of a table or in the form of an equation with the tensile strength TS as a variable. The information associating the tensile strength TS and the hydrogen content parameter C S may be stored in the storage unit 22 as the surface concentration relationship information 22f as a characteristic common to the candidate metal materials.

[0047] P H2 is the hydrogen pressure in the hydrogen atmosphere.

[0048] The processor 24 can estimate the hydrogen content parameter C S on the surface of the candidate metal material based on the tensile strength TS of the candidate metal material and the surface concentration relationship information 22f.

[0049] If the mechanism of crack propagation 42 is the same, the hydrogen concentration at the tip of crack 42 is determined by the hydrogen concentration parameter C. S The larger the value, the larger it becomes, and also the hydrogen pressure P H2 It is thought that the larger the value of P, the greater the value of P. In particular, hydrogen pressure P H2 The influence of this is considered to be significant. Therefore, as mentioned above, the hydrogen concentration parameter C S Hydrogen pressure P H2 By multiplying by the square root of , the hydrogen concentration at the tip of crack 42 can be expressed relatively and quantitatively.

[0050] Hydrogen concentration C at the tip of crack 42 S ·P H2 1 / 2 Therefore, the hydrogen concentration distribution C at a distance x from the tip of the crack 42 can be expressed using the diffusion coefficient D in the following equation 1.

[0051]

number

[0052] The distance x from the tip of crack 42 is the distance in the depth direction of the metal material from the tip of crack 42.

[0053] D is the diffusion coefficient D(×10) -10 m 2 ·S -1 Figure 6 is a graph showing the relationship between tensile strength TS (MPa) and the diffusion coefficient D. As shown in the figure, the diffusion coefficient D tends to decrease as the tensile strength TS increases. In other words, hydrogen diffusion is slower in high-strength steel. This relationship between tensile strength TS and the diffusion coefficient D can be known, for example, through experiments. The relationship between tensile strength TS and the diffusion coefficient D may be specified in the form of a table, or it may be specified in the form of an equation with tensile strength TS as a variable. Information relating tensile strength TS and the diffusion coefficient D may be stored in the memory unit 22 as diffusion coefficient relationship information 22g as a common property of candidate metal materials.

[0054] The processor 24 can estimate the diffusion coefficient D of a candidate metal material based on the tensile strength TS of the candidate metal material and the diffusion coefficient relationship information 22g.

[0055] t is the time corresponding to the load frequency f that can be used when assuming a fatigue test is performed on the candidate metal material, and is expressed as, for example, half of one cycle, i.e., t = 1 / (2f). Note that if f is a high frequency of 5 Hz or higher, hydrogen may not reach the tip of the crack 42, so f may be set to less than 5 Hz.

[0056] Equation 1 is about tensile strength TS and hydrogen pressure P. H2 Based on the information of time t, this can be considered an equation for identifying the hydrogen concentration distribution information in the depth direction from the tip of the crack 42. As described below, the processor 24 can calculate the amount of hydrogen in the plastic region PE at the tip of the crack 42 based on the number 1 as said hydrogen concentration distribution information.

[0057] We consider evaluating the ease with which fatigue cracks 42 propagate based on the hydrogen concentration distribution represented by the above number 1.

[0058] First, the more hydrogen contained in the plastic region PE at the tip of crack 42, the more likely it is that hydrogen will be trapped in the transition at the tip of crack 42, and the easier it will be for crack 42 to propagate. Therefore, it is conceivable to use the amount of hydrogen MA in the plastic region PE as the first intermediate evaluation value.

[0059] In Figure 4, the distance from the tip of the crack 42 to the inner side of the plastic region is ω. p Therefore, the hydrogen content MA in the plastic region PE is given by equation 1, from x=0 to x=ω p It can be considered as the value obtained by integrating up to a certain point.

[0060] Furthermore, the distance ω from the inner side of the plastic region PE at the tip of crack 42. p This can be represented by the following number 2.

[0061]

number

[0062] Note: K max K is the maximum stress intensity factor. For example, based on the usage conditions of the candidate metal material, the shape of the metal material and the load acting on the metal are specified. Also, the length of the crack 42 to be evaluated is assumed. Then, for example, assuming a mode in which the crack 42 opens, the maximum stress intensity factor K in the crack 42 is calculated based on the load acting on the crack 42, the length of the crack 42, etc. max This is required.

