Intelligent control method for titanium alloy VAR smelting stirring strength

Abstract

The invention discloses an intelligent control method for titanium alloy VAR smelting stirring strength, and relates to the technical field of metal material smelting, the intelligent control method comprises the following steps: S1, calculating stirring acting force distribution in a VAR smelting process; s2, calculating a flow velocity field and a temperature field of the molten pool according to the acting force distribution; s3, constructing a vortex field distribution model according to the flow velocity field and the temperature field; s4, optimizing a molten pool electromagnetic stirring force field according to the vortex field; s5, adjusting an arc scanning mode based on the optimized electromagnetic stirring force field; s6, performing arc scanning real-time regulation and control based on dynamic flow feedback; by arranging an electromagnetic stirring control model based on eddy current field optimization, accurate regulation and control of molten pool flowing are achieved, stirring uniformity is improved, smelting quality is optimized, unstable electromagnetic stirring force calculation is adopted, the stirring intensity is dynamically adjusted in combination with the eddy current induction effect, and the flow velocity distribution of a molten pool is more uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material smelting, and specifically provides an intelligent control method for the stirring intensity of titanium alloy VAR melting. Background Art

[0002] During the titanium alloy VAR melting process, the arc heating effect causes the electrode to melt layer by layer and form a molten pool. The flow state of the molten pool determines the compositional uniformity, microstructure stability, and internal defect conditions of the final ingot, and electromagnetic stirring is a key factor affecting the flow of the molten pool. The existing electromagnetic stirring control methods for VAR melting mainly calculate based on the steady-state electromagnetic force field and adopt a stirring strategy with fixed parameters. However, the traditional methods have the following deficiencies: 1. In the prior art, most existing electromagnetic stirring calculation methods are based on the steady-state electromagnetic force field model and do not fully consider the transient effect of the eddy current field. Since eddy currents are generated inside the molten pool due to electromagnetic induction during the VAR melting process, which in turn affects the flow velocity distribution of the molten pool, the traditional methods fail to effectively utilize the eddy current field to optimize the stirring force, resulting in uneven local flow and increasing the risk of alloy composition segregation; 2. In the prior art, the existing electromagnetic stirring strategies for VAR melting usually adjust the electromagnetic force with fixed parameters. However, the flow velocity field and temperature field of the molten pool will undergo complex dynamic changes during the melting process, and the traditional methods cannot optimize and adjust the electromagnetic force according to the actual state of the molten pool, resulting in local flow strengthening or weakening, making it difficult to ensure the stirring uniformity and affecting the overall quality of the ingot. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides an intelligent control method for the stirring intensity of titanium alloy VAR melting to solve the problems raised in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, an embodiment of the present invention provides an intelligent control method for the stirring intensity of titanium alloy VAR melting, including the following steps: S1. Calculate the distribution of stirring forces during the VAR melting process; S2. Calculate the flow velocity field and temperature field of the molten pool according to the force distribution; S3. Construct an eddy current field distribution model based on the flow velocity field and temperature field; S4. Optimize the electromagnetic stirring force field of the molten pool according to the eddy current field; S5. Adjust the arc scanning mode based on the optimized electromagnetic stirring force field; S6. Perform real-time regulation of arc scanning based on dynamic flow feedback.

[0005] To further optimize this technical solution, during the VAR melting process in step S1, the stirring force in the molten pool is the core physical quantity affecting the quality of the final ingot. The stirring force received by the molten pool includes: electromagnetic force, thermal convection force, and arc pressure.

[0006] To further optimize this technical solution, step S2 describes its flow characteristics through the unsteady incompressible Navier-Stokes equation, and its formula model is: ; Where, is the density of the molten pool metal; is the physical time during the molten pool melting process; is the flow velocity field of the molten pool; is the internal pressure of the molten pool; is the dynamic viscosity; is the acceleration due to gravity; is the volume average force density.

