Method for reducing ladle sand defects in thick-section high manganese steel wheel-shaped castings and its castings

Abstract

The present invention discloses a method for reducing the defect of steel ladle sand of a thick-section high-manganese steel wheel-shaped casting and its casting, including setting a heating riser at the hub hot node on one side of the wheel-shaped casting; setting an external chiller at the hub hot node position symmetrical to the wheel-shaped casting and the heating riser; fixing a refractory ceramic riser conformal spacer at the intersection of the hub and the spoke at the lower part of the wheel-shaped casting heating riser, one end face of the ceramic riser spacer is in contact with and fixedly connected to the arc surface formed by the hub and the spoke of the wheel-shaped casting, and the other end face is parallel to the end face of the wheel-shaped casting and the outer arc of the inner cavity is consistent with the diameter of the heating riser. The casting system and the conformal refractory ceramic riser spacer are used to replace the hub riser entity patch and combined with the heating riser sleeve to improve the steel ladle sand at the root of the riser; a metal pipe sleeve hole core sealed with molding sand is set at the hoisting hole of the wheel-shaped casting to eliminate the defect of steel ladle sand at the hoisting hole; the defect of steel ladle sand at the groove is improved by using chromite sand with low binder in the groove and the like.

Description

Technical Field

[0001] The invention relates to the technical field of casting, in particular to a method for alleviating the defects of steel ladle sand of a thick-section high-manganese steel wheel-shaped casting and a casting thereof. Background Art

[0002] Ladle sand is a kind of sand sticking defect often encountered in the production of thick and large-section castings in sand casting. When the metal liquid infiltrates into the cavity, the pressure P 液 Greater than the radius r of the pores between sand particles 砂 The critical osmotic pressure P 临 When the casting is partially or completely sintered, a layer of mechanical mixture of sand and metal will adhere to the surface of the casting. Most of the time, it will be accompanied by high-temperature sintering of the molding sand. If it occurs in a small hole, it may block the hole. It is extremely difficult to remove such defects by scrapping. If it is removed by cold grinding, it will greatly consume man-hours and delay production progress. If it is removed by hot melting, the high temperature will induce the transformation of the structure in the casting and the precipitation of carbides at the grain boundaries, causing cracking in the heat-affected zone, and there is a great risk of scrapping. Especially for high-manganese steel materials, which have poor thermal conductivity and prolonged heat storage time of molten steel, it is more likely to cause ladle sand defects in thick and large sections.

[0003] Specifically, in order to ensure smooth shrinkage compensation of the riser of wheel-shaped castings, it is generally necessary to set a riser subsidy at the intersection of the hub and the spoke. Due to the setting of the riser subsidy, the size of the hot node at the root of the riser is enlarged, increasing the probability of the occurrence of ladle sand defects here. At the same time, sand cores are used for molding during casting. Due to the size of the lifting hole, the hole core has a weak ability to withstand the heat of molten steel, resulting in the lifting hole core being under the heat of high-temperature molten steel, resulting in infiltration and sintering ladle sand defects. The normal cleaning process can basically not be completed, and most of them can only be scrapped. In addition, due to the small space in the weight-reducing grooves on the castings, the sand mold is difficult to compact. Only one side of the groove sand mold can dissipate heat and exhaust, and the other sides are surrounded by high-temperature molten steel. The sand mold is subjected to strong heat, so ladle sand defects often occur, increasing the difficulty of cleaning the castings.

[0004] In summary, castings manufactured with existing technologies have defects such as ladle sand (sand penetration) at the root of the riser, the hoisting hole and the groove, resulting in a 100% rework rate for castings and a yield rate of less than 70%. The above causes a large waste of production and also brings a lot of inconvenience to the company's mass production of high quality. Summary of the invention

[0005] To solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides a method for reducing the ladle sand defects of thick-section high manganese steel wheel-shaped castings and its castings, which shortens the heat storage time of high-temperature molten steel, effectively reduces the contact between high-temperature molten steel and core sand, improves the refractoriness of the sand and shortens the crystallization and solidification time of the molten steel, effectively improves the quality problem of ladle sand defects, the surface quality of the casting is excellent, it can be used for mass production, saves resources, and has a high yield rate.

