A method and system for determining the solidification sequence of each position of a casting

Abstract

A method and system for determining the solidification sequence of each position of a casting, specifically relating to a method and system for determining the solidification sequence of each position of a casting during counter-gravity casting, in order to solve the problem that in the counter-gravity casting process, due to the complex structure of the casting and the different solidification sequences of each position of different castings, metallurgical defects will appear in the casting during solidification, resulting in high production cost, low production efficiency and low metallurgical quality of the casting. It includes calculating the ratio of the actual cross-sectional area to the corresponding perimeter at each position of the casting, drawing a ratio curve of the actual cross-sectional area to the perimeter according to all ratios; fitting the ratio curve of the actual cross-sectional area to the perimeter using a straight line fitting method, generating a designed solidification time straight line, comparing the designed solidification time straight line with the ratio curve of the actual cross-sectional area to the perimeter, determining the riser action area and the chill action area, and obtaining the solidification sequence of each position of the casting. It belongs to the field of casting.

Description

Technical Field

[0001] The invention relates to a method and a system for determining the solidification sequence of various positions of a casting, and in particular to a method and a system for determining the solidification sequence of various positions of a casting in a counter-gravity casting process, and belongs to the field of casting. Background Art

[0002] In the traditional gravity casting process, the casting and filling of the casting are usually completed by gravity. Since the metallurgical quality of the casting is generally difficult to control, there are metallurgical defects such as insufficient pouring, cold shut, air entrainment and slag inclusion, which will cause the casting to fail to meet the use requirements. At the same time, the production process of gravity casting is numerous and the process control process is cumbersome, resulting in low production efficiency of the product. The anti-gravity casting process generally has the advantages of stable filling and high metallurgical quality of the prepared castings. This is mainly due to the adjustable pressure of the casting process, which can overcome the shortcomings of traditional gravity casting. However, in the process of anti-gravity casting, the structure of the casting is generally more complicated, and different positions of different castings have different solidification sequences, which makes the castings have metallurgical defects during solidification, resulting in high production cost of castings, low production efficiency, and low metallurgical quality of castings. Therefore, how to obtain a reasonable solidification sequence is an issue that needs to be considered in the anti-gravity casting process. Summary of the invention

[0003] In order to solve the problem that in the counter-gravity casting process, due to the complex structure of the casting and the different solidification sequences at different positions of different castings, metallurgical defects will appear in the castings during solidification, resulting in high casting production cost, low production efficiency and low metallurgical quality of the castings, the present invention further proposes a method and system for determining the solidification sequence of various positions of the castings.

[0004] The technical solution adopted by the present invention is:

[0005] It includes the following steps:

[0006] S1. Calculate the ratio of the actual cross-sectional area to the corresponding perimeter at each position of the casting, and draw a ratio curve of the actual cross-sectional area to the perimeter based on all the ratios;

[0007] S2. Fitting the ratio curve of the actual cross-sectional area to the perimeter by a straight line fitting method to generate a designed solidification time straight line, comparing the designed solidification time straight line with the ratio curve of the actual cross-sectional area to the perimeter, determining the riser action area and the chill action area, and obtaining the solidification sequence of each position of the casting;

[0008] The straight line fitting method includes a single straight line fitting method, a two straight line single peak fitting method and a two straight line multi-peak fitting method;

[0009] The single straight line fitting method is to linearly fit the ratios of all actual cross-sectional areas to perimeters to obtain a fitting straight line;

[0010] The two-straight-line single-peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the self-defined peak point, and perform linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines intersect at the peak point, that is, the curve composed of the two fitting straight lines contains only one peak.

[0011] The two straight line multi-peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the user-defined peak point, and perform linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines have no intersection and are independent of each other.

