Embedded high manganese steel frog hole casting process

Abstract

The invention provides an embedded high manganese steel frog hole casting process. A lower casting mold is manufactured; a bolt hole core seat is additionally arranged on the lower casting mold corresponding to a bolt hole position of the embedded high manganese steel frog; bolt hole sand cores are arranged in one-to-one correspondence with the bolt hole core seats, and cavities of the bolt hole sand cores are used for forming cast holes; molding sand fills the periphery of the bolt hole sand core to connect the bolt hole sand core with the lower casting mold into a whole; manufacturing an upper casting mold; the upper casting mold is subjected to tamping treatment corresponding to bolt holes of the high-manganese steel frog; and the upper and lower casting molds are closed and then cast to realize hole casting. The technical problems that the embedded high manganese steel frog is low in hole casting precision, large in difficulty and high in cost are solved, hole casting is achieved under the condition that the casting mold parting surface structure is not changed, the enterprise production cost is reduced, the hole casting size and position precision are ensured, and the quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of operation transportation metallurgical core casting, and particularly relates to an embedded high manganese steel frog casting hole process. Background Art

[0002] The frog company of China Railway Baqiao Group has been producing various high manganese steel frogs for a long time, including embedded high manganese steel frogs. In the past, when casting embedded high manganese steel frogs, bolt holes were not cast, and post-processing machining was used to drill bolt holes for assembling rails on both sides of the frog. Due to the high internal quality requirements of the casting body, poor position accuracy of the casting holes, and difficulty in cleaning the sodium silicate sand cores in the bolt holes of the casting later, the bolt holes of embedded high manganese steel frogs have long been formed by machining drilling and milling processes. However, the wall thickness of the embedded high manganese steel frog is relatively thick, the rail wall and the hole axis are not perpendicular, the drilling difficulty is large, and the drill bit consumption is large during drilling; moreover, because the product structure of the embedded frog cannot be changed, the number of supporting toolings required for frog manufacturing is large and the modification cost is high, resulting in high production costs. Therefore, the following improved technical solutions are proposed. Summary of the Invention

[0003] The technical problem solved by the present invention: Provide an embedded high manganese steel frog casting hole process to solve the technical problems of low casting hole accuracy, large difficulty, and high cost of embedded high manganese steel frog casting holes.

[0004] The technical solution adopted by the present invention: An embedded high manganese steel frog casting hole process, manufacturing a lower mold; adding bolt hole core seats corresponding to the bolt hole positions of the embedded high manganese steel frog to the lower mold; providing bolt hole sand cores corresponding to the bolt hole core seats one by one, and the cavity of the bolt hole sand core is used for forming casting holes; filling the surrounding of the bolt hole sand core with molding sand to connect the bolt hole sand core with the lower mold as a whole; manufacturing an upper mold; performing filling treatment on the bolt hole positions of the upper mold corresponding to the high manganese steel frog; pouring after the upper and lower molds are assembled to achieve casting holes.

[0005] In the above technical solution, preferably: The bolt hole sand core is made of forsterite original sand with resin as the binder.

[0006] In the above technical solution, further: The bolt hole sand core includes a common sand core and a special sand core; the common sand core is used for making through holes, and the special sand core is used for making non-through holes.

[0007] In the above technical solution, further: The bolt hole positions of the upper mold corresponding to the high manganese steel frog are filled in with a draft angle of 1:15.

[0008] In the above technical solution, further: The bolt hole core seat is 70 - 120 mm long and 0.1 - 2 mm thick.

[0009] In the above technical solution, further: It also includes an operation of removing flash after casting holes.

[0010] In the above technical solution, preferably: Knock off the flash or gouge out the flash after heat treatment.

[0011] Advantages of the present invention compared with the prior art:

[0012] 1. Without changing the structure of the mold parting surface, a bolt hole core seat is added to the lower mold, and the position of the bolt hole in the upper mold is filled. Cast holes are realized without changing the frog structure, reducing the production cost of enterprises.

