A casting method having a transversely large planar casting

Abstract

The present application relates to a kind of casting method with transverse large plane castings, belong to casting technical field, solve the problem that the castings with transverse large plane in prior art are prone to large area loose and shrinkage cavity defects when casting.The casting method of the present application, by reasonably regulating the thickness of the transverse large plane during casting, it is controlled within a certain range, effectively reduces the large area loose and shrinkage cavity defects caused by the wall thickness of the casting when casting, improves the internal quality of the casting and the performance of the body.

Description

[0001] The present application relates to the technical field of casting, in particular to a casting method for a casting with a large transverse plane. BACKGROUND

[0002] A casting with a large transverse plane refers to a casting with one or more large plane structures extending significantly transversely. These large planes can be flat, concave, or have bosses, etc. Such castings can meet different engineering and application requirements, such as providing stable support surfaces, mounting interfaces, or accommodating other components, and are widely used in engineering fields such as mechanical manufacturing, automobile manufacturing, aerospace, etc.

[0003] However, castings with large transverse planes face some challenges during casting. Due to the presence of large planes, hot spots and uneven solidification may occur during the solidification of the liquid metal, leading to porosity and shrinkage defects. In addition, the wall thickness at the large transverse plane is difficult to control properly during casting, affecting the metal cooling and solidification time. When the liquid metal shrinks, it cannot be replenished in time, further increasing the risk of defects, and large-area porosity and shrinkage defects are prone to occur, reducing the performance of the casting. Moreover, the qualified rate of large-area repair welding is low, and the risk of casting scrap is high. SUMMARY

[0004] In view of the above analysis, the embodiments of the present application aim to provide a casting method for a casting with a large transverse plane to solve one of the following technical problems: (1) castings with large transverse planes are prone to produce large-area porosity and shrinkage defects during casting, reducing the performance of the casting; (2) the wall thickness of castings with large transverse planes is difficult to control properly during casting, affecting the performance of the casting; (3) the wall thickness of the blind cavity of the casting mold with a large transverse plane cannot be directly detected using conventional methods.

[0005] In one aspect, the present application provides a casting method for a casting with a large transverse plane, comprising the following steps:

[0006] S1, designing a pouring system;

[0007] S2, assembling the mold, placing the mud columns in the four quadrants on the inner core large transverse plane;

[0008] S3, continue to assemble the mold, form a blind cavity of the mold at the large transverse plane, and complete the mold assembly;

[0009] S4, disassemble the upper mold at the large transverse plane, detect the thickness of the four mud columns at the blind cavity of the mold, take the average value as the wall thickness δ of the blind cavity of the mold, if the difference Δ between δ and the theoretical wall thickness δ0 of the blind cavity of the mold is greater than or equal to 5 mm, adjust the parting surface at the large transverse plane, eliminate a certain amount A to correct the wall thickness;

[0010] S5, repeating the operation of S3 until the difference between delta and the theoretical wall thickness delta0 of the blind cavity of the mold is less than 5mm, and the mold combination is completed;

[0011] S6, pouring the molten metal for casting.

[0012] Further, the transverse large plane has an area of greater than or equal to 0.5 square meters.

[0013] Further, the transverse large plane comprises a plane, a concave surface or a convex surface to meet different engineering and application requirements.

[0014] Further, in S2, the mud column has the characteristics of easy deformation under pressure and permanent deformation without rebound after the pressure disappears, and the strength is 5-10MPa.

[0015] Further, the number of mud columns is 4, and the placed mud columns are respectively located at the positions close to the middle of the corresponding quadrants.

[0016] Further, the height h of the mud column is greater than or equal to delta+5mm or h is greater than or equal to delta0+10mm; delta0 is the theoretical wall thickness of the blind cavity of the mold; and delta is the wall thickness of the blind cavity of the mold measured in S4.

[0017] Further, in S4, the cutting position is at the parting surface of the transverse large plane, that is, the bottom of the upper mold or the upper part of the lower mold at the parting surface of the transverse large plane is cut.

[0018] Further, the cutting amount A satisfies: delta-delta0-5<=A<=delta-delta0.

[0019] Further, in S6, the pouring temperature is 710-720 DEG C, and the filling speed is 0.02 atm.