[0007] To further optimize this technical solution, in step S3, based on the magnetohydrodynamics (MHD) theory, combined with the influence of the temperature gradient on the induced current and magnetic induction field, an eddy current field calculation model is constructed. According to the conductivity and magnetic permeability showing spatial non-uniformity, a temperature gradient correction term is introduced in the eddy current field calculation; Influence of the conductivity gradient: ; Where, is the molten pool temperature; is the conductivity at the reference temperature ; is the temperature change coefficient of the conductivity; Correction of the induced current density: ; Where, refers to the internal electric field in the molten pool; refers to the internal magnetic field in the molten pool; refers to the change in the conductivity of the material with temperature; is the corrected induced current density; The first term is the standard induced current calculation formula; The second item Indicates the influence of the temperature gradient on the induced current.

[0008] To further optimize this technical solution, the magnetic induction equation is introduced in step S3. In the standard magnetic induction equation, the distribution of eddy currents is determined by the curl of the current density: ; Where is the induced current density, is the change in magnetic permeability caused by the change in temperature; Based on the local conductivity change caused by the temperature gradient, a correction term is introduced into this equation: ; Where the additional correction term reflects the influence of the change in temperature gradient on the local induced magnetic field, making the eddy currents show a more complex distribution form in the region with a large temperature gradient.

[0009] To further optimize this technical solution, in step S3, based on the gradient influence of conductivity, the correction of the induced current density, and the magnetic induction equation, this step has the following calculation process: Input the temperature field calculated in step S2 into the formula and the flow velocity field , calculate the temperature gradient and correct the conductivity distribution ; Introduce the gradient term of conductivity with respect to temperature , calculate the corrected induced current density ; Use the corrected magnetic induction equation to solve the eddy current field ; Output the eddy current field distribution and use it to optimize the electromagnetic stirring scheme in step S4.

[0010] To further optimize this technical solution, in step S4, solve the electromagnetic force field and optimize the electromagnetic stirring scheme, including the calculation of the electromagnetic force field. The core acting force of electromagnetic stirring comes from the Lorentz force: .

[0011] To further optimize this technical solution, in step S4, optimize the electromagnetic stirring distribution by combining the temperature gradient: The flow inside the molten pool is driven by the electromagnetic force and can be expressed by the momentum equation as: ; To make the distribution of the electromagnetic stirring force field more uniform in different regions, introduce a flow field correction coefficient Make adjustments: ; Among them, the correction coefficient is determined by the flow velocity deviation: ; Among them, is the adjustment coefficient, which controls the correction intensity; represents the velocity gradient of the local flow field and is used to adjust the magnitude of the electromagnetic force; Normalization term makes the correction factor vary between 0 and 1.

[0012] To further optimize this technical solution, the step S4 has the following calculation process: Input the eddy current field calculated in step S3 into the formula and the corrected induced current density , and calculate the electromagnetic force field ; Analyze the electromagnetic force field on the molten pool flow velocity field and calculate the correction coefficient ; Calculate the optimized electromagnetic stirring force field , and use it to adjust the arc scanning mode in step S5.

[0013] To further optimize this technical solution, the adjustment of the arc scanning mode in step S5 needs to meet the stability requirements of the molten pool flow, and a correction equation based on the balance of electromagnetic force and surface tension is adopted: ; Among them, is the thermal conductivity; is the surface tension coefficient; is the disturbance of the molten pool surface height.

[0014] In a second aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, where the memory stores a computer program, and among them: when the computer program instructions are executed by the processor, the steps of an intelligent control method for the stirring intensity of titanium alloy VAR melting as described in the first aspect of the present invention are implemented.

[0015] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and among them: when the computer program instructions are executed by the processor, the steps of an intelligent control method for the stirring intensity of titanium alloy VAR melting as described in the first aspect of the present invention are implemented.

