Method, System, Electronic Device and Storage Medium for Determining Temperature Field of Hot Rolled Strip Steel

Abstract

The present application relates to a method, system, electronic device and storage medium for determining the temperature field of hot-rolled strip steel. The method for determining the temperature field of hot-rolled strip steel includes obtaining the geometric parameters, thermodynamic parameters and physical property parameters of the hot-rolled strip steel, dividing a number of nodes in the thickness direction according to the thickness of the hot-rolled strip steel to determine the spatial step size, determining the time step size according to the total duration and the preset number of iterations, determining the initial phase proportion coefficient according to the initial temperature field and the phase transformation temperature, transforming the initial temperature field into an initial enthalpy field through a pre-determined mapping relationship between the ferrite enthalpy, austenite enthalpy and temperature, establishing a differential equation of enthalpy conduction, and using the difference method to iteratively solve the differential equation of enthalpy conduction to obtain the final enthalpy field, and transforming the final enthalpy field into a temperature field through a pre-determined mapping relationship between the ferrite temperature, austenite temperature and enthalpy field. The present application determines the enthalpy field of hot-rolled strip steel, takes into account the latent heat of phase change, and improves the accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of steel rolling, and particularly to a method, a system, an electronic device and a storage medium for determining the temperature field of hot-rolled strip steel. Background Art

[0002] Hot-rolled strip steel refers to strips and sheets produced by hot-rolling. Generally, the thickness of hot-rolled strip steel is 1.2 - 8 mm. Hot-rolled strip steel can be used directly as hot-rolled steel plates or as billets for cold rolling, welded pipes, and cold-formed sections. Hot-rolled strip steel is widely used in fields such as automobiles, electric motors, chemical engineering, and shipbuilding.

[0003] Hot-rolled strip steel has the following characteristics: high requirements for dimensional accuracy (mainly thickness accuracy), flat plate shape, high requirements for surface quality (such as no surface defects), and high requirements for mechanical properties, process properties, and physical and chemical properties. During the rolling process, the frictional heat in the rolling zone and the deformation heat of the hot-rolled strip steel during the deformation stage will cause the temperature of the hot-rolled strip steel to rise. The deformation heat itself is affected by the strain, strain rate, and temperature conduction of the hot-rolled strip steel. This temperature rise will cause softening of the hot-rolled strip steel material on the one hand and affect the plate shape quality of the hot-rolled strip steel on the other hand. Therefore, determining the temperature field of hot-rolled strip steel is crucial for the quality of hot-rolled strip steel.

[0004] In the related art, the differential method is generally used to solve the heat conduction differential equation, and directly using temperature for iterative calculation cannot well track or reflect the physical metallurgical process of phase change, and it is difficult to consider the latent heat of phase change, resulting in certain errors in the calculation. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the present application provides a method, a system, an electronic device and a storage medium for determining the temperature field of hot-rolled strip steel. In solving the heat conduction differential equation, enthalpy field is used for iteration to overcome the disadvantage that the phase change process cannot be tracked during the temperature field iteration process.

[0006] In the first aspect, the present application provides a method for determining the temperature field of hot-rolled strip steel, including:

[0007] Obtaining the geometric parameters, thermodynamic parameters and physical property parameters of the hot-rolled strip steel. The geometric parameters include: the thickness of the hot-rolled strip steel; the thermodynamic parameters include: the initial temperature field of the hot-rolled strip steel, the phase transformation temperature of the hot-rolled strip steel, the phase transformation enthalpy of the hot-rolled strip steel, the relationship function between ferrite enthalpy, austenite enthalpy and temperature; the physical property parameters include: the total duration of the temperature field to be determined, the specific heat capacity at constant pressure of each phase of the hot-rolled strip steel corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled strip steel, the thermal expansion coefficient of the hot-rolled strip steel at different temperatures, and the density of the hot-rolled strip steel at room temperature;

[0008] Divide a number of nodes in the thickness direction according to the thickness of the hot-rolled strip, determine the spatial step size, and all the nodes are evenly distributed in sequence along the thickness direction of the hot-rolled strip;

[0009] Determine the time step size according to the total duration and the preset number of iterations;

[0010] Determine the initial phase proportion coefficient according to the initial temperature field and the phase transformation temperature;

[0011] Convert the initial temperature field into an initial enthalpy field through a pre-determined mapping relationship between the ferrite enthalpy, austenite enthalpy and temperature;

[0012] Establish a differential equation for enthalpy conduction, and use the difference method to iteratively solve the differential equation for enthalpy conduction to obtain the final enthalpy field;

[0013] Convert the final enthalpy field into a temperature field through a pre-determined mapping relationship between the ferrite temperature, austenite temperature and enthalpy field.

[0014] In an exemplary embodiment of the present application, the determination methods of the spatial step size and the time step size include:

[0015]

[0016]

[0017] Among them, Δx is the spatial step size; h is the thickness of the hot-rolled strip; n is the number of nodes divided in the thickness direction; Δt is the time step size, t cal is the total duration; N is the preset number of iterations.

[0018] In an exemplary embodiment of the present application, determining the initial phase proportion coefficient according to the initial condition parameters includes:

[0019] Determine the initial central temperature according to the initial temperature field;

[0020] Determine the proportion coefficient of the initial ferrite phase and the austenite phase proportion coefficient according to the initial central temperature and the phase transformation temperature.

[0021] In an exemplary embodiment of the present application, the determination process of determining the two-phase proportion coefficient according to the initial central temperature and the phase transformation temperature includes:

[0022]

[0023] f au = 1 - f fe ;;

[0024] Among them, f fe is the initial ferrite phase proportion coefficient; f auis the austenite phase ratio coefficient; T c is the initial center temperature; T Ac3 is the phase transition temperature.

[0025] In an exemplary embodiment of the present application, the enthalpy conduction differential equation is:

[0026]

[0027] Where ρ is the density of the node; λ is the thermal conductivity of the node; x is the distance between the node and the surface of the hot-rolled steel in the thickness direction; c p is the constant-pressure specific heat capacity of the node.

