Method and apparatus for smelting of casting iron melt for ADI spheroidal graphite cast iron casting forming

Abstract

The application relates to the technical field of molten iron smelting, in particular to a casting molten iron smelting method and device for ADI nodular cast iron casting forming, which comprises the following steps: acquiring the spheroidizing agent adding speed in the spheroidizing reaction process and the molten iron temperature data in the spheroidizing reaction process according to the spheroidizing process flow of the ADI casting molten iron smelting; analyzing the discontinuous change difference values of various monitoring data in the spheroidizing process, acquiring the control bias characteristic values of various monitoring data in the spheroidizing process and the judgment coefficients of feedback error adjustment, and using the control bias characteristic values and the judgment coefficients to regulate various monitoring data in the spheroidizing process; analyzing the compensation coefficients of various monitoring data in the spheroidizing process to adjust the stirring intensity current in the inoculation process stage of the ADI casting molten iron smelting; after the inoculation process, the molten iron composition is rechecked, the deslagging agent is added after the molten iron is placed in the pouring ladle, the floating dross is removed, and the molten iron is poured out. The application can precisely control the casting molten iron smelting process and improve the molten iron smelting quality.

Description

Technical Field

[0001] The present application relates to the technical field of molten iron smelting, and in particular to a method and apparatus for smelting molten iron for ADI ductile iron casting. Background Art

[0002] In the casting process of ADI ductile iron, the quality of the smelting process is directly related to key indicators such as the uniformity of the chemical composition of the molten iron, the graphite spheroidization rate, and the impurity content. If the molten iron composition is not properly controlled (for example, the carbon and silicon content exceed the specified range), the graphite morphology will deteriorate; insufficient spheroidization or inoculation treatment will reduce the toughness of the cast iron, and may even prevent the formation of the ideal ausbainite structure after heat treatment, ultimately affecting the mechanical properties of ADI and the qualified rate of finished products.

[0003] Currently, PLC control systems enable real-time monitoring of process parameter changes during the casting iron smelting process, allowing precise adjustment of parameters such as addition amount, temperature, and stirring intensity, effectively improving smelting efficiency and stability. However, current automated smelting technology struggles to achieve precise control when dealing with large fluctuations in the spheroidizing reaction during the spheroidizing inoculation process. This results in poor smelting quality consistency, failing to meet the molten iron quality requirements for ADI ductile iron applications, and consequently impacting the quality of subsequent ductile iron castings. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a method and apparatus for smelting molten iron for ADI ductile iron casting. The technical solutions adopted are as follows:

[0005] The present application provides a method for smelting molten iron for ADI ductile iron casting, comprising the following steps:

[0006] For the spheroidization process of ADI foundry iron smelting, various monitoring data during the spheroidization reaction are obtained, including the spheroidizing agent addition rate and the molten iron temperature data during the spheroidization reaction;

[0007] The sliding window sizes of various monitoring data are set based on the distribution of changes in various monitoring data. Based on the data differences of various monitoring data in different sliding windows, the discontinuous change difference values ​​of various monitoring data in each sliding window are obtained. Based on the degree of difference between the monitoring data and the preset standard parameter values ​​in the sliding windows of various monitoring data, the control deviation characteristic values ​​of various monitoring data in the spheroidization process are obtained in combination with the discontinuous change difference values. Based on the differences between the various monitoring data and the standard parameter values, the judgment coefficients for feedback error adjustment of various monitoring data are obtained, so as to extract the feedback error characteristic values ​​corresponding to various monitoring data in the spheroidization process, which are used to control various monitoring data in the spheroidization process.

[0008] Based on the average level of the feedback error characteristic values ​​corresponding to various monitoring data during the spheroidization process, the compensation coefficients of various monitoring data during the spheroidization process are obtained. According to the average level of the compensation coefficients of all monitoring data during the spheroidization process, the stirring intensity and current of the ADI casting molten iron smelting inoculation stage are adjusted. After the inoculation treatment, the composition of the molten iron is re-inspected, and the slag remover is added after the molten iron is allowed to stand in the ladle. The slag is removed before pouring.