[0016] Compared with the prior art, the present invention provides an intelligent control method for the stirring intensity of titanium alloy VAR melting, which has the following beneficial effects: This intelligent control method for the stirring intensity of titanium alloy VAR melting sets an electromagnetic stirring control model optimized based on the eddy current field, and uses machine learning and deep learning technologies to achieve precise regulation of the molten pool flow, improve the stirring uniformity, and optimize the melting quality. This method calculates the unsteady electromagnetic stirring force, and dynamically adjusts the stirring intensity in combination with the eddy current induction effect, making the flow velocity distribution of the molten pool more uniform, effectively reducing the phenomenon of overly strong or overly weak local flow, reducing alloy composition segregation, and improving the uniformity of the ingot structure. At the same time, by constructing a multi-field coupling model of the electromagnetic force field, temperature field and flow velocity field, the internal state of the molten pool is calculated in real time, and the electromagnetic stirring force distribution is optimized according to the temperature gradient and flow characteristics of the molten pool to achieve adaptive regulation. Compared with the stirring method with fixed parameters in traditional VAR melting, this method can effectively improve the stability of the melting process, reduce the ingot defects caused by uneven flow, improve the overall quality and tissue stability of titanium alloy ingots, thereby optimizing the VAR melting process and improving the performance of alloy materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of an intelligent control method for the stirring intensity of titanium alloy VAR melting proposed by the present invention; Figure 2 It is a schematic flow diagram of the eddy current field model construction of an intelligent control method for the stirring intensity of titanium alloy VAR melting proposed by the present invention; Figure 3 It is a schematic flow diagram of the electromagnetic force field solution of an intelligent control method for the stirring intensity of titanium alloy VAR melting proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the drawings of the specification.

[0020] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0021] Secondly, the "one embodiment" or "embodiment" mentioned herein refers to a specific feature, structure or characteristic that may be included in at least one implementation manner of the present invention. The "in one embodiment" appearing in different places in this specification does not all refer to the same embodiment, nor is it an individual or selectively mutually exclusive embodiment with other embodiments.

[0022] Embodiment 1: Referring to Figures 1 to 3 , this is the first embodiment of the present invention. This embodiment provides an intelligent control method for the stirring intensity of titanium alloy VAR melting, including the following steps: S1. Calculate the distribution of stirring forces during the VAR melting process; During the VAR melting process in step S1, the stirring force in the molten pool is the core physical quantity affecting the quality of the final ingot. The stirring force received by the molten pool includes: electromagnetic force, thermal convection force and arc pressure; The total expression of the molten pool stirring force is: ; Where is the induced current density in the molten pool; is the magnetic induction intensity inside the molten pool; is the molten pool metal density; is the acceleration due to gravity; is the coefficient of thermal expansion; is the molten pool temperature, is the reference temperature; is the arc pressure distribution; is the molten pool area; represents the unit vector in the vertical direction; In the formula, the electromagnetic stirring force term represents the Lorentz force formed by the cross product of the induced current density and the magnetic induction intensity , which is the direct source of the electromagnetic stirring effect excited by the input current through the arc during the VAR melting process; The thermal buoyancy term represents the natural convection driving term formed by the density difference caused by uneven temperature, and is used to describe the contribution of the thermal buoyancy caused by the temperature gradient inside the molten pool to the stirring flow; The arc pressure gradient term It represents the uneven pressure generated by the electric arc on the molten pool surface, which affects the surface flow characteristics. It supplements the quantitative description of the disturbance of the upper liquid of the molten pool during the formation of effects such as gas expansion and plasma jet by the electric arc heat source, and reflects its driving effect on surface disturbance and radial flow.

