Casting method and castings

Abstract

The present disclosure provides a casting method and a casting, the casting method comprising: dividing the casting into different temperature zones according to the predicted surface temperature distribution of the casting to be produced at a set time. A sand mold assembly is prepared according to each temperature zone. The sand mold assembly includes a shell structure and a cooling portion, the shell structure having a casting cavity formed in the center and a plurality of hollow areas formed on the outside corresponding to the temperature zones, wherein a cooling portion is provided in the selected hollow area. The required water absorption of the cooling portion is determined. Water is injected into the corresponding hollow area according to the required water absorption of each cooling portion. A melt is poured into the casting cavity, and a casting is formed after cooling. In this way, the casting can be cooled according to the set cooling sequence, thereby preventing the top of the casting from cooling rapidly and causing the channel for pouring the melt to be blocked.

Description

Technical Field

[0001] The present disclosure relates to the field of casting, and in particular to a casting method and a casting. Background Art

[0002] Sand casting is a widely used casting process in which molten metal is poured into a sand mold and cooled and solidified to form a casting. The low cooling capacity of sand molds results in coarse grains and relatively poor casting performance. To improve the performance of the casting, some sand casting processes employ localized cooling control by placing chillers within the sand mold. The chillers are encased within the sand mold. This results in uncontrolled cooling rates at various locations on the casting during the cooling process, potentially leading to rapid cooling at the top of the casting, resulting in blockage of the pouring channel. Summary of the Invention

[0003] The present disclosure provides a casting method and a casting to solve at least some of the problems in the related art.

[0004] The present disclosure provides a casting method, comprising:

[0005] Different temperature zones are formed based on the predicted surface temperature distribution of the casting to be produced at a set time;

[0006] A sand mold assembly is prepared according to each of the temperature zones; the sand mold assembly includes a shell structure and a cooling portion, the shell structure having a casting cavity formed in the center and a plurality of hollow areas formed on the outside corresponding to the temperature zones, wherein the cooling portion is provided in a selected hollow area;

[0007] determining the required water absorption of the cooling unit;

[0008] injecting water into the corresponding hollow area according to the required water absorption amount of each cooling part; and

[0009] A melt is poured into the casting cavity and cooled to form the casting.

[0010] Furthermore, determining the required water absorption amount of the cooling unit includes:

[0011] Determining a standard temperature of each temperature zone at the set time according to the number of temperature zones divided during prediction, and the lowest and highest temperatures of the surface of the casting to be produced at the set time;

[0012] Determine a maximum difference among the obtained multiple differences based on a difference between a standard temperature of each temperature zone at the set time and a temperature of each grid unit on the casting corresponding to the temperature zone at the set time;

[0013] The required water absorption of the cooling portion in the hollow area corresponding to the temperature zone is determined based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time and the cooling intensity coefficient.

[0014] Furthermore, determining the standard temperature of each temperature zone at the set time according to the number of divisions of the temperature zone during prediction, the minimum temperature and the maximum temperature of the surface of the casting to be produced at the set time, includes:

[0015] The standard temperature of each temperature zone at the set time is determined by the following relationship:

[0016]

[0017] is the standard temperature of each temperature zone numbered a at the set time, T min is the minimum temperature of the surface of the casting to be produced at the set time, T max is the maximum surface temperature of the casting to be produced at the set time, a is the number of the temperature zones formed by dividing the casting to be produced from bottom to top in the height direction, and b is the number of divisions of the temperature zones.

[0018] Furthermore, determining the maximum difference among the obtained multiple differences based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time includes:

[0019] The maximum difference among the obtained multiple differences is determined by the following relationship:

[0020]

[0021] ΔT max is the maximum difference among the multiple differences obtained, T i,j,k For each temperature zone numbered a, the temperature of the grid cell on the casting whose coordinates are represented as (i, j, k) at the set time.