[0020] Further, after S6, solidification, cooling, pressure relief, removal of the mold, taking out the casting, and cleaning the excess part on the surface of the casting are needed to finally obtain the casting.

[0021] Compared with the prior art, the present application can at least achieve one of the following beneficial effects:

[0022] (1) The traditional method has the problem that the transverse large plane casting is prone to large-area porosity and shrinkage hole defects during casting, which reduces the performance of the casting. The present application controls the wall thickness of the transverse large plane during casting to a certain range, effectively reduces the large-area porosity and shrinkage hole defects caused by the excessive wall thickness of the transverse large plane, and improves the performance and quality of the casting.

[0023] (2) The traditional method has the problem that the wall thickness of the large horizontal plane in the casting process is difficult to control, which affects the performance of the casting. The present application adds a permanently deformed mud-like substance during the mold assembly process, and reasonably controls the wall thickness of the mold cavity at the large horizontal plane according to the deformation of the mud-like substance, thereby avoiding the problem of performance degradation of the casting caused by improper wall thickness control.

[0024] (3) The mold cavity at the large horizontal plane is a blind cavity, and the traditional method such as using a plug gauge or a caliper cannot directly detect the wall thickness thereof. The present application adds a mud-like substance during the mold assembly process, and measures the size of the mud-like substance before and after deformation to calculate the wall thickness of the blind cavity mold. The method is simple and convenient, and solves the problem that the conventional method cannot detect the wall thickness of the blind cavity mold.

[0025] In the present application, the above technical solutions can be combined with each other to realize more preferred combination solutions. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the present application. The purpose and other advantages of the present application can be achieved and obtained from the contents specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the application and are incorporated herein and constitute a part of the application. The drawings illustrate embodiments of the application and, together with the description, serve to explain the principles of the application. In the drawings:

[0027] Figure 1 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 1;

[0028] Figure 2 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 2;

[0029] Figure 3 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 2;

[0030] Figure 4 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 2;

[0031] Figure 5 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 2;

[0032] Figure 6 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 1;

[0033] Figure 7 A schematic diagram of a blind cavity mold with a large horizontal plane for Example 1;

[0034] REFERENCE NUMERALS:

[0035] 1 - mud column; 2 - bottom box; 3 - first outer shape; 4 - second outer shape; 5 - large horizontal plane; 6 - inner core; 7 - third outer shape. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present application will be described in detail below with reference to the drawings, which form a part of this application. The drawings illustrate embodiments of the application and serve to explain the principles of the application, but are not intended to limit the scope thereof.

[0037] The present application is mainly directed to a casting method of a casting with a large transverse plane when using a sand mold or graphite mold for low pressure casting.

[0038] On the one hand, the casting with a large transverse plane is more prone to large-area porosity and shrinkage defects in the casting process due to the particularity of the large plane. On the other hand, when using a sand mold or graphite mold for low pressure casting, the wall thickness is more prone to improper control in the casting process due to the particularity of low pressure casting, affecting the performance of the casting.

[0039] In view of the above problems, one specific embodiment of the present application discloses a casting method of a casting with a large transverse plane, comprising the following steps:

[0040] S1, designing a pouring system;

[0041] S2, assembling the mold, placing the mud column in the four quadrants on the inner core of the large transverse plane;

[0042] S3, continuing to assemble the mold to form a blind cavity of the mold at the large transverse plane, and completing the mold assembly;

[0043] S4, disassembling the upper mold at the large transverse plane, detecting the thickness of the four mud columns at the blind cavity of the mold, and taking the average value as the wall thickness δ of the blind cavity of the mold; if the difference Δ between δ and the theoretical wall thickness δ0 of the blind cavity of the mold is ≥5mm, adjusting the parting surface at the large transverse plane to eliminate a certain amount A to correct the wall thickness;

[0044] S5, repeating the operation of S3 until the mold assembly is completed;

[0045] S6, pouring the metal liquid for casting.

[0046] Specifically, in S1, the pouring system is designed according to the structural characteristics, material, size and production requirements of the casting, including the gate, the sprue, the cross runner and the ingate.