[0023] S2. Calculate the flow velocity field and temperature field of the molten pool according to the force distribution; The flow velocity field and temperature field are not only directly related to the scientificity and accuracy of smelting quality control, but also provide a physical basis for key process links such as stirring intensity control, electric arc trajectory design, and defect prediction; During the optimization process of the molten pool shape, based on the expression , establish a calculation model for the flow velocity field and temperature field of the molten pool; The above-mentioned step S2 describes its flow characteristics through the unsteady incompressible Navier-Stokes equation, and its formula model is: ; In the formula, is the volume-averaged force density: , is the volume of the molten pool area ; is the inertial force term, which describes the annular recirculation phenomenon formed by high-speed disturbance in the center or edge area of the molten pool, and is a direct manifestation of the self-organization disturbance of the fluid. The first term represents the inertial response caused by the change of velocity with time under unsteady conditions; the second term represents the local acceleration in the velocity field, that is, the momentum transfer generated when the fluid moves with the flow velocity field; is the density of the molten pool metal; is the physical time during the molten pool smelting process; is the flow velocity field of the molten pool; is the internal pressure of the molten pool; represents viscous shear, that is, wall friction. Its physical meaning is that the relative motion between fluids generates a velocity gradient under the action of viscosity, reflecting the internal shear stress; is the dynamic viscosity; is the gravity buoyancy term; is the gravitational acceleration; This equation is used to solve the flow velocity inside the molten pool , reflects the motion state of the liquid metal inside the molten pool, and provides a convection term for the temperature field calculation; The temperature distribution of the molten pool is affected by heat conduction, convective heat transfer, and Joule heat effect. The temperature field is represented by the energy conservation equation: ; where, is the specific heat capacity; is the thermal conductivity; is the Joule heat: , where is the temperature-dependent electrical conductivity, is the induced current density; The total external force calculated using step S1 is used to solve the Navier-Stokes equation to obtain the flow velocity field of the molten pool ; Substitute the obtained into the temperature field equation , combined with the Joule heat to calculate the temperature field , where specifically represents the instantaneous temperature value at any point in the molten pool space at time ; Output the calculation results of the flow velocity field and the temperature field for the eddy current field calculation in step S3 to make the electromagnetic stirring process more accurate; The two control equations together constitute the most core heat flow field modeling module in the VAR process of titanium alloy, providing physical calculation support for the establishment of the subsequent eddy current field distribution model.

[0024] S3. Construct an eddy current field distribution model based on the flow velocity field and the temperature field; Based on the magnetohydrodynamics (MHD) theory, combined with the influence of the temperature gradient on the induced current and the magnetic induction field, construct an eddy current field calculation model; According to the spatial inhomogeneity of the electrical conductivity and the magnetic permeability of the material, introduce a temperature gradient correction term in the eddy current field calculation; Influence of the gradient of electrical conductivity: ; where, is the molten pool temperature; is the electrical conductivity at the reference temperature ; is the temperature change coefficient of the electrical conductivity; According to the influence of temperature on the induced current density, correct the induced current density: ; Among them, refers to the internal electric field of the molten pool; refers to the internal magnetic field of the molten pool; refers to the change in the electrical conductivity of the material with temperature; is the corrected induced current density; The first term is the standard calculation formula for induced current; The second term represents the influence of the temperature gradient on the induced current, making the current distribution show different spatial gradient changes in the high-temperature and low-temperature regions; In the standard magnetic induction equation, the distribution of eddy currents is determined by the curl of the current density: ; Among them, is the induced current density, is the change in magnetic permeability caused by the change in temperature; Based on the local conductivity change caused by the temperature gradient, a correction term is introduced into this equation: ; Among them, the additional correction term reflects the influence of the change in temperature gradient on the local induced magnetic field, making the eddy currents show a more complex distribution form in the region with a large temperature gradient; The calculation process is as follows: Input the temperature field and flow velocity field calculated in step S2 into the formula to calculate the temperature gradient and correct the conductivity distribution ; Introduce the gradient term of conductivity with respect to temperature , and calculate the corrected induced current density ; Use the corrected magnetic induction equation to solve the eddy current field ; Output the distribution of the eddy current field and use it to optimize the electromagnetic stirring scheme in step S4; This step introduces the dynamic regulation effect of the molten pool temperature gradient on the conductivity and magnetic induction intensity, and establishes an eddy current field correction model with the characteristics of space-varying coefficients. Different from the existing mature technologies that use fixed physical property parameters to calculate the induced current and magnetic field, this method uses the temperature gradient correction term and the eddy current correction term The non-linear dynamic adaptive regulation of the spatial distribution of the eddy current field is realized. This processing method can significantly improve the matching degree between the induced magnetic field and the actual temperature field, effectively support the subsequent intelligent arc path optimization and stirring intensity control, and fill the gap of local stirring failure caused by the decoupling of the electromagnetic model and the thermal field in the traditional method.