[0028] In an exemplary embodiment of the present application, the enthalpy conduction differential equation is iteratively solved using a difference method, including:

[0029] According to the enthalpy field at the current moment, determine the average enthalpy value;

[0030] Update the proportional coefficients of the two phases according to the average enthalpy value at the current moment;

[0031] According to the current enthalpy value of each node and the enthalpy conduction differential equation, the constant pressure specific heat capacity and thermal conductivity of each phase are determined;

[0032] Update the constant pressure specific heat capacity and thermal conductivity of each node according to the proportional coefficient of the two phases at the current moment;

[0033] Determining the temperature of each node according to the enthalpy value of each node at the current moment and the predetermined mapping relationship between the ferrite temperature, the austenite temperature and the enthalpy field;

[0034] Determine the thermal expansion coefficient of each node based on the temperature of each node at the current moment and a preset mapping relationship between the temperature and the thermal expansion coefficient;

[0035] Update the density of each node at the current moment based on the thermal expansion coefficient of each node at the current moment and the density of steel material at room temperature;

[0036] The enthalpy conduction differential equation is updated according to the updated density, constant-pressure specific heat capacity and thermal conductivity, and the enthalpy field at the next moment is solved according to the updated enthalpy conduction differential equation.

[0037] In an exemplary embodiment of the present application, the method for determining the average enthalpy value according to the enthalpy field at the current moment includes:

[0038]

[0039] Among them, H avg is the average enthalpy value; Δα is the relative position difference between two adjacent nodes, Δαi-1 = α i -α i-1 , where h·α = xh is the thickness of the hot-rolled strip, and x is the distance from the node in the thickness direction to the surface of the hot-rolled strip; is the enthalpy value at node i at time p; is the enthalpy value at node i + 1 at time p.

[0040] In an exemplary embodiment of the present application, the update method for updating the proportionality coefficients of the two phases according to the average enthalpy value at the current moment includes:

[0041]

[0042] f au = 1 - f fe

[0043] where f fe is the proportionality coefficient of the ferrite phase; f au is the proportionality coefficient of the austenite phase; H Ac3 is the enthalpy value at the phase transformation point; H avg is the average enthalpy value; ΔH is the enthalpy change of the complete transformation of austenite to ferrite, i.e., the phase transformation enthalpy.

[0044] In an exemplary embodiment of the present application, the update method for updating the specific heat capacity at constant pressure and the thermal conductivity of the hot-rolled strip according to the updated phase proportionality coefficients includes:

[0045] c p = c p1 ·f fe + c p2 ·f au

[0046] λ = λ1·f fe + λ2·f au

[0047] where c p1 , c p2 are respectively the specific heat capacity at constant pressure of the ferrite phase and the specific heat capacity at constant pressure of the austenite phase at the current moment; λ1 and λ2 are respectively the thermal conductivity of the ferrite phase and the thermal conductivity of the austenite phase at the current moment; f fe , f au are respectively the proportionality coefficient of the ferrite phase and the proportionality coefficient of the austenite phase at the current moment.

[0048] In an exemplary embodiment of the present application, the update method for updating the density of each node at the current moment according to the thermal expansion coefficient of each node at the current moment and the density of the steel material at room temperature includes:

[0049]

[0050] Where ρ is the density at the current moment; ρ0 is the density at room temperature; and α is the coefficient of thermal expansion at the current moment.

[0051] In a second aspect, the present application provides a system for determining the temperature field of hot-rolled strip steel, the determination system comprising:

[0052] An acquisition module, configured to acquire the geometric parameters, thermodynamic parameters, and physical property parameters of the hot-rolled strip steel, where the geometric parameters include the thickness; the thermodynamic parameters include the initial temperature field of the hot-rolled strip steel, the phase transformation temperature of the hot-rolled strip steel, and the phase transformation enthalpy of the hot-rolled strip steel, the relationship function between the ferrite enthalpy, austenite enthalpy, and temperature; the physical property parameters include: the total duration of the temperature field to be determined, the specific heat capacity at constant pressure of each phase of the hot-rolled strip steel corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled strip steel, the coefficient of thermal expansion of the hot-rolled strip steel at different temperatures, and the density of the hot-rolled strip steel at room temperature;

[0053] A determination module, configured to divide a plurality of nodes in the thickness direction according to the thickness of the hot-rolled strip steel, determine the spatial step size, and all the nodes are evenly distributed in sequence along the thickness direction of the hot-rolled strip steel, determine the time step size according to the total duration and the preset number of iterations, determine the initial phase proportion coefficient according to the initial temperature field and the phase transformation temperature, transform the initial temperature field into an initial enthalpy field through the relationship function between the ferrite enthalpy, austenite enthalpy, and temperature, establish a differential equation of enthalpy conduction, and perform iterative solution on the differential equation of enthalpy conduction by using the difference method to obtain the final enthalpy field, and transform the final enthalpy field into a temperature field through the pre-determined mapping relationship between the ferrite temperature, austenite temperature, and enthalpy field.

[0054] In a third aspect, the present application provides an electronic device, the electronic device comprising:

[0055] One or more processors;

[0056] A storage device, configured to store one or more programs, and when the one or more programs are executed by the one or more processors, the electronic device implements the method for determining the temperature field of hot-rolled strip steel as described above.

[0057] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor of a computer, the computer executes the method for determining the temperature field of hot-rolled strip steel as described above.

[0058] The method, system, electronic device, and storage medium for determining the temperature field of hot-rolled strip steel of the present application have the following

[0059] Beneficial effects:

[0060] This application determines the real-time enthalpy, and then determines the real-time temperature based on the real-time enthalpy, thereby obtaining the temperature field. That is, by determining the enthalpy field of the hot-rolled strip steel, the latent heat of phase change generated by the transformation of austenite to ferrite during the hot-rolling process is effectively considered, thereby improving the accuracy of the obtained temperature field of the hot-rolled strip steel.