[0047] Specifically, in S2, before placing the mud column, the lower outer mold at the transverse large plane parting surface is sequentially loaded, the wall thickness is adjusted during loading to ensure that the wall thickness of each outer circular cavity is uniform; the asbestos rope is placed on the upper surface of each outer mold to ensure that there is no gap between the adjacent upper and lower outer molds. In S3, the continuous casting mold assembly refers to the upper outer mold at the transverse large plane parting surface being continuously loaded, the wall thickness is adjusted during loading to ensure that the wall thickness of each outer circular cavity is uniform; the asbestos rope is placed on the upper surface of each outer mold to ensure that there is no gap between the adjacent upper and lower outer molds. The adjustment of the wall thickness is that the wall thickness difference of the four points corresponding to the cross intersection lines of the outer circular cavity is not greater than 1 mm measured by the caliper.

[0048] Further, due to the particularity of low-pressure casting, the wall thickness is more prone to be improperly controlled during casting, affecting the performance of the casting.

[0049] Specifically, low-pressure casting needs to introduce air or inert gas into the sealed crucible to make the metal liquid fill the mold cavity under the action of air pressure. If the upper and lower parting surfaces are not sealed well, it will cause air leakage and affect the filling. Therefore, low-pressure casting has high requirements for sealing, and during the process of mold assembly, a sealing material (asbestos rope or mud rope, etc.) needs to be placed between the upper and lower parting surfaces to seal.

[0050] Specifically, after placing the sealing material between the upper and lower parting surfaces, the height of the outer mold will be raised to a certain extent. The casting cavity located in the transverse plane will cause the wall thickness of the casting cavity to increase due to the lifting of the upper outer mold. The wall thickness of the casting cavity refers to the distance between the outer mold and the inner core of the casting mold. Since the inner core is generally fixed, the adjustment of the wall thickness of the casting cavity is mainly realized by adjusting the position of the outer mold.

[0051] When the total thickness of the sealing material is too high, the wall thickness of the transverse plane increases too much, which is prone to cause porosity and shrinkage defects. When the transverse plane is a large plane, the casting is more susceptible to changes in wall thickness, resulting in large-area porosity and shrinkage defects, affecting the performance of the casting.

[0052] Further, the transverse large plane has an area of ≥0.5 square meters. This area range will cause the heat to be lost slowly due to the large size of the casting, the cooling speed of the casting during pouring is slow, the solidification time is long, and the metal liquid has more time to shrink during the solidification process, while the feeding ability is limited, which is more prone to large-area porosity and shrinkage defects.

[0053] Further, the transverse large plane includes a plane, a concave surface, or a boss, etc. It can be a diversified feature in casting design to meet different engineering and application requirements. For example, Figure 4 As shown in FIG. 5, it is a kind of rotary body casting with a transverse large plane, and the transverse large plane 5 is a boss. Figure 1 As shown in FIG. 6, it is a kind of rotary body casting with a transverse large plane, and the transverse large plane 5 is a plane.

[0054] Further, in S3, the blind cavity is located at the transverse macroplane, and is formed after the outer shape of the upper part of the installation is covered, and the cavity cannot be seen from the outside, and the wall thickness cannot be directly detected by conventional methods such as a feeler gauge or a caliper.

[0055] The invention adds the mud column in the mold combination process, and measures the size of the mud before and after deformation to calculate the wall thickness of the blind cavity mold, thereby solving the problem that the wall thickness of the blind cavity mold cannot be detected by conventional methods.

[0056] Further, in S2, the mud column has the permanent deformation characteristics of being easily deformed under pressure and not rebounding after the pressure disappears, and the strength is 5-10 MPa, which can ensure the accuracy of the measurement results.

[0057] Preferably, the mud column is made of purple clay mud.

[0058] Further, in S2, the number of mud columns is 4, and the mud columns are placed at positions close to the middle of the corresponding quadrants after placement, which can ensure the representativeness of the measurement results.

[0059] Further, in S2, the height h of the mud column is greater than or equal to δ+5mm or h≥δ0+10mm; δ0 is the theoretical wall thickness of the blind cavity of the mold; and δ is the wall thickness of the blind cavity of the mold measured in S4.