[0022] Furthermore, determining the required water absorption of the cooling portion in the hollow area corresponding to the temperature zone according to the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time and the cooling intensity coefficient includes:

[0023] The required water absorption of the cooling part in the hollow area corresponding to the temperature area numbered a is determined by the following relationship:

[0024]

[0025] m w is the required water absorption of the cooling part in the hollow area corresponding to the temperature area, c is the cooling intensity coefficient, where, N is the total number of grid cells on the casting corresponding to the temperature zone numbered a, m w_max It is the maximum water absorption capacity of the cooling part in a hollow area.

[0026] Furthermore, the step of injecting water into the corresponding hollow area according to the required water absorption amount of each cooling part includes:

[0027] Determining the required water injection time corresponding to the required water absorption amount according to the corresponding relationship between the water absorption amount and the water injection time under different types of the cooling parts;

[0028] Water is injected into the corresponding hollow area according to the required water injection time.

[0029] Furthermore, before pouring the melt into the casting cavity and forming the casting after cooling, the method further comprises:

[0030] Place the water-filled sand mold component for a set period of time.

[0031] Furthermore, the shell-type structure includes a main body and a plurality of raised structures protruding from the outside of the main body, the plurality of raised structures are arranged at intervals along the height direction of the main body, and the main body and two adjacent raised structures enclose the hollow area.

[0032] Furthermore, the thickness of the protruding structure is greater than or equal to 5 mm; and / or

[0033] The length of the protruding structure extending from the outer side of the main body is greater than or equal to 30 mm; and / or

[0034] The ratio of the distance between two adjacent protruding structures away from the side of the main body to the length of the protruding structure extending from the outer side of the main body is less than or equal to 3; and / or

[0035] The angle between the extending direction of the protruding structure and the horizontal direction is greater than or equal to -10°.

[0036] The present disclosure provides a casting, which is prepared by the casting method described in any one of the above embodiments.

[0037] The disclosed embodiments provide a casting method that can divide the surface of a casting to be produced into different temperature zones based on the predicted temperature distribution at a set time. The cooling rate is controlled by the contents of the hollowed-out areas formed in the sand mold assembly corresponding to the temperature zones. A cooling section is provided in the selected hollowed-out area to accelerate the cooling rate at locations with higher surface temperatures on the casting. Furthermore, by determining the required water absorption of the cooling section, the casting can be cooled according to a set cooling sequence, thereby preventing the top of the casting from cooling rapidly and causing blockage in the channel for pouring the melt.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] Figure 1 Shown is a schematic plan view of a sand mold assembly according to one embodiment of the present disclosure;

[0041] Figure 2 Shown is a flow chart of a casting method according to one embodiment of the present disclosure;

[0042] Figure 3 Shown Figure 2 A further flow chart of the casting method shown;

[0043] Figure 4 Shown Figure 2 A further flow diagram of the casting method is shown. DETAILED DESCRIPTION

[0044] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0045] The following describes the casting method and castings of the embodiments of the present disclosure in detail with reference to the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0046] See also Figure 1 and Figure 2As shown, the embodiment of the present disclosure provides a casting method that can be applied to the casting of metals such as iron, steel, and nonferrous metals. The casting method may include steps S101 to S105.

[0047] In step S101, based on the predicted temperature distribution on the surface of the casting to be produced at the set time, different temperature zones are formed. The range of the set time can be between 1min and 30min. A temperature distribution model of the surface of the casting to be produced at the set time can be established by software, and different temperature zones are formed according to the temperature distribution model. In one embodiment, based on the predicted temperature distribution on the surface of the casting to be produced at the set time, a temperature interval value is determined. According to the determined temperature interval value, different temperature zones are formed. Wherein, a temperature zone has a plurality of temperature nodes, and the temperature difference between each temperature node in the same temperature zone is less than or equal to the temperature interval value. Different castings to be produced have different surface temperature distributions at the set time, and the temperature zones formed by the division are different, so that the casting method can be applied to the cooling process of different castings.

