Method, system and electronic instrument for calculating ferrite content in cast iron parts

Abstract

The present invention provides a method, a system and an electronic instrument for calculating the ferrite content in cast iron parts. The method for calculating the ferrite content in cast iron parts includes the following processes: obtaining multiple material samples of the cast iron part to be measured; heating the multiple material samples to 900 degrees Celsius at the same speed and cooling them to 300 degrees Celsius at different fixed cooling speeds; S3 obtaining a cooling speed coefficient and multiple cooling coefficient parameters according to the fixed cooling speed of each material sample, and constructing a cooling coefficient equation according to the multiple cooling coefficient parameters; obtaining the temperature-time change curve of the cast iron part to be measured; according to the temperature-time change curve, using the cooling coefficient equation and a preset ferrite generation rate equation, obtaining the change curve of the ferrite generation rate with time in the cast iron part to be measured; integrating the ferrite generation rate in the time interval when the ferrite generation rate occurs to obtain the content of the ferrite matrix in the cast iron part. It solves the problem that the ferrite content in cast iron parts cannot be accurately calculated in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of casting processes, and in particular to a method, system, and electronic instrument for calculating the ferrite content in cast iron parts. Background Art

[0002] The matrix structure of cast iron parts is mainly divided into ferrite and pearlite, and their proportions play a crucial role in the performance of cast iron parts. In the production of cast iron parts, strict requirements are imposed on the matrix structure. Due to the slow cooling rate of large cast iron parts, the cooling rate has a direct impact on the precipitation ratio of ferrite, and the proportion of ferrite directly affects the formulation of subsequent heat treatment processes. However, in the commonly used measurement methods, it is impossible to accurately calculate the ferrite content in cast iron parts, resulting in defects such as sand sticking and shrinkage porosity in cast iron parts, and reducing the overall performance of cast iron parts. Therefore, there is a need to provide a method, system, and electronic instrument for calculating the ferrite content in cast iron parts. Summary of the Invention

[0003] In view of the deficiencies and defects in the prior art, the present invention provides a method, system, and electronic instrument for calculating the ferrite content in cast iron parts to improve the problem that the ferrite content in cast iron parts cannot be accurately calculated in the prior art.

[0004] To achieve the above object and other related objects, the present invention provides a method for calculating the ferrite content in cast iron parts, including the following processes:

[0005] S1. Obtain multiple material samples of the cast iron part to be measured;

[0006] S2. Heat the multiple material samples to 900 degrees Celsius at the same speed and cool them to 300 degrees Celsius at different cooling rates;

[0007] S3. Obtain a cooling rate coefficient and multiple cooling coefficient parameters according to the cooling rate of each material sample, and construct a cooling coefficient equation according to the multiple cooling coefficient parameters;

[0008] S4. Obtain the temperature-time change curve of the cast iron part to be measured;

[0009] S5. According to the temperature-time change curve, use the cooling coefficient equation and a preset ferrite generation rate equation to obtain the change curve of the ferrite generation rate over time in the cast iron part to be measured;

[0010] S6. Integrate the ferrite generation rate over the time interval during which the ferrite generation rate occurs to obtain the content of the ferrite matrix in the cast iron part.

[0011] In an embodiment of the present invention, the multiple material samples meet the test requirements of a differential scanning calorimeter device.

[0012] In an embodiment of the present invention, S3 includes the following processes:

[0013] Obtain the cooling rate coefficient of the current material specimen according to the cooling rate of the current material specimen;

[0014] Using the method of mathematical regression for the cooling rate coefficients of each material specimen, solve the first cooling coefficient parameter, the second cooling coefficient parameter, and the third cooling coefficient parameter, and construct the cooling coefficient equation a = αv 2 +βv + γ, where a is the cooling rate coefficient of the current material specimen, v is the cooling rate of the current material specimen, α is the first cooling coefficient parameter, β is the second cooling coefficient parameter, and γ is the third cooling coefficient parameter.

[0015] In an embodiment of the present invention, S5 includes the following processes:

[0016] S51. Obtain the temperature and the slope of each point in the temperature change curve over time, and obtain the cooling coefficient of each point according to the cooling coefficient equation;

[0017] S52. Obtain the ferrite formation rate of each point through the ferrite formation rate equation according to the temperature of each point and the cooling coefficient of each point;

[0018] S53. Obtain the change curve of the ferrite formation rate over time in the cast iron part to be measured according to the ferrite formation rate and time of each point.