[0060] Specifically, when the thickness of the seal between each parting surface after the mold combination is completed is greater than 5mm, the wall thickness δ of the blind cavity of the mold is thickened by about 5mm compared to the theoretical wall thickness δ0, that is, δ=δ0+5mm, which will cause the solidification speed to slow down and the structure to be poorly compensated. The height h of the mud column should be greater than a certain value (such as 5mm) of δ, so as to ensure that the mud column is compressed and thinned after the mold combination is completed, and the height of the deformed mud column is finally measured as the actual wall thickness of the blind cavity. Therefore, the height h of the mud column is set to h≥δ+5mm or h≥δ0+10mm in the invention.

[0061] Preferably, δ0+10mm≤h≤δ0+20mm, so as to ensure that there is enough compression.

[0062] In one embodiment, the theoretical wall thickness δ0 of the blind cavity of the mold is 11-15mm, and the wall thickness δ of the blind cavity of the mold measured in S4 is 16-20mm.

[0063] In one possible embodiment, the thickness of the part constituting the blind cavity is 5mm, and a 6mm allowance is needed when machining the outer surface of the part, so as to facilitate subsequent machining or correction, and therefore the required theoretical wall thickness δ0 of the blind cavity is 11mm, and the wall thickness of the blind cavity should reach 11mm after actual machining is completed, so as to meet the design requirements.

[0064] Further, in S4, whether the mold blind cavity wall thickness needs to be reasonably regulated by cutting is judged according to whether Δ is greater than or equal to 5 mm. The cutting position is at the transverse large plane parting surface, that is, the bottom of the upper outer mold or the upper part of the lower outer mold at the transverse large plane parting surface is cut.

[0065] Further, in S4, the cutting amount A satisfies: δ-δ0-5≤A≤δ-δ0.

[0066] Specifically, when δ-δ0=Δ≥5 mm, the blind cavity wall thickness thickens to 5 mm, that is, the wall thickness is greater than or equal to 16 mm, and numerical simulation results and production practice verify that when the wall thickness is greater than or equal to 15, the transverse large plane is prone to porosity and shrinkage hole defects, which affect the performance of the casting. The blind cavity wall thickness needs to be reduced.

[0067] The present application reduces the blind cavity wall thickness by cutting a certain amount A. After cutting, the position of the upper part of the outer mold of the blind cavity will move downward by A, so that the blind cavity wall thickness is reduced. At this time, the actual wall thickness of the blind cavity is δ-A, which needs to satisfy that it is not less than the theoretical wall thickness δ0 (that is, δ-A≥δ0) to meet the requirements, and the thickening relative to the theoretical wall thickness δ0 is not higher than 5 mm (that is, δ-A-δ0≤5). In summary, the cutting amount A needs to satisfy: δ-δ0-5≤A≤δ-δ0.

[0068] Specifically, in S6, the pouring temperature is 710-720℃, and the filling speed is 0.02 atm.

[0069] It should be noted that the conventional aluminum alloy casting pouring temperature is 690-700℃, and the filling speed is 0.014 atm. However, the casting with a transverse large plane structure needs a higher pouring temperature and a higher filling speed. A higher pouring temperature helps the molten metal to better fill the mold cavity, reducing the risk of cold shut and underfilling. A higher filling speed helps the molten metal to be uniformly distributed in the mold cavity, reducing the cold shut in local areas.

[0070] In one embodiment, a casting with a transverse large plane, when pouring molten metal for casting, the pouring temperature is 710-720℃, and the filling speed is 0.02 atm; the working pressure is 0.4 MPa, so that the molten metal can overcome the flow resistance and better fill the mold cavity; the liquid rising speed is 0.015 atm, to ensure that the molten metal rises smoothly and avoids splashing; the crust pressure difference is 0.03 atm, and the holding pressure difference is 0.07 atm, to facilitate the uniform distribution of the molten metal in the mold cavity; the crust time is 10 s, to ensure the rapid solidification of the surface layer of the casting; and the holding time is 300 s, to ensure that the molten metal maintains pressure for a long time, so as to compensate and reduce shrinkage defects.

