Die for pig casting machine

Abstract

A die for a pig casting machine comprises a forming die cavity, a protective edge is arranged at the upper end of the forming die cavity, and a dovetail groove is formed in the protective edge. Lifting lug steel cores are arranged at the two ends of the forming die cavity and connected with the protective edges in a matched mode through dovetail grooves. A coating layer is arranged on the outer side of the lifting lug steel core, the coating layer is a titanium alloy layer, and a WC-Co hard alloy coating is arranged on the surface of the titanium alloy layer; the upper side and the lower side of the lifting lug are each provided with a brazing layer, and the brazing layers are alloy brazing layers. The problem that the hanging lug is prone to cracking is solved, cost and installation and maintenance convenience are taken into account, the reliability and stability of the pig casting machine mold are improved, and smooth production is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of mold technology and relates to a mold for casting iron machines. Background Technology

[0002] In the production of yellow phosphorus, the first dry slag removal process was adopted. This process uses a casting machine and introduces steel casting machine technology and equipment. The process flow is as follows: high-temperature slag at 1460℃ and ferrophosphate are discharged from the slag outlet and iron outlet respectively. Ferrophosphate settles and is collected and stored. The slag is removed by dry slag removal. The high-temperature hot flue gas generated by the heat energy of the high-temperature slag is used to dry the phosphate rock raw material. The cooled slag is sent to the yellow phosphorus slag ultrafine powder unit by belt conveyor to produce ultrafine powder and silicon fertilizer. This process changes the environmental impact of traditional water-quenched slag and makes full use of the waste heat of the slag to reduce energy consumption. Air is used as the cooling medium to cool the high-temperature liquid slag to achieve dry slag removal.

[0003] However, in actual production and use, the casting machine molds used in this process have revealed numerous problems. The overall service life of the molds is short, averaging only 2-6 months; the lugs are prone to cracking; cracking occurs frequently; corrosion resistance is poor, leading to severe corrosion; and fatigue resistance is inadequate, causing damage to connecting parts due to fatigue during slag unloading. These problems necessitate frequent mold replacements, resulting in high maintenance costs, severely impacting dry slag production and the heat utilization rate of phosphate slag, which in turn directly affects the production of phosphate slag ultrafine powder and silicon fertilizer, thus hindering the efficient and stable operation of the entire production system.

[0004] After reviewing relevant materials, it was found that common solutions to problems such as short mold life mainly focus on improving mold materials. For example, chromium in high-chromium cast iron can form stable carbides, significantly improving the hardness and wear resistance of the mold, thereby extending its service life to a certain extent and reducing failures caused by wear. Simultaneously, its improved heat resistance helps cope with high-temperature slag environments. However, this material is expensive, and chromium may cause some environmental pollution; cost and environmental factors must be comprehensively considered in large-scale production applications. Other solutions involve alloying ordinary cast iron materials, adding various alloying elements to optimize mold performance. The advantage is that the proportion of alloying elements can be adjusted according to specific needs, specifically improving the mold's strength, toughness, and corrosion resistance. However, the alloying process is complex to control; improper element ratios may not achieve the desired effect or even produce negative consequences.

[0005] For example, patent CN114918374A discloses a mold for direct granulation of molten iron on a casting machine. By setting up multiple rows of forming cavities, ribs, flow dividers, overlapping nozzles, heads, guards, and ears, and optimizing the dimensions and materials of each component, it achieves continuous casting and direct granulation of molten iron on the casting machine. The advantages of this mold are that it solves problems such as difficult demolding, flash, and clumping caused by smaller particle sizes. It has low investment, eliminates the need for crushing and screening processes, reduces pollution emissions and safety risks, and meets the requirements of low cost, high efficiency, safety, and environmental friendliness. However, the mold structure is relatively complex, and the manufacturing process requires high precision.

[0006] Taking into account the advantages and disadvantages of existing solutions, this utility model aims to develop a cast iron machine mold that can effectively solve the problem of easy cracking of the hanging ear, while also taking into account cost, ease of installation and maintenance, and matching with the overall performance of the mold, by starting from the structural design of the hanging ear, material selection, and overall synergistic optimization with the mold. This will improve the reliability and stability of the cast iron machine mold and ensure the smooth operation of production. Summary of the Invention

[0007] This invention provides a mold for cast iron machines to solve the problem of easy cracking of the lugs, while taking into account cost, ease of installation and maintenance, improving the reliability and stability of cast iron machine molds, and ensuring smooth production.

[0008] To solve the above problems, the technical solution adopted by the invention is as follows:

[0009] A mold for a cast iron machine includes a forming cavity, with a protective rim at the upper end of the forming cavity and a dovetail groove on the protective rim; lifting lugs are provided at both ends of the forming cavity and are connected to the protective rim through the dovetail grooves; a cladding layer is provided on the outer side of the lifting lugs, the cladding layer being a titanium alloy layer, and a WC-Co hard alloy coating is provided on the surface of the titanium alloy layer; brazing layers are provided on both the upper and lower sides of the lifting lugs, the brazing layers being alloy brazing layers.