[0009] Preferably, the setting of the sliding window size of the various monitoring data further includes: arranging the various monitoring data obtained at the current moment and before in chronological order and extracting the extreme values ​​of each monitoring data; for various monitoring data, counting the average value of the number of interval data between any two adjacent extreme values; and rounding up the average value as the sliding window size of the various monitoring data.

[0010] Preferably, the method for obtaining the difference values ​​of the intermittent changes of the various monitoring data in each sliding window is:

[0011] ;in, Indicates that the t-th monitoring data is in The difference value of discontinuous changes in a sliding window; Indicates that the t-th monitoring data is in and DTW distance of data in a sliding window; Indicates the tth type of monitoring data and The cosine similarity between the feature vectors of the discontinuous changes in the sliding window data, represents an exponential function with a natural constant as base, Indicates the number of sliding windows for the t-th type of monitoring data.

[0012] Preferably, the acquisition of the characteristic vector further includes: for various monitoring data, calculating the range, mean, variance of the monitoring data in the sliding window, as well as the mean and variance of the difference between the various monitoring data and their preset standard parameter values, and the calculation results together constitute the characteristic vectors of the discontinuous changes in the sliding window data of various monitoring data.

[0013] Preferably, the method for obtaining the control deviation characteristic values ​​of various monitoring data during the spheroidization process is:

[0014] ;

[0015] in, Indicates the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process; Indicates the tth type of monitoring data The mean of the difference between each data in the sliding window and the preset standard parameter value; and Respectively represent the tth type of monitoring data and The difference value of the discontinuous change of the sliding window; n represents the number of sliding windows of the t-th type of monitoring data.

[0016] Preferably, the method for obtaining the judgment coefficient for adjusting the feedback error of the various monitoring data is:

[0017] ;in, It represents the judgment coefficient of the error adjustment of the t-th monitoring data feedback at the current moment, It represents the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process, Indicates the difference between the t-th monitoring data at the current moment and its standard parameter value.

[0018] Preferably, the step of extracting the feedback error characteristic values ​​corresponding to various monitoring data during the spheroidization process further includes:

[0019] Preset judgment coefficient threshold ,when and When , the control deviation characteristic value of the t-th monitoring data at the current moment is recorded as the feedback error characteristic value corresponding to the t-th monitoring data at the current moment, and is used as the feedback error to regulate the t-th monitoring data during the spheroidization process.

[0020] Preferably, the method for obtaining the compensation coefficients of various monitoring data during the spheroidization process is:

[0021] The average value of the normalized results of all feedback error characteristic values ​​extracted from various monitoring data in the spheroidization process at the current moment and before is used as the compensation coefficient of various monitoring data in the spheroidization process.

[0022] Preferably, the adjusting of the stirring intensity current during the ADI cast iron molten smelting and inoculation treatment stage further comprises:

[0023] The calculation formula for the adjusted stirring intensity current value is: ;in, Indicates the adjusted stirring intensity current value; represents the initial value of the stirring intensity current, It represents the mean value of the compensation coefficient of all monitoring data during the spheroidization process.

[0024] An embodiment of the present application also provides a cast iron smelting device for ADI ductile iron casting molding, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-mentioned cast iron smelting methods for ADI ductile iron casting molding.