[0071] Specifically, after S6, solidification, cooling, pressure relief, disassembly of the mold, removal of the casting, and cleaning of the excess parts on the surface of the casting are required to finally obtain the casting. The excess parts include the sprue, the riser, the flash, and the burr, etc.

[0072] Compared with the prior art, the casting method with a transverse large-plane casting provided by the embodiment solves the problem of the large-area porosity and shrinkage cavity defects of the transverse large-plane casting in the casting process, which reduces the performance of the casting. The wall thickness of the blind cavity is controlled within a certain range during the mold assembly process, which effectively reduces the large-area porosity and shrinkage cavity defects caused by the transverse large-plane wall thickness, improves the internal quality qualification rate and the performance of the casting. In addition, the present application also solves the problem that the wall thickness of the transverse large-plane blind cavity mold cannot be directly detected.

[0073] The present application will be further described below by combining the embodiments in the specification, but the embodiments are only used for the present application and not limit the present application.

[0074] Embodiment 1

[0075] A casting method with a transverse large-plane casting, comprising the following steps:

[0076] S1, designing a pouring system;

[0077] S2, mold assembly, placing the inner core 6 in the center of the bottom box 2, and firmly sticking after positioning; placing a circle of asbestos rope on the upper surface of the outside of the bottom box 2 cavity; loading the first outer shape 3 from top to bottom, adjusting the wall thickness during the loading process; placing four mud columns with a height of 21 mm in the four quadrants of the cross intersection line on the upper surface of the transverse large plane; placing a circle of asbestos rope on the upper surface of the first outer shape 3 to ensure that there is no gap between the adjacent outer shapes above and below;

[0078] S3, continue mold assembly, load the second outer shape 4, form a mold blind cavity at the transverse large plane, and complete the mold assembly;

[0079] S4, disassemble the upper mold at the parting surface of the transverse large plane 5, detect the thickness of the four mud columns at the mold blind cavity, which are 17 mm, 16.5 mm, 17.5 mm, and 17.4 mm respectively, take the average value of 17.1 mm as the mold blind cavity wall thickness δ; the theoretical wall thickness δ0 of the blind cavity is 11 mm, and the wall thickness difference Δ of the blind cavity is 6.1 mm > 5 mm, so the upper plane of the outer shape at the transverse large plane is cut off, and the cutting amount A is 4 mm;

[0080] S5, repeat the operation of S3 until the mold assembly is completed;

[0081] S6, pouring metal liquid for casting, the pouring temperature is 710℃, and the filling speed is 0.02 atm.

[0082] Example 2

[0083] A casting method for a casting with a transverse large plane, comprising the following steps:

[0084] S1, design a pouring system;

[0085] S2, mold assembly, place the inner core 6 in the center of the bottom box 2, and fix it firmly with glue after positioning. Place a circle of asbestos rope on the upper surface of the outside of the bottom box 2 cavity. Install the first outer shape 3 from top to bottom, and adjust the wall thickness during installation. Place four mud columns with a height of 30mm in the four quadrants of the cross intersection line on the upper surface of the inner core transverse large plane. Place a circle of asbestos rope on the upper surface of the first outer shape 3 to ensure that there is no gap between the adjacent outer shapes above and below.

[0086] S3, continue mold assembly, install the second outer shape 4 from top to bottom, and form a mold blind cavity at the transverse large plane. Adjust the wall thickness of the four tail cover outer circles during installation to ensure that the wall thickness of the four tail cover outer circle cavities is uniform, and the wall thickness difference of the four tail cover outer circle cavities is not greater than 1mm. Place a circle of asbestos rope on the upper surface of the second outer shape 4. Install the third outer shape 7, and the mold assembly is completed.

[0087] S4, disassemble the upper mold at the transverse large plane 5 parting surface, detect the thickness of the four mud-like objects at the transverse large plane mold blind cavity, which are 22mm, 22.5mm, 23mm and 22.8mm respectively, and the average value is 22.6mm, which is the wall thickness δ of the mold blind cavity at this position. The theoretical wall thickness δ0 of the blind cavity is 15mm, and the wall thickness difference Δ of the blind cavity is 7.6mm>5mm. The upper plane of the outer shape at the transverse large plane is cut off, and the cut-off amount A is 5mm.