[0063] Furthermore, ΔK is the range of the stress intensity factor, and R σ is the load ratio. Stress intensity factor range ΔK, load ratio R σ This can also be determined based on the usage conditions of the candidate metal material.

[0064] Maximum stress intensity factor K max , stress intensity factor range ΔK, load ratio R σ This may be information included in the usage condition information 22a stored in the memory unit 22, or it may be information obtained based on the usage condition information 22a.

[0065] σ YS σ is the yield stress of the candidate metal material. YS This is a physical property specific to the candidate metal material and should preferably be included in the physical property information 22b.

[0066] If the usage condition information 22a includes stress information corresponding to the stress applied to the tip of the crack 42, the processor 24 can estimate the plastic region PE based on the material property information 22b and the said stress information.

[0067] The above equations 1 and 2 are known formulas. In equation 1, the hydrogen concentration parameter C S The tensile strength Ts of the candidate metal material, identified by the physical property information 22b, and the surface concentration relationship information 22f are used to determine the diffusion coefficient D. The diffusion coefficient D is determined by the same tensile strength Ts and the diffusion coefficient relationship information 22g.

[0068] Hydrogen pressure P in a hydrogen atmosphere H2 The time t can be the information included in the usage conditions information 22a.

[0069] Therefore, equation 1 can be considered as an expression where only x is the variable. In other words, processor 24 uses equation 1 to determine the hydrogen concentration parameter C S And the diffusion coefficient D and the hydrogen pressure P H2 Based on this and the time t information, hydrogen concentration distribution information can be estimated.

[0070] In Mathematics 2, for example, the maximum stress intensity factor K max σ is a value included in the usage conditions information 22a or a value determined based on the usage conditions information 22a, YS This can be considered information included in the material property information 22b. Therefore, the distance ω p This can be considered a constant that is determined according to the physical properties and usage conditions of the candidate metal material.

[0071] Then, for distance x, take equation 1, from 0 to distance ω p By integrating over this range, the amount of hydrogen MA contained in the plastic region PE can be obtained as the first intermediate evaluation value.

[0072] Next, as shown by arrow A in Figure 4, if a hydrogen concentration distribution exists within the metal material, a force may arise to compensate for the concentration difference. Therefore, it is thought that the steeper the hydrogen concentration gradient at the tip of the crack 42, the greater the driving force for hydrogen transport within the metal material.

[0073] Therefore, we consider setting the second intermediate evaluation value MB to a value corresponding to the hydrogen concentration gradient at the tip of crack 42.

[0074] The value corresponding to the hydrogen concentration gradient at the tip of crack 42 may be the hydrogen concentration gradient at the tip of crack 42 itself. For example, the value corresponding to the hydrogen concentration gradient at the tip of crack 42 may be the slope in Equation 1. More specifically, the value corresponding to the hydrogen concentration gradient at the tip of crack 42 may be the slope at x=0 in Equation 1. Here, the slope at x=0 in Equation 1 is CS ·(P H2 (D·t)) 1 / 2 That is the case.

[0075] The larger the first intermediate evaluation value MA, the easier it is for crack 42 to propagate. The larger the second intermediate evaluation value MB, the easier it is for crack 42 to propagate. Therefore, an equation for calculating the fatigue crack propulsion force in hydrogen should be set up with the first intermediate evaluation value MA and the second intermediate evaluation value MB as parameters, such that the fatigue crack propulsion force in hydrogen increases as the first intermediate evaluation value MA increases, and the fatigue crack propulsion force in hydrogen increases as the second intermediate evaluation value MB increases. For example, the fatigue crack propulsion force E in hydrogen may be calculated by the following equation 3.

[0076]

number

[0077] For example, the hydrogen fatigue crack thrust force may be calculated by integrating the first intermediate evaluation value MA and the second intermediate evaluation value MB as factors. In this case, one or both of the first intermediate evaluation value MA and the second intermediate evaluation value MB may be exponents.

[0078] It is not mandatory to multiply the first intermediate evaluation value MA and the second intermediate evaluation value MB as factors. For example, the hydrogen fatigue crack thrust force may be calculated by adding the first intermediate evaluation value MA and the second intermediate evaluation value MB. In this case, a coefficient may be multiplied by one or both of the first intermediate evaluation value MA and the second intermediate evaluation value MB.