[0025] S4. Optimize the electromagnetic stirring force field of the molten pool according to the eddy current field; In this step, the electromagnetic stirring force field is solved and the electromagnetic stirring scheme is optimized, including: Calculate the electromagnetic force field The core acting force of electromagnetic stirring comes from the Lorentz force: ; In step S4, the Lorentz force is calculated by substituting the induced current density corrected through the eddy current field calculation . The electromagnetic stirring force is the dominant external force source for the fluid motion inside the molten pool during the VAR process of titanium alloy. By calculating the cross product of the corrected induced current density and the magnetic induction intensity , the Lorentz force can be obtained, which can effectively drive the flow of molten pool metal, break the local stagnant area caused by density difference and temperature gradient, and prevent the occurrence of quality defects such as impurity segregation, shrinkage cavity, and grain coarsening; Optimize the electromagnetic stirring distribution in combination with the temperature gradient The flow inside the molten pool is driven by the electromagnetic force and can be expressed by the momentum equation as: ; This equation is the basic control equation for calculating and iteratively reconstructing the instantaneous flow velocity field inside the molten pool . By substituting into the right side of this equation, the flow velocity vector field can be obtained through numerical iteration, which is used to evaluate the local intensity and turbulence characteristics of the stirring distribution. The iteratively obtained flow velocity field is fed back to step S5; To make the distribution of the electromagnetic stirring force field more uniform in different regions, a flow field correction coefficient is introduced for adjustment: ; Among them, the correction coefficient is determined by the flow velocity deviation: ; Among them, is the adjustment coefficient to control the correction intensity; represents the velocity gradient of the local flow field and is used to adjust the magnitude of the electromagnetic force; Normalization term Make the correction factor vary between 0 and 1; The non-uniformity of the electromagnetic stirring force distribution is the basis of the subsequent introduction of the adjustment factor , can be Perform regional corrections to control local stirring intensity as needed, improve stirring uniformity and directionality, and finally adjust the arc scanning path in step S5 to coordinate stirring with heat input; The calculation process is as follows: Enter the eddy current field calculated in step S3 into the formula and the corrected induced current density ,calculate ; analyze Velocity field of the molten pool Calculate the correction factor ; Calculation of the optimized electromagnetic stirring force field , and used to adjust the arc scanning mode in step S5; In this step, Coupled with the temperature field and velocity field in real time, the temperature field will affect the conductivity and magnetic induction intensity Changes, which in turn affect and The velocity field is affected by The effect of the electromagnetic field on the fluid field forms a non-steady-state dynamic regulation, thereby constructing a closed-loop feedback system of "temperature field → electromagnetic field → stirring force → flow field → temperature field", which is impossible to achieve by decoupling the electromagnetic field and fluid field in traditional technology. This step constructs a nonlinear coupling model to calculate the electromagnetic stirring force together with the molten pool velocity field and temperature field to form an adaptive electromagnetic force optimization strategy. Compared with the traditional fixed parameter adjustment method, this method can dynamically correct the electromagnetic effect, improve the stirring efficiency, reduce the flow field inhomogeneity, thereby optimizing the molten pool morphology and reducing the segregation of alloy components.

[0026] S5. Adjusting arc scanning mode based on optimized electromagnetic stirring force field; The adjustment of arc scanning mode needs to meet the stability requirements of molten pool flow, and adopts the correction equation based on the balance of electromagnetic force and surface tension: ; in, is the thermal conductivity; is the surface tension coefficient; The molten pool surface is highly disturbed; This equation reflects the coupled equilibrium relationship among the heat conduction driven by the temperature gradient inside the molten pool (the first term), the action of the electromagnetic stirring force in the liquid metal (the second term), and the capillary restoring force caused by surface perturbations (the third term). It is used to evaluate whether the arc scanning mode meets the stability conditions of the molten pool surface, that is, when the residual of this equation is minimized, the surface perturbation of the molten pool is minimized and the surface morphology is the most stable; The residual of the coupled equation for molten pool stability is: ; : the residual of the equilibrium equation at point ; The residual functional of this correction equation is: ; When the residual is minimized, the optimized electromagnetic stirring force field should satisfy: .

[0027] Based on this equation, adjust the arc scanning speed and path : ; where is the adjustment coefficient to make the arc scanning path adapt to the flow characteristics of the molten pool; This formula is the dynamic update model of the arc scanning path, and its function is to generate real-time scanning path corrections in the non-equilibrium region. By adjusting the arc path in real time, the stirring intensity gradually approaches the optimal equilibrium region.