[0048] In step S102, a sand mold assembly 10 is prepared according to each temperature zone. The sand mold assembly 10 includes a shell structure 11 and a cooling part 12. The cooling part 12 can be one of loose sand and hydrogel, and multiple cooling parts 12 can include at least one of loose sand and hydrogel. The cooling part 12 made of the above material has a large water absorption capacity and a good cooling effect. The cooling part 12 can also use other cooling media, which is not limited by the present disclosure. By using the cooling part 12 for cooling, there is no need to add additional cooling structures such as cold iron, and the structure is simple. In one embodiment, the shell structure 11 can be a mixture of sand and adhesive, and the cooling part 12 can be loose sand (i.e., sand without adhesive added). In this way, the sand mold assembly 10 can be directly prepared by 3D printing technology, and the preparation method is simple. A casting cavity 13 is formed in the center of the shell structure 11, and multiple hollow areas 14 are formed on the outside corresponding to the temperature zones. The hollow area 14 corresponds to the temperature zone. Among them, one hollow area 14 can correspond to one temperature zone, or multiple hollow areas 14 can correspond to one temperature zone. Each hollow area 14 can serve as a controlled cooling unit. A cooling section 12 is provided within a selected hollow area 14. The selected hollow area 14 can be the entire hollow area 14 or a portion thereof. The type of cooling section 12 provided within different selected hollow areas 14 can be the same, such as all selected hollow areas 14 being provided with loose sand. The type of cooling section 12 provided within different selected hollow areas 14 can also be different, such as some selected hollow areas 14 being provided with loose sand while others being provided with hydrogel. Unselected hollow areas 14 can be left empty or provided with insulation sleeves. In one embodiment, the hollow areas for which cooling sections 12 are provided can be selected based on the temperature zones. For example, cooling sections 12 can be provided within hollow areas 14 corresponding to high-temperature zones on the casting surface to accelerate cooling. Hollow areas 14 corresponding to low-temperature zones on the casting surface can be left empty, or insulation sleeves can be provided within hollow areas 14 corresponding to low-temperature zones on the casting surface to slow cooling. When the shell structure 11 is a mixture of sand and adhesive, and the cooling part 12 is loose sand, after preparing the sand mold component 10 by 3D printing technology, it is necessary to clean the loose sand in the casting cavity 13 and retain the loose sand in the selected hollow area 14. The water absorption properties of the loose sand that has not been removed in the selected hollow area 14 can be used to regulate the cooling rate at different positions during the cooling process.

[0049] In one embodiment, the shell structure 11 includes a main body 15 and a plurality of protruding structures 16 protruding from the outside of the main body 15. The thickness of the main body 15 can be set according to each temperature zone. A casting cavity 13 is formed in the center of the main body 15, and the casting cavity 13 is used to accommodate the melt. The protruding structure 16 is formed protruding from the outside of the main body 15. The protruding structure 16 can be plate-shaped, and a reinforcing rib plate can be used. The protruding structure 16 can be a straight plate or a bent plate. Figure 1 As shown in FIG, the raised structure 16 at the upper end of the main body 15 is a straight plate, while the raised structure 16 at the lower end of the main body 15 is a bent plate. Multiple raised structures 16 are spaced apart along the height direction of the main body 15. The main body 15 and two adjacent raised structures 16 enclose a hollow area 14. The hollow area 14 is formed by the main body 15 and two adjacent raised structures 16, making the method of forming the hollow area 14 simple and highly feasible.

[0050] In one embodiment, the thickness e of the protruding structure 16 is greater than or equal to 5 mm, that is, e≥5 mm. In this way, the protruding structure 16 has high strength and can better support the cooling portion 12.

[0051] In one embodiment, the length d of the protruding structure 16 extending from the outer side of the main body 15 is greater than or equal to 30 mm, that is, d≥30 mm. The hollow area 14 thus formed has a more suitable capacity and can accommodate more cooling parts 12.

[0052] In one embodiment, the ratio of the distance t between two adjacent protrusion structures 16 away from the side of the main body 15 to the length d of the protrusion structure 16 extending from the outer side of the main body 15 is less than or equal to 3, that is, The distance t between two adjacent protrusions 16 away from the main body 15 is the equivalent diameter of the hollow area 14. The ratio of the distance t to the length d is less than or equal to 3, which can prevent the cooling portion 12 from falling out of the hollow area 14.