[0025] As can be seen from the above, the method and apparatus for smelting molten iron for ADI ductile iron casting provided in this application have at least the following beneficial effects:

[0026] This application takes into account that in the casting process of ADI ductile iron, the smelting of cast iron is a key basic step that determines the quality of ductile iron. In the production control of the traditional smelting process, the influence of the fluctuation of the spheroidization reaction on the parameter control is not fully considered during the spheroidization inoculation stage, resulting in a large deviation in the actual control. Therefore, this application analyzes the characteristics of the phased parameter changes of the monitoring data collected during the spheroidization inoculation treatment stage, accurately extracts the control deviation caused by the dynamic changes of the spheroidization reaction in the actual control process, and optimizes and adjusts the feedback error in the spheroidization treatment process based on the extraction results;

[0027] The present application further considers the coupling characteristics between the spheroidization and inoculation treatment stages, and adaptively compensates and adjusts the stirring intensity of the inoculation treatment stage according to the adjustment results of the spheroidization treatment stage. The beneficial effect is that it fully considers the coupling relationship of the spheroidization and inoculation treatment in the actual control process, implements the joint adjustment of precise optimization control and compensation of the spheroidization and inoculation treatment processes, thereby achieving precise control of the casting molten iron smelting process and improving the molten iron smelting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 This is a flow chart of the steps of the molten iron smelting method for ADI ductile iron casting provided in this application. DETAILED DESCRIPTION

[0030] To further illustrate the technical means and effects employed by this application to achieve the intended invention objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the method and apparatus for smelting molten iron for ADI ductile iron casting according to this application, including its specific implementation, structure, features, and effects. In the following description, references to different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0031] Unless otherwise specified and limited, terms such as "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the article or device comprising the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items. All technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs.

[0032] The specific scheme of the casting iron smelting method and device for ADI ductile iron casting provided by this application is described in detail below with reference to the accompanying drawings.

[0033] See also Figure 1 , which shows a flowchart of the steps of a method for smelting molten iron for ADI ductile iron casting provided by one embodiment of the present application, comprising the following steps:

[0034] Step 1: For the spheroidization process of ADI foundry iron smelting, various monitoring data are obtained during the spheroidization reaction, including the spheroidizing agent addition rate and the molten iron temperature data during the spheroidization reaction.

[0035] In the present embodiment, the raw materials are first matched and melted, and the raw materials are matched according to a ratio of 55% to 70% pig iron, 20% to 30% scrap steel, and 10% to 15% recycled material. Preferably, in the present embodiment, the raw materials are 60% pig iron, 25% scrap steel, and 13% recycled material. The raw materials are rusted and degreased before entering the furnace, and the recycled material is crushed into 50-100mm blocks. The raw materials are put into a medium-frequency induction furnace, and the scrap steel and recycled material are added first, followed by the pig iron. The furnace power is adjusted by the PLC control system to raise the molten iron temperature to 1450-1550°C for melting. The melting time is about 2-5 hours. The medium-frequency induction furnace is equipped with a power of 500-2000kW and a frequency of 1-10kHz, adopts a magnesia lining, and an electromagnetic stirring coil is used to assist the raw materials in uniform melting. Preferably, in this embodiment, the temperature of the molten iron is raised to 1500°C, the melting time is 3 hours, the power of the medium frequency induction furnace is 1000kW and the frequency is 5kHz. In actual application scenarios, the embodiment can set the raw material ratio and the parameters of the melting process by itself, and there is no special restriction on this in this embodiment.

[0036] After the molten iron is melted, the composition is regulated. In this embodiment, a direct-reading spectrometer is used to detect the contents of elements such as C, Si, Mn, S, and P. Based on the test results, alloys such as ferrosilicon and ferromanganese are added through a screw conveyor automatic feeder to regulate the carbon content to 4.3% to 4.7% and the silicon content to 1.8% to 2.8% to ensure graphitization ability and heat treatment performance. Preferably, in this embodiment, the carbon content is 4.5% and the silicon content is 2.3%. In specific practical application scenarios, the implementer controls it by himself and no special restrictions are made here.