[0061] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. Brief Description of the Drawings

[0062] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments consistent with this application, and are used together with the specification to explain the principles of this application. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0063] Figure 1 is a flowchart of a method for determining the temperature field of a hot-rolled strip steel shown in an exemplary embodiment of this application;

[0064] Figure 2 is Figure 1 a flowchart of determining the initial phase ratio coefficient according to the initial condition parameters in step S140 in the shown embodiment in an exemplary embodiment;

[0065] Figure 3 is Figure 1 a flowchart of iteratively solving the enthalpy conduction differential equation using the difference method in step S160 in the shown embodiment in an exemplary embodiment;

[0066] Figure 4 is a graph showing the change trend of the phase ratio coefficient in the method for determining the temperature field of a hot-rolled strip steel shown in a specific embodiment;

[0067] Figure 5 is a block diagram of a system for determining the temperature field of a hot-rolled strip steel shown in an exemplary embodiment of this application;

[0068] Figure 6 shows a schematic structural diagram of a computer system of an electronic device suitable for implementing the embodiments of this application. Detailed Description of the Embodiments

[0069] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed according to different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention, rather than for limiting the protection scope of the present invention.

[0070] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0071] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0072] Please refer to Figure 1 , Figure 1 which is a flowchart of a method for determining the temperature field of hot-rolled strip steel shown in an exemplary embodiment of this application.

[0073] As Figure 1 shown, in an exemplary embodiment of this application, the method for determining the temperature field of hot-rolled strip steel at least includes steps S110 to S170, which are introduced in detail as follows:

[0074] Step S110. Obtain the geometric parameters, thermodynamic parameters, and physical property parameters of the hot-rolled strip steel;

[0075] It should be noted that the geometric parameters include: the thickness of the hot-rolled strip steel;

[0076] The thermodynamic parameters include: the initial temperature field of the hot-rolled strip steel, the phase transformation temperature of the hot-rolled strip steel, and the phase transformation enthalpy of the hot-rolled strip steel, the relationship function between ferrite enthalpy, austenite enthalpy, and temperature;

[0077] The physical property parameters include: the total duration of the temperature field to be determined, the specific heat capacity at constant pressure of each phase of the hot-rolled strip steel corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled strip steel, the thermal expansion coefficient of the hot-rolled strip steel at different temperatures, and the density of the hot-rolled strip steel at room temperature;

[0078] Step S120. Divide a number of nodes in the thickness direction according to the thickness of the hot-rolled strip steel to determine the spatial step size;

[0079] Specifically, the determination method of the spatial step size includes:

[0080]

[0081] Δx is the spatial step size, with the unit of m; the unit is m; n is the number of nodes divided in the thickness direction, where n

[0082] is greater than 1; all nodes are uniformly arranged in sequence along the thickness direction of the hot-rolled strip steel;

[0083] Step S130. Determine the time step size according to the total duration and the preset number of iterations;

[0084] Specifically, the determination method of the time step size includes:

[0085]

[0086] where Δt is the time step size, with the unit of s; t cal is the total duration, with the unit of s; N is the preset number of iterations.

[0087] Step S140. Determine the initial phase proportion coefficient according to the initial temperature field and the phase transformation temperature;

[0088] Step S150. Transform the initial temperature field into an initial enthalpy field through the pre-determined mapping relationship between the ferrite enthalpy, austenite enthalpy, and temperature;

[0089] The pre-determined mapping relationship between the ferrite enthalpy, austenite enthalpy, and temperature includes the pre-determined mapping relationship between the ferrite enthalpy and temperature and the pre-determined mapping relationship between the austenite enthalpy and temperature. The pre-determined mapping relationship between the ferrite enthalpy and temperature includes the ferrite enthalpy and temperature, and the pre-determined mapping relationship between the austenite enthalpy and temperature includes the austenite enthalpy and temperature. The pre-determined mapping relationship between the ferrite enthalpy and temperature and the pre-determined mapping relationship between the austenite enthalpy and temperature can be obtained by experimental fitting. For example, test the ferrite enthalpy and austenite enthalpy under a series of temperature conditions to be determined, and use software (such as EXCEL or ORGIN software, etc.) to fit the relationship between temperature and ferrite enthalpy and austenite enthalpy, then the pre-determined mapping relationship between the ferrite enthalpy and temperature and the pre-determined mapping relationship between the austenite enthalpy and the corresponding temperature can be obtained.

[0090] Then, the initial temperature field is transformed into an initial enthalpy field through a pre-determined mapping relationship among the ferrite enthalpy, austenite enthalpy, and temperature, and the initial phase ratio coefficients; specifically, the austenite enthalpy and ferrite enthalpy can be obtained through the pre-determined mapping relationship among the ferrite enthalpy, austenite enthalpy, and temperature and the temperature values of each node in the initial temperature field. Then, the austenite enthalpy and ferrite enthalpy are respectively multiplied by their corresponding initial phase ratio coefficients and summed to obtain the enthalpy value of the corresponding node, that is, the initial temperature field is transformed into an enthalpy field.

[0091] Step S160. Establish a differential equation for enthalpy conduction, and use the difference method to iteratively solve the differential equation for enthalpy conduction to obtain the final enthalpy field;

[0092] Specifically, the differential equation for enthalpy conduction is:

[0093]

[0094] where ρ is the density of the node, with the unit of kg / m 3 ; λ is the thermal conductivity of the node, with the unit of W / (m·K); x is the distance between the node and the surface of the hot-rolled steel along the thickness direction, with the unit of m; c p is the specific heat capacity at constant pressure of the node, with the unit of J / (kg·K).

[0095] Step S170. Transform the final enthalpy field into a temperature field through a pre-determined mapping relationship among the ferrite temperature, austenite temperature, and enthalpy field.

