JP6447276B2 - Carburization analysis apparatus and carburization analysis method - Google Patents

Description

  The present invention relates to a technique of a carburization analysis apparatus and a carburization analysis method for analyzing a carburization amount of a carburized object.

  For example, as shown in Patent Document 1, conventionally, carburizing that diffuses and infiltrates carbon into the surface layer of the carburized material by placing the carburized material such as steel in a processing space to which the carburizing gas is supplied. Processing is in progress. According to such a carburizing treatment, the surface layer of the carburized product can be hardened, and the wear resistance of the surface of the carburized product can be improved.

  By the way, the carbon impregnation rate into the carburized product varies depending on various requirements such as the concentration of the carbon-containing compound contained in the carburizing gas supplied to the processing space and the shape of the carburized product. For this reason, prior to actual carburizing treatment, an attempt has been made to numerically analyze the carburizing amount of the carburized material and to set the optimum carburizing conditions based on the result.

  For example, Patent Document 2 discloses a state quantity calculating step for calculating a state quantity of carburizing gas in a boundary region with a carburized object by fluid analysis, and calculating a carbon concentration on the surface of the carburized object from the state quantity. Carburizing amount for setting the carbon inflow amount to the carburized material according to the surface carbon concentration calculating step to be performed and the carbon concentration on the surface of the carburized material, and calculating the carburizing amount based on the carbon inflow amount A carburization analysis method having a calculation step is disclosed.

JP 2004-59959 A JP 2011-26658 A

  Usually, in the carburizing process (especially vacuum carburizing process), the spatial scale of the substance diffusion phenomenon in the solid is very small compared to the spatial scale of the fluid convection or fluid diffusion phenomenon. If the fluid convection, fluid diffusion, and material diffusion in the solid are analyzed at the same time, it becomes extremely inefficient in terms of calculation scale and calculation time.

  Then, an object of this invention is to provide the carburizing analysis apparatus and carburizing analysis method which can shorten the calculation time of the carburizing amount of the carburized material.

The present invention is a carburization analysis device for analyzing the amount of carburization for a carburized object placed in a processing space for performing carburizing treatment, and includes a continuous equation, a fluid equation of motion, an energy equation, a transport equation of gas components, And a fluid analysis unit that calculates a steady solution of the carbon adsorption rate to the carburized product based on the solid surface chemical reaction formula, and a carbon in the carburized product using the steady solution of the carbon adsorption rate. And an in-solid diffusion analysis unit for calculating the carburization amount based on the diffusion equation.

  Further, in the carburization analysis apparatus, the fluid analysis unit is configured such that a ratio of a time until the fluid diffusion in the processing space reaches a steady state and a time until the fluid convection in the processing space reaches a steady state is a predetermined value or more. Calculates a steady solution of the gas flow velocity of the processing space based on the continuity equation, the fluid equation of motion, the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation, It is preferable to calculate a steady solution of the carbon adsorption rate based on the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation using a steady solution.

The present invention also relates to a carburizing analysis method for analyzing the carburizing amount of a carburized object placed in a processing space for performing carburizing treatment, and includes a continuous equation, a fluid equation of motion, an energy equation, and transportation of gas components. Based on the equation and the solid surface chemical reaction equation, a fluid analysis step of calculating a steady solution of the carbon adsorption rate on the carburized product, and using the steady solution of the carbon adsorption rate, And a solid diffusion analysis step of calculating the carburization amount based on the carbon diffusion equation.

  Further, in the carburization analysis method, in the fluid analysis step, when a ratio of a time until the fluid diffusion in the processing space reaches a steady state and a time until the fluid convection in the processing space reaches a steady state is a predetermined value or more. Based on the equation of continuity, the equation of fluid motion, the energy equation, the transport equation of the gas component, and the chemical reaction formula of the solid surface, a steady solution of the gas flow rate of the processing space is calculated, and the steady state of the gas flow rate is calculated. It is preferable to calculate a steady solution of the carbon adsorption rate based on the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation using a solution.