[0053] In one embodiment, the angle α between the extending direction of the protruding structure 16 and the horizontal direction is greater than or equal to -10°, that is, α≥-10°. In this way, the protruding structure 16 has an appropriate inclination angle, which can prevent the cooling portion 12 from falling out of the hollow area 14 due to gravity.

[0054] In step S103, the required water absorption capacity of the cooling unit 12 is determined. The required water absorption capacity of the cooling unit 12 does not exceed its saturated water absorption capacity. This prevents excessive moisture content in the shell structure 11 caused by dripping or seeping water from the surface of the cooling unit 12, further preventing defects such as pores in the casting. The required water absorption capacity of the cooling unit 12 can be determined based on the temperature (temperature distribution and temperature range) of the casting to be produced and the required cooling sequence for the casting to be produced. The cooling sequence can refer to sequential cooling or simultaneous cooling.

[0055] In step S104, water is injected into the corresponding hollow areas 14 based on the required water absorption capacity of each cooling section 12. Water can be injected into the corresponding hollow areas 14 using a syringe, dropper, pipe, nozzle, or other means. If the cooling section 12 is loose sand, the above water injection method allows the loose sand to evenly absorb water through capillary action. Furthermore, when water is injected into the corresponding hollow areas 14, it is absorbed by the cooling section 12, thus preventing contact between the melt poured into the casting cavity 13 and the water, ensuring safe and reliable operation.

[0056] In step S105, a melt is poured into the casting cavity 13 and a casting is formed after cooling. The melt can be a liquid after the metal such as iron, steel, nonferrous metal, etc. is melted. The molten metal can be cooled in the casting cavity 13 to form a casting. During the cooling process, the heat will first be conducted to the shell structure 11, and then transferred to the outside through the contents in the hollow area 14. The insulation sleeve in the unselected hollow area 14 can reduce the cooling rate. The cooling part 12 in the selected hollow area 14 can accelerate the cooling rate, and the cooling rate is related to the water absorption of the cooling part 12. Among them, the higher the water absorption of the cooling part 12, the faster the cooling rate.

[0057] The embodiment of the present disclosure provides a casting method, which can divide and form different temperature zones according to the predicted temperature distribution of the surface of the casting to be produced at a set time. The cooling rate is controlled by the content of the hollow area 14 formed by the sand mold assembly 10 corresponding to the temperature zone, wherein a cooling part 12 is provided in the selected hollow area 14, which can accelerate the cooling rate of the position with higher surface temperature of the casting. And by determining the required water absorption amount of the cooling part 12, the casting can be cooled according to the set cooling sequence, thereby preventing the top of the casting from cooling rapidly and causing the channel for pouring the melt to be blocked. At the same time, rapid cooling of the casting can be achieved, shortening the residence time of the casting in the sand mold assembly 10, improving production efficiency while reducing the thermal stress of the casting, thereby reducing the risk of deformation and cracks, and improving the performance of the casting.

[0058] In one embodiment, after pouring the melt into the casting cavity 13 and cooling it to form a casting, the process further includes: stabilizing the water-filled sand mold assembly 10 for a set period of time. The set period is less than or equal to seven days. This prevents water from the cooling portion 12 from seeping into the shell structure 11, further preventing defects such as pores from forming in the casting. Stabilizing the water-filled sand mold assembly 10 for a set period of time facilitates sufficient water absorption by the cooling portion 12, thereby ensuring the cooling effect of the cooling portion 12.

[0059] See also Figure 3 As shown, in one embodiment, determining the required water absorption amount of the cooling unit 12 may include steps S201 to S203.

[0060] In step S201 , the standard temperature of each temperature zone at a set time is determined according to the number of temperature zones divided during prediction and the minimum and maximum surface temperatures of the casting to be produced at the set time.