[0096] Specifically, the pre-determined mapping relationship among the ferrite temperature, austenite temperature, and enthalpy includes the pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and enthalpy. The pre-determined mapping relationship between the ferrite temperature and enthalpy includes the ferrite temperature and enthalpy, and the pre-determined mapping relationship between the austenite temperature and enthalpy includes the austenite temperature and enthalpy. The pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and enthalpy can be obtained through experimental fitting. For example, the ferrite temperature and austenite temperature at a series of enthalpy values under different temperature conditions are tested, and the relationship between the enthalpy and the ferrite temperature and austenite temperature is fitted through software (such as EXCEL or ORGIN software, etc.), so as to obtain the pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and the corresponding temperature of the enthalpy.

[0097] Then, the final enthalpy field is converted into a temperature field through the predetermined mapping relationship between the ferrite temperature, austenite temperature and enthalpy and the updated phase proportional coefficient; specifically, the austenite temperature and ferrite temperature can be obtained through the predetermined mapping relationship between the ferrite temperature, austenite temperature and enthalpy and the enthalpy value of each node in the final enthalpy field, and then the austenite temperature and ferrite temperature are multiplied by their corresponding respective updated phase proportional coefficients and then added to obtain the temperature field of the corresponding node, that is, the final enthalpy field is converted into a temperature field.

[0098] The related art generally uses the difference method to solve the heat conduction differential equation. After studying the related art, the inventors found that when using the difference method to solve the heat conduction differential equation, directly using the temperature field for iterative solution cannot effectively track the phase transformation process, resulting in a low accuracy of the determined temperature field of the hot-rolled steel strip. Therefore, the inventors considered determining the real-time thermal enthalpy and then determining the real-time temperature based on the real-time thermal enthalpy to obtain the temperature field. In other words, by determining the enthalpy field of the hot-rolled steel strip, the latent heat of phase transformation generated by the transformation of austenite to ferrite during hot rolling is effectively considered, thereby improving the accuracy of the determined temperature field of the hot-rolled steel strip.

[0099] See also Figure 2 , Figure 2 for Figure 1 The illustrated embodiment is a flow chart of determining the initial phase proportional coefficient according to the initial condition parameters in step S140 in an exemplary embodiment.

[0100] like Figure 2 As shown, in an exemplary embodiment of the present application, Figure 1 In the embodiment shown, the process of determining the initial phase proportional coefficient according to the initial condition parameters in step S140 includes steps S210 and S220, which are described in detail as follows:

[0101] Step S210. Determine the initial center temperature according to the initial temperature field;

[0102] Specifically, the initial temperature of the center point of the hot-rolled steel strip can be determined according to the initial temperature field.

[0103] For example, if the number of nodes is an even number and the nodes are uniformly distributed in sequence along the thickness direction of the hot-rolled strip, the average value of the initial temperatures of the two nodes located in the middle is the initial center temperature.

[0104] Step S220: Determine the initial ferrite phase proportional coefficient and the initial austenite phase proportional coefficient according to the initial center temperature and the phase transformation temperature.

[0105] Specifically, the method for determining the initial ferrite phase proportional coefficient and the austenite phase proportional coefficient based on the initial center temperature and the phase transformation temperature includes:

[0106]

[0107] f au = 1 - f fe (5);

[0109] Wherein, f fe is the initial ferrite phase proportion coefficient; f au is the austenite phase proportion coefficient; T c is the initial center temperature, in K; T Ac3 is the phase transformation temperature, in K.

[0110] Please refer to Figure 3 , Figure 3 which is Figure 1 the flowchart of the iterative solution of the enthalpy conduction differential equation by using the difference method in step S160 in the embodiment shown in an exemplary embodiment.

[0111] As Figure 3 shown, in an exemplary embodiment of the present application, Figure 1 the process of the iterative solution of the enthalpy conduction differential equation by using the difference method in step S160 in the embodiment shown includes steps S310 to S380, which are introduced in detail as follows:

[0112] Step S310. Determine the average enthalpy value according to the enthalpy field at the current moment;

[0113] Specifically, the method for determining the average enthalpy value according to the enthalpy field at the current moment includes:

[0114]

[0115] Wherein, H avg is the average enthalpy value, in J / kg; Δα is the relative position difference between two adjacent nodes, Δα i-1 = α i - α i-1 , h·α = x, i is greater than or equal to 1, h is the thickness of the hot-rolled strip, in m; x is the distance from the node in the thickness direction to the surface of the hot-rolled strip, in m; is the enthalpy value at the i-th node at time p, in J / kg; is the enthalpy value at the (i + 1)-th node at time p, in J / kg.

[0116] Step S320. Update the proportion coefficients of the two phases according to the average enthalpy value at the current moment;

[0117] Specifically, the method for updating the proportion coefficients of the two phases according to the average enthalpy value at the current moment includes:

[0118]

[0119] f au =1-f fe

[0120] Among them, f fe is the ferrite phase ratio coefficient; f au is the austenite phase ratio coefficient; H Ac3 is the enthalpy value of the phase change point, in J / kg; H avg is the average enthalpy value, in J / kg; ΔH is the enthalpy change of complete transformation of austenite to ferrite, in J / kg.

[0121] Step S320. Update the proportional coefficients of the two phases according to the average enthalpy value at the current moment;

[0122] Step S330. Determine the constant-pressure specific heat capacity and thermal conductivity of each phase based on the current enthalpy value of each node and the enthalpy conduction differential equation;

[0123] The enthalpy conduction differential equation includes enthalpy value, specific heat capacity of each phase at constant pressure and thermal conductivity of each phase, and is used to determine the specific heat capacity of each phase at constant pressure and thermal conductivity of each phase based on the enthalpy value and the enthalpy conduction differential equation.

[0124] Step S340. Update the constant pressure specific heat capacity and thermal conductivity of each node according to the current two-phase proportionality coefficient;

[0125] Specifically, the updating method for updating the constant pressure specific heat capacity and thermal conductivity of the hot-rolled strip according to the updated phase proportional coefficient includes:

[0126] c p =c p1 ·f fe +c p2 ·f au (8);

[0127] λ=λ1·f fe +λ2·f au (9);

[0128] Among them, c p1 、c p2 The constant pressure specific heat capacity of the ferrite phase and the constant pressure specific heat capacity of the austenite phase at the current moment, respectively, in J / (kg·K); λ1 and λ2 are the thermal conductivity coefficients of the ferrite phase and the thermal conductivity coefficients of the austenite phase at the current moment, respectively, in W / (m 2 ·K); f fe 、f au are the proportional coefficients of the ferrite phase and the austenite phase at the current moment respectively.