[0079] The hydrogen fatigue crack thrust force may be calculated by combining multiple calculations of the first intermediate evaluation value MA and the second intermediate evaluation value MB, or by combining them with other parameters.

[0080] Figure 7 shows the hydrogen fatigue crack propulsion force E calculated based on the usage condition information 22a and the physical property information 22b, and the acceleration rate of the fatigue crack propagation rate (da / dN) determined experimentally. H2 ) / (da / dN RT-AirThis figure shows the relationship between the two factors. Experiments are conducted in standard air and a hydrogen-containing atmosphere using metal materials and conditions corresponding to the usage condition information 22a and the physical property information 22b, and the crack propagation rate is measured. The ratio of the crack propagation rate in the hydrogen-containing atmosphere to the crack propagation rate in the standard air is considered the acceleration rate of the fatigue crack propagation rate. The horizontal axis shows the fatigue crack propulsion force E in hydrogen calculated based on Equation 3, and the vertical axis shows the acceleration rate (da / dN) obtained experimentally. H2 ) / (da / dN RT-Air This indicates that...

[0081] The following conditions were set according to the usage conditions information 22a and the physical properties information 22b.

[0082] First, as a common condition, the load ratio R σ The stress intensity factor range is 0.1, and the stress intensity factor range is ΔK = 25 MPa. 1 / 2 The frequency was set to f ≤ 1 Hz.

[0083] The following three steel materials were selected as candidate metal materials: The first is SCM440 according to JIS standards. The second is 34CrMo4 according to ISO standards. The third is SCN435 according to JIS standards.

[0084] For SCM440, the tensile strength TS is 1200 MPa, σ YS Let the pressure be 1100 MPa, and the hydrogen pressure P H2 The pressure was varied within the range of 0.001-10 MPa. The coordinates of the SCM440 are shown as circular dots.

[0085] For 34CrMo4, the tensile strength TS is 1050 MPa, σ YS Let the pressure be 950 MPa, and the hydrogen pressure P H2 The pressure was varied within the range of 10-45 MPa. The coordinates of 34CrMo4 are shown as square dots.

[0086] For SCM435, the tensile strength TS is 830 MPa, σ YS Let the pressure be 730 MPa, and the hydrogen pressure P H2 The pressure was varied within the range of 0.7-90 MPa. The coordinates of the SCM435 are shown as points on a triangle.

[0087] As shown in the figure, there is a positive correlation between the fatigue crack thrust force E in hydrogen and the acceleration rate; as the fatigue crack thrust force E in hydrogen increases, the acceleration rate also increases. Therefore, the experimental results also indicate that the fatigue crack thrust force E in hydrogen is suitable for evaluating the degree of acceleration of crack propagation 42 due to hydrogen.

[0088] In Figure 7, the data approximation curve L is obtained. The approximation curve L may be obtained by, for example, the least squares method. The above approximation curve L can be used as acceleration rate relationship information 22d for estimating the acceleration rate based on the calculated hydrogen fatigue crack thrust force E.

[0089] The acceleration rate is the ratio of the crack propagation rate of crack 42 in a hydrogen-containing atmosphere to the crack propagation rate of crack 42 in a standard atmosphere. Therefore, if the acceleration rate is known, the effects of a hydrogen atmosphere can be intuitively understood.

[0090] Furthermore, in Figure 7, the range where the slope of the approximation curve L is gentle may be designated as the recommended range, the range where the slope of the approximation curve L is steep may be designated as the usable range, and the range beyond the usable range where the slope of the approximation curve L becomes gentle again may be designated as the range for reconsideration.

[0091] The boundaries of the recommended range, usable range, and reconsideration range may be determined, for example, based on the coordinates of the inflection points of the approximation curve L. The boundaries may also be arbitrarily determined by an individual.

[0092] The evaluation criterion value 22c may be set based on the above boundary. The evaluation criterion value 22c may be set as a value for determining appropriateness based on the fatigue crack thrust force E in hydrogen, or as a value for determining appropriateness based on the acceleration rate.

[0093] Figure 8 is a flowchart showing an example of processing by processor 24.

[0094] As shown in step S1, it is determined whether or not a selection assistance instruction is given. For example, if a selection assistance instruction is given by the user of this device 20, the process proceeds to step S2.