[0013] 2. The present invention uses molding sand to fill the periphery of the bolt hole core, connecting the bolt hole core with the lower mold as a whole, and it will not shake randomly due to the gap between the upper and lower molds at the parting surface. In addition, the cavity of the bolt hole core matches the size of the cast hole, with lower requirements for the flatness of the template, ensuring the relative size of the bolt hole and the casting hole accuracy of the frog.

[0014] 3. The bolt hole core of the present invention is made of forsterite original sand with resin as the binder. On the premise of ensuring that no chemical reaction occurs between the molten steel and the core, it is convenient for cleaning the molding sand in the bolt hole of the later casting; the core has high strength and is not easy to deform or damage; it is not easy to thermally expand, with reliable dimensional accuracy; the formed dense core structure reduces porosity and shrinkage defects; the core molding strengthening and curing speed is fast, with high production efficiency; the core surface is smooth, reducing burr defects; it is non-toxic and harmless, environmentally friendly; the core is easy to process and trim, meeting specific requirements and having wide applicability.

[0015] 4. The standardized design of the common core and the customized design of the special core of the present invention optimize the production efficiency, ensure the quality of the casting, reduce material waste, and improve the resource utilization rate.

[0016] 5. The size design of 70 - 120 mm in length of the present invention enables the bolt hole core seat to save space during installation and adapt to a compact installation environment; a thickness of 0.1 - 2 mm ensures that while ensuring strength, the weight is reduced as much as possible, conforming to the lightweight design trend; the compact structure and standardized size make the bolt hole core seat more convenient and fast during assembly, which helps to improve the assembly efficiency and reduce the assembly cost.

[0017] 6. Removing the flash of the present invention can beautify the surface of the casting, making it smooth and clean, improving the qualified rate of the product, ensuring that the casting size meets the design requirements, improving the accuracy and reliability, ensuring the smooth fitting and installation of the casting, reducing the measurement error, enhancing the strength and durability of the casting, reducing the scrap rate, and increasing the yield rate of the product.

[0018] 7. Knocking off the flash of the present invention has advantages in terms of efficiency and cost, and is suitable for the removal requirements of small castings and simple shapes; gouging after heat treatment is more efficient and accurate when dealing with large castings and complex shapes, and has advantages in improving the surface quality and dimensional accuracy of the casting. Description of the Drawings

[0019] Figure 1 This is a schematic structural diagram after the lower core is set in the lower mold of the present invention;

[0020] Figure 2 is Figure 1 an enlarged view of the C-C cross-section in

[0021] Figure 3 is Figure 1 an enlarged view of the G-G cross-section in

[0022] Figure 4 is Figure 1 an enlarged view of the W-W cross-section in

[0023] Figure 5 This is a process flow chart of the present invention;

[0024] In the figure: 1 - bolt hole core seat. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying Figures 1-5 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 protection scope of the present invention.

[0026] (As Figure 5 shown) An embedded high manganese steel frog casting hole process, manufacturing the lower mold. Manufacturing the bolt hole core seat 1: The lower mold is provided with a bolt hole core seat 1 corresponding to the bolt hole position of the embedded high manganese steel frog, combined with Figure 1 . Making the bolt hole core sand: There is a bolt hole core sand corresponding to the bolt hole core seat 1 one by one, and the cavity of the bolt hole core sand is used for forming the casting hole.

[0027] It should be noted that: Under the condition that the structure of the mold parting surface remains unchanged, only the core seat and the core sand need to be changed, which can realize flexible assembly of casting hole production, greatly reduce the production cost, and at the same time, the cavity of the bolt hole core sand is adapted to the hole type, meeting the hole making accuracy requirements.

[0028] The molding sand fills the periphery of the bolt hole core sand to integrate the bolt hole core sand with the lower mold.