[0129] Step S350: Determine the temperature of each node based on the enthalpy value of each node at the current moment and the predetermined mapping relationship between the ferrite temperature, the austenite temperature, and the enthalpy field;

[0130] Assume that for a certain steel grade, the predetermined mapping relationship between austenite enthalpy and the corresponding temperature and the predetermined mapping relationship between ferrite enthalpy and the corresponding temperature are polynomial types, such as:

[0131] T au =A0+A1·H (10)

[0132] T fe =B0+B1·H (11)

[0133] Where A0, A1, B0, and B1 are polynomial coefficients, which are determined based on experimental fitting.

[0134] Then, the temperature of each node is obtained according to formula (12);

[0135] T=f fe ·T fe +f au ·T au (12);

[0136] Where T is the temperature of the corresponding node in °C, T fe , T au are the temperatures of the ferrite phase and austenite phase when the thermal enthalpy is H, in °C; f phase is the proportional coefficient of the ferrite phase.

[0137] Step S360: Determine the thermal expansion coefficient of each node based on the current temperature of each node and a preset mapping relationship between temperature and thermal expansion coefficient;

[0138] The preset mapping relationship between the temperature and the thermal expansion coefficient includes the temperature and the thermal expansion coefficient, and is used to determine the thermal expansion coefficient based on the mapping relationship between the two and the temperature.

[0139] Step S370. Update the density of each node at the current moment based on the thermal expansion coefficient of each node at the current moment and the density of steel material at room temperature;

[0140] Specifically, based on the thermal expansion coefficient of each node at the current moment and the density of steel material at room temperature, the updating method of updating the density of each node at the current moment includes:

[0141]

[0142] Where ρ is the density at the current moment, in kg / m 3; ρ0 is the density at room temperature, in kg / m 3 ; α is the thermal expansion coefficient at the current moment.

[0143] Step S380: Update the enthalpy conduction differential equation according to the updated density, constant-pressure specific heat capacity, and thermal conductivity, and solve the enthalpy field at the next moment according to the updated enthalpy conduction differential equation.

[0144] like Figure 4 As shown, in a specific embodiment, the method for determining the temperature field of the hot-rolled strip is as follows:

[0145] Obtain geometric parameters, thermodynamic parameters and physical properties of hot rolled strip

[0146] Geometric parameters include: thickness of hot-rolled strip; thermodynamic parameters include: initial temperature field of hot-rolled strip, phase transformation temperature and phase transformation enthalpy of hot-rolled strip, relationship function between ferrite enthalpy, austenite enthalpy and temperature; physical property parameters include: total duration of the temperature field to be determined, constant pressure specific heat capacity of each phase of hot-rolled strip corresponding to different enthalpy values, thermal conductivity of each phase of hot-rolled strip, thermal expansion coefficient of hot-rolled strip at different temperatures, and density of hot-rolled strip at room temperature;

[0147] According to the thickness of the hot-rolled strip, several nodes are divided in the thickness direction to determine the spatial step length;

[0148]

[0149] Δx is the spatial step length, in m; n is the number of nodes divided in the thickness direction, where n is

[0150] If it is greater than 1, all nodes are evenly arranged in sequence along the thickness direction of the hot-rolled strip;

[0151] Determine the time step based on the total time and the preset number of iterations;

[0152]

[0153] Where Δt is the time step, in seconds; t cal is the total duration in seconds; N is the preset number of iterations.

[0154] Determine the initial center temperature according to the initial temperature field. Specifically, determine the initial temperature of the center point of the hot-rolled steel strip according to the initial temperature field.

[0155] According to the initial center temperature and phase transformation temperature, the initial ferrite phase proportion coefficient and austenite phase proportion coefficient are determined:

[0156]

[0157] fau = 1 - f fe (5);

[0159] where f fe is the initial ferrite phase proportion coefficient; f au is the austenite phase proportion coefficient; T c is the initial center temperature, in °C; T Ac3 is the phase transformation temperature, in °C;

[0160] The initial temperature field is transformed into an initial enthalpy field through a pre-determined mapping relationship among the ferrite enthalpy, austenite enthalpy, and temperature;

[0161] The initial temperature field is transformed into an initial enthalpy field through a pre-determined mapping relationship among the ferrite enthalpy, austenite enthalpy, temperature, and the initial phase proportion coefficient; specifically, through the pre-determined mapping relationship among the initial temperature field, ferrite enthalpy, austenite enthalpy, and temperature, the austenite enthalpy and ferrite enthalpy can be obtained, and then the austenite enthalpy and ferrite enthalpy are respectively multiplied by their corresponding updated phase proportion coefficients and summed to obtain the temperature value of the corresponding node;

[0162] Establish the enthalpy conduction differential equation, and the enthalpy conduction differential equation is specifically:

[0163]

[0164] where ρ is the density of the node, in kg / m 3 ; λ is the thermal conductivity of the node, in W / (m·K); x is the distance between the node and the surface of the hot-rolled steel along the thickness direction, in m; c p is the specific heat capacity at constant pressure of the node, in J / (kg·K).

[0165] Determine the average enthalpy value based on the enthalpy field at the current moment:

[0166]

[0167] where H avg is the average enthalpy value, in J / kg; Δα is the relative position difference between two adjacent nodes, Δα i-1 = α i - α i-1 , h·α = x; is the enthalpy value at the i-th node at the p-th moment, in J / kg; is the enthalpy value at the (i + 1)-th node at the p-th moment, in J / kg.