[0037] After further adjusting the composition, the spheroidization process during the ADI casting iron smelting process begins. In this embodiment, a spheroidizing agent is added to the molten iron via a cored wire feeder at a rate of 0.5-2 m / s. In this embodiment, the spheroidizing agent is magnesium alloy cored wire with a diameter of 10-12 mm and a magnesium content of 50%-60%. The amount added is 0.8%-1.2% of the molten iron's mass. Preferably, the magnesium alloy cored wire is added at a rate of 1 m / s, has a diameter of 11 mm, and a magnesium content of 55%, and the amount added is 1% of the molten iron's mass. Simultaneously, during the spheroidization reaction, the molten iron temperature is maintained at 1380-1450°C using an 80kW bottom electric heater. The addition of the spheroidizing agent converts the graphite into spherical shapes. The reaction temperature must be maintained at 1380-1450°C to prevent excessive magnesium burnout.

[0038] In the actual smelting of ADI cast iron, after the composition is adjusted, spheroidization is required. By adding spheroidizing elements to the molten iron, the graphite is transformed into spheres to improve the mechanical properties of the cast iron. During this process, the stability of the spheroidizing agent addition rate is crucial. Too fast a rate can lead to the escape of magnesium vapor, reduced absorption, and molten iron splashing; too slow a rate can lead to incomplete reaction, excessive temperature loss, and decreased spheroidization.

[0039] Therefore, in order to achieve precise control, various monitoring data during the spheroidization process are collected in real time. In this embodiment, the monitoring data include the spheroidizing agent addition rate and the molten iron temperature during the spheroidization reaction. The spheroidizing agent addition rate and the molten iron temperature during the spheroidization reaction are collected in real time through a speed sensor and a temperature sensor, which serve as the basic monitoring data for real-time optimization control of the spheroidization process.

[0040] Step 2: The sliding window size of various monitoring data is set according to the change distribution of various monitoring data. According to the data difference of various monitoring data in different sliding windows, the discontinuous change difference value of various monitoring data in each sliding window is obtained. According to the difference degree between the monitoring data and the preset standard parameter value in the sliding window of various monitoring data, combined with the said discontinuous change difference value, the control deviation characteristic value of various monitoring data in the spheroidization process is obtained. According to the difference between various monitoring data and the standard parameter value, the judgment coefficient of feedback error adjustment of various monitoring data is obtained, so as to extract the feedback error characteristic value corresponding to various monitoring data in the spheroidization process, which is used to control various monitoring data in the spheroidization process.

[0041] Furthermore, considering the dynamic coupling relationship between the addition of spheroidizing agent and temperature control during the spheroidizing process, that is, the bubbles generated by the spheroidizing reaction will increase the wire feeding resistance and cause the spheroidizing agent addition rate to decrease, while the local temperature difference caused by heat loss and heating system error will further affect the wire feeding resistance, ultimately leading to parameter control deviation and affecting the graphite refinement effect in the subsequent inoculation stage, in this embodiment, the real-time control process of the spheroidizing process is optimized:

[0042] (1) First, the speed and temperature data collected up to the current moment are denoised using a Wiener filter to eliminate the influence of environmental interference; the various monitoring data before and after denoising are arranged in time series to extract the extreme values ​​of each monitoring data; for various monitoring data, the number of interval data between adjacent extreme values ​​is counted, and the average value of all interval data is rounded up as the sliding window size of various monitoring data, that is, the sliding window for local feature analysis is determined based on the dynamic change characteristics of the data over time during the monitoring process, and then the local change characteristics of the monitoring data caused by the dynamic changes of the spheroidization reaction and environmental interference with the spheroidization process are accurately analyzed.