[0029] It should be noted that: The filling of the molding sand can ensure the precise positioning of the bolt hole core in the lower mold, avoiding possible offsets or misalignments during the casting process, thus ensuring the accurate position of the bolt hole. Through the filling of the molding sand, the bolt hole core is tightly connected to the lower mold, forming an integral structure. This connection method enhances the stability of the casting, making it less prone to deformation or damage during subsequent processing and use. The filling of the molding sand simplifies the casting process, avoiding the cumbersome steps of multiple assemblies and fixings required in traditional casting. This not only improves the casting efficiency but also reduces the production cost. Since the filling of the molding sand can ensure the close contact between the bolt hole core and the lower mold, it reduces the residual gas and impurities during the casting process, thereby improving the quality of the casting. The integral structure formed after the filling of the molding sand enhances the connection strength between the bolt hole core and the lower mold. This strong connection ensures that the casting can withstand greater loads and impacts during use, increasing the service life of the product. The filling of the molding sand avoids the material waste caused by multiple assemblies and fixings in traditional casting. This not only reduces the production cost but also conforms to the environmental protection concept. The molding sand filling technology improves the utilization rate of resources, which is of great significance for promoting sustainable development and green manufacturing.

[0030] Manufacture the upper mold. Fill the bolt hole position: The bolt hole position corresponding to the high manganese steel frog on the upper mold is filled and treated.

[0031] It should be noted that: The filling treatment ensures the precise positioning of the bolt hole position in the upper mold, avoiding possible deviations during the casting process, thus ensuring the accurate position of the bolt hole of the finished frog. Through the filling treatment, the casting materials around the bolt hole position can form a more uniform and dense structure, which helps to improve the overall consistency and stability of the frog. The filling treatment can effectively prevent the formation of air holes and inclusions during the casting process. These defects may affect the mechanical properties and service life of the frog. The filling treatment can also reduce the tendency of cracks to occur during the casting process because the uniform casting structure helps to disperse and relieve stress concentration.

[0032] Close the mold and pour: After closing the upper and lower molds, pouring is carried out to form the casting hole.

[0033] It should be noted that: After the upper and lower molds are assembled and then poured, it can ensure the tight fit between the molds, reduce casting defects such as porosity, shrinkage cavities, and sand inclusions caused by loose parting surfaces. These defects will seriously affect the mechanical properties and service life of the castings. Pouring directly after the upper and lower molds are assembled eliminates the need for additional steps such as parting and assembly, thus simplifying the casting process, improving production efficiency. The simplified casting process means a shorter production cycle, which helps to quickly respond to market demands and reduce production costs. Pouring after assembly can ensure the full flow and filling of the molten metal in the mold, thereby improving the density and mechanical properties of the castings. Pouring after the upper and lower molds are assembled can meet the requirements of various complex hole patterns, such as blind holes, inclined holes, and cross holes, thus satisfying a wider range of application scenarios. The flexibility of pouring after assembly enables the casting process to be optimized and adjusted according to the structural characteristics of different castings, improving the adaptability and flexibility of casting. Pouring after assembly can ensure the full utilization of the molten metal in the mold and reduce material waste caused by loose parting surfaces. Pouring after assembly can improve the utilization rate of the sand box, reduce production costs and environmental impacts by optimizing the mold design and pouring process.

[0034] In the above embodiments, preferably: The bolt hole core is made of forsterite natural sand with resin as the binder.