[0061] In step S202, the maximum difference among the obtained multiple differences is determined based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time. Each temperature zone includes multiple grid units divided and formed on the casting to be produced. The maximum difference among the obtained multiple differences is determined based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit in the temperature zone at the set time. For example: at the set time, the first difference between the standard temperature of the first temperature zone and the temperature of the first grid unit in the first temperature zone at the set time, the second difference between the standard temperature of the first temperature zone and the temperature of the second grid unit in the first temperature zone, ..., the Mth difference between the standard temperature of the first temperature zone and the temperature of the Mth grid unit in the first temperature zone. Among the multiple differences obtained above, the maximum difference is determined, that is, the maximum difference among the first difference, the second difference, ..., and the Mth difference. The method for determining the maximum difference among the obtained multiple differences in the second temperature zone, ..., and the Wth temperature zone is as described above.

[0062] In step S203, the required water absorption capacity of the cooling portion within the hollowed-out area corresponding to each temperature zone is determined based on the difference, maximum difference, and cooling intensity coefficient between the standard temperature of each temperature zone at a set time and the temperature of each grid cell on the casting corresponding to that temperature zone at the set time. This method for determining the required water absorption capacity is simple and easy to operate.

[0063] In one embodiment, determining the standard temperature of each temperature zone at a set time according to the number of temperature zones divided during prediction and the minimum and maximum temperatures of the surface of the casting to be produced at the set time includes:

[0064] The standard temperature of each temperature zone at the set time is determined by the following relationship:

[0065]

[0066] is the standard temperature of the temperature zone numbered a at the set time, T min is the minimum surface temperature of the casting to be produced at the set time, T max is the maximum surface temperature of the casting to be produced at the set time, a is the number of the temperature zones formed by dividing the casting to be produced from bottom to top in the height direction, and b is the number of temperature zones divided. a is a natural number selected from 1, 2, 3, ..., b in sequence to determine the standard temperature of each temperature zone at the set time.

[0067] In one embodiment, determining a maximum difference among a plurality of obtained differences based on a difference between a standard temperature of each temperature zone at a set time and a temperature of each grid unit on the casting corresponding to the temperature zone at the set time comprises:

[0068] The maximum difference among the obtained multiple differences is determined by the following relationship:

[0069]

[0070] ΔT max is the maximum difference among the multiple differences obtained, T i,j,k The temperature of the grid unit on the casting whose coordinates are represented by (i, j, k) corresponding to the temperature zone numbered a at the set time.

[0071] In one embodiment, the required water absorption of the cooling portion in the hollow area corresponding to the temperature zone is determined based on the difference between the standard temperature of each temperature zone at a set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time and the cooling intensity coefficient, including:

[0072] The required water absorption of the cooling part in the hollow area corresponding to the temperature area numbered a is determined by the following relationship:

[0073]

[0074] m w is the required water absorption of the cooling part in the hollow area corresponding to the temperature zone, c is the cooling intensity coefficient, where, N is the total number of grid cells on the casting corresponding to the temperature zone numbered a, m w_max It is the maximum water absorption of the cooling part in a hollow area.

[0075] See also Figure 4As shown, in one embodiment, according to the required water absorption amount of each cooling part 12, water is injected into the corresponding hollow area 14, which may include steps S301 to S302.

[0076] In step S301, the required water filling duration corresponding to the required water intake is determined based on the corresponding relationship between water intake and water filling duration for different types of cooling units 12. Cooling units 12 of the same type have a fixed corresponding relationship between water intake and water filling duration, and the required water intake duration corresponding to the required water intake can be compared and confirmed within this relationship.

[0077] In step S302, water is injected into the corresponding hollow area 14 according to the required water injection time. In this way, by controlling the length of the water injection time, it can be determined whether the cooling unit 12 has reached the required water absorption. This method of determining whether the cooling unit 12 has reached the required water absorption is simple and easy to implement.

[0078] The present disclosure provides a casting, which is prepared by the above-mentioned casting method. It should be noted that the description of the casting method in the above-mentioned embodiments and implementation methods is also applicable to the casting of the embodiment of the present disclosure.