  ADVANTAGE OF THE INVENTION According to this invention, the carburizing analysis apparatus and carburizing analysis method which can shorten the calculation time of the carburizing amount of to-be-carburized processed material can be provided.

It is a block diagram which shows an example of a structure of the carburizing analysis apparatus which concerns on this embodiment. It is a flowchart which shows an example of the carburizing analysis method of this embodiment. The model figure of the to-be-carburized thing processed into one dimension only in the depth direction of the to-be-carburized thing is shown. It is a figure which shows the result of the carbon concentration of the depth direction of the to-be-carburized processed material calculated | required in the Example. It is a figure which shows the result of the carburizing amount with respect to the processing time calculated | required in the Example.

  Hereinafter, an example of an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram illustrating an example of the configuration of the carburization analysis apparatus according to the present embodiment. A carburizing analysis apparatus 100 in FIG. 1 is an apparatus that analyzes a carburizing amount with respect to a carburized object (for example, a steel material) placed in a processing space (for example, a carburizing furnace) for performing a carburizing process. Carburizing gas (for example, C ₂ H ₂ ) for diffusing and penetrating carbon into the carburized material is supplied to the processing space.

  Each block constituting the carburizing analysis apparatus 100 of FIG. 1 can be realized in hardware by elements and mechanical devices such as a CPU (central processing unit) of a computer, and in software by a computer program or the like. However, here, functional blocks realized by their cooperation are depicted. Therefore, those skilled in the art who have touched this specification will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  In FIG. 1, the carburizing analysis device 100 is connected to an input device 102 and an output device 104. The input device 102 may be a keyboard, a mouse, or the like for receiving user input related to processing executed by the carburizing analysis device 100. The input device 102 may be configured to receive input from a network such as the Internet or a recording medium such as a CD or a DVD. The output device 104 may be a display device such as a display or a printing device such as a printer.

  The carburizing analysis apparatus 100 includes a condition setting unit 106, a fluid analysis unit 110, an in-solid diffusion analysis unit 112, a data holding unit 114, and a display control unit 116.

  The various condition setting unit 106 sets various conditions necessary for fluid analysis of a fluid (such as carburizing gas) in the processing space based on input information input from the user via the input device 102. Various conditions used for fluid analysis include inflow rate, mass fraction, processing space temperature, processing space pressure, mesh data, maximum calculation time, reaction rate coefficient, diffusion coefficient, calculation time increment, each physical property value (viscosity coefficient, Diffusion coefficient, etc.). Here, the inflow flow rate is the flow rate of the carburizing gas supplied to the processing space. Moreover, a mass fraction is a ratio of the mass of the substance which comprises carburizing gas. The mesh data represents the shape of the processing space, and represents the shape of a collection of a plurality of minute areas. The mesh data also includes conditions for defining the exchange of physical quantities between these divided areas.

  The fluid analysis unit 110 includes a complete coupling analysis unit 118 and a gas component transport analysis unit 120. The fully coupled analysis unit 118 performs fluid analysis using a continuous equation, a fluid equation of motion, an energy equation, a gas component transport equation, and a solid surface chemical reaction equation, which will be described later, and the gas flow rate or carburized carbon in the processing space. A steady solution of the rate of carbon adsorption on the treated material is calculated. The gas component transport analysis unit 120 performs a fluid analysis using an energy equation, a gas component transport equation, and a solid surface chemical reaction equation by using a steady solution of the gas flow velocity in the processing space, to the carburized workpiece. The steady solution of the carbon adsorption rate is calculated. Although details will be described later, for example, it is estimated that the time until the gas flow rate in the processing space reaches a steady state is much shorter than the time until the carbon adsorption rate on the carburized material reaches a steady state. In the case where Λ (described later) is greater than or equal to a predetermined value, the fluid analysis is performed in the complete coupling analysis unit 118 until a steady solution of the gas flow velocity in the processing space is obtained, and the gas component transport analysis unit 120. Then, using the obtained steady solution of the gas flow rate, the fluid analysis is executed until the steady solution of the carbon adsorption rate is obtained. Further, for example, when it is estimated that the time until the gas flow rate in the processing space reaches a steady state is the same as the time until the carbon adsorption rate on the carburized material reaches a steady state (Λ to be described later) Is less than a predetermined value), fluid analysis is performed in the complete coupled analysis unit 118 until the carbon adsorption rate on the carburized material reaches a steady state.