[0035] It should be noted that: The raw forsterite sand has a high refractoriness and hardness. After being combined with the resin binder, it can significantly improve the strength of the sand core, enabling it to withstand the impact and pressure of the molten metal during casting and not being easily deformed or damaged. The raw forsterite sand has good thermal stability and chemical stability, and can maintain the stability of the sand core structure at high temperatures, not being prone to thermal expansion or chemical reactions, thereby ensuring the dimensional accuracy and surface quality of the casting. The resin binder can evenly cover the surface of the raw forsterite sand, forming a dense sand core structure, effectively preventing the penetration of molten metal and gas inclusions, and reducing the generation of casting defects such as gas holes and shrinkage cavities. The forsterite sand core with a resin binder has a relatively fast molding and curing speed, which helps to shorten the casting cycle and improve production efficiency. The forsterite sand core has a high hardness and wear resistance, and can maintain the smoothness and integrity of the sand core surface during casting, thereby ensuring the surface quality of the casting and reducing the generation of defects such as scars and burrs. The resin binder can ensure the dimensional stability of the sand core during the curing process, enabling the casting to maintain a high dimensional accuracy after cooling and solidification, meeting the requirements of precision casting. The raw forsterite sand is a natural mineral material, non-toxic and harmless, and is easy to recycle and reuse, meeting the environmental protection requirements. At the same time, the resin binder is also relatively environmentally friendly and will not cause pollution to the environment. Although the costs of the raw forsterite sand and the resin binder are relatively high, because they can significantly improve the casting efficiency and the quality of the casting, the scrap rate and rework costs are reduced, and the overall production cost is effectively controlled. The forsterite sand core with resin as the binder is suitable for the forming of various alloys and castings with complex shapes, and has high flexibility and adaptability. The resin binder sand core has good machinability and trimability after curing, facilitating subsequent processing and trimming operations to meet specific application requirements.

[0036] In the above embodiments, further: The bolt hole sand core includes a common sand core and a special sand core; the common sand core is used for making through holes, and the special sand core is used for making non-through holes.

[0037] It should be noted that: Standardized shared cores are usually used for making through-holes, which helps to ensure the consistency of the size and shape of the same through-holes in different castings. The use of standardized cores reduces the errors caused by manual production and improves the casting accuracy. For making blind holes, customized special cores are used, which can be precisely designed according to the specific shape and size requirements of the casting. The use of customized cores ensures the perfect fit of the blind holes with other parts of the casting and improves the overall casting accuracy. Due to its standardized design, the shared core can be mass-produced and reused, which greatly reduces the production cost and improves the production efficiency. Although the special core needs to be customized, it can be flexibly adjusted according to the production requirements. This flexibility enables the foundry to quickly respond to market changes and meet the customized needs of different customers. The universality of the shared core: The shared core has been strictly tested and verified to ensure its stable and reliable quality and performance. The through-holes made with the shared core have good dimensional accuracy and surface quality, improving the overall quality of the casting. The precision of the special core: The special core is precisely designed and manufactured according to the specific requirements of the casting, ensuring the position accuracy and shape accuracy of the blind hole. The core with high precision helps to reduce casting defects and improve the reliability and durability of the casting. The reuse of the shared core reduces the waste of core materials and lowers the production cost. Although the special core needs to be customized, the material consumption can be reduced through optimized design, further reducing the cost. The standardized and customized core design makes the resource utilization rate higher in the casting process. Efficient resource utilization helps to reduce energy consumption and environmental pollution, achieving green casting.

[0038] In the above embodiments, further: The upper mold corresponding to the bolt hole positions of the high manganese steel frog is filled solid with a draft angle of 1:15.

[0039] It should be noted that: The design of a 1:15 draft angle enables the casting to be more easily removed from the mold after cooling and solidification, avoiding damage to the casting or wear of the mold caused by difficult demolding. The 1:15 draft angle is carefully calculated to ensure smooth demolding while avoiding material waste and inaccurate casting dimensions caused by too large a draft angle. The smooth demolding process reduces defects such as cracks and deformations in the casting due to uneven stress during demolding, improving the overall quality of the casting. The reasonable design of a 1:15 draft angle simplifies the casting process, reduces the additional processing and treatment steps required due to difficult demolding, and lowers the production cost. The smooth demolding process improves the production efficiency, enabling the foundry to quickly respond to market demands. The design that is easy to demold reduces the stress on the mold during demolding, extends the service life of the mold, and lowers the cost of mold replacement and maintenance.

[0040] In the above embodiments, further: (such as Figures 2 to 3As shown, the bolt hole core seat 1 is 70 - 120 mm long and 0.1 - 2 mm thick.