[0012] Furthermore, in S2, the solidification sequence of the casting is determined by a single straight line fitting method, and the specific process is as follows:

[0013] When the ratio curve of the actual cross-sectional area to the perimeter is approximately linear or has no significant change, the single straight line fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting straight line. The greater the slope of the cross-sectional area curve fitting straight line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the cross-sectional area curve fitting straight line is less than the critical slope of the corresponding alloy system, the slope of the cross-sectional area curve fitting straight line is corrected to obtain the designed solidification time straight line; when the slope of the cross-sectional area curve fitting straight line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting straight line is used as the designed solidification time straight line. The designed solidification time straight line is compared with the ratio curve of the actual cross-sectional area to the perimeter to determine the riser action area and the chill action area, and the solidification order of each position of the casting is obtained.

[0014] Furthermore, the slope of the cross-sectional area curve fitting line is corrected, and the specific process is as follows:

[0015] The cross-sectional area curve fitting straight line is rotated around the center point to obtain the designed solidification time straight line with a critical slope.

[0016] Furthermore, the designed solidification time straight line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area. The specific process is:

[0017] If the ratio curve of actual cross-sectional area to circumference is above the final solidification time straight line, it is the riser action area, otherwise, it is the chiller action area.

[0018] Furthermore, in S2, the solidification sequence of the casting is determined by using a two-straight-line single-peak fitting method, and the specific process is as follows:

[0019] When the ratio curve of the actual cross-sectional area to the perimeter has multiple intervals of variation with large fluctuations, the two-straight-line single-peak fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting line. The greater the slope of each fitting line in the cross-sectional area curve fitting line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the fitting line in the cross-sectional area curve fitting line is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected to obtain the designed solidification time line; when the slope of the fitting line in the cross-sectional area curve fitting line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the designed solidification time line, and the designed solidification time line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area, and obtain the solidification order of each position of the casting.

[0020] Furthermore, the slope of the current fitting straight line is corrected in the solidification sequence of the casting determined by the two-straight-line single-peak fitting method, and the specific process is as follows:

[0021] If the slope of one of the fitting lines of the cross-sectional area curve is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected, that is, the current fitting line is rotated around the center point to obtain the design solidification time line I with the critical slope, and the design solidification time line I is intersected with another fitting line at the peak point for splicing to obtain the final design solidification time line;

[0022] If the slopes of the two fitting lines in the cross-sectional area curve fitting line are both less than the critical slope of the corresponding alloy system, the slopes of the two fitting lines are respectively corrected, that is, each fitting line is rotated around the corresponding center point to obtain two designed solidification time lines, and the two designed solidification time lines are intersected at the peak point for splicing to obtain the final designed solidification time line.

[0023] Furthermore, in S2, the solidification sequence of the casting is determined by using a two-straight-line multi-peak fitting method, and the specific process is as follows:

[0024] When the wall thickness of the casting changes greatly, the two-line multi-peak fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting line. The greater the slope of each fitting line in the cross-sectional area curve fitting line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the fitting line in the cross-sectional area curve fitting line is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected to obtain the designed solidification time line; when the slope of the fitting line in the cross-sectional area curve fitting line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the designed solidification time line. The designed solidification time line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area, and the solidification order of each position of the casting is obtained.

[0025] Furthermore, the slope of the current fitting straight line is corrected in the solidification sequence of the casting determined by the two-straight-line multi-peak fitting method, and the specific process is as follows:

[0026] If the slope of one of the fitting lines of the cross-sectional area curve is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected, that is, the current fitting line is rotated around the center point to obtain the design solidification time line I with the critical slope, and the design solidification time line I is intersected with another fitting line at the peak point for splicing to obtain the final design solidification time line;

[0027] If the slopes of the two fitting lines in the cross-sectional area curve fitting line are both less than the critical slope of the corresponding alloy system, the slopes of the two fitting lines are respectively corrected, that is, each fitting line is rotated around the corresponding center point to obtain two designed solidification time lines, and the two designed solidification time lines are intersected at the peak point for splicing to obtain the final designed solidification time line.

[0028] A system for determining the solidification sequence of various positions of a casting comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any step of a method for determining the solidification sequence of various positions of a casting is implemented.

[0029] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any step of a method for determining a solidification sequence of various positions of a casting is implemented.