[0043] Based on the determined sliding window lengths for each monitoring data, the data discontinuity change characteristics of each type of monitoring data within its respective sliding windows are analyzed. In this embodiment, for each monitoring data, the range, mean, and variance of the monitoring data within the sliding window, as well as the mean and variance of the difference between the various monitoring data and their preset standard parameter values, are calculated. These together constitute the characteristic vectors of the data discontinuity change in each sliding window of the various monitoring data, which are used to reflect the dynamic impact characteristics of the spheroidization reaction on the control parameters. Since the speed and temperature changes at different stages of the spheroidization reaction process vary significantly, the local control differences under different processing processes are analyzed. That is, based on the data differences of the various monitoring data within different sliding windows, the data discontinuity change difference values ​​of the various monitoring data in each sliding window are calculated. The specific calculation relationship is:

[0044] ;

[0045] in, Indicates that the t-th monitoring data is in The difference value of discontinuous changes in a sliding window; Indicates that the t-th monitoring data is in and DTW distance of data in a sliding window; Indicates the tth type of monitoring data and The cosine similarity between the feature vectors of the sliding windows, Represents an exponential function with a natural constant as the base, its purpose is to normalize the result of cosine similarity to avoid the denominator being 0; Indicates the number of sliding windows for the t-th type of monitoring data.

[0046] By comparing the parameter differences and data change characteristics of different time intervals, accurate analysis is performed. If the intermittent characteristic differences and monitoring data time series differences are greater, it indicates that the dynamic changes of the spheroidization reaction have a more significant impact on the parameter control of the current interval, thereby achieving accurate analysis of the parameter control characteristics under the influence of the spheroidization reaction.

[0047] (2) Based on the above analysis, the intermittent change difference value of each monitoring data in each sliding window can be obtained during the spheroidization process, and a comprehensive continuous impact characteristic analysis of the control deviation of each monitoring data in the spheroidization stage can be performed.

[0048] Specifically, for each type of monitoring data, based on the discontinuous change difference value within each sliding window, the control deviation characteristic value during the spheroidization process is calculated, and the calculation relationship is as follows:

[0049] ;

[0050] in, Indicates the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process; Indicates the tth type of monitoring data The mean of the difference between each data in the sliding window and the preset standard parameter value; and Respectively represent the tth type of monitoring data and The difference value of the discontinuous change of the sliding window; n represents the number of sliding windows of the t-th type of monitoring data.

[0051] Among them, the larger the calculated control deviation characteristic value during the spheroidization process is, the more discontinuous the control deviation is due to the dynamic changes of the spheroidization reaction during the spheroidization process. The larger the deviation of the actual control error corresponding to the current spheroidization process moment compared with the current feedback error is, the higher the instability of the amount of spheroidizer added during the actual spheroidization process may be, and the longer the temperature instability may last.

[0052] Therefore, in order to further achieve precise control of parameters during the spheroidization process and avoid intermittent control deviations caused by dynamic changes in the spheroidization reaction, it is necessary to judge and adjust the feedback errors at different times. If, based on the analysis of parameter change characteristics during the actual control process, it is found that the control deviation at the current moment is significantly larger than the control error at that moment, it indicates that the spheroidization process is affected by the changes in the spheroidization reaction and there is a large control error. This may lead to a prolonged effect of the actual spheroidizer addition amount and temperature instability, further exacerbating the actual control error in the spheroidization process and seriously affecting the spheroidization effect.

[0053] This embodiment uses a feedback control strategy to achieve real-time control of the spheroidizing agent addition rate and temperature during the spheroidization process. Based on the comparison results of the control deviation characteristic value of the spheroidization process at different times and the current feedback error, the feedback error in the control process is judged and adjusted. The specific adjustment process is as follows: First, the judgment coefficient of the feedback error adjustment is calculated, and its calculation formula is: ;in, It represents the judgment coefficient of the error adjustment of the t-th monitoring data feedback at the current moment, It represents the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process, Indicates the difference between the t-th monitoring data at the current moment and its standard parameter value.

[0054] Furthermore, the threshold of the judgment coefficient is preset In this embodiment, The value is 0.2. For the t-th monitoring data, if and , indicating that the real-time feedback error is significantly different from the actual error at the current moment due to the changes in the spheroidization reaction. At this time, the current control deviation characteristic value is recorded as the feedback error characteristic value, and used as the feedback error to implement real-time control of the monitoring data using the PLC control system to improve the control accuracy of the spheroidization process monitoring data. Otherwise, control is performed based on the real-time feedback error to avoid excessive response in the control process. Through the above processing, real-time monitoring and dynamic adjustment of various monitoring data controls during the spheroidization process are achieved. The specific control process of the PLC control system is well known to those skilled in the art and is not specifically limited in this embodiment.