[0019] In an embodiment of the present invention, the content calculation formula of the ferrite matrix in the cast iron part is: where F is the content of the ferrite matrix in the cast iron part, is the ferrite formation rate at the t-th moment, t begin is the starting time, t end is the ending time.

[0020] In an embodiment of the present invention, the number of the material specimens is 6.

[0021] In an embodiment of the present invention, when the cast iron part to be measured is a large nodular cast iron wind power hub casting, α = -32.2, β = 907.35, and γ = 25.24.

[0022] In an embodiment of the present invention, the method for obtaining the temperature change curve over time is: perform 3D modeling and solidification simulation on the shape of the cast iron part to be measured, monitor the area where the ferrite formation rate needs to be measured and controlled, and obtain and save the temperature change curve over time of the area where the ferrite formation rate is measured and controlled.

[0023] In an embodiment of the present invention, there is also provided a system for calculating the ferrite content in a cast iron part, the system comprising:

[0024] A material acquisition module for acquiring multiple material samples of the cast iron part to be measured;

[0025] A cooling module for heating the multiple material samples to 900 degrees Celsius at the same speed and cooling them to 300 degrees Celsius at different cooling speeds;

[0026] A cooling coefficient equation parameter calculation module for obtaining a cooling speed coefficient and a plurality of cooling coefficient parameters according to the cooling speed of each material sample, and constructing a cooling coefficient equation according to the plurality of cooling coefficient parameters;

[0027] A temperature versus time curve acquisition module for obtaining a temperature versus time curve in the cast iron part to be measured;

[0028] A ferrite generation rate versus time curve acquisition module for obtaining a curve of the change of the ferrite generation rate with time in the cast iron part to be measured according to the temperature versus time curve, using the cooling coefficient equation and a preset ferrite generation rate equation;

[0029] A ferrite content calculation module for integrating the ferrite generation rate over the time interval during which the ferrite generation rate occurs to obtain the content of the ferrite matrix in the cast iron part.

[0030] In an embodiment of the present invention, there is also provided an electronic instrument, which, when measuring a cast iron part using the electronic instrument, causes the electronic instrument to execute the method for calculating the ferrite content in a cast iron part described in any one of the above.

[0031] In summary, the present invention provides a method, a system and an electronic instrument for calculating the ferrite content in a cast iron part. By cooling multiple obtained material samples at different cooling speeds respectively, three cooling coefficient parameters are obtained, and a cooling coefficient equation is constructed. Then, a temperature versus time curve in the cast iron part to be measured is obtained, and according to this temperature versus time curve, each temperature and the corresponding time are selected. By measuring the cooling rate of the cast iron part at the current temperature, the cooling speed coefficient corresponding to each time is obtained. By calculating the generation rate of ferrite at the current moment. Integrating the ferrite generation rate over the time interval during which the reaction occurs, the content of the ferrite matrix in the cast iron part at the final location is obtained. The problem of inaccurate calculation of the ferrite content in large cast iron parts is solved. By formulating a reasonable heat treatment process, a ferrite ratio meeting the requirements can be obtained with the most reasonable energy consumption, the ferrite content in the cast iron part can be accurately predicted, and thus a cast iron part with performance meeting the requirements can be obtained. The objectives and optimization directions for process parameter control are provided. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0033] Figure 1 It shows a schematic flowchart of a method for calculating the ferrite content in cast iron parts in an embodiment of the present invention;

[0034] Figure 2 It shows a schematic flowchart of step S3 in an embodiment of the present invention;

[0035] Figure 3 It shows a schematic flowchart of step S5 in an embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram of the principle structure of a system for calculating the ferrite content in cast iron parts in an embodiment of the present invention. Detailed implementation manners

[0037] The following uses specific specific examples to illustrate the implementation manners of the present invention. 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 implementation manners. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope of implementation of the present invention.

[0038] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although only the components related to the present invention are shown in the diagrams and are not drawn according to the number, shape and size of the components in actual implementation, the form, quantity and proportion of each component in actual implementation can be arbitrarily changed, and the component layout form may also be more complex.