[0030] Beneficial effects:

[0031] The present invention draws a ratio change curve according to the ratio of the actual cross-sectional area to the perimeter at each position of the casting, and obtains the solidification time of each position of the casting according to the ratio curve. The larger the ratio of the actual cross-sectional area to the perimeter, the longer the solidification time, so that the position where the casting tends to solidify first and the position where the casting solidifies later can be reflected. A straight line fitting method is used to fit the ratio curve of the actual cross-sectional area to the perimeter to generate a designed solidification time straight line. The straight line fitting method includes a single straight line fitting method, a two-line single-peak fitting method and a two-line multi-peak fitting method. The designed solidification time straight line is compared with the ratio curve of the actual cross-sectional area to the perimeter to determine the riser action area and the chill action area. According to the riser action area and the chill action area, the control scheme of the solidification sequence of each position of the casting is inferred, and the casting metallurgical defects are reduced by giving the casting shrinkage compensation. The present invention describes the relationship between the process parameters of the anti-gravity casting solidification sequence and the casting structure through a digital method, which greatly reduces the production cost of the casting, improves the production efficiency, significantly shortens the casting production time, and improves the metallurgical quality of the casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of single straight line fitting;

[0033] Figure 2 It is a schematic diagram of two straight line single peak fitting;

[0034] Figure 3 It is a schematic diagram of multi-peak fitting of two straight lines; DETAILED DESCRIPTION

[0035] Specific implementation method 1: Combination Figure 1-Figure 3 The present embodiment is described. The method for determining the solidification sequence of each position of a casting described in the present embodiment comprises the following steps:

[0036] S1. Calculate the ratio of the actual cross-sectional area to the corresponding perimeter at each position of the casting, draw a ratio curve of the actual cross-sectional area to the perimeter based on all the ratios, and obtain the solidification time at each position of the casting based on the ratio curve. For casting, the solidification time at each position of the casting depends on the thickness of the casting position. The solidification time of the casting at the thin wall is short, and the larger the ratio of the actual cross-sectional area to the perimeter, the more molten metal mass needs to be cast at this position, and the longer the solidification time.

[0037] S2. Use the straight line fitting method to fit the ratio curve of the actual cross-sectional area to the circumference, generate the designed solidification time straight line, compare the designed solidification time straight line with the ratio curve of the actual cross-sectional area to the circumference, determine the riser action area and the chill action area, and obtain the solidification order of each position of the casting.

[0038] The essence of designing the solidification time line and determining the riser action area and the chiller action area is to form a suitable temperature gradient in the casting (i.e. the temperature difference between the thin wall and the thick wall / the distance between them) to solve the problem of metallurgical defects when the casting is solidified.

[0039] The straight line fitting methods include single straight line fitting method, two straight line single peak fitting method and two straight line multi-peak fitting method.

[0040] The single straight line fitting method is to linearly fit the ratios of all actual cross-sectional areas to the perimeter to obtain a fitting straight line.

[0041] like Figure 1 As shown, when the ratio curve of the actual cross-sectional area to the perimeter is approximately linear or has no significant change, the single straight line fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter, that is, to fit the ratio of the cross-sectional area to the corresponding perimeter at all positions of the casting, so that the positions where the casting tends to solidify first and the positions where the casting solidifies later can be reflected, and the cross-sectional area curve fitting straight line is generated. The cross-sectional area curve fitting straight line actually reflects the temperature gradient in the casting, that is, the solidification order. The greater the slope of the cross-sectional area curve fitting straight line, the greater the solidification temperature gradient in the casting. However, since different alloy systems have different critical temperature gradients, that is, there are different critical slopes K, in order to form a suitable temperature gradient in the casting (that is, the temperature difference between the thin wall and the thick wall / the distance between them), it is necessary to ensure that the temperature gradient in the casting is higher than the critical temperature gradient, because when the temperature gradient in the casting is less than the critical temperature gradient, even with a riser and a chill, the metallurgical defects cannot be eliminated.