[0055] Step 3: Based on the average level of the feedback error characteristic values ​​corresponding to various monitoring data during the spheroidization process, the compensation coefficients of various monitoring data during the spheroidization process are obtained. According to the average level of the compensation coefficients of all monitoring data during the spheroidization process, the stirring intensity and current of the ADI casting molten iron smelting inoculation treatment stage are adjusted. After the inoculation treatment, the molten iron composition is re-inspected, and a slag remover is added after the molten iron is allowed to stand in the ladle. The slag is removed from the furnace and poured.

[0056] Immediately after spheroidization, an inoculant is added through a stream inoculation device at a flow rate of 5-10 kg / min. The inoculant is primarily ferrosilicon with a particle size of 5-20 mm and an amount of 0.6%-1.0% of the mass of the molten iron. Electromagnetic stirring is used for 3-8 minutes to increase the spheroidization rate to over 90%. Preferably, in this embodiment, the inoculant is added at a flow rate of 8 kg / min, an amount of 0.8% of the mass of the molten iron, and the electromagnetic stirring time is 5 minutes, which increases the spheroidization rate to 97%.

[0057] Specifically, in this embodiment, during the inoculation treatment stage, an electromagnetic stirring device is used to perform stirring operations according to set parameters. Eddy currents are generated in the molten iron by the principle of electromagnetic induction. The stirring intensity is controlled by adjusting the current intensity and frequency to form a vortex with a depth of 15 cm on the surface of the molten iron, thereby ensuring uniform dispersion of the spheroidizing agent and the inoculant, and promoting the collision, aggregation, and floating of inclusions and the escape of gas. In this embodiment, the stirring time is 8 minutes to ensure that the spheroidizing agent is fully dissolved, suppress excessive temperature loss, and prevent spheroidization degradation.

[0058] Inoculation requires the addition of an inoculant after spheroidization to promote graphite refinement, and spheroidization uniformity is ensured by thorough mixing of the spheroidizer and inoculant. Data changes during the spheroidization and inoculation stages exhibit significant coupling characteristics: excessively low temperatures after spheroidization slow the dissolution of the inoculant, while prolonged stirring time exacerbates the temperature drop. Excessive temperature loss during the spheroidization stage compresses the temperature operating window during the inoculation stage. Unstable spheroidizer addition rates require increased stirring intensity to compensate, but this can cause slag entrainment and compromise the inoculation effect. Temperature stratification during the spheroidization stage can lead to localized overheating and decomposition of the inoculant. Furthermore, temperature deviations during the spheroidization stage increase the difficulty of temperature control during the inoculation stage, while insufficient stirring during the inoculation stage prevents residual inclusions from the spheroidization stage from fully floating, leading to porosity defects during the casting stage.

[0059] Based on the above analysis, in order to achieve accurate compensation for the instability of the parameters in the spheroidization stage during the inoculation process, this embodiment dynamically adjusts the control parameters of the inoculation process according to the parameter control deviation caused by the changes in the spheroidization reaction at each control moment of the spheroidization process. The specific process is as follows:

[0060] First, the control deviation characteristic value corresponding to each monitoring data in the spheroidization process is obtained, and the feedback error characteristic values ​​corresponding to the current moment and all previous moments are extracted through the judgment coefficient. Furthermore, the feedback error characteristic values ​​at the current moment and all previous moments are used as input, and a normalization algorithm is used to obtain the normalized results of each feedback error characteristic value. The average value of the normalized results of all feedback error characteristic values ​​is used as the compensation coefficient for each monitoring data in the spheroidization process. The larger the compensation coefficient, the worse the stability of the corresponding parameter control process in the spheroidization process, and the larger the stirring parameter compensation is required.