[0168] Update the proportion coefficients of the two phases based on the average enthalpy value at the current moment:

[0169]

[0170] f au = 1 - f fe

[0171] where f fe is the ferrite phase proportion coefficient; f au is the austenite phase proportion coefficient; H Ac3 is the enthalpy value at the phase transformation point, with the unit of J / kg; H avg is the average enthalpy value, with the unit of J / kg; ΔH is the enthalpy change when austenite is completely transformed into ferrite, with the unit of J / kg.

[0172] Exemplarily, if the number of nodes is even and the nodes are evenly distributed in sequence along the thickness direction of the hot-rolled strip, then the average value of the initial temperatures of the two nodes in the exact middle is the initial center temperature.

[0173] Determine the average enthalpy value according to the enthalpy field at the current moment:

[0174]

[0175] where H avg is the average enthalpy value, with the unit of J / kg; Δα is the relative position difference between two adjacent nodes, Δα i-1 = α i - α i-1 , h·α = x, i is greater than or equal to 1, h is the thickness of the hot-rolled strip, with the unit of m; x is the distance from the node to the surface of the hot-rolled strip in the thickness direction, with the unit of m; is the enthalpy value at the i-th node at time p, with the unit of J / kg; is the enthalpy value at the (i + 1)-th node at time p, with the unit of J / kg.

[0176] Determine the specific heat capacity at constant pressure and the thermal conductivity of each phase according to the enthalpy value of each node at the current moment and the enthalpy conduction differential equation;

[0177] Update the specific heat capacity at constant pressure and the thermal conductivity of the hot-rolled strip according to the updated phase proportion coefficient:

[0178] c p = c p1 ·f fe + c p2 ·f au (8);

[0179] λ = λ1·f fe + λ2·f au (9);

[0180] where c p1 、c p2are the specific heat capacities at constant pressure of the ferrite phase and the austenite phase at the current moment, with the unit of J / (kg·K); λ1 and λ2 are the thermal conductivities of the ferrite phase and the austenite phase at the current moment, with the unit of W / (m 2 ·K); f fe and f au are the proportionality coefficients of the ferrite phase and the austenite phase at the current moment respectively.

[0181] Determine the temperature of each node according to the enthalpy value of each node at the current moment and the mapping relationship.

[0182] Specifically, assume that for a certain steel grade, the pre-determined mapping relationship between austenite enthalpy and the corresponding temperature and the pre-determined mapping relationship between ferrite enthalpy and the corresponding temperature are polynomial types, such as:

[0183] T au = A0 + A1·H(10)

[0184] T fe = B0 + B1·H(11)

[0185] where A0, A1, B0, and B1 are polynomial coefficients, determined by experimental fitting.

[0186] Then obtain the temperature of each node according to formula (12);

[0187] T = f fe ·T fe + f au ·T au (12);

[0188] where T is the temperature of the corresponding node, with the unit of °C, T fe and T au are the temperatures of the ferrite phase and the austenite phase when the heat enthalpy is H, with the unit of °C; f phase is the proportionality coefficient of the ferrite phase.

[0189] Determine the thermal expansion coefficient of each node according to the temperature of each node at the current moment and the pre-set mapping relationship between temperature and thermal expansion coefficient;

[0190] Update the density of each node at the current moment according to the thermal expansion coefficient of each node at the current moment and the density of the steel material at room temperature:

[0191]

[0192] where ρ is the density at the current moment, with the unit of kg / m 3 ; ρ0 is the density at room temperature, with the unit of kg / m 3; α is the coefficient of thermal expansion at the current moment.

[0193] Update the enthalpy conduction differential equation according to the updated density, specific heat capacity at constant pressure, and thermal conductivity, and solve the enthalpy field at the next moment according to the updated enthalpy conduction differential equation.

[0194] Convert the final enthalpy field into a temperature field through a pre-determined mapping relationship between the ferrite temperature, austenite temperature, and enthalpy.

[0195] Specifically, the pre-determined mapping relationship between the ferrite temperature, austenite temperature, and enthalpy includes the pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and enthalpy. The pre-determined mapping relationship between the ferrite temperature and enthalpy includes the ferrite temperature and enthalpy, and the pre-determined mapping relationship between the austenite temperature and enthalpy includes the austenite temperature and enthalpy. The pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and enthalpy can be obtained by experimental fitting. For example, measure the ferrite temperature and austenite temperature in the hot-rolled strip to be determined under a series of temperature conditions and the enthalpy values, and fit the relationship between the enthalpy and the ferrite temperature and austenite temperature through software (such as EXCEL or ORGIN software, etc.), then the pre-determined mapping relationship between the ferrite temperature and enthalpy and the pre-determined mapping relationship between the austenite temperature and the corresponding temperature of the enthalpy can be obtained.

[0196] Then convert the final enthalpy field into a temperature field through the pre-determined mapping relationship between the ferrite temperature, austenite temperature, and enthalpy and the updated phase ratio coefficient; specifically, the austenite temperature and ferrite temperature can be obtained through the pre-determined mapping relationship between the ferrite temperature, austenite temperature, and enthalpy and the enthalpy values of each node in the final enthalpy field, and then multiply the austenite temperature and ferrite temperature by their respective updated phase ratio coefficients and sum them to obtain the temperature field of the corresponding node, that is, convert the final enthalpy field into a temperature field.