[0042] Since the generated cross-sectional area curve fitting line cannot completely conform to the actual solidification conditions, when the slope of the cross-sectional area curve fitting line is less than the critical slope K of the corresponding alloy system, it is necessary to correct the slope of the cross-sectional area curve fitting line, that is, rotate the cross-sectional area curve fitting line around the center point to obtain a design solidification time line with a slope of the critical slope K, which conforms to the action characteristics of the riser chill. When the slope of the cross-sectional area curve fitting line is greater than or equal to the critical slope K of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the design solidification time line. Compare the design solidification time line with the actual cross-sectional area to circumference ratio curve to determine the riser action area and the chill action area. If the actual cross-sectional area to circumference ratio curve is above the final solidification time line, it is the riser action area, otherwise, it is the chill action area, and the solidification order of each position of the casting is obtained. In such as Figure 1The starting position of the middle casting height (horizontal axis) is shown as the riser action area. Obviously, this area is connected to the casting system and should be the shrinkage compensation area of ​​the casting system. Because the counter-gravity casting process connects the casting system below, the casting system is the last solidification part, and the casting metallurgical defects are reduced by compensating the shrinkage of the casting.

[0043] The two straight line single peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the self-defined peak point, and perform linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines intersect at the peak point, that is, the curve composed of the two fitting straight lines contains only one peak. The peak point needs to be processed in sections because the cross section of the casting is not the same. The peak value of the peak point can be fuzzily defined by the user.

[0044] When the actual cross-sectional area to perimeter ratio curve has multiple fluctuation intervals, the single solidification sequence obtained by the single straight line fitting method will not meet the shrinkage compensation requirements. For example, the bottom and top moduli of common shell castings are large, and the middle wall thickness is thin. In this case, the middle should solidify first and the two ends should solidify later. Then two fitting straight lines can better reflect the solidification sequence of the casting than a single fitting straight line. Figure 2As shown in FIG. 1 , like the single straight line fitting, the two straight line single peak fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the circumference to generate a cross-sectional area curve fitting straight line (a curve composed of the above two fitting straight lines). The greater the slope of each fitting straight line in the cross-sectional area curve fitting straight line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes K, when the slope of the fitting straight line in the cross-sectional area curve fitting straight line is less than the critical slope K of the corresponding alloy system, the slope of the current fitting straight line is corrected, that is, if the slope of a fitting straight line in the cross-sectional area curve fitting straight line is less than the critical slope K of the corresponding alloy system, the slope of the current fitting straight line is corrected, that is, the current fitting straight line is rotated around the center point, and the result is: The design solidification time line with a slope of critical slope K is obtained, and the design solidification time line I is obtained. The design solidification time line I is spliced ​​with another fitting line at the peak point to obtain the final design solidification time line; if the slopes of the two fitting lines in the cross-sectional area curve fitting line are less than the critical slope K of the corresponding alloy system, the slopes of the two fitting lines are corrected respectively, that is, each fitting line is rotated around the corresponding center point to obtain two design solidification time lines, and the two design solidification time lines are spliced ​​at the peak point to obtain the final design solidification time line; when the slope of the fitting line in the cross-sectional area curve fitting line is greater than or equal to the critical slope K of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the design solidification time line. Compare the design solidification time line with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chiller action area. If the actual cross-sectional area to perimeter ratio curve is above the final solidification time line, it is the riser action area, otherwise, it is the chiller action area, and the solidification order of each position of the casting is obtained. Because the two straight line fitting is closer to the structural characteristics of the casting, the calculation results of the action area of ​​the chill and riser are more accurate.

[0045] The two straight line multi-peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the user-defined peak point, and perform independent linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines have no intersection and the slopes of the two straight lines are independent of each other.