[0088] S5, repeat the operation of S3 until the mold assembly is completed;

[0089] S6, pour the molten metal to cast, the pouring temperature is 720℃, and the filling speed is 0.02atm.

[0090] Example 3

[0091] A casting method for a casting with a transverse large plane, comprising the following steps:

[0092] S1, design a pouring system;

[0093] S2, mold assembly, place the inner core 6 in the center of the bottom box 2, and fix it firmly with glue after positioning. Place a circle of asbestos rope on the upper surface of the outside of the bottom box 2 cavity. Install the first outer shape 3 from top to bottom, and adjust the wall thickness during installation. Place four mud columns with a height of 30mm in the four quadrants of the cross intersection line on the upper surface of the inner core transverse large plane. Place a circle of asbestos rope on the upper surface of the first outer shape 3 to ensure that there is no gap between the adjacent outer shapes above and below.

[0094] S3, continue the mold combination, load the second outer shape 4 from top to bottom, form a blind cavity of the mold at the transverse large plane, adjust the wall thickness of the four tail cover outer circle mold cavity during loading, ensure that the wall thickness of the four tail cover outer circle mold cavity is uniform, the wall thickness difference of the four tail cover outer circle mold cavity is not greater than 1mm measured by the caliper; place a circle of asbestos rope on the upper surface of the second outer shape 4; load the third outer shape 7, and the mold combination is completed;

[0095] S4, disassemble the upper mold at the parting surface of the transverse large plane 5, detect the thickness of the four mud-like objects at the blind cavity of the transverse large plane mold, which are 17mm, 17.5mm, 17.5mm and 17.2mm respectively, and the average value is 17.3mm, which is the wall thickness δ of the mold blind cavity at this position; the theoretical wall thickness δ0 of the blind cavity is 13mm, the wall thickness difference Δ at the blind cavity is 4.3mm < 5mm, and the thickness difference meets the requirements and does not need to be processed.

[0096] S5, repeat the operation of S3 until the mold combination is completed;

[0097] S6, pour the molten metal for casting, the pouring temperature is 715℃, and the filling speed is 0.02atm.

[0098] Example 4

[0099] A casting method for a casting with a transverse large plane, comprising the following steps:

[0100] S1, design the pouring system;

[0101] S2, mold combination, place the inner core 6 in the center of the bottom box 2, fix it firmly with glue after positioning, and place a circle of asbestos rope on the upper surface outside the cavity of the bottom box 2; load the first outer shape 3 from top to bottom, adjust the wall thickness during loading; place four mud columns with a height of 33mm in the four quadrants of the cross intersection line on the transverse large plane of the inner core; place a circle of asbestos rope on the upper surface of the first outer shape 3 to ensure that there is no gap between the adjacent outer shapes above and below;

[0102] S3, continue the mold combination, load the second outer shape 4, and form a blind cavity of the mold at the transverse large plane, and the mold combination is completed;

[0103] S4, disassemble the upper mold at the parting surface of the transverse large plane 5, detect the thickness of the four mud-like objects at the blind cavity of the transverse large plane mold, which are 19mm, 19.5mm, 19.5mm and 19.4mm respectively, and the average value is 19.4mm, which is the wall thickness δ of the mold blind cavity at this position; the theoretical wall thickness δ0 of the blind cavity is 13mm, the wall thickness difference Δ at the blind cavity is 6.4mm > 5mm, the upper plane of the outer shape at the transverse large plane is cut off, and the cutting amount A is 4mm;

[0104] S5, repeat the operation of S3 until the mold combination is completed;

[0105] S6, pouring the molten metal for casting, the pouring temperature is 710℃, and the filling speed is 0.02 atm.

[0106] Comparative Example 1

[0107] The difference between Example 1 and Comparative Example 1 is that the height of the mud column in step (2) is 10mm, and at this time, because the height of the mud column is not enough, the height of the mud column does not change when the thickness of the four muds is detected in step (4), and is 10mm, and finally no cutting treatment is performed, resulting in a large wall thickness of the casting.

[0108] Comparative Example 2

[0109] The difference between Example 1 and Comparative Example 2 is that the cutting amount A in step (4) is 7mm, and at this time, because the cutting amount A is too large, the wall thickness of the final casting is too small.