  The fluid analysis unit 110 is not particularly limited as long as it has a function of calculating a steady solution of the carbon adsorption rate on the carburized material by the above equation, but it can shorten the time required for the fluid analysis. From a viewpoint, when Λ, which will be described later, is greater than or equal to a predetermined value, a steady solution of the gas flow velocity in the processing space is calculated based on a continuous equation, fluid equation of motion, energy equation, gas component transport equation, and solid surface chemical reaction equation And a function for calculating a steady solution of the carbon adsorption rate on the carburized material based on the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation using the steady solution of the gas flow rate. Is preferred.

  The in-solid diffusion analysis unit 112 uses the steady solution of the carbon adsorption rate to the carburized material calculated by the fluid analyzing unit 110, and based on the carbon diffusion equation in the carburized material to be described later, the amount of carburization. Is calculated.

  The data holding unit 114 holds the carburization amount calculated by the in-solid diffusion analysis unit 112 as data. In addition, the display control unit 116 causes the output device 104 to display the carburizing amount held in the data holding unit 114 as the time variation of the carburizing amount and the carbon concentration distribution in the carburized product.

  Below, operation | movement of the carburizing analysis apparatus 100 which concerns on this embodiment is demonstrated according to the flowchart shown in FIG.

  In step S10, various conditions used for the fluid analysis of the fluid (carburizing gas, etc.) in the processing space in which the carburizing process is performed are set by the various condition setting unit 106.

In step S12, the fully coupled analysis unit 118 constituting the fluid analysis unit 110 couples the equations represented by the equations (1) to (6) under the above-described various conditions, A fluid analysis of the fluid is performed. By calculating the equations represented by the equations (1) to (6) in combination, the gas flow rate (u _j ) in the treatment space, the carbon adsorption rate (Ws) to the carburized material, etc. are obtained. However, in the complete coupling analysis unit 118, as will be described later, until the gas flow rate (u _j ) in the processing space or the carbon adsorption rate (Ws) to the carburized material becomes steady, the equation (1) ~ Calculate Equation (6) repeatedly. Here, the steady state means a state in which the physical quantity (for example, gas flow rate (u _j )) obtained by coupling Equations (1) to (6) hardly changes over time. The value of the physical quantity in that state is set as a steady solution (for example, a steady solution of gas flow rate).

Equation (1) is a continuous equation. Equation (2) is a fluid motion equation and is represented by the Navier-Stokes equation. Equation (3) is an energy equation. Equation (4) is a gas component transport equation. Assuming that the flow velocity of the fluid is sufficiently smaller than the sonic velocity (low Mach number approximation), the pressure is a reference pressure P ₀ (constant value) and a variation P from the reference pressure (in the formula (2)). The expression is separated. However, the present embodiment is not limited to this solution, and any solution may be used as long as it is a solution that can handle the density change of the fluid.