[0046] If there is an intersection between two straight line single-peak fittings, the slopes of the two straight lines will have a certain correlation. However, in fact, for castings with large changes in wall thickness, the solidification time at different positions may vary greatly and be independent. For this reason, when the wall thickness of the casting varies greatly, the two straight line multi-peak fitting method is used to linearly fit all the actual cross-sectional area to perimeter ratios to generate a cross-sectional area curve fitting line. The greater the slope of each fitting line in the cross-sectional area curve fitting line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes K, when the slope of the fitting line in the cross-sectional area curve fitting line is less than the critical slope K of the corresponding alloy system, the slope of the current fitting line is corrected. The correction method is the same as the two straight line single-peak fitting method. The method for correction is consistent, and the designed solidification time straight line is obtained; when the slope of the fitting straight line in the cross-sectional area curve fitting straight line is greater than or equal to the critical slope K of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting straight line is used as the designed solidification time straight line, and the designed solidification time straight line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area. If the actual cross-sectional area to perimeter ratio curve is above the final solidification time straight line, it is the riser action area, otherwise, it is the chill action area, and the solidification order of each position of the casting is obtained.

[0047] like Figure 3 As shown in the figure, this fitting can better reflect the local structural change relationship of the casting and more accurately find the position in the casting structure where the solidification sequence needs to be changed. The solidification sequence change is to compare the size and height of the characteristic value and the designed solidification time line. Because the slopes of the two straight lines are independent of each other, the local solidification sequence control of the casting is more flexible and more in line with the characteristics of structural changes. This fitting method can determine the wall thickness position in the middle area of ​​the casting, and determine the range of action of the riser in this area, and its relationship with other areas.

[0048] Conventional process design has no precise data basis. According to the change of casting wall thickness, the solidification sequence and riser scheme are roughly estimated. Then, numerical simulation or trial production is combined to verify and optimize the process. The design process relies on experience, has a certain degree of blindness, and has a long cycle. The advantage of this invention is that it provides a quantitative basis for process design, and the design results are closer to the structural characteristics of the casting itself, and the design process is more scientific and convenient.

[0049] Specific implementation method 2: Combination Figure 1-Figure 3 To illustrate this embodiment, a system for determining the solidification order of various positions of a casting described in this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any step of a method for determining the solidification order of various positions of a casting is implemented.

[0050] Specific implementation method three: Combination Figure 1-Figure 3 The present embodiment is described as a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any step of a method for determining a solidification sequence of various positions of a casting is implemented.

Claims

1. A method for determining the solidification sequence of various positions of a casting, characterized in that: It includes the following steps: S1. Calculate the ratio of the actual cross-sectional area to the corresponding perimeter at each position of the casting, and draw a ratio curve of the actual cross-sectional area to the perimeter based on all the ratios; S2. Fitting the ratio curve of the actual cross-sectional area to the perimeter by a straight line fitting method to generate a designed solidification time straight line, comparing the designed solidification time straight line with the ratio curve of the actual cross-sectional area to the perimeter, determining the riser action area and the chill action area, and obtaining the solidification sequence of each position of the casting; The straight line fitting method includes a single straight line fitting method, a two straight line single peak fitting method and a two straight line multi-peak fitting method; The single straight line fitting method is to linearly fit the ratios of all actual cross-sectional areas to perimeters to obtain a fitting straight line; The solidification sequence of the casting is determined by the single straight line fitting method. The specific process is as follows: When the ratio curve of the actual cross-sectional area to the perimeter is approximately linear or has no significant change, a single straight line fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting straight line. The greater the slope of the cross-sectional area curve fitting straight line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the cross-sectional area curve fitting straight line is less than the critical slope of the corresponding alloy system, the slope of the cross-sectional area curve fitting straight line is corrected to obtain a designed solidification time straight line; when the slope of the cross-sectional area curve fitting straight line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting straight line is used as the designed solidification time straight line, and the designed solidification time straight line is compared with the ratio curve of the actual cross-sectional area to the perimeter to determine the riser action area and the chill action area, and obtain the solidification order of each position of the casting; The two-straight-line single-peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the self-defined peak point, and perform linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines intersect at the peak point, that is, the curve composed of the two fitting straight lines contains only one peak. The solidification sequence of the casting is determined by using the two-straight-line single-peak fitting method. The specific process is as follows: When the ratio curve of the actual cross-sectional area to the perimeter has multiple intervals of variation with large fluctuations, a two-straight-line single-peak fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting line. The greater the slope of each fitting line in the cross-sectional area curve fitting line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the fitting line in the cross-sectional area curve fitting line is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected to obtain a designed solidification time line; when the slope of the fitting line in the cross-sectional area curve fitting line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the designed solidification time line, and the designed solidification time line is compared with the ratio curve of the actual cross-sectional area to the perimeter to determine the riser action area and the chill action area, and obtain the solidification order of each position of the casting; The two-straight-line multi-peak fitting method is to divide the actual cross-sectional area to perimeter ratio curve into two parts according to the self-defined peak point, and perform linear fitting on each part to obtain two fitting straight lines. The two fitting straight lines have no intersection and are independent of each other. The solidification sequence of the casting is determined by using the two-line multi-peak fitting method. The specific process is as follows: When the wall thickness of the casting changes greatly, the two-line multi-peak fitting method is used to linearly fit all the ratios of the actual cross-sectional area to the perimeter to generate a cross-sectional area curve fitting line. The greater the slope of each fitting line in the cross-sectional area curve fitting line, the greater the solidification temperature gradient in the casting. Since different alloy systems have different critical temperature gradients, that is, different critical slopes, when the slope of the fitting line in the cross-sectional area curve fitting line is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected to obtain the designed solidification time line; when the slope of the fitting line in the cross-sectional area curve fitting line is greater than or equal to the critical slope of the corresponding alloy system, no correction is required, and the cross-sectional area curve fitting line is used as the designed solidification time line. The designed solidification time line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area, and the solidification order of each position of the casting is obtained.