[0095] In step S2, physical property information 22b is received. In the next step S3, usage condition information 22a is received. For example, the user assumes the usage conditions of the equipment and candidate metal materials, and inputs the physical property information 22b and usage condition information 22a corresponding to the usage conditions and candidate metal materials to the metal material selection support device 20 using the input interface 30, etc. This information is stored in the storage unit 22. The storage unit 22 also has evaluation criterion values ​​22c, acceleration rate related information 22d, surface concentration related information 22f, and diffusion coefficient related information 22g stored in advance.

[0096] In the next step S4, the amount of hydrogen MA at the tip of the crack 42 is calculated as a first intermediate evaluation value based on the usage condition information 22a and the physical property information 22b.

[0097] In the next step S5, the hydrogen concentration gradient MB is calculated as a second intermediate evaluation value based on the usage condition information 22a and the physical property information 22b. Note that steps S4 and S5 may be processed in the reverse order.

[0098] In the next step S6, the hydrogen fatigue crack thrust force E is calculated based on the hydrogen amount MA and the hydrogen concentration gradient MB. For example, the hydrogen fatigue crack thrust force E is calculated by multiplying the hydrogen amount MA by the hydrogen concentration gradient MB.

[0099] In the next step S7, the appropriateness of using the metal material 40 is determined by comparing the thrust force E with the evaluation standard value 22c. For example, if the thrust force E is less than the standard value at the boundary between the recommended range and the usable range, it may be determined to be recommended, and if it exceeds the standard value, it may be determined to be usable. If the thrust force E is the same as the standard value, it may be determined to be either recommended or usable. Similarly, if the thrust force E is less than the standard value at the boundary between the usable range and the range to be reconsidered, it may be determined to be usable, and if it exceeds the standard value, it may be determined to require reconsideration. If the thrust force E is the same as the standard value, it may be determined to be either usable or to require reconsideration.

[0100] In the next step S8, the acceleration rate is estimated based on the propulsion force E and the acceleration rate relationship information 22d. The determination of suitability for use in step S7 may be made by comparing the estimated acceleration rate with the evaluation standard value 22c set for that acceleration rate.

[0101] In step S9, the display device 32 is controlled based on the results obtained in either or both of steps S7 and S8.

[0102] Figure 9 shows an example of the display of the display device 32. As shown in the figure, the calculated hydrogen fatigue crack propulsion force may be displayed as a numerical value. The result of the suitability for use judgment may also be displayed. Suitability for use may be displayed as, for example, "The suitability for use of this candidate metal material is 'suitable'." Suitability for use may be displayed as "recommended" or "reconsider." Suitability for use may also be displayed as a figure, symbol, etc.

[0103] Furthermore, the estimated acceleration rate may be displayed as a numerical value. Also, coordinates corresponding to the calculated hydrogen fatigue crack thrust and the estimated acceleration rate may be displayed on the graph. An approximation curve L may be displayed on the graph. The graph may also show the ranges of suitability for use.

[0104] Based on the results of the above suitability assessment, one or more of the numerical values ​​representing propulsion force and acceleration rate, and the coordinate positions on the graph, are controlled to change based on the input usage condition information 22a and physical property information 22b.

[0105] The user can determine the suitability of using the candidate metal material by reviewing the calculation results. If necessary, they can change the candidate metal material or revise the usage conditions. The user then inputs selection support instructions to the device 20 again and changes at least one of the physical property information 22b and the usage condition information 22a. The above process is then repeated, and the results corresponding to the changed information are displayed on the display device 32.

[0106] Therefore, even without actually conducting experiments, the suitability of metal materials can be inferred, and the selection of metal materials under predetermined conditions can be easily carried out.

[0107] The results of suitability for use, the numerical values ​​representing thrust and acceleration rate, and the coordinate positions in the graph displayed on the display device 32 are examples of support information based on the hydrogen fatigue crack thrust force E.

[0108] According to the metal material selection support device 20, metal material selection support method, and program 22e configured as described above, a hydrogen fatigue crack propulsion force E is calculated based on the physical property information 22b and usage condition information 22a of the candidate metal material to evaluate the ease with which fatigue cracks 42 propagate in the candidate metal material in a hydrogen-containing atmosphere. Therefore, based on the propulsion force E, it is possible to infer whether the candidate metal material is suitable for use under the given usage conditions and hydrogen atmosphere before the candidate metal material is actually tested. This makes it possible to easily select metal materials to be exposed to hydrogen gas.