[0028] S6. Perform real-time control of arc scanning based on dynamic flow feedback; Introduce a real-time control method based on dynamic flow feedback to continuously adjust the arc scanning path to compensate for the melting instability caused by uneven flow; Establish a dynamic flow feedback model ; where, reflects the current overall stability deviation of the molten pool; is the calculation area of the molten pool; When , it indicates that the interaction among the temperature gradient, flow velocity field, and electromagnetic force inside the molten pool has not reached equilibrium, and the arc scanning path needs to be adjusted in real time; Calculate the arc scanning correction amount To compensate for the deviation caused by , define the arc scanning correction amount : ; Among them, is the feedback control coefficient, used to adjust the correction intensity; is the integral variable at the historical moment, ; At the historical moment The measured deviation of the molten pool stability; This formula accumulates the feedback error through integration, gradually corrects the arc path, and realizes the control of the molten pool stability; Calculate the final arc scanning path ; Among them, is the optimized arc scanning path in step S5; is the dynamic feedback correction amount; The model in the real-time control method includes: Input the arc scanning path of step S5 into the formula ; Calculate the deviation of the molten pool stability To judge whether there is uneven smelting; Calculate the correction amount , and superimpose it on the original path to form the final arc scanning path ; Continuously calculate during the smelting process , dynamically adjust to ensure the stability of the molten pool shape; Most of the existing VAR arc scanning methods are preset paths, which cannot respond to the changes in the molten pool flow in real time, resulting in local overheating or uneven flow. This step proposes a real-time control method for arc scanning based on the feedback of the molten pool flow. By calculating the deviation of the molten pool stability and making dynamic corrections, the arc path can adapt to the changes in the molten pool state. Compared with the fixed scanning path, this method can adjust the arc movement according to the molten pool flow, improve the smelting stability, reduce local defects, and improve the tissue uniformity of titanium alloy.

[0029] Embodiment 2: This embodiment also provides a computer device, which is applicable to the situation of an intelligent control method for the stirring intensity of titanium alloy VAR smelting, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement an intelligent control method for the stirring intensity of titanium alloy VAR smelting as proposed in the above embodiment.

[0030] This embodiment also provides a storage medium, on which a computer program is stored. When the program is executed by a processor, it implements an intelligent control method for the stirring intensity of titanium alloy VAR melting as proposed in the above embodiment.

[0031] The computer device can be a terminal. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner. The wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, a touchpad, or a mouse, etc.

[0032] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs, etc., which can store program codes.

[0033] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in conjunction with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0034] More specific examples (non-exhaustive list) of computer-readable media include the following: electrical connections (electronic devices) having one or more wirings, portable computer diskettes (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber devices, and portable compact disc read-only memory (CDROM). Additionally, the computer-readable media can even be paper or other suitable media on which a program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then storing it in a computer memory.

[0035] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, the multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0036] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An intelligent control method for the stirring intensity of VAR melting of titanium alloy, characterized in that It includes the following steps: S1. Calculate the stirring force distribution during VAR melting; S2. Calculate the flow velocity field and temperature field of the molten pool according to the force distribution; S3. Construct an eddy current field distribution model based on the flow velocity field and temperature field; S4. Optimize the electromagnetic stirring force field of the molten pool according to the eddy current field; S5. Adjust the arc scanning mode based on the optimized electromagnetic stirring force field; S6. Perform real-time control of arc scanning based on dynamic flow feedback.

2. The intelligent control method for the stirring intensity of titanium alloy VAR melting according to claim 1, characterized in that, During the VAR melting process in step S1, the stirring force in the molten pool is the core physical quantity affecting the quality of the final ingot. The stirring force received by the molten pool includes: electromagnetic force, thermal convection force, and arc pressure.