[0061] Furthermore, the agitation intensity and current of the inoculation stage are adjusted based on the compensation coefficient of each monitoring data during the spheroidization process. The adjustment relationship is:

[0062] ;in, Indicates the adjusted stirring intensity current value; Indicates the initial value of the stirring intensity current. In this embodiment, to prevent slag entrainment from affecting the inoculation effect, the initial value is set to 500A. In actual application scenarios, the implementer can set it by himself; It represents the mean value of the compensation coefficient of all monitoring data during the spheroidization process. That is, the larger the compensation coefficient, the greater the instability of the spheroidizing agent addition speed and temperature due to the influence of the spheroidization reaction changes during the spheroidization stage. In this case, a relatively large stirring intensity current needs to be set in the inoculation stage for compensation to improve the effects of the spheroidization and inoculation treatments.

[0063] Based on the above process to obtain the adjusted stirring intensity current value, the stirring intensity current and the molten iron temperature during the inoculation treatment process are collected through the sensor, and the collected data are transmitted to the PLC control system to control the stirring intensity current during the inoculation treatment stage.

[0064] Further, after the inoculation treatment is completed, the molten iron is adjusted and tapped and poured. Specifically, in the present embodiment, the molten iron composition is rechecked after the inoculation treatment is completed, and when the deviation is more than ±0.05%, the alloy is supplemented, the temperature is adjusted to 1380-1420℃ by an infrared temperature measuring instrument, and in the present embodiment, the temperature is adjusted to 1400℃. The molten iron is placed in a ladle for 3 minutes, 0.5% CaO (calcium oxide) based deslagging agent is added to remove the dross, and after the removal is completed, the molten iron smelting is completed, and the tapping and pouring can be performed.

[0065] Based on the same inventive concept as the above method, the present embodiment also provides a molten iron smelting device for ADI ductile cast iron casting forming, which comprises a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the steps of the molten iron smelting method for ADI ductile cast iron casting forming according to any one of the above embodiments when executing the computer program.

[0066] It can be understood that the above-mentioned sequence of the embodiments is only for description, and does not represent the advantages and disadvantages of the embodiments. And the above describes the specific embodiments of the present application. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0067] Each embodiment in the present specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

[0068] The above is only the embodiment of the present application, and is not used to limit the scope of the present application. Any equivalent structure or equivalent process conversion using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the protection scope of the present application.

Claims

1. A method for smelting molten iron for ADI ductile iron casting, characterized in that: The following steps are involved: For the spheroidization process of ADI foundry iron smelting, various monitoring data during the spheroidization reaction are obtained, including the spheroidizing agent addition rate and the molten iron temperature data during the spheroidization reaction; The sliding window sizes of various monitoring data are set based on the distribution of changes in various monitoring data. Based on the data differences of various monitoring data in different sliding windows, the discontinuous change difference values ​​of various monitoring data in each sliding window are obtained. Based on the degree of difference between the monitoring data and the preset standard parameter values ​​in the sliding windows of various monitoring data, the control deviation characteristic values ​​of various monitoring data in the spheroidization process are obtained in combination with the discontinuous change difference values. Based on the differences between the various monitoring data and the standard parameter values, the judgment coefficients for feedback error adjustment of various monitoring data are obtained, so as to extract the feedback error characteristic values ​​corresponding to various monitoring data in the spheroidization process, which are used to control various monitoring data in the spheroidization process. Based on the average level of the feedback error characteristic values ​​corresponding to various monitoring data during the spheroidization process, the compensation coefficients of various monitoring data during the spheroidization process are obtained. According to the average level of the compensation coefficients of all monitoring data during the spheroidization process, the stirring intensity and current of the ADI casting molten iron smelting inoculation stage are adjusted. After the inoculation treatment, the composition of the molten iron is re-inspected, and the slag remover is added after the molten iron is allowed to stand in the ladle. The slag is removed before pouring.