[0109] Furthermore, field tests may be conducted on the selected metal materials. Even in this case, the selection process becomes easier compared to conducting field tests on all candidate metal materials, as the number of candidate metal materials to be tested is narrowed down by using this embodiment.

[0110] Furthermore, if the acceleration rate of a candidate metal material can be estimated based on the fatigue crack thrust force in hydrogen and the acceleration rate relationship information 22d, the effect of hydrogen on the metal material can be conceptually easily grasped based on that acceleration rate.

[0111] Furthermore, based on the physical property information 22b and the usage condition information 22a, a first intermediate evaluation value MA corresponding to the amount of hydrogen at the tip of the crack 42 and a second intermediate evaluation value MB corresponding to the hydrogen concentration gradient at the tip of the crack 42 are calculated, and the hydrogen fatigue crack propulsion force E is calculated based on the first intermediate evaluation value MA and the second intermediate evaluation value MB. This makes it possible to appropriately indicate the ease with which the fatigue crack propulsion force in hydrogen propagates the fatigue crack 42.

[0112] Furthermore, the more hydrogen contained in the plastic region PE at the tip of the crack 42, the more likely it is that hydrogen will be trapped in the atomic arrangement transition at the tip of the crack 42, making it easier for the crack 42 to propagate. Therefore, if the first intermediate evaluation value MA is taken as the amount of hydrogen in the plastic region PE at the tip of the crack 42, then the hydrogen fatigue crack propulsion force E can appropriately indicate how easily the fatigue crack 42 propagates.

[0113] Furthermore, tensile strength TS and hydrogen pressure P H2 Based on the information of time t, number 2 is identified as hydrogen concentration distribution information in the depth direction from the tip of the crack 42, and the amount of hydrogen in the plastic region PE at the tip of the crack 42 can be calculated based on this hydrogen concentration distribution information.

[0114] More specifically, the hydrogen concentration parameter C is determined based on the tensile strength TS and surface concentration relationship information 22f. S The tensile strength TS and the diffusion coefficient relationship information 22g are estimated, and the diffusion coefficient D is estimated, and the hydrogen concentration parameter C is estimated. S And the diffusion coefficient D and the hydrogen pressure P H2 Based on this and the time t information, hydrogen concentration distribution information can be estimated.

[0115] Furthermore, the usage condition information 22a includes the maximum stress intensity factor K as stress information corresponding to the stress applied to the tip of the crack 42. max , stress intensity factor range ΔK, load ratio Rσ Alternatively, if information for determining them is included, the depth of the plastic region ω can be determined based on the material property information 22b and the stress information. p The depth of the plastic region ω can be estimated. p Based on this, the amount of hydrogen MA contained in the plastic region PE can be appropriately estimated.

[0116] Furthermore, by calculating the hydrogen fatigue crack thrust force E by integrating the first intermediate evaluation value MA and the second intermediate evaluation value MB as factors, it is possible to evaluate the hydrogen fatigue crack thrust force E while considering the mutual influence between the first intermediate evaluation value MA and the second intermediate evaluation value MB.

[0117] Furthermore, by comparing the value based on the hydrogen fatigue crack propulsion force E with the evaluation standard value 22c, the suitability of the candidate metal material 40 can be determined, and the suitability of using the candidate metal material 40 can be easily determined.

[0118] Furthermore, by displaying one or more of the following as support information on the display device 32—the results of suitability for use, numerical values ​​representing thrust force and acceleration rate, and coordinate positions on a graph—the support information based on fatigue crack thrust force in hydrogen becomes easier to recognize, and the selection of metal materials can be facilitated.

[0119] Furthermore, the configurations described in each of the above embodiments and modifications can be combined as appropriate, as long as they do not contradict each other.

[0120] {Note} This disclosure discloses the following aspects:

[0121] The first embodiment is a metal material selection support device for assisting in the selection of a metal material to be used in a hydrogen-containing atmosphere, comprising: a storage unit for storing physical property information of a candidate metal material and usage condition information of the candidate metal material; and a processing unit for calculating a hydrogen fatigue crack propulsion force for evaluating the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere, based on the physical property information and the usage condition information.