[0006] The technical solution of the present invention is as follows:

[0007] On the one hand, a method for reducing the ladle sand defects of thick-section high manganese steel wheel-shaped castings provided by the present invention includes:

[0008] Set a heating riser at the hot spot of the hub on one side of the wheel-shaped casting;

[0009] Set an external chiller at the hot spot of the hub symmetric to the heating riser of the wheel-shaped casting;

[0010] A refractory ceramic riser conforming spacer is fixedly arranged at the intersection position of the hub and the spoke below the heating riser of the wheel-shaped casting. One end face of the refractory ceramic riser spacer fits and is fixedly connected to the arc surface formed by the hub, spoke and rim of the wheel-shaped casting, and the other end face is parallel to the end face of the wheel-shaped casting and the outer arc of the inner cavity matches the diameter of the heating riser;

[0011] Set a metal sleeve hole core blocked by sand at the lifting hole of the wheel-shaped casting. Threads are provided on the outer circumferential surface of the metal sleeve hole core, and it is threadedly connected to the wheel-shaped casting through the threads.

[0012] Further, when threadedly connecting, coarse-thread threads are used for connection.

[0013] Further, dry sand and chromite sand are filled inside the lifting hole, and the chromite sand is located at both ends of the metal sleeve, the dry sand is located between the chromite sands at both ends inside the metal sleeve, and the outer end faces of the chromite sands at both ends are flush with the outer end face of the metal sleeve.

[0014] Further, the thickness of the metal sleeve is greater than or equal to 7 mm.

[0015] Further, a chromite facing sand layer is placed at the groove on the surface of the wheel-shaped casting.

[0016] Further, the thickness of the chromite facing sand layer is: 30 mm - 50 mm.

[0017] Further, the rim diameter of the wheel-shaped casting / hub diameter > 2, and the cross-sectional thickness at the intersection of the hub and the central spoke is ≥ 300 mm.

[0018] On the other hand, a wheel-shaped casting provided by the present invention is manufactured by using the method for reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting as described above.

[0019] The main advantages of the technical solution of the present invention are as follows:

[0020] For a method of reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention, a heating riser is arranged at the hot spot of the hub on one side of the wheel-shaped casting; an external chiller is arranged at the position of the hot spot of the hub symmetrical to the heating riser of the wheel-shaped casting; and a refractory ceramic riser conforming spacer is fixedly arranged at the intersection position of the lower part of the hub and the spokes of the heating riser of the wheel-shaped casting, so as to reduce the metal liquid infiltration pressure P 液 and the hot spot size at the root of the riser, shorten the heat storage time of the high-temperature molten steel, and reduce the heat action time between the molten steel and the molding sand, thereby effectively improving the ladle sand defects at the root of the riser, and the method of using the external chiller is convenient for operation and cleaning.

[0021] Furthermore, for a method of reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention, by arranging a metal sleeve core hole plugged with molding sand at the lifting hole of the wheel-shaped casting, it can effectively reduce the contact between the high-temperature molten steel and the core molding sand of the hole, and prevent the occurrence of ladle sand defects at the lifting hole core; and the threaded connection method of the metal sleeve core hole is convenient for operation, and the operation efficiency is improved by using coarse-thread threads.