Where u _j is the gas flow rate in the processing space, ρ is the density (kg / m ³ ), t is the time (s), u _i is the velocity vector, and p is the fluctuation pressure from the reference pressure (kg / m / s ² ), μ is a viscosity coefficient (Pa · s), g is gravitational acceleration (m / s ² ), T is temperature (K), Cp is constant pressure specific heat (J / kg / K), λ is thermal conductivity (W / M / k), Y _i is the mass fraction of each gas component in the processing space, D _i is the effective diffusion coefficient (m ² / s) of each gas component in the processing space, and P ₀ is the reference pressure (kg / m / s ² ), R is a gas constant (J / mol / K), and M is a molecular weight (kg / mol). In addition, as a typical calculation method of each physical property value, a method based on Chapman-Enskog theory (Chemical Engineering Handbook, 6th edition, edited by Chemical Engineering Society, Maruzen, 1999) can be mentioned. The calculation method is not limited, and any calculation method may be used.

Ws in Equation (1) and Equation (4) is the surface reaction rate between the fluid in the treatment space and the surface of the carburized product. As the surface reaction, for example, a carbon adsorption reaction from the carburizing gas to the surface of the carburized material is assumed. Therefore, the surface reaction rate Ws is calculated using the solid surface chemical reaction formula of the following formula (6). Calculated as the rate of carbon adsorption (kg / m ³ / s) on the object. The following formula (6) is a formula expressed by an Arrehenius type adsorption reaction model, and is a case where the carburizing gas is C ₂ H ₂ .

In the formula, C _C2H2 is the molar concentration (mol / m ³ ) of C ₂ H _{2 in} the vicinity of the carburized object surface, A _ad is a frequency factor (m / s), and E _ad is the activation energy ( J / mol). A _ad and E _ad are appropriately identified by performing a preliminary experiment or the like for each type of carburizing gas.

  Here, in the fluid analysis of the complete coupling analysis unit 118, when the time until the fluid diffusion in the processing space reaches a steady state / the time until the fluid convection in the processing space reaches a steady state is a predetermined value or more, From the equations expressed by 1) to (6), the process proceeds to step S14 when a steady solution of the gas flow velocity in the processing space is obtained. On the other hand, when the time until the fluid diffusion in the processing space reaches a steady state / the time until the fluid convection in the processing space reaches a steady state is less than a predetermined value, the process proceeds to step S16 and the fluid analysis of the fully coupled analysis unit 118 is performed. Is continued as it is. Hereinafter, the time until the fluid diffusion in the processing space reaches a steady state / the time until the fluid convection in the processing space reaches a steady state will be described.

  The time until the fluid diffusion in the processing space reaches a steady state / the time until the fluid convection in the processing space reaches a steady state is represented by the following equation (7).

In the equation, L ^g is the distance from the inflow portion where the carburizing gas flows into the processing space to the carburized object, D ^g is the diffusion coefficient of the carburizing gas, and U _in is the inflow rate of the carburizing gas. Since these parameters are values set as various conditions in the calculation of the fluid analysis, Λ is obtained when the fluid analysis is executed. The time until the fluid diffusion in the processing space reaches a steady state corresponds to the time until the carbon adsorption rate on the carburized material reaches a steady state, and the time until the fluid convection in the processing space reaches a steady state This corresponds to the time until the gas flow rate in the inside reaches a steady state. Therefore, as the value of Λ increases, the time until the gas flow rate in the processing space reaches a steady state is much shorter than the time until the carbon adsorption rate on the carburized material reaches a steady state. It is estimated that as the value of Λ is smaller, the time until the carbon adsorption rate on the carburized material reaches a steady state is the same as or shorter than the time until the gas flow velocity in the treatment space reaches a steady state. The

  The predetermined value may be set as appropriate from the viewpoint of reducing the amount of calculation for obtaining a steady solution of the carbon adsorption rate on the carburized material, but is preferably set in a range of 10 or more, for example. In FIG. 2, the predetermined value is set to 10. That is, if Λ is 10 or more, the time until the gas flow rate in the processing space reaches a steady state is much shorter than the time until the carbon adsorption rate on the carburized material reaches a steady state. presume. In this case, the complete coupled analysis unit 118 repeats the calculations of the above equations (1) to (6), and at the stage where the steady solution of the gas flow rate in the processing space is obtained, It transmits to the gas component transport analysis part 120, and the fluid analysis in the complete coupling analysis part 118 is stopped (hereinafter, step S14 described later). If Λ is less than 10, the time until the carbon adsorption rate on the carburized material reaches a steady state is estimated to be the same as (or short) the time until the gas flow rate in the processing space reaches a steady state. To do. In this case, the complete coupling analysis unit 118 continuously repeats the calculations of the above formulas (1) to (6) (hereinafter, step S16 described later).