[0122] Based on the physical properties and usage conditions of the candidate metal material, a hydrogen fatigue crack propulsion force is calculated to evaluate the ease with which fatigue cracks propagate in the candidate metal material in a hydrogen-containing atmosphere. Therefore, it is possible to estimate whether the candidate metal material is suitable for use under the given usage conditions and hydrogen atmosphere before it is actually tested. This can facilitate the selection of metal materials to be exposed to hydrogen gas.

[0123] The second embodiment is a metal material selection support device according to the first embodiment, wherein the storage unit stores acceleration rate relationship information relating the hydrogen fatigue crack propulsion force and the acceleration rate of fatigue crack propagation due to hydrogen, and the processing unit estimates the acceleration rate of the candidate metal material based on the hydrogen fatigue crack propulsion force of the candidate metal material and the acceleration rate relationship information.

[0124] In this case, since the acceleration rate of fatigue crack propagation due to hydrogen is determined based on the fatigue crack propulsion force in hydrogen, the effect of hydrogen on the metal material can be conceptually easily grasped.

[0125] A third embodiment is a metal material selection support device according to the first or second embodiment, wherein the processing unit calculates a first intermediate evaluation value corresponding to the amount of hydrogen at the tip of a crack expected to occur in the candidate metal material, and a second intermediate evaluation value corresponding to the hydrogen concentration gradient at the tip of the crack, based on the physical property information and the usage condition information, and calculates the hydrogen fatigue crack propulsion force based on the first intermediate evaluation value and the second intermediate evaluation value.

[0126] It is believed that the greater the amount of hydrogen at the crack tip, the more easily the crack propagates. Furthermore, it is believed that the greater the hydrogen concentration gradient at the crack tip, the more easily the crack propagates. Therefore, the hydrogen fatigue crack propulsion force is calculated based on a first intermediate evaluation value corresponding to the amount of hydrogen at the crack tip and a second intermediate evaluation value corresponding to the hydrogen concentration gradient at the crack tip. This allows the hydrogen fatigue crack propulsion force to appropriately indicate the ease with which a fatigue crack propagates.

[0127] The fourth embodiment is a metal material selection support device according to the third embodiment, wherein the first intermediate evaluation value is the amount of hydrogen in the plastic region at the tip of the crack.

[0128] It is believed that the more hydrogen present in the plastic region at the crack tip, the more likely the hydrogen is to be trapped in the atomic arrangement transition at the crack tip, thus facilitating crack propagation. Therefore, the first intermediate evaluation value is set to the amount of hydrogen in the plastic region at the crack tip. This allows the hydrogen-induced fatigue crack propulsion force to appropriately indicate the ease with which fatigue cracks propagate.

[0129] A fifth embodiment is a metal material selection support device according to the fourth embodiment, wherein the physical property information includes the tensile strength of the candidate metal material, the usage condition information includes hydrogen pressure and time information, and the processing unit identifies hydrogen concentration distribution information in the depth direction from the tip of the crack based on the tensile strength, the hydrogen pressure and the time information, and calculates the amount of hydrogen in the plastic region at the tip of the crack based on the hydrogen concentration distribution information.

[0130] This allows the amount of hydrogen in the plastic region at the crack tip to be calculated based on physical property information and usage conditions.

[0131] The sixth embodiment is a metal material selection support device according to the fifth embodiment, wherein the storage unit stores surface concentration relationship information relating the tensile strength to the surface hydrogen concentration parameter and diffusion coefficient relationship information relating the tensile strength to the diffusion coefficient, and the processing unit performs the following: a process of estimating the surface hydrogen concentration parameter of the candidate metal material based on the tensile strength of the candidate metal material and the surface concentration relationship information; a process of estimating the diffusion coefficient of the candidate metal material based on the tensile strength of the candidate metal material and the diffusion coefficient relationship information; and a process of estimating the hydrogen concentration distribution information based on the surface hydrogen concentration parameter of the candidate metal material, the diffusion coefficient of the candidate metal material, the hydrogen pressure, and the time information.

[0132] This allows for the estimation of hydrogen concentration distribution information based on the tensile strength of the candidate metal material, hydrogen pressure, and time information.