2. The method for smelting molten iron for ADI ductile iron casting according to claim 1, wherein: The setting of the sliding window size of the various monitoring data further includes: arranging the various monitoring data obtained at the current moment and before in chronological order and extracting the extreme values ​​of each monitoring data; for various monitoring data, calculating the average value of the number of interval data between any two adjacent extreme values; and rounding up the average value as the sliding window size of the various monitoring data.

3. The method for smelting molten iron for casting ADI ductile iron according to claim 1, wherein: The method for obtaining the difference value of the intermittent change of the various monitoring data in each sliding window is as follows: ;in, Indicates that the t-th monitoring data is in The difference value of discontinuous changes in a sliding window; Indicates that the t-th monitoring data is in and DTW distance of data in a sliding window; Indicates the tth type of monitoring data and The cosine similarity between the feature vectors of the discontinuous changes in the sliding window data, represents an exponential function with a natural constant as base, Indicates the number of sliding windows for the t-th type of monitoring data.

4. The method for smelting molten iron for ADI ductile iron casting according to claim 3, wherein: The acquisition of the characteristic vector further includes: for various monitoring data, calculating the range, mean, variance of the monitoring data in the sliding window, as well as the mean and variance of the difference between the various monitoring data and their preset standard parameter values, and the calculation results together constitute the characteristic vectors of the discontinuous changes in the sliding window data of various monitoring data.

5. The method for smelting molten iron for casting ADI ductile iron according to claim 1, wherein: The method for obtaining the control deviation characteristic values ​​of various monitoring data during the spheroidization process is as follows: ； in, Indicates the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process; Indicates the tth type of monitoring data The mean of the difference between each data in the sliding window and the preset standard parameter value; and Respectively represent the tth type of monitoring data and The difference value of the discontinuous change of the sliding window; n represents the number of sliding windows of the t-th type of monitoring data.

6. The method for smelting molten iron for ADI ductile iron casting according to claim 1, wherein: The method for obtaining the judgment coefficient for adjusting the feedback error of the various monitoring data is as follows: ;in, It represents the judgment coefficient of the error adjustment of the t-th monitoring data feedback at the current moment, It represents the control deviation characteristic value of the t-th monitoring data at the current moment in the spheroidization process, Indicates the difference between the t-th monitoring data at the current moment and its standard parameter value.

7. The method for smelting molten iron for casting ADI ductile iron according to claim 6, wherein: The method of extracting the feedback error characteristic values ​​corresponding to various monitoring data during the spheroidization process further includes: Preset judgment coefficient threshold ,when and When , the control deviation characteristic value of the t-th monitoring data at the current moment is recorded as the feedback error characteristic value corresponding to the t-th monitoring data at the current moment, and is used as the feedback error to regulate the t-th monitoring data during the spheroidization process.

8. The method for smelting molten iron for ADI ductile iron casting according to claim 1, wherein: The method for obtaining the compensation coefficients of various monitoring data during the spheroidization process is as follows: The average value of the normalized results of all feedback error characteristic values ​​extracted from various monitoring data in the spheroidization process at the current moment and before is used as the compensation coefficient of various monitoring data in the spheroidization process.

9. The method for smelting molten iron for ADI ductile iron casting according to claim 1, wherein: The adjusting of the stirring intensity current during the ADI cast iron molten smelting and inoculation treatment stage further includes: The calculation formula for the adjusted stirring intensity current value is: ;in, Indicates the adjusted stirring intensity current value; represents the initial value of the stirring intensity current, It represents the mean value of the compensation coefficient of all monitoring data during the spheroidization process.

10. A molten iron smelting device for ADI ductile iron casting, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the cast iron smelting method for ADI ductile iron casting are implemented as described in any one of claims 1 to 9.

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