  In step S <b> 14, the gas component transport analysis unit 120 is expressed by the equations (8) to (11) using the steady solution data of the gas flow velocity in the processing space transmitted from the complete coupling analysis unit 118. The equation is iteratively calculated and a steady solution of the carbon adsorption rate on the carburized material is obtained.

Equation (8) is an energy equation. Equation (9) is a gas component transport equation. Equation (10) is used to determine the density ρ of the fluid. Equation (11) is a solid surface chemical reaction equation represented by an Arrehenius type adsorption reaction model (when carburizing gas is C ₂ H ₂ ).

U ⁻ _j in the equations (8) and (9) is an average advection velocity, and a steady solution of the gas flow velocity in the processing space is fitted to this parameter. The parameters in other formulas are as described above.

  In this way, by utilizing the steady solution of the gas flow velocity in the processing space, the energy equation, the gas component transport equation, and the solid surface chemical reaction equation are coupled, and by repeatedly calculating these, Find the steady solution of carbon adsorption rate. In other words, when calculating the steady solution of the carbon adsorption rate on the carburized material, it is not necessary to solve the continuous equation and fluid equation of motion by using the steady solution of the gas flow velocity in the processing space. It is possible to greatly reduce the calculation time related to.

  In step S16, the complete coupled analysis unit 118 continuously calculates the equations expressed by the equations (1) to (6) repeatedly to obtain a steady solution of the carbon adsorption rate (Ws) on the carburized material. . When Λ is less than a predetermined value, that is, the time until the carbon adsorption rate on the carburized material reaches a steady state is estimated to be the same as or longer than the time until the gas flow velocity in the treatment space reaches a steady state. In this case, since the steady solution of the gas flow rate cannot be transferred, it is not possible to solve only the equations (8) to (11) using the steady solution of the gas flow rate in the processing space.

  Steady solution data of the carbon adsorption rate on the carburized material obtained by the fluid analysis unit 110 (fully coupled analysis unit 118 or gas component transport analysis unit 120) is transmitted to the in-solid diffusion analysis unit 112.

  In step S18, based on the diffusion equation of carbon in the carburized material, the in-solid diffusion analysis unit 112 uses the steady solution of the carbon adsorption rate on the carburized material transmitted from the fluid analyzing unit 110. The amount of carburization is required. The diffusion equation of carbon in the carburized product is expressed by equation (12).

In the formula, ρ _A is the carburized material density (kg / m ³ ), Y _C is the carbon mass fraction in the carburized material, and D _C is the diffusion coefficient of carbon in the carburized material (m ² / s). The diffusion coefficient of carbon in the carburized material may be obtained by a preliminary experiment or the like, or data reported as an experimental result may be used. For example, the diffusion coefficient of carbon in the γ phase of austenite is described in a non-patent document (Wells, C. et al., Diffusion coefficient of carbon in austenite, Trans. Am. Inst. Min. Metal. Eng., 188 (1950). ) Etc.

Moreover, it is desirable to set the boundary condition of the diffusion equation based on mesh data that is one-dimensionalized only in the depth direction at an arbitrary point of the carburized material. FIG. 3 shows a model diagram of the carburized product that is one-dimensionalized only in the depth direction of the carburized product. Using the model of the carburized material shown in FIG. 3, the carbon mass fraction corresponding to the solid solution limit of the carbon concentration on the surface of the carburized material is T _Csat , and the initial carbon (before carburizing treatment) in the carburized material. When the mass fraction is Y _C0 , the boundary conditions are set as the following formulas (13) to (15). Then, a steady solution of the carbon adsorption rate on the carburized material is applied to _WS in Equation (13).