[0197] Please refer to Figure 5 , the embodiment of the present application also provides a determination system M500 for the temperature field of a hot-rolled strip, and the determination system M500 for the temperature field of the hot-rolled strip includes:

[0198] An acquisition module M510, configured to obtain the geometric parameters, thermodynamic parameters, and physical property parameters of the hot-rolled strip;

[0199] The geometric parameters include the thickness;

[0200] The thermodynamic parameters include the initial temperature field of the hot-rolled strip, the phase transformation temperature of the hot-rolled strip, the phase transformation enthalpy of the hot-rolled strip, and the relationship function between the ferrite enthalpy, austenite enthalpy, and temperature;

[0201] Physical property parameters include: the total duration of the temperature field to be determined, the specific heat capacity of each phase of the hot-rolled strip at constant pressure corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled strip, the thermal expansion coefficient of the hot-rolled strip at different temperatures, and the density of the hot-rolled strip at room temperature;

[0202] Determination module M520 is used to divide a number of nodes in the thickness direction according to the thickness of the hot-rolled strip, determine the spatial step size, determine the time step size according to the total time and the preset number of iterations, determine the initial phase proportional coefficient according to the initial temperature field and the phase transformation temperature, transform the initial temperature field into the initial enthalpy field through the relationship function of ferrite enthalpy, austenite enthalpy and temperature, establish the enthalpy conduction differential equation, use the difference method to iteratively solve the enthalpy conduction differential equation to obtain the final enthalpy field, and transform the final enthalpy field into the temperature field through the predetermined mapping relationship between ferrite temperature, austenite temperature and enthalpy field.

[0203] It should be noted that the system for determining the temperature field of a hot-rolled steel strip provided in the above-mentioned embodiment and the method for determining the temperature field of a hot-rolled steel strip provided in the above-mentioned embodiment are based on the same concept. The specific manner in which each module and unit performs operations has been described in detail in the method embodiments and will not be repeated here. In actual applications, the system for determining the temperature field of a hot-rolled steel strip provided in the above-mentioned embodiment can allocate the aforementioned functions to different functional modules as needed, i.e., divide the internal structure of the device.

[0204] The present application also provides an electronic device, comprising: a processor; a memory for storing one or more programs. When the one or more programs are executed by one or more processors, the electronic device implements the method for determining the temperature field of hot-rolled strip provided in the above-mentioned embodiments.

[0205] Figure 6 The following is a schematic diagram showing the structure of a computer system suitable for implementing an electronic device according to an embodiment of the present application. Figure 6 The computer system 600 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0206] like Figure 6As shown, the computer system 600 includes a central processing unit (CPU) 601, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 602 or the program loaded from the storage part 608 to the random access memory (RAM) 603, such as executing the method described in the above embodiment. The RAM 603 also stores various programs and data required for system operation. The CPU 601, ROM 602, and RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0207] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, and the like; an output section 607 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 608 including a hard disk; and a communication section 609 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. Removable media 611, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 610 as needed, so that computer programs read therefrom can be installed into the storage section 608 as needed.

[0208] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 609, and / or installed from a removable medium 611. When the computer program is executed by the central processing unit (CPU) 601, the various functions defined in the system of the present application are executed.

[0209] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication portion, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), various functions defined in the system of the present application are executed.

[0210] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication portion, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), various functions defined in the system of the present application are executed.

[0211] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable computer program. This propagated data signal can take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0212] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. Among them, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0213] The units involved in the embodiments described in this application can be implemented in software or in hardware, and the described units can also be provided in a processor. Among them, the names of these units do not constitute a limitation on the units themselves in some cases.

[0214] Another aspect of this application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of the computer, the computer is caused to execute the method for determining the temperature field of hot-rolled strip as described above. The computer-readable storage medium can be included in the electronic device described in the above embodiments, or can exist alone without being assembled into the electronic device.

[0215] Another aspect of this application also provides a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method for determining the temperature field of hot-rolled strip provided in the above various embodiments.

[0216] The above embodiments are only used to exemplarily illustrate the principles and effects of the present invention, rather than to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for determining the temperature field of hot-rolled strip steel, characterized in that, The determination method includes: Obtaining geometric parameters, thermodynamic parameters, and physical parameters of the hot-rolled steel strip, wherein the geometric parameters include: the thickness of the hot-rolled steel strip; the thermodynamic parameters include: the initial temperature field of the hot-rolled steel strip, the phase transformation temperature and phase transformation enthalpy of the hot-rolled steel strip, and the relationship function between the ferrite enthalpy and the austenite enthalpy and the temperature; and the physical parameters include: the total duration of the temperature field to be determined, the constant pressure specific heat capacity of each phase of the hot-rolled steel strip corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled steel strip, the thermal expansion coefficient of the hot-rolled steel strip at different temperatures, and the density of the hot-rolled steel strip at room temperature; According to the thickness of the hot-rolled strip, a number of nodes are divided in the thickness direction, and a spatial step length is determined, and all the nodes are uniformly distributed in sequence along the thickness direction of the hot-rolled strip; Determine the time step based on the total time and the preset number of iterations; determining an initial phase proportional coefficient according to the initial temperature field and the phase transition temperature; The initial temperature field is converted into an initial enthalpy field through a predetermined mapping relationship between ferrite enthalpy, austenite enthalpy and temperature; Establish the enthalpy conduction differential equation; According to the enthalpy field at the current moment, the average enthalpy value is determined. According to the enthalpy field at the current moment, the average enthalpy value is determined by: Among them, is the average enthalpy value; is the relative position difference between two adjacent nodes, , ; h is the thickness of the hot-rolled strip, x is the distance from the node in the thickness direction to the surface of the hot-rolled strip, is at the moment the enthalpy value at the node; is at the moment the enthalpy value at the node; Update the proportional coefficients of the two phases according to the average enthalpy value at the current moment; According to the current enthalpy value of each node and the enthalpy conduction differential equation, the constant pressure specific heat capacity and thermal conductivity of each phase are determined; Update the constant pressure specific heat capacity and thermal conductivity of each node according to the proportional coefficient of the two phases at the current moment; Determining the temperature of each node according to the enthalpy value of each node at the current moment and the predetermined mapping relationship between the ferrite temperature, the austenite temperature and the enthalpy field; Determine the thermal expansion coefficient of each node based on the temperature of each node at the current moment and a preset mapping relationship between the temperature and the thermal expansion coefficient; Update the density of each node at the current moment based on the thermal expansion coefficient of each node at the current moment and the density of steel material at room temperature; updating the enthalpy conduction differential equation according to the updated density, constant-pressure specific heat capacity, and thermal conductivity, and solving the enthalpy field at the next moment according to the updated enthalpy conduction differential equation; The final enthalpy field is converted into a temperature field through a predetermined mapping relationship between the ferrite temperature, the austenite temperature and the enthalpy field.