[0133] The seventh embodiment is a metal material selection support device according to any one of the fourth to sixth embodiments, wherein the usage condition information includes stress information corresponding to the stress applied to the tip of the crack, and the processing unit estimates the plastic region based on the physical property information and the stress information.

[0134] This allows the plastic region to be estimated based on material property information and stress information.

[0135] The eighth aspect is a metal material selection support device according to any one of the third to seventh aspects, wherein the second intermediate evaluation value is the hydrogen concentration gradient at the tip of the crack.

[0136] It is believed that the greater the hydrogen concentration gradient at the crack tip, the greater the driving force for hydrogen transport in the metallic material, and the easier it is for the crack to propagate. Therefore, the second intermediate evaluation value is set as the hydrogen concentration gradient at the crack tip. This allows the hydrogen fatigue crack propulsion force to appropriately indicate the ease with which fatigue cracks propagate.

[0137] The ninth embodiment is a metal material selection support device according to any one of the third to eighth embodiments, wherein the processing unit calculates the hydrogen fatigue crack propulsion force by integrating the first intermediate evaluation value and the second intermediate evaluation value as factors.

[0138] This allows for the evaluation of fatigue crack thrust in hydrogen while considering the mutual influence between the first and second intermediate evaluation values.

[0139] The tenth embodiment is a metal material selection support device according to any one of the first to ninth embodiments, wherein the storage unit stores evaluation criteria values, and the processing unit determines the suitability of the candidate metal material by comparing a value based on the hydrogen fatigue crack propulsion force with the evaluation criteria values.

[0140] This makes it easy to determine whether or not a candidate metal material is suitable for use.

[0141] The eleventh embodiment is a metal material selection support device according to any one of the first to ten, further comprising a display unit that displays support information based on the hydrogen fatigue crack propulsion force.

[0142] This allows the display unit to be seen by users, enabling them to recognize support information based on fatigue crack propulsion force in hydrogen, and thus facilitating the selection of metal materials.

[0143] The twelfth aspect is a metal material selection support method for assisting in the selection of a metal material to be used in a hydrogen-containing atmosphere, the method comprising: identifying physical property information of a candidate metal material; identifying usage condition information of the candidate metal material; and calculating a hydrogen fatigue crack propulsion force for evaluating the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere, based on the physical property information and the usage condition information.

[0144] According to this metal material selection support method, the hydrogen fatigue crack propulsion force is calculated based on the physical property information and usage condition information of the candidate metal material, to evaluate the ease with which fatigue cracks propagate in a hydrogen-containing atmosphere. Therefore, it is possible to infer whether the candidate metal material is suitable for use under the given usage conditions and in a hydrogen atmosphere before it is actually tested. This makes the selection of metal materials to be exposed to hydrogen gas much easier.

[0145] The 13th aspect is a program for assisting in the selection of a metal material to be used in a hydrogen-containing atmosphere, which causes a computer to perform the following processes: receiving physical property information of a candidate metal material; receiving usage condition information of the candidate metal material; and calculating a hydrogen fatigue crack propulsion force based on the physical property information and the usage condition information to evaluate the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere.

[0146] According to this program, based on the physical properties and usage conditions of the candidate metal material, the hydrogen fatigue crack propulsion force is calculated to evaluate the ease with which fatigue cracks propagate in a hydrogen-containing atmosphere. Therefore, it is possible to estimate whether the candidate metal material is suitable for use under the given usage conditions and in a hydrogen atmosphere before it is actually tested. This can facilitate the selection of metal materials to be exposed to hydrogen gas.

[0147] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0148] The above description is illustrative in all respects, and the invention is not limited thereto. It is understood that countless variations not illustrated can be conceivable without falling outside the scope of this invention. [Explanation of Symbols]

[0149] 20 Metal material selection support device 22 Memory section 22a Terms of Use Information 22b Physical property information 22c Evaluation Criteria 22d Acceleration rate related information 22e Program 22f Surface concentration related information 22g diffusion coefficient related information 24 processors 32 Display device 40 Metal materials 42, 42a cracks PE plastic region

Claims

1. A metal material selection support device that assists in selecting metal materials to be used in a hydrogen-containing atmosphere, A storage unit that stores information on the physical properties of candidate metal materials and information on the usage conditions of the candidate metal materials, A processing unit that calculates a hydrogen fatigue crack propulsion force for evaluating the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere, based on the aforementioned physical property information and the aforementioned usage condition information. A metal material selection support device equipped with the following features.