  Thus, the amount of carburization is calculated | required by calculating Formula (12)-(15) using the steady solution of the carbon adsorption rate to a carburized material. The obtained carburizing amount is stored in the data holding unit 114 as data. In step S <b> 20, the display control unit 116 outputs the stored carburizing amount data to the output device 104. Note that the display control unit 116 may output carburizing amount data as a time change of the carburizing amount, a carbon concentration distribution in the carburized material, or the like.

  In this embodiment, fluid analysis using equations (1) to (6) (continuous equation, fluid equation of motion, energy equation, gas component transport equation, solid surface chemical reaction equation), After obtaining a steady solution of the carbon adsorption rate, using the steady solution of the carbon adsorption rate to the carburized product, carbon diffusion analysis in the carburized product using equations (12) to (15) In order to obtain the carburizing amount, for example, while performing the fluid analysis using the equations (1) to (6), the carbon diffusion analysis in the carburized product using the equations (12) to (15) is performed. Compared with the case where the amount of carburization is calculated, it is not necessary to solve the equations (1) to (6) in the calculation of the amount of carburization, so that the calculation time can be greatly shortened.

  Furthermore, in this embodiment, when obtaining a steady solution of the carbon adsorption rate on the carburized material, if Λ is equal to or greater than a predetermined value, the steady solution of the gas flow rate in the treatment space obtained by the fluid analysis is used. Based on the equations (8) to (11) (energy equation, gas component transport equation, solid surface chemical reaction equation), by obtaining a steady solution of the carbon adsorption rate on the carburized material, for example, continuous This eliminates the need to solve the above equation and the fluid equation of motion, so that the calculation time for fluid analysis can be greatly shortened. In addition, the calculation which calculates | requires the amount of carburization by performing the carbon diffusion analysis in the to-be-carburized processed material using Formula (12)-(15), performing the fluid analysis using Formula (1)-(6). In the method, even if Λ is greater than or equal to a predetermined value, in other words, even when the gas flow velocity in the processing space reaches a steady state at an early stage, the calculation formula cannot be omitted, so the calculation time is enormous. It becomes.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

In the examples, a three-dimensional numerical simulation in the carburizing furnace on which the carburized product was placed was performed and compared with the corresponding experimental results. The corresponding experimental conditions were as follows: the carburizing gas was C ₂ H ₂ , the furnace pressure was about 1200 Pa, the furnace temperature was 950 ° C., the carburized material was SCr20, and the carburizing gas supply time was 240 seconds. . Immediately after the supply of C ₂ H _{2 was} stopped, the SCr20 was cooled, and the carbon concentration distribution of the SCr20 was measured by EPMA (Electron Probe Micro Analyzer).

  In the three-dimensional numerical simulation, in addition to the above conditions, various conditions such as inflow velocity corresponding to the input flow rate and various parameters for calculating the physical property values were set.

Moreover, the following reaction formula was set as a chemical reaction showing carbon adsorption from C ₂ H ₂ to the surface of SCr20.
C ₂ H ₂ → 2C + H ₂ ↑

  Under the above-mentioned various conditions, equations (1) to (6) (continuous equation, fluid motion equation, energy equation, gas component transport equation, solid chemical surface reaction equation) are coupled and fluid analysis is performed did. Here, under the conditions of the example, Λ was 30 or more and Λ ≧ 10 or more. Accordingly, a steady solution of the gas flow rate in the processing space is obtained by the equations (1) to (6), and the carbon adsorption to the carburized material is obtained by the equations (8) to (11) using the steady solution. A steady speed solution was obtained.