3. An intelligent control method for the stirring intensity of VAR melting of titanium alloy according to claim 1, characterized in that, In step S2, its flow characteristics are described by the unsteady incompressible Navier-Stokes equation, and its formula model is: ； Among them, is the density of the molten pool metal; is the physical time during the bath smelting process; is the molten pool flow velocity field; is the internal pressure of the molten pool; is the kinematic viscosity; is the acceleration due to gravity; is the volume-averaged force density.

4. An intelligent control method for the stirring intensity of VAR melting of titanium alloy according to claim 1, characterized in that, In the step S3, based on the magnetohydrodynamics theory, considering the influence of the temperature gradient on the induced current and the magnetic induction field, a calculation model of the eddy current field is constructed. According to the electrical conductivity of the material and the magnetic permeability showing spatial inhomogeneity, a temperature gradient correction term is introduced in the calculation of the eddy current field; Influence of the gradient of conductivity: ； Among them, is the molten pool temperature; as the reference temperature conductivity under; is the temperature coefficient of change of the conductivity; According to the influence of temperature on the induced current density, correct the induced current density: ； Among them, refers to the internal electric field of the molten pool; refers to the magnetic field inside the molten pool; refers to the change in the conductivity of a material with temperature; is the corrected induced current density; The first item is the standard induced current calculation formula; The second item Indicates the influence of the temperature gradient on the induced current.

5. An intelligent control method for the stirring intensity of titanium alloy VAR melting, according to claim 2, characterized in that In step S3, introduce the magnetic induction equation. In the standard magnetic induction equation, the distribution of eddy currents is determined by the curl of the current density: ； Among them, is the induced current density, is the change in magnetic permeability caused by the change in temperature; Based on the local conductivity change caused by the temperature gradient, introduce a correction term into this equation: ； Among them, the additional correction term reflects the influence of the change in temperature gradient on the local induced magnetic field.

6. The intelligent control method for the stirring intensity of titanium alloy VAR melting according to claim 2, characterized in that, In step S3, based on the influence of the conductivity gradient, the correction of the induced current density, and the magnetic induction equation, this step has the following calculation process: Input the temperature field and velocity field calculated in step S2 into the formula, and calculate the temperature gradient and correct the conductivity distribution ; Introduce the gradient term of conductivity with respect to temperature , and calculate the corrected induced current density ; Solve the eddy current field using the corrected magnetic induction equation ; Output the eddy current field distribution and use it in step S4 to optimize the electromagnetic stirring scheme.

7. An intelligent control method for the stirring intensity of VAR melting of titanium alloy according to claim 1, characterized in that, In step S4, solve the electromagnetic force field and optimize the electromagnetic stirring scheme, including the calculation of the electromagnetic force field. The core acting force of electromagnetic stirring comes from the Lorentz force: 。 8. An intelligent control method for the stirring intensity of titanium alloy VAR melting, according to claim 5, characterized in that In step S4, optimize the electromagnetic stirring distribution in combination with the temperature gradient: The flow inside the molten pool is driven by the electromagnetic force and is expressed by the momentum equation as: ； To make the distribution of the electromagnetic stirring force field more uniform in different regions, a flow field correction coefficient is introduced for adjustment: ； where Correction factor Determined by the flow velocity deviation: ； Among them, is an adjustment coefficient to control the correction intensity; Represents the velocity gradient of the local flow field and is used to adjust the magnitude of the electromagnetic force; Normalization term Vary the correction factor between 0 and 1.

9. The intelligent control method for stirring intensity in VAR melting of titanium alloy according to claim 5, characterized in that, Step S4 has the following calculation process: Input the eddy current field calculated in step S3 into the formula and the corrected induced current density to calculate the electromagnetic force field ; Analyze the electromagnetic force field On the flow velocity field of the molten pool The influence of, calculate the correction coefficient ; Calculated optimized electromagnetic stirring force field and is used to adjust the arc scanning mode in step S5.

10. An intelligent control method for the stirring intensity of titanium alloy VAR melting, according to claim 1, characterized in that, In step S5, the adjustment of the arc scanning mode needs to meet the stability requirements of the molten pool flow, and a correction equation based on the balance of electromagnetic force and surface tension is adopted: ； wherein, is the thermal conductivity; is the surface tension coefficient; is the height disturbance of the molten pool surface.

Images