[0022] Furthermore, for a method of reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention, by using chromite sand with a low binder content at grooves and other places, it not only reduces the contact reaction gas pressure, but also improves the refractoriness of the molding sand and shortens the crystallization and solidification time of the molten steel, thereby effectively improving the quality problems caused by the ladle sand defects at the grooves. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 is a schematic diagram of the overall structure of a wheel-shaped casting in a method for reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention;

[0025] Figure 2 is a schematic diagram of a perspective structure of a refractory ceramic riser spacer arranged on a wheel-shaped casting in a method for reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention;

[0026] Figure 3 is a top view schematic diagram of the overall structure of a wheel-shaped casting in a method for reducing the ladle sand defects of a thick-section high manganese steel wheel-shaped casting of the present invention;

[0027] Figure 4 Schematic diagram of the metal pipe sleeve hole core and its internal filling structure in a method for reducing ladle sand defects of a thick-section high manganese steel wheel-shaped casting according to the present invention;

[0028] Figure 5 is Figure 4 An enlarged view of region I of.

[0029] Description of reference numerals:

[0030] 1, wheel-shaped casting; 2, metal pipe sleeve hole core; 3, chromite sand; 4, dry sand; 5, hub; 6, rim; 7, lifting hole; 8, weight reduction groove; 9, refractory ceramic riser spacer; 10, external chill; 11, exothermic riser; 12, spoke. Specific embodiments

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0032] The technical solutions provided by the embodiments of the present invention will be described in detail below in conjunction with the drawings.

[0033] In a method for reducing ladle sand defects of a thick-section high manganese steel wheel-shaped casting according to the present invention, the ratio of the diameter of the rim 6 to the diameter of the hub 5 of the wheel-shaped casting 1 is greater than 2, the diameter of the lifting hole 7 is less than 80 mm, the cross-sectional thickness of the wheel-shaped casting 1 (the cross-sectional thickness at the intersection of the hub 5 and the central spoke) is greater than or equal to 300 mm, and it is high manganese steel with poor thermal conductivity. Example 1

[0034] As shown in the attached Figures 1 to 3 figures, the embodiments of the present invention provide a method for reducing ladle sand defects of a thick-section high manganese steel wheel-shaped casting 1, and the method includes:

[0035] An exothermic riser 11 is provided at the hot spot of the hub 5 on one side of the wheel-shaped casting, and an external chill 10 is provided at the position of the hot spot of the hub 5 symmetric to the exothermic riser 11 of the wheel-shaped casting;

[0036] A refractory ceramic riser spacer 9 is fixedly provided at the intersection position of the hub 5 and the spoke 12 below the exothermic riser 11 of the wheel-shaped casting. One end face of the refractory ceramic riser spacer 9 is in fit and fixed connection with the arc surface formed by the hub 5, the spoke 12, and the rim 6 of the wheel-shaped casting, and the other end face is parallel to the end face of the wheel-shaped casting 1 and the external arc of the inner cavity is in line with the diameter of the exothermic riser 11.

[0037] Specifically, the exothermic riser 11 is preferably of a cylindrical structure, and the dimensions and size of the cylindrical structure are determined according to the modulus method, that is, M 冒 = 1.2M 件 ; It should be noted that when setting the exothermic riser 11 for specific different wheel-shaped castings 1, according to M 冒 = 1.2M 件 a dedicated cylindrical exothermic riser 11 is set.

[0038] It should be noted that: the shape of the external chill 10 is designed and selected according to the shape of the part of the wheel-shaped casting 1 that needs to be chilled.

[0039] Specifically, the shape of the external chill 10 is designed and selected according to the shape of the part of the wheel-shaped casting 1 that needs to be chilled; the material selected for the external chill 10 has good thermal conductivity, a sufficiently high melting point and a large heat capacity, and the external chill 10 needs to meet the parameter requirement of δ = 100 mm; when the fabricated external chill 10 is in contact with the wheel-shaped casting 1, the surface of the side of the external chill 10 in contact with the wheel-shaped casting 1 is flat. Secondly, the contact surface of the reusable external chill 10 with the steel casting needs to be ground with a grinding wheel and coated with a coating and dried before use. When placing the external chill 10 on the wheel-shaped casting 1, it should be placed in a position where it is not easy to fall off. If there are multiple rows of chills, they should be arranged crosswise and the spacing should be appropriate, depending on the actual situation.