[0039] Please refer to Figure 1 , Figure 1Schematic flow chart of a method for calculating the ferrite content in a cast iron part in an embodiment of the present invention. The present invention provides a method for calculating the ferrite content in a cast iron part. By cooling multiple obtained material specimens at different cooling rates respectively, three cooling coefficient parameters are obtained, and a cooling coefficient equation is constructed. Then, the temperature-time change curve of the cast iron part to be measured is obtained, and each temperature and the corresponding time are selected according to the temperature-time change curve. By measuring the cooling rate of the cast iron part at the current temperature, the cooling rate coefficient corresponding to each time is obtained. By calculating the generation rate of ferrite at the current moment. Integrating the ferrite generation rate over the time interval during which the reaction occurs, the content of the ferrite matrix in the cast iron part at the final location is obtained. The problem of inaccurate calculation of the ferrite content in large cast iron parts is solved. By formulating a reasonable heat treatment process, the required ferrite ratio is obtained with the most reasonable energy consumption, and the ferrite content in the cast iron part can be accurately predicted, so as to obtain a cast iron part with performance meeting the requirements. The goal and optimization direction of process parameter control are provided.

[0040] Please refer to Figure 1 , the present invention provides a method for calculating the ferrite content in a cast iron part, including the following processes:

[0041] S1. Obtain multiple material specimens of the cast iron part to be measured.

[0042] In order to obtain the ferrite content in the cast iron part and adjust the relevant process parameters in a timely manner according to the ferrite content, and provide the goal and optimization direction for the process parameter control, it is first necessary to prepare samples of the materials used in the cast iron part to be measured to obtain multiple material specimens. In an embodiment of the present invention, the multiple material specimens meet the test requirements of a differential scanning calorimeter (DSC). Optionally, the material specimens can be of any size and shape that meet the test requirements of the used differential scanning calorimeter equipment, and the specific size and shape are not limited. It can be understood that the number of material specimens can be adaptively selected by those skilled in the art according to the measurement accuracy requirements and is not limited here. Considering both the measurement accuracy and the measurement efficiency, in an embodiment of the present invention, 6 material specimens are used.

[0043] S2. Heat the multiple material specimens to 900 degrees Celsius at the same speed and cool them to 300 degrees Celsius at different fixed cooling rates.

[0044] At the same heating rate, the six material samples obtained above are heated to 900 degrees Celsius, and then the temperature of each material sample is controlled using a differential heat scanner to steadily decrease from above the austenite temperature to the phase change stop temperature at multiple different fixed cooling rates. Specifically, in an embodiment of the present invention, the multiple different fixed cooling rates are respectively 3 K / min (i.e., 3 Kelvin per minute), 5 K / min, 10 K / min, 15 K / min, 20 K / min, and 25 K / min. It should be noted that in this application, for the fixed cooling rate, various methods can be adopted, including but not limited to arithmetic progressions, actual common cooling rate lists, etc.

[0045] S3. Obtain a cooling rate coefficient and multiple cooling coefficient parameters according to the fixed cooling rate of each material sample, and construct a cooling coefficient equation based on the multiple cooling coefficient parameters.

[0046] Specifically, please refer to Figure 2 , Figure 2 which shows a schematic flow chart of step S3 in an embodiment of the present invention. In an embodiment of the present invention, step S3 includes the following processes:

[0047] S31. Obtain the cooling rate coefficient of the current material sample according to the fixed cooling rate of the current material sample;

[0048] S32. Use mathematical regression on the cooling rate coefficients of each material sample to solve for the first cooling coefficient parameter, the second cooling coefficient parameter, and the third cooling coefficient parameter, and construct a cooling coefficient equation a = αv 2 + βv + γ, where a is the cooling rate coefficient of the current material sample, v is the cooling rate of the current material sample, α is the first cooling coefficient parameter, β is the second cooling coefficient parameter, and γ is the third cooling coefficient parameter.