[0079] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A casting method, characterized in that: include: Different temperature zones are formed based on the predicted surface temperature distribution of the casting to be produced at a set time; A sand mold assembly is prepared according to each of the temperature zones; the sand mold assembly includes a shell structure and a cooling portion, the shell structure having a casting cavity formed in the center and a plurality of hollow areas formed on the outside corresponding to the temperature zones, wherein the cooling portion is provided in a selected hollow area; the cooling portion is accommodated in the hollow area; the cooling portion is one of loose sand and hydrogel; the shell structure includes a main body and a plurality of protruding structures protruding from the outside of the main body, the plurality of protruding structures are arranged at intervals along the height direction of the main body, the main body and two adjacent protruding structures enclose the hollow area to form the cooling portion, and the protruding structures support the cooling portion; determining the required water absorption of the cooling unit; According to the required water absorption of each cooling unit, water is injected into the corresponding hollow area; according to the corresponding relationship between the water absorption and the water injection time under different types of cooling units, the required water injection time corresponding to the required water absorption is determined; according to the required water injection time, water is injected into the corresponding hollow area; and A melt is poured into the casting cavity and cooled to form the casting.

2. The casting method according to claim 1, characterized in that The determining the required water absorption amount of the cooling unit includes: Determining a standard temperature of each temperature zone at the set time according to the number of temperature zones divided during prediction, and the lowest and highest temperatures of the surface of the casting to be produced at the set time; Determine a maximum difference among the obtained multiple differences based on a difference between a standard temperature of each temperature zone at the set time and a temperature of each grid unit on the casting corresponding to the temperature zone at the set time; The required water absorption of the cooling portion in the hollow area corresponding to the temperature zone is determined based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time and the cooling intensity coefficient.

3. The casting method according to claim 2, characterized in that The step of determining the standard temperature of each temperature zone at the set time according to the number of temperature zones divided during prediction and the minimum and maximum temperatures of the surface of the casting to be produced at the set time comprises: The standard temperature of each temperature zone at the set time is determined by the following relationship: is the standard temperature of each temperature zone numbered a at the set time, T min is the minimum temperature of the surface of the casting to be produced at the set time, T max is the maximum surface temperature of the casting to be produced at the set time, a is the number of the temperature zones formed by dividing the casting to be produced from bottom to top in the height direction, and b is the number of divisions of the temperature zones.

4. The casting method according to claim 3, characterized in that Determining the maximum difference among the obtained multiple differences based on the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time includes: The maximum difference among the obtained multiple differences is determined by the following relationship: ΔT max is the maximum difference among the multiple differences obtained, T i,j,k For each temperature zone numbered a, the temperature of the grid cell on the casting whose coordinates are represented as (i, j, k) at the set time.

5. The casting method according to claim 4, characterized in that The step of determining the required water absorption of the cooling portion in the hollow area corresponding to the temperature zone according to the difference between the standard temperature of each temperature zone at the set time and the temperature of each grid unit on the casting corresponding to the temperature zone at the set time and the cooling intensity coefficient includes: The required water absorption of the cooling part in the hollow area corresponding to the temperature area numbered a is determined by the following relationship: m w is the required water absorption of the cooling part in the hollow area corresponding to the temperature area, c is the cooling intensity coefficient, where, N is the total number of grid cells on the casting corresponding to the temperature zone numbered a, m w_max It is the maximum water absorption capacity of the cooling part in a hollow area.

6. The casting method according to claim 1, characterized in that The method further comprises: pouring the melt into the casting cavity and cooling the casting to form a casting. Place the water-filled sand mold component for a set period of time.

7. The casting method according to claim 1, characterized in that The thickness of the protruding structure is greater than or equal to 5 mm; and / or The length of the protruding structure extending from the outer side of the main body is greater than or equal to 30 mm; and / or The ratio of the distance between two adjacent protruding structures away from the side of the main body to the length of the protruding structure extending from the outer side of the main body is less than or equal to 3; and / or The angle between the extending direction of the protruding structure and the horizontal direction is greater than or equal to -10°.

8. A casting, characterized in that: The method is prepared by the casting method according to any one of claims 1 to 7.

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