  Next, the amount of carburization was calculated | required by Formula (12)-(15) using the steady solution of the carbon adsorption rate to a carburized material. The carburization amount was expressed as the carburization amount with respect to the treatment time and the carbon concentration in the depth direction of the carburized product. These results are shown in FIG.4 and FIG.5 with the said experimental result.

  As can be seen from the results of FIGS. 4 and 5, the carbon amount obtained from the three-dimensional numerical simulation of the example was a value approximated to the experimental result. That is, it was confirmed that the example has a very high calculation accuracy.

  In the example, it took about 2 days to obtain the amount of carburization after the carburizing process after 240 seconds. On the other hand, the equations (1) to (6) are coupled and the fluid analysis is performed, and the equations (12) to (15) are executed to obtain the carburizing amount after the carburizing process after 240 seconds. Estimating the time required for this will require about 10,000 days. Note that the calculation time in this case does not take into account the increase in calculation load caused by making the mesh data very fine, and further restrictions on the time step caused by the fine mesh data. Furthermore, the calculation time increases.

  As described above, the calculation method of the embodiment has a longer calculation time than the calculation method in which the equations (12) to (15) are executed while the equations (1) to (6) are coupled and the fluid analysis is performed. It can be said that this can be shortened. And the calculation result of an Example approximates with an experimental result, and it can be said that high calculation accuracy is guaranteed.

In the embodiment, although the C ₂ H ₂ relates carburizing as a raw material, the present embodiment is not limited thereto. Also, the carburized material, furnace temperature, furnace pressure, etc. are not limited to the examples. The present invention can be modified without changing the gist thereof, and they are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Carburizing analysis apparatus, 102 Input apparatus, 104 Output apparatus, 106 Various condition setting parts, 110 Fluid analysis part, 112 Solid diffusion analysis part, 114 Data holding part, 116 Display control part, 118 Complete coupling analysis part, 120 Gas Component transport analysis department.

Claims (4)

A carburization analysis device for analyzing the amount of carburization for a carburized object placed in a processing space for performing carburizing treatment,
A fluid analysis unit that calculates a steady solution of a carbon adsorption rate on the carburized material based on a continuous equation, a fluid equation of motion, an energy equation, a gas component transport equation, and a solid surface chemical reaction equation;
A carburization analysis apparatus comprising: an in-solid diffusion analysis unit that calculates the carburization amount based on a diffusion equation of carbon in a carburized product using a steady solution of the carbon adsorption rate. 2. The carburization analysis apparatus according to claim 1, wherein the fluid analysis unit is configured such that a ratio of a time until the fluid diffusion in the processing space reaches a steady state and a time until the fluid convection in the processing space reaches a steady state is a predetermined value or more. In this case, a steady solution of the gas flow rate in the processing space is calculated based on the continuous equation, the fluid equation of motion, the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation, A carburization analysis apparatus that calculates a steady solution of the carbon adsorption rate based on the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation using a steady solution of a gas flow rate. A carburization analysis method for analyzing a carburizing amount for a carburized object placed in a processing space for performing a carburizing process,
A fluid analysis step for calculating a steady solution of a carbon adsorption rate on the carburized material based on a continuous equation, a fluid equation of motion, an energy equation, a transport equation of a gas component, and a solid surface chemical reaction equation;
A carburization analysis method comprising: an in-solid diffusion analysis step of calculating the carburization amount based on a diffusion equation of carbon in a carburized product using a steady solution of the carbon adsorption rate. 4. The carburizing analysis method according to claim 3, wherein, in the fluid analysis step, a ratio of a time until the fluid diffusion in the processing space reaches a steady state and a time until the fluid convection in the processing space reaches a steady state is a predetermined value or more. In this case, a steady solution of the gas flow velocity in the processing space is calculated based on the continuous equation, the fluid equation of motion, the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation, and the gas A carburization analysis method, wherein a steady solution of the carbon adsorption rate is calculated based on the energy equation, the transport equation of the gas component, and the solid surface chemical reaction equation using a steady solution of a flow velocity.

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