[0049] Calculate the cooling rate coefficient of the current material sample according to the fixed cooling rate of the current material sample according to the cooling coefficient equation formula (1),

[0050] a = αv 2 + βv + γ (1)

[0051] Wherein, a is the cooling rate coefficient of the current material sample, v is the cooling rate of the current material sample, α is the first cooling coefficient parameter, β is the second cooling coefficient parameter, and γ is the third cooling coefficient parameter. Since α, β, and γ are unknown parameters in the cooling coefficient equation, the calculated cooling rate coefficients of each material sample are expressions containing the above three unknown parameters. Considering the possibility of equivalent equations, 6 material samples are used in this application to obtain 6 cooling coefficient equations. According to the standard of GB / T 9441-2009 "Metallographic Inspection of Ductile Iron", measure the total final increment of ferrite in the sample and substitute it back into the above formula (1) to determine the value of each cooling rate coefficient a. By means of mathematical statistical regression of different cooling rates v and the corresponding cooling rate coefficients a, the specific values of α, β, and γ that meet the accuracy can be obtained, and according to the obtained specific values of α, β, and γ, a cooling coefficient equation is constructed. At this time, only the cooling rate is the unknown in the cooling coefficient equation.

[0052] It should be noted that since the above α, β, and γ are related to factors such as the type and performance of the material, in order to improve the accuracy of ferrite measurement, for different materials, it is necessary to measure again to determine the values of the three parameters α, β, and γ of the current material. However, for a specific material, it can be measured only once. For the same or other materials with similar physical properties, the previously determined parameters can be directly cited without having to re-measure and determine. Therefore, this measurement method not only greatly improves the measurement efficiency but also improves the accuracy of measuring the ferrite content.

[0053] Further, as an alternative implementation manner, in the above formula (1), for large ductile iron wind power hub castings, a parameter combination that can be directly obtained through experiments is α = -32.2, β = 907.35, γ = 25.24, or other parameter combinations obtained through the subsequent cooling rate parameter coefficient determination method.

[0054] S4. Obtain the temperature-time change curve of the cast iron part to be measured.

[0055] Using simulation or measurement methods, obtain the temperature-time change curve of the part to be calculated of the cast iron part to be measured. Specifically, in order to obtain a more accurate temperature change curve and provide reliable data support for the subsequent calculation of ferrite, in an embodiment of the present invention, the method for obtaining the temperature-time change curve is as follows: perform 3D modeling and solidification simulation on the shape of the cast iron part to be measured, monitor the area where the ferrite formation rate needs to be measured and controlled, and obtain and save the temperature-time change curve of the area where the ferrite formation rate is measured and controlled. Further, considering that although the above operations can obtain a relatively accurate temperature-time change curve, it takes a long time. Therefore, in another embodiment of the present invention, the temperature-time change curve can also be actually measured by means of thermocouples or infrared measurement. Those skilled in the art can comprehensively consider the above multiple factors, balance efficiency and accuracy, and adaptively select a suitable scheme for obtaining the temperature-time change curve according to their own needs, which is not limited here.

[0056] S5. According to the temperature-time change curve, use the cooling coefficient equation and the preset ferrite generation rate equation to obtain the change curve of the ferrite generation rate with time in the cast iron part to be measured.

[0057] Specifically, please refer to Figure 3 , Figure 3 which shows the flow schematic diagram of step S5 in an embodiment of the present invention. In an embodiment of the present invention, step S5 includes the following processes:

[0058] S51. Obtain the temperature of each point and the slope of each point in the temperature-time change curve, and obtain the cooling coefficient of each point according to the cooling coefficient equation.

[0059] S52. According to the temperature of each point and the cooling coefficient of each point, obtain the ferrite generation rate of each point through the ferrite generation rate formula.

[0060] S53. According to the ferrite generation rate of each point and time, obtain the change curve of the ferrite generation rate with time in the cast iron part to be measured.

[0061] Successively substitute the temperature of each point and the corresponding slope in the temperature-time change curve of the cast iron part to be measured, and measure the cooling rate of each point into the above cooling coefficient equation (1) to obtain the cooling coefficient corresponding to each point. It can be understood that the measurement methods of the cooling rate include, but are not limited to, direct measurement using thermocouples, non-contact measurement such as infrared temperature measurement, or obtaining the cooling rate by numerical simulation.