2. The method for determining the temperature field of hot-rolled strip steel according to claim 1, characterized in that The spatial step and time step are determined by: Among them, is the spatial step size; h is the thickness of the hot-rolled strip; is the number of nodes divided in the thickness direction; is the time step size, is the total duration; is the preset number of iterations.

3. The method for determining the temperature field of hot-rolled strip according to claim 1, characterized in that: Determining an initial phase proportional coefficient according to the initial temperature field and the phase transition temperature includes: determining an initial center temperature according to the initial temperature field; The initial ferrite phase proportional coefficient and the initial austenite phase proportional coefficient are determined according to the initial center temperature and the phase transformation temperature.

4. The method for determining the temperature field of a hot-rolled strip according to claim 3, characterized in that: The process of determining the two-phase proportional coefficient according to the initial center temperature and the phase transition temperature includes: Among them, is the initial ferrite phase proportion coefficient; is the austenite phase proportion coefficient; is the initial central temperature; is the phase transformation temperature.

5. The method for determining the temperature field of hot-rolled strip steel according to claim 1, characterized in that, The enthalpy conduction differential equation is: Among them, is the density of the node; is the thermal conductivity of the node; is the distance between the node and the surface of the hot-rolled steel along the thickness direction; is the specific heat capacity at constant pressure of the node.

6. The method for determining the temperature field of hot-rolled strip steel according to claim 1, characterized in that, According to the average enthalpy value at the current moment, the updating method of the proportional coefficient of the two phases includes: Among them, is the ferrite phase proportion coefficient; is the austenite phase proportion coefficient; is the enthalpy value of the phase transformation point; is the average enthalpy value; is the enthalpy change of the complete transformation of austenite into ferrite, that is, the phase transformation enthalpy.

7. The method for determining the temperature field of hot-rolled strip steel according to claim 1, characterized in that, The updating method for updating the constant pressure specific heat capacity and thermal conductivity of the hot-rolled strip according to the updated phase proportional coefficient includes: in, 、 are the constant-pressure specific heat capacity of the ferrite phase and the constant-pressure specific heat capacity of the austenite phase at the current moment respectively; 、 are the thermal conductivity of the ferrite phase and the thermal conductivity of the austenite phase at the current moment respectively; 、 are the proportional coefficients of the ferrite phase and the austenite phase at the current moment respectively.

8. The method for determining the temperature field of hot-rolled strip steel according to claim 1, characterized in that, Based on the thermal expansion coefficient of each node at the current moment and the density of steel material at room temperature, the updating method for updating the density of each node at the current moment includes: Among them, is the density at the current moment; is the density at room temperature; is the coefficient of thermal expansion at the current moment.

9. A system for determining the temperature field of hot-rolled strip steel, characterized in that: The determination system comprises: An acquisition module is configured to acquire geometric parameters, thermodynamic parameters, and physical parameters of the hot-rolled steel strip, wherein the geometric parameters include thickness; the thermodynamic parameters include the initial temperature field of the hot-rolled steel strip, the phase transition temperature and phase transition enthalpy of the hot-rolled steel strip, and the relationship function between the ferrite enthalpy and austenite enthalpy and temperature; and the physical parameters include: the total duration of the temperature field to be determined, the constant-pressure specific heat capacity of each phase of the hot-rolled steel strip corresponding to different enthalpy values, the thermal conductivity of each phase of the hot-rolled steel strip, the thermal expansion coefficient of the hot-rolled steel strip at different temperatures, and the density of the hot-rolled steel strip at room temperature. A determination module is used to divide a number of nodes in the thickness direction according to the thickness of the hot-rolled strip, determine a spatial step length, and evenly distribute all the nodes in the thickness direction of the hot-rolled strip in sequence. The time step length is determined according to the total time and the preset number of iterations. The initial phase proportional coefficient is determined according to the initial temperature field and the phase transformation temperature. The initial temperature field is converted into an initial enthalpy field through a predetermined mapping relationship between ferrite enthalpy, austenite enthalpy and temperature. An enthalpy conduction differential equation is established. The average enthalpy value is determined according to the enthalpy field at the current moment. The determination method of the average enthalpy value according to the enthalpy field at the current moment includes: Among them, is the average enthalpy value; is the relative position difference between two adjacent nodes, , ; h is the thickness of the hot-rolled strip, x is the distance from the node in the thickness direction to the surface of the hot-rolled strip, is at the moment of the enthalpy value at the node; is at the moment of the enthalpy value at the node; According to the average enthalpy value at the current moment, update the proportionality coefficients of the two phases; According to the enthalpy value of each current node and the differential equation of enthalpy conduction, determine the specific heat capacity at constant pressure and the thermal conductivity of each phase; According to the proportionality coefficients of the two phases at the current moment, update the specific heat capacity at constant pressure and the thermal conductivity of each node; The temperature of each node is determined based on the enthalpy value of each node at the current moment and the predetermined mapping relationship between the ferrite temperature, the austenite temperature and the enthalpy field; the thermal expansion coefficient of each node is determined based on the temperature of each node at the current moment and the preset mapping relationship between the temperature and the thermal expansion coefficient; the density of each node at the current moment is updated based on the thermal expansion coefficient of each node at the current moment and the density of the steel material at room temperature; the enthalpy conduction differential equation is updated based on the updated density, constant-pressure specific heat capacity and thermal conductivity, and the enthalpy field at the next moment is solved based on the updated enthalpy conduction differential equation; and the final enthalpy field is converted into a temperature field through the predetermined mapping relationship between the ferrite temperature, the austenite temperature and the enthalpy field.

10. An electronic device, characterized in that: The electronic device comprises: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the method for determining the temperature field of the hot-rolled strip as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the computer program is executed by a processor of a computer, the computer is caused to execute the method for determining the temperature field of a hot-rolled strip as claimed in any one of claims 1 to 8.

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