[0041] For specific dimensions, see the following table:

[0042] a b c Dimension range 70 - 120 mm 0 - 2 mm 0.1 - 1 mm

[0043] It should be noted that: The dimension design of 70 - 120 mm in length enables the bolt hole core seat to save space during installation and adapt to various compact installation environments. The thickness of 0.1 - 2 mm ensures that while maintaining strength, it reduces weight as much as possible, conforming to the trend of lightweight design. Despite the thin thickness, through reasonable material selection and structural design, the bolt hole core seat 1 can still maintain sufficient strength and durability, ensuring its stability when bearing the bolt tightening force and the reliability of long-term use. For example, for the bolt hole core seat 1 made of materials such as stainless steel, its excellent corrosion resistance can resist the erosion of various harsh environmental conditions, helping to extend the service life of the component and reducing the risk of failures caused by corrosion. The compact structure and standardized dimensions make the bolt hole core seat 1 more convenient and fast to assemble, which helps to improve the assembly efficiency and reduce the assembly cost.

[0044] In the above embodiment, further: It also includes the operation of removing flash after casting the hole.

[0045] It should be noted that: Removing flash can significantly beautify the surface of the casting, making it smoother and neater, meeting customer requirements. Flash is one of the common defects in the casting process. Removing flash can reduce the defects on the surface of the casting and improve the qualified rate of the product. Flash may affect the dimensional accuracy of the casting. Removing flash can ensure that the dimensions of the casting meet the design requirements, improving the accuracy and reliability of the product. Precise dimensions help to ensure the smooth fitting and installation of the casting with other components. Removing flash can reduce the measurement errors caused by the existence of flash, making the dimensions of the casting more accurate and reliable. Flash may weaken the strength of the casting. Removing flash can enhance the strength and durability of the casting, making it more in line with the usage requirements. Flash may cause the casting to become a scrap. Removing flash can reduce the scrap rate and increase the yield rate of the product.

[0046] In the above embodiment, preferably: Knock off the flash or remove the flash by air gouging after heat treatment.

[0047] It should be noted that the operation of knocking off the flash is relatively simple, usually does not require complex equipment and processes, and is easy to implement. The operator only needs to use appropriate tools such as hammers, chisels, etc. to carry out the removal operation. Knocking off the flash can be carried out immediately after casting, without waiting for the completion of other processes such as heat treatment, which helps to shorten the production cycle and improve production efficiency. The tool and material costs required for knocking off the flash are relatively low, the operation is simple, and the labor cost required is also low. For small castings, knocking off the flash is an effective removal method, which can quickly and accurately remove the flash on the castings, ensuring the dimensional accuracy and appearance quality of the castings.

[0048] After heat treatment, gouging is used to remove the flash. After heat treatment, the internal stress of the casting is released. At this time, carrying out gouging to remove the flash can reduce the deformation risk of the casting, which helps to ensure the dimensional stability and shape accuracy of the casting. Gouging is an efficient metal cutting method that can accurately remove the flash on the casting. Compared with knocking off the flash, the surface of the casting after gouging is smoother and neater, which helps to improve the overall quality of the product. For large castings, knocking off the flash may be difficult and time-consuming. At this time, using gouging to remove the flash after heat treatment is a more efficient and accurate method. Gouging can be adjusted according to the shape and size of the casting to meet different removal requirements, which makes gouging more flexible when removing the flash on castings with complex shapes.

[0049] Therefore, knocking off the flash has advantages in terms of efficiency and cost, and is suitable for the removal requirements of small castings and simple shapes. Although the equipment and labor costs of gouging after heat treatment are relatively high, it is more efficient and accurate when dealing with large castings and complex shapes. Gouging after heat treatment has advantages in improving the surface quality and dimensional accuracy of the casting. It can accurately remove the flash to ensure that the appearance and performance of the casting meet the requirements. Knocking off the flash and gouging to remove the flash each have their own applicability, and can be selected according to the size, shape of the casting and the removal requirements. At the same time, gouging shows better flexibility and can adapt to more variable removal requirements.

[0050] From the above description, it can be found that: without changing the structure of the mold parting surface, bolt hole core seats are added to the lower mold, and the positions of the bolt holes on the upper mold are filled. Cast holes are realized without changing the frog structure, reducing the production cost of the enterprise.