[0040] Preferably, the thickness of the refractory ceramic riser spacer 9 at the joint with the casting body is 20 mm to 30 mm, and the thickness of the remaining parts is 50 mm to 60 mm.

[0041] Specifically, a metal sleeve hole core 2 sealed with molding sand is provided at the lifting hole 7 of the wheel-shaped casting 1.

[0042] Specifically, the metal sleeve hole core 2 is threadedly connected to the body of the wheel-shaped casting 1.

[0043] Specifically, as Figure 5 shown, a coarse-thread screw is used for the threaded connection.

[0044] With such a setting, the bonding force between the metal sleeve hole core 2 and the casting body can be improved.

[0045] Specifically, as Figure 4 shown, dry sand 4 and chromite molding sand 3 are filled inside the metal sleeve hole core 2 in the lifting hole 7, and the chromite molding sand 3 is located at both ends of the metal sleeve hole core 2, the dry sand 4 is located between the chromite molding sands 3 at both ends inside the metal sleeve, and the outer end faces of the chromite molding sands 3 at both ends are flush with the outer end face of the metal sleeve hole core 2.

[0046] With such a setting, the metal pipe sleeve core hole 2 at the lifting hole 7 is blocked with molding sand, effectively reducing the contact between the high-temperature molten steel and the molding sand of the core hole, and eliminating the generation of ladle sand defects at the core of the lifting hole 7.

[0047] Specifically, in the present invention, the diameter dimension of the lifting hole 7 of the wheel-shaped casting is relatively small, and preferably the diameter of the lifting hole 7 < 80 mm.

[0048] Specifically, the thickness (wall thickness) of the metal pipe sleeve core hole 2 is greater than or equal to 7 mm, as Figure 4 shown in A.

[0049] With such a setting, it can ensure that the metal pipe sleeve core hole 2 has a certain strength while ensuring threaded connection.

[0050] Specifically, the size specification of the metal sleeve is determined according to the diameter of the lifting hole 7, and preferably the metal sleeve core hole 2 is made of a steel pipe of Q235 material.

[0051] Specifically, a chromite facing sand layer is placed at the groove on the surface of the wheel-shaped casting 1.

[0052] Preferably, the binder is a binder with a low resin addition amount, and the resin addition amount is 0.8%.

[0053] Specifically, the thickness of the chromite facing sand layer is: 30 mm - 50 mm.

[0054] Specifically, the diameter of the rim 6 of the wheel-shaped casting 1 / the diameter of the hub 5 > 2, and the cross-sectional thickness at the intersection of the hub 5 and the central spoke 12 ≥ 300 mm.

[0055] Specifically, a method for reducing ladle sand defects of a thick-section high manganese steel wheel-shaped casting in the present invention, in addition to using the above method, further includes:

[0056] When pouring the wheel-shaped casting 1, the pouring temperature is: 1415 ± 5 °C;

[0057] When coating the surface of the poured wheel-shaped casting 1 with a coating, the coating applied is a magnesite powder alcohol-based coating;

[0058] When pouring the wheel-shaped casting 1, the pouring method used is: the bottom pouring method of the refractory brick pipe at the rim 6;

[0059] An air outlet structure is provided in the wheel-shaped casting 1. Specifically, air outlet ropes are provided in the mold and core of the wheel-shaped casting 1, and air channels are provided on the upper end hub 5 and rim 6 surfaces, etc.;

[0060] Direct external chill irons 10 are provided at the hot spots of the hub 5 and rim 6 opposite to the exothermic riser 11;

[0061] With such settings, by the above method, it is possible to ensure smooth liquid flow during pouring, unobstructed gas path, and sufficient feeding capacity of the exothermic riser 11. Embodiment 2

[0062] A wheel-shaped casting provided by the present invention is manufactured by the above method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings.