[0062] Substitute the cooling coefficient corresponding to each point and the temperature of this point into the ferrite generation rate formula (2) to obtain the ferrite generation rate corresponding to each point:

[0063]

[0064] Among them, is the ferrite formation rate at time t, with the unit of % / s, Q is the rate parameter, taking the value of 88.77 kJ / mol, R is the ideal gas constant, and t is the temperature corresponding to the current cooling coefficient. By statistically analyzing the ferrite formation rate at each point and the corresponding time, the variation curve of the ferrite formation rate with time in the cast iron part to be measured can be obtained.

[0065] S6. Integrate the ferrite formation rate over the time interval during which the ferrite formation rate occurs to obtain the content of the ferrite matrix in the cast iron part.

[0066] According to the time interval during which the ferrite formation rate occurs, substitute the ferrite formation rate at each point into the ferrite content formula (3), and integrate the ferrite formation rate to obtain the content of the ferrite matrix in the cast iron part to be measured:

[0067]

[0068] Among them, F is the content of the ferrite matrix in the cast iron part, t begin is the starting time, and t end is the ending time. Further, the ferrite growth percentage can also be obtained, thereby guiding the control of process parameters. As an alternative implementation, the above integral solving method includes: numerical solving by means of other software with numerical solving functions, and substituting the simplified result after directly performing a definite integral on the equation into the data.

[0069] Please refer to Figure 4 , Figure 4Schematic diagram of the principle structure of a system for calculating the ferrite content in cast iron parts in an embodiment of the present invention. In an embodiment of the present invention, a system 1 for calculating the ferrite content in cast iron parts is further provided, including a material acquisition module 11, a cooling module 12, a cooling coefficient equation parameter calculation module 13, a temperature change curve acquisition module 14, a ferrite generation rate change curve acquisition module 15, and a ferrite content calculation module 16. Among them, the above-mentioned material acquisition module 11 is used to acquire multiple material samples of the cast iron part to be tested; the above-mentioned cooling module 12 is used to heat the multiple material samples to 900 degrees Celsius at the same speed and cool them to 300 degrees Celsius at different cooling speeds; the above-mentioned cooling coefficient equation parameter calculation module 13 is used to obtain a cooling speed coefficient and multiple cooling coefficient parameters according to the cooling speed of each material sample, and construct a cooling coefficient equation according to the multiple cooling coefficient parameters; the above-mentioned temperature change curve acquisition module 14 is used to obtain the temperature change curve with time in the cast iron part to be tested; the above-mentioned ferrite generation rate change curve acquisition module 15 is used to obtain the change curve of the ferrite generation rate with time in the cast iron part to be tested according to the temperature change curve with time, using the cooling coefficient equation and a preset ferrite generation rate equation; the above-mentioned ferrite content calculation module 16 is used to integrate the ferrite generation rate in the time interval when the ferrite generation rate occurs to obtain the content of the ferrite matrix in the cast iron part.

[0070] In an embodiment of the present invention, an electronic instrument with differential scanning calorimetry function is further provided, and its function is to precisely control the temperature change and be able to monitor the change of the required heating power.

[0071] It should be noted that, in order to highlight the innovative part of the present invention, modules that are not closely related to solving the technical problems proposed by the present invention are not introduced in this embodiment, but this does not mean that there are no other modules in this embodiment.

[0072] In addition, those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described system can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here. In the embodiments provided by the present invention, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces, and the indirect coupling or communication connection of devices or units can be in electrical, mechanical or other forms.

[0073] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] In addition, in each embodiment of the present invention, the functional modules can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional units.

[0075] In summary, for a specific part of the casting product to be produced in the cast iron production process, this part is filled with molten cast iron metal during the filling stage, and it should solidify into a perfect casting without casting defects in the design. The ferrite content in the final casting can be calculated through changes in the cooling parameters during the solidification process, or the control target of the solidification parameters can be deduced from the process target ferrite content. The ferrite content in the cast iron can be accurately predicted, thereby providing the target and optimization direction for process parameter control. It can be widely applied to the parameter control of process production lines that require the ferrite content in cast iron. Therefore, the present invention has high utilization value and practical significance.