2. A method for determining the solidification sequence of various positions of a casting according to claim 1, characterized in that: The slope of the cross-sectional area curve fitting straight line is corrected, and the specific process is as follows: The cross-sectional area curve fitting straight line is rotated around the center point to obtain the designed solidification time straight line with a critical slope.

3. A method for determining the solidification sequence of various positions of a casting according to claim 2, characterized in that: The designed solidification time straight line is compared with the actual cross-sectional area to perimeter ratio curve to determine the riser action area and the chill action area. The specific process is: If the ratio curve of actual cross-sectional area to circumference is above the final solidification time straight line, it is the riser action area, otherwise, it is the chiller action area.

4. A method for determining the solidification sequence of various positions of a casting according to claim 3, characterized in that: The slope of the current fitting straight line is corrected in the solidification sequence of the casting determined by the two-straight-line single-peak fitting method. The specific process is as follows: If the slope of one of the fitting lines of the cross-sectional area curve is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected, that is, the current fitting line is rotated around the center point to obtain the design solidification time line I with the critical slope, and the design solidification time line I is intersected with another fitting line at the peak point for splicing to obtain the final design solidification time line; If the slopes of the two fitting lines in the cross-sectional area curve fitting line are both less than the critical slope of the corresponding alloy system, the slopes of the two fitting lines are respectively corrected, that is, each fitting line is rotated around the corresponding center point to obtain two designed solidification time lines, and the two designed solidification time lines are intersected at the peak point for splicing to obtain the final designed solidification time line.

5. A method for determining the solidification sequence of various positions of a casting according to claim 4, characterized in that: The slope of the current fitting straight line is corrected in the solidification sequence of the casting determined by the two-straight-line multi-peak fitting method. The specific process is as follows: If the slope of one of the fitting lines of the cross-sectional area curve is less than the critical slope of the corresponding alloy system, the slope of the current fitting line is corrected, that is, the current fitting line is rotated around the center point to obtain the design solidification time line I with the critical slope, and the design solidification time line I is intersected with another fitting line at the peak point for splicing to obtain the final design solidification time line; If the slopes of the two fitting lines in the cross-sectional area curve fitting line are both less than the critical slope of the corresponding alloy system, the slopes of the two fitting lines are respectively corrected, that is, each fitting line is rotated around the corresponding center point to obtain two designed solidification time lines, and the two designed solidification time lines are intersected at the peak point for splicing to obtain the final designed solidification time line.

6. A system for determining the solidification sequence of various positions of a casting, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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