[0063] A wheel-shaped casting 1 of the present invention can reduce ladle sand of thick-section high manganese steel wheel-shaped castings 1, including at the hot spot of the hub on one side of the wheel-shaped casting 1. According to the modulus method, that is, M 冒 = 1.2M 件 a special cylindrical exothermic riser 11 is set; at the position of the hub hot spot symmetrical to the wheel-shaped casting 1 and the exothermic riser 11, an external chiller 10 (δ = 100 mm) is set; at the intersection position of the lower hub 5 and the spoke 12 of the wheel-shaped casting 1 under the exothermic riser 11, a refractory ceramic riser conforming spacer 9 is fixedly arranged. The thickness of the refractory ceramic riser conforming spacer 9 at the joint with the body of the wheel-shaped casting 1 is 20 mm - 30 mm, and the thickness of the rest is 50 mm - 60 mm. One end face of the refractory ceramic riser conforming spacer 9 fits and is fixedly connected to the arc surface formed by the hub 5, the rim 6, and the spoke 12, and the other end face is parallel to the end face of the wheel-shaped casting 1 and the outer arc of the inner cavity matches the diameter of the exothermic riser 11, which can shorten the heat storage time of the high-temperature molten steel, effectively reduce the contact between the high-temperature molten steel and the core sand, improve the refractoriness of the sand, and shorten the crystallization and solidification time of the molten steel, effectively improving the quality problem of ladle sand defects.

[0064] Specifically, when casting a wheel-shaped casting 1 of the present invention, the above method is adopted, which specifically includes:

[0065] (1) Calculate the hot spot modulus M of the casting according to the casting structure 件 , establish the riser modulus M 冒 = 1.2M 件 and the quantity (theoretical riser continuity of the wheel-shaped casting 1), change the two hub 5 insulating risers with symmetrical distribution to one exothermic riser 11 on one side and the way of directly placing external chillers 10 on the symmetrical side, and reduce the riser height to reduce the metal liquid infiltration pressure P 液 , and at the same time use the conforming refractory ceramic riser spacer 9 to replace the riser solid subsidy of the hub 5. On the premise of ensuring the smooth feeding channel of the riser, reduce the hot spot size at the root of the riser, shorten the heat storage time of the high-temperature molten steel, and reduce the thermal action intensity between the molten steel and the sand, thereby effectively improving the ladle sand defects at the root of the riser;

[0066] (2)Determine the specifications of the metal pipe sleeve hole core 2 according to the size of the lifting hole 7. After actual test verification, Q235 steel pipe is selected, and it is ensured that the wall thickness is ≥ 7 mm. At the same time, coarse-thread threads are machined on the outer circumferential surface of the pipe sleeve to improve the bonding force between the steel sleeve and the casting body. The upper and lower ends of the pipe sleeve are blocked with chromite sand 3, and chromite dry sand 4 is filled in the middle. The lifting hole 7 uses sand to block the metal pipe sleeve hole core 2, effectively reducing the contact between the high-temperature molten steel and the core sand, and eliminating the generation of steel ladle sand defects at the core of the lifting hole 7;

[0067] (3)For parts such as the weight reduction groove 8 where heat dissipation and gas exhaust are poor and the thermal effect of the molten steel is strong, by using chromite sand with a low binder (resin addition amount of 0.8%), on the premise of ensuring the strength of the sand mold, both the contact reaction gas pressure is reduced and the refractoriness of the molding sand is improved. At the same time, the crystallization and solidification time of the molten steel is shortened, thus effectively improving the quality problem of steel ladle sand defects at the groove.

[0068] In addition, through the following: pouring temperature: 1415 ± 5 °C; coating: brushing magnesia powder alcohol-based coating on the surface; gating system: adopting the bottom gating method with a refractory brick pipe flange 6; gas outlet: air outlet ropes are arranged in the mold and core, and air outlet channels are arranged on the upper end hub 5 and flange 6 surfaces; chill: direct external chills 10 are arranged at the hot spots of the hub 5 and flange 6 opposite the riser; through the above methods and steps, it is ensured that the liquid flow is stable, the gas path is unobstructed, and the riser feeding capacity is sufficient during pouring.