[0051] The present invention uses molding sand to fill the periphery of the bolt hole core so that the bolt hole core is integrated with the lower mold, and it will not shake randomly due to the gap between the upper and lower molds at the parting surface. In addition, the cavity of the bolt hole core matches the size of the cast hole, and the requirement for the flatness of the template is relatively low, ensuring the relative size of the bolt hole and the casting hole accuracy of the frog.

[0052] The bolt hole core of the present invention is made of forsterite natural sand with resin as the binder. On the premise of ensuring that no chemical reaction occurs between the molten steel and the core, it is convenient for cleaning the internal sand of the bolt hole of the casting in the later stage; the core has high strength and is not easily deformed or damaged; it is not easily thermally expanded and has reliable dimensional accuracy; the formed dense core structure reduces the defects of gas holes and shrinkage holes; the core molding has a fast strengthening and curing speed and high production efficiency; the surface of the core is smooth, reducing burr defects; it is non-toxic, harmless and environmentally friendly; the core is easy to process and trim to meet specific requirements and has wide applicability.

[0053] The standardized design of the shared core and the customized design of the special core of the present invention optimize the production efficiency, ensure the quality of the casting, reduce material waste and improve the resource utilization rate.

[0054] The size design of 70 - 120 mm in length of the present invention enables the bolt hole core seat to save space during installation and adapt to a compact installation environment; a thickness of 0.1 - 2 mm ensures that while ensuring strength, the weight is reduced as much as possible, conforming to the trend of lightweight design; the compact structure and standardized size make the bolt hole core seat more convenient and fast during assembly, which helps to improve the assembly efficiency and reduce the assembly cost.

[0055] Removing the flash of the present invention can beautify the surface of the casting, making it smooth and clean, improving the qualified rate of the product, ensuring that the dimensions of the casting meet the design requirements, improving the accuracy and reliability, ensuring the smooth fitting and installation of the casting, reducing the measurement error, enhancing the strength and durability of the casting, reducing the rejection rate and increasing the yield rate of the product.

[0056] Removing the flash by knocking of the present invention has advantages in terms of efficiency and cost and is suitable for the removal requirements of small castings and simple shapes; gas gouging after heat treatment is more efficient and accurate when dealing with large castings and complex shapes and has advantages in improving the surface quality and dimensional accuracy of the casting.

[0057] It should be understood that although this specification is described according to one embodiment, this embodiment does not only contain an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in this embodiment can also be appropriately arranged and combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An embedded high manganese steel frog hole casting process, characterized in that: The lower casting mold is manufactured; bolt hole core seats (1) are added to the lower casting mold corresponding to the bolt hole positions of the embedded high manganese steel frog; bolt hole sand cores are provided one by one corresponding to the bolt hole core seats (1), and the cavity of the bolt hole sand core is used to form the casting hole; the bolt hole sand core is filled with molding sand so that the bolt hole sand core and the lower casting mold are connected as a whole; an upper casting mold is manufactured; the bolt hole positions of the upper casting mold corresponding to the high manganese steel frog are filled and processed; the upper and lower casting molds are combined and then poured to realize the casting hole.

2. The process according to claim 1, characterized in that: The bolt hole sand core is made of forsterite raw sand with resin as a binder.

3. The process according to claim 1 or 2, characterized in that: The bolt hole sand core includes a common sand core and a special sand core; the common sand core is used for making through holes, and the special sand core is used for making non-through holes.

4. The process according to claim 1, characterized in that: The bolt holes of the upper casting corresponding to the high manganese steel frog are filled with a draft angle of 1:

15.

5. The process according to claim 1, characterized in that: The bolt hole core seat (1) is 70-120 mm long and 0.1-2 mm thick.

6. The process according to claim 1, characterized in that: It also includes the flash removal operation after casting the hole.

7. The process according to claim 6, characterized in that: Smash off or remove flash by air planing after heat treatment.

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