[0076] The above embodiments are only illustrative of the principles and effects of the present invention and are not used 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 made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for calculating the ferrite content in cast iron parts, characterized in that, It includes the following processes: S1. Obtain multiple material samples of the cast iron part to be tested; S2. Heat the multiple material samples to 900 degrees Celsius at the same speed and cool them to 300 degrees Celsius at different fixed cooling speeds; S3. Obtain the cooling rate coefficient and multiple cooling coefficient parameters according to the fixed cooling speed of each material sample, and construct a cooling coefficient equation based on the multiple cooling coefficient parameters; S4. Obtain the curve of the temperature of the cast iron part to be tested changing with time; S5. According to the curve of the temperature changing with time, use the cooling coefficient equation and the preset ferrite formation rate equation to obtain the curve of the ferrite formation rate changing with time in the cast iron part to be tested; S6. Integrate the ferrite formation rate in the time interval when the ferrite formation rate occurs to obtain the content of the ferrite matrix in the cast iron part to be tested.

2. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, The multiple material samples meet the test requirements of the differential scanning calorimeter equipment.

3. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, S3 includes the following processes: S31. Obtain the cooling rate coefficient of the current material sample according to the fixed cooling speed of the current material sample; S32. Using the method of mathematical regression for the cooling rate coefficients of each material sample, solve the first cooling coefficient parameter, the second cooling coefficient parameter, and the third cooling coefficient parameter, and construct a cooling coefficient equation \(a = \alpha v\) 2 + \(\beta v+\gamma\), where \(a\) is the cooling rate coefficient of the current material sample, \(v\) is the cooling rate of the current material sample, \(\alpha\) is the first cooling coefficient parameter, \(\beta\) is the second cooling coefficient parameter, and \(\gamma\) is the third cooling coefficient parameter.

4. The method for calculating the ferrite content in cast iron parts according to claim 3, characterized in that, When the cast iron part to be tested is a large nodular iron wind power hub casting, α = -32.2, β = 907.35, γ = 25.

24.

5. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, The way to obtain the curve of the temperature changing with time is: perform 3D modeling and solidification simulation on the shape of the cast iron part to be tested, monitor the area where the ferrite formation rate needs to be measured and controlled, and obtain and save the curve of the temperature of the area where the ferrite formation rate is measured and controlled changing with time.

6. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, S5 includes the following processes: S51. Obtain the temperature of each point and the slope of each point in the curve of the temperature changing with time, and obtain the cooling coefficient of each point according to the cooling coefficient equation; S52. According to the temperature of each point and the cooling coefficient of each point, obtain the ferrite formation rate of each point through the ferrite formation rate equation; S53. According to the ferrite formation rate of each point and time, obtain the curve of the ferrite formation rate changing with time in the cast iron part to be tested.

7. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, The calculation method for the content of the ferrite matrix in the cast iron part to be measured is as follows: where F is the content of the ferrite matrix in the cast iron part to be measured, is the ferrite formation rate at the t-th moment, and t begin is the starting time, and t end is the ending time.

8. The method for calculating the ferrite content in cast iron parts according to claim 1, characterized in that, The number of the material samples is 6.

9. A system for calculating the ferrite content in cast iron parts, characterized in that, The system includes: A material acquisition module, which is used to obtain multiple material samples of the cast iron part to be tested; A cooling module, which is used to heat the multiple material samples to 900 degrees Celsius at the same speed and cool them to 300 degrees Celsius at different cooling speeds; A cooling coefficient equation parameter calculation module, which is used to obtain the cooling rate coefficient and multiple cooling coefficient parameters according to the cooling speed of each material sample, and construct a cooling coefficient equation based on the multiple cooling coefficient parameters; A temperature-time curve acquisition module, which is used to obtain the curve of the temperature in the cast iron part to be tested changing with time; A ferrite formation rate-time curve acquisition module, which is used to obtain the curve of the ferrite formation rate changing with time in the cast iron part to be tested according to the curve of the temperature changing with time, using the cooling coefficient equation and the preset ferrite formation rate equation; A ferrite content calculation module, which is used to integrate the ferrite formation rate in the time interval when the ferrite formation rate occurs to obtain the content of the ferrite matrix in the cast iron part to be tested.

10. An electronic instrument, characterized in that, When using the electronic instrument to measure a cast iron part, the electronic instrument is made to execute the method for calculating the ferrite content in the cast iron part according to any one of claims 1-8.

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