[0069] With such settings, a method for reducing steel ladle sand defects in thick-section high manganese steel wheel-shaped castings and its castings of the present invention utilize the optimized design of the gating and risering system and the use of a conformal refractory ceramic riser spacer 9 to replace the solid riser pad of the hub 5 and combine with the use of a riser sleeve 11, reducing the metal liquid infiltration pressure P 液 and the hot spot size at the riser root, shortening the heat storage time of the high-temperature molten steel, reducing the thermal action time between the molten steel and the molding sand, thus effectively improving the steel ladle sand at the riser root; the lifting hole 7 uses sand to block the metal pipe sleeve hole core 2, effectively reducing the contact between the high-temperature molten steel and the core sand, and can effectively reduce the contact between the high-temperature molten steel and the core sand, eliminating the occurrence of steel ladle sand defects at the core of the lifting hole 7; the use of chromite sand with a low binder content at the groove and other places not only reduces the contact reaction gas pressure but also improves the refractoriness of the molding sand and shortens the crystallization and solidification time of the molten steel, thus effectively improving the quality problem of steel ladle sand defects at the groove.

[0070] In summary, the wheel-shaped casting 1 is manufactured by the method of the present invention, solving the problem of steel ladle sand at the lifting hole 7, and at the same time solving the problems of steel ladle sand at the riser root and the groove and other places. The qualified rate of the casting reaches 100%, the surface quality of the casting is excellent, and it can be used for mass production.

[0071] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. In addition, in this text, "front", "rear", "left", "right", "upper" and "lower" are all referenced with respect to the placement state shown in the drawings.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reducing ladle sand defects in thick-section high manganese steel wheel-shaped castings, characterized in that Including: A heating riser is arranged at the hot spot of the hub on one side of the wheel-shaped casting; External chill is arranged at the position of the hot spot of the hub symmetrical to the heating riser of the wheel-shaped casting; A refractory ceramic riser conforming spacer is fixedly arranged at the intersection position of the hub and the spokes below the heating riser of the wheel-shaped casting, and one end face of the refractory ceramic riser conforming spacer fits and is fixedly connected with the arc surface formed by the hub and the rim, and the other end face is parallel to the end face of the wheel-shaped casting and the outer arc of the inner cavity matches the diameter of the heating riser; A metal sleeve core plugged with molding sand is arranged at the lifting hole of the wheel-shaped casting, and threads are arranged on the outer circumferential surface of the metal sleeve core, and the metal sleeve core is threadedly connected with the wheel-shaped casting through the threads.

2. The method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to claim 1, characterized in that, The threads used in the threaded connection are coarse threads.

3. The method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to claim 1, characterized in that Dry sand and chromite molding sand are filled inside the metal sleeve core of the lifting hole, and the chromite molding sand is located at both ends of the metal sleeve, the dry sand is located between the chromite molding sands at both ends inside the metal sleeve, and the outer end faces of the chromite molding sands at both ends are flush with the outer end face of the metal sleeve core.

4. The method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to claim 1, characterized in that The wall thickness of the metal sleeve core is greater than or equal to 7 mm.

5. The method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to claim 1, characterized in that, A chromite facing sand layer is placed at the groove on the surface of the wheel-shaped casting.

6. The method for reducing ladle sand defects in thick-section high manganese steel wheel-shaped castings according to claim 5, characterized in that, The thickness of the chromite facing sand layer is: 30 mm to 50 mm.

7. The method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to claim 1, characterized in that, The rim diameter / hub diameter of the wheel-shaped casting > 2, and the cross-sectional thickness at the intersection of the hub and the central spokes ≥ 300 mm.

8. A wheel-shaped casting, characterized in that, Manufactured by using the method for reducing ladle sand defects of thick-section high manganese steel wheel-shaped castings according to any one of claims 1-7.

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