2. A metal material selection support device according to claim 1, The memory unit stores acceleration rate relationship information relating the hydrogen fatigue crack propulsion force and the acceleration rate of fatigue crack propagation due to hydrogen, The processing unit is a metal material selection support device that estimates the acceleration rate of the candidate metal material based on the hydrogen fatigue crack propulsion force of the candidate metal material and the acceleration rate relationship information.

3. A metal material selection support device according to claim 1 or claim 2, The processing unit calculates a first intermediate evaluation value corresponding to the amount of hydrogen at the tip of a crack expected to occur in the candidate metal material, and a second intermediate evaluation value corresponding to the hydrogen concentration gradient at the tip of the crack, based on the physical property information and the usage condition information, and calculates the hydrogen fatigue crack propulsion force based on the first intermediate evaluation value and the second intermediate evaluation value, in a metal material selection support device.

4. A metal material selection support device according to claim 3, The first intermediate evaluation value is the amount of hydrogen in the plastic region at the tip of the crack, in a metal material selection support device.

5. A metal material selection support device according to claim 4, The aforementioned physical property information includes the tensile strength of the candidate metal material. The aforementioned usage condition information includes hydrogen pressure and time information. The processing unit identifies the hydrogen concentration distribution information in the depth direction from the tip of the crack based on the tensile strength, the hydrogen pressure, and the time information. A metal material selection support device that calculates the amount of hydrogen in the plastic region at the tip of the crack based on the hydrogen concentration distribution information.

6. A metal material selection support device according to claim 5, The memory unit stores surface concentration relationship information relating the tensile strength to the surface hydrogen concentration parameter, and diffusion coefficient relationship information relating the tensile strength to the diffusion coefficient. The aforementioned processing unit, A process for estimating the surface hydrogen concentration parameter of the candidate metal material based on the tensile strength of the candidate metal material and the surface concentration relationship information, A process for estimating the diffusion coefficient of the candidate metal material based on the relationship information between the tensile strength of the candidate metal material and the diffusion coefficient, A metal material selection support device that estimates hydrogen concentration distribution information based on the surface hydrogen concentration parameter of the candidate metal material, the diffusion coefficient of the candidate metal material, the hydrogen pressure, and the time information.

7. A metal material selection support device according to claim 4, The aforementioned usage condition information includes stress information corresponding to the stress applied to the tip of the crack, The processing unit is a metal material selection support device that estimates the plastic region based on the physical property information and the stress information.

8. A metal material selection support device according to claim 3, The metal material selection support device wherein the second intermediate evaluation value is the hydrogen concentration gradient at the tip of the crack.

9. A metal material selection support device according to claim 3, The processing unit calculates the hydrogen fatigue crack propulsion force by integrating the first intermediate evaluation value and the second intermediate evaluation value as factors, and is a metal material selection support device.

10. A metal material selection support device according to claim 1 or claim 2, The aforementioned storage unit stores evaluation criteria values, The processing unit is a metal material selection support device that determines the suitability of the candidate metal material for use by comparing the value based on the hydrogen fatigue crack propulsion force with the evaluation standard value.

11. A metal material selection support device according to claim 1 or claim 2, A metal material selection support device further comprising a display unit that displays support information based on the hydrogen fatigue crack propulsion force.

12. A metal material selection support method that assists in selecting metal materials to be used in a hydrogen-containing atmosphere, Identify the physical properties of candidate metal materials, The usage conditions information for the aforementioned candidate metal material is identified, A metal material selection support method that calculates a hydrogen fatigue crack propulsion force to evaluate the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere, based on the aforementioned physical property information and the aforementioned usage condition information.

13. A program to support the selection of metal materials used in hydrogen-containing atmospheres, On the computer, A process for receiving physical property information of candidate metal materials, A process for receiving information on the usage conditions of the candidate metal material, A process for calculating a hydrogen fatigue crack propulsion force to evaluate the ease with which fatigue cracks propagate in the candidate metal material in the hydrogen-containing atmosphere, based on the aforementioned physical property information and the aforementioned usage condition information, A program to execute.

Images