[0110] Comparative Example 3

[0111] The difference between Example 1 and Comparative Example 3 is that the cutting amount A in step (4) is 1mm, and at this time, because the cutting amount A is too small, the wall thickness of the casting is too large.

[0112] Comparative Example 4

[0113] The difference between Example 1 and Comparative Example 4 is that the pouring temperature in step (6) is 750℃, and the cooling speed at the transverse large plane is slow, which is easy to produce porosity and shrinkage defects.

[0114] Characterization results

[0115] The castings are subjected to radiographic inspection and metallographic inspection, and the detection results are shown in Table 1, wherein the examples of the application do not have porosity and shrinkage defects, and the comparative examples have different degrees of porosity and shrinkage defects.

[0116] Table 1 Radiographic inspection and metallographic inspection results

[0117]

[0118] One of the castings cast by the examples and comparative examples is taken respectively, and is dissected at the transverse plane, and 6 mechanical property tensile samples are cut at different positions, and the bulk mechanical properties are detected, and based on the comprehensive consideration of the material mechanical properties, the tensile strength Rm≥350MPa, the yield strength RP0.2≥270MPa, and the elongation A≥4% are defined as qualified.

[0119] The detection results are shown in Table 2, wherein the bulk mechanical properties of the 6 samples of Example 1 are qualified, and the tensile strength and yield strength of the 6 samples of Comparative Example 1 are not qualified.

[0120] Table 2 Bulk mechanical property detection results of the transverse large plane

[0121]

[0122] In summary, the wall thickness regulated by the present application can effectively reduce the large area porosity and shrinkage defects caused by the transverse large plane wall thickness, and improve the internal quality qualification rate and the bulk performance of the casting.

[0123] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be covered within the protection scope of the present application.

Claims

1. A casting method for casting a transversely large planar casting, characterized by, The method comprises the following steps: S1, designing a pouring system; S2, assembling a mold, placing mud columns in four quadrants on a horizontal large plane of an inner core, the mud columns having a permanent deformation characteristic of being easily deformed under pressure and having no rebound after the pressure disappears, and having a strength of 5-10 MPa; S3, continuing the mold assembly to form a blind cavity of the mold at the horizontal large plane, and completing the mold assembly; S4, disassembling the upper mold at the horizontal large plane, detecting the thickness of the four mud columns at the blind cavity of the mold, and taking the average value as the wall thickness δ of the blind cavity of the mold at the horizontal large plane; if the difference Δ between the wall thickness δ and the theoretical wall thickness δ0 of the blind cavity of the mold is greater than or equal to 5 mm, adjusting the parting surface at the horizontal large plane, and correcting the wall thickness by eliminating a certain amount of mold material from the bottom of the upper outer mold or the upper part of the lower outer mold at the parting surface of the horizontal large plane, the elimination amount of the mold material being A; S5, repeating the operation of S3 until the difference Δ between the wall thickness δ and the theoretical wall thickness δ0 of the blind cavity of the mold is less than 5 mm, and completing the mold assembly; S6, pouring molten metal for casting.

2. The method of claim 1, wherein, The horizontal large plane has an area of greater than or equal to 0.5 square meters.

3. The method of claim 2, wherein, The horizontal large plane comprises a plane, a concave surface, or a convex platform to meet different engineering and application requirements.

4. The method of claim 1, wherein, The number of the mud columns is four, and the mud columns are respectively placed at positions close to the middle of the corresponding quadrants.

5. The method of claim 4, wherein, The height h of the mud column is greater than or equal to δ+5 mm or h≥δ0+10 mm; δ0 is the theoretical wall thickness of the blind cavity of the mold; and δ is the wall thickness of the blind cavity of the mold measured in S4.

6. The method of claim 1, wherein, The elimination amount A satisfies δ-δ0-5≤A≤δ-δ0.

7. The method of claim 1, wherein, In S6, the pouring temperature is 710-720℃, and the filling speed is 0.02 atm.

8. The method according to claim 1 or 7, characterized in that, After S6, solidification, cooling, pressure relief, disassembly of the mold, removal of the casting, and cleaning of the excess parts on the surface of the casting are required to finally obtain the casting.

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