[0010] The principle of this design is as follows: the forming cavity is used to shape the cast iron. The dovetail groove on the guard provides a stable mounting position and connection method for the lifting lug steel core, which provides the leverage point for lifting and handling the mold. The outer titanium alloy cladding layer has high strength and good corrosion resistance, which enhances the mechanical properties and durability of the lifting lug steel core. The WC-Co hard alloy coating on the surface further improves wear resistance and scratch resistance. The alloy brazing layers on the upper and lower sides can firmly connect the lifting lug steel core to other components, ensuring the stability and reliability of the lifting lug steel core during lifting and use.

[0011] The beneficial effects of this solution are:

[0012] The dovetail groove design on the upper edge of the molding cavity makes the installation of the lifting lug steel core more stable, less prone to loosening and falling off. It effectively prevents the lifting lug steel core from accidentally detaching during hoisting and handling, thus ensuring operational safety. The titanium alloy cladding layer on the outside of the lifting lug steel core greatly improves its strength and corrosion resistance, extends its service life, and reduces the increased costs and production interruptions caused by frequent replacement of the lifting lug steel core. The WC-Co hard alloy coating on the surface of the titanium alloy layer significantly enhances the wear resistance and scratch resistance of the lifting lug steel core, enabling it to maintain good performance for a long time in harsh working environments and reducing the risk of damage caused by wear and scratches.

[0013] Furthermore, the alloy brazing layers on the upper and lower sides of the lifting lug ensure the firmness of the connection between the lifting lug steel core and other components, reducing safety hazards caused by loose connections during use, and also helping to improve the overall structural stability of the mold.

[0014] Furthermore, reinforcing ribs are provided on both sides of the forming cavity. These reinforcing ribs are connected to the guard edge through a dovetail groove. The reinforcing ribs can enhance the structural strength of the forming cavity, making it less prone to deformation when subjected to the pressure and impact of cast iron, thereby ensuring the dimensional accuracy and quality of the cast iron product. The connection method of connecting the reinforcing ribs with the guard edge through the dovetail groove is stable and reliable, ensuring that the reinforcing ribs will not loosen or shift during operation.

[0015] Furthermore, the reinforcing ribs on both sides of the guard edge and the lifting lugs at both ends form a rectangular frame, and the lifting lugs and the two ends of the reinforcing ribs are fixedly connected by welding. The rectangular frame structure enhances the overall stability and rigidity of the mold. When subjected to heavy loads and complex stresses, it can effectively prevent mold deformation, ensure the shape accuracy and dimensional accuracy of the forming cavity, thereby improving the quality of cast iron products. Moreover, the rectangular structure allows the frame to evenly distribute the force to various parts when the mold is subjected to external forces, reducing local stress concentration and extending the service life of the mold.

[0016] Furthermore, the brazed layer is arranged in a triangular pyramidal structure, which has good stability and load-bearing capacity. When subjected to tensile and shear forces during hoisting, it can more effectively disperse stress, reduce local stress concentration, and thus improve the connection strength and durability of the brazed layer.

[0017] Furthermore, the connection points between the reinforcing ribs and the lifting lug steel cores within the dovetail groove are all sandblasted. This sandblasting process increases the surface roughness of the connection points, thereby increasing the friction. This makes the installation of the reinforcing ribs and lifting lug steel cores within the dovetail groove more stable, less prone to slippage or displacement, and improves the stability of the mold during use.

[0018] Furthermore, the coating layer is coated using a hot isostatic pressing (HIP) process. The HIP process can achieve a tight bond between the coating layer and the lug steel core, eliminate interfacial porosity and defects, improve the bonding strength and interfacial stability, thereby enhancing the overall performance of the lug steel core.

[0019] Furthermore, the alloy brazing layer uses Ni-Cr-B-Si alloy brazing filler metal with a thickness of 0.5-1.5 mm. Ni-Cr-B-Si alloy brazing filler metal has good wettability and fluidity, which can fully fill the weld seam during the brazing process, forming a uniform, continuous and defect-free brazed joint, improving the sealing and strength of the connection. Choosing a brazing layer thickness of 0.5-1.5 mm can provide sufficient connection strength while avoiding the increased cost and thermal stress concentration caused by an excessively thick brazing layer. A thinner brazing layer helps to reduce the range of the heat-affected zone and reduce the impact on the properties of the base material. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of this utility model;

[0021] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0022] Figure 3 for Figure 2 A magnified view of a portion of the image;

[0023] Figure 4 This is a cross-sectional view of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of this utility model;

[0025] Figure 6 for Figure 5 A magnified view of part I. Detailed Implementation

[0026] The reference numerals in the accompanying drawings include: 1. Molding cavity; 2. Rib; 3. Guard edge; 4. Dovetail groove; 5. Lifting lug steel core; 6. Covering layer; 7. Protective layer; 8. Brazing layer; 9. Brazing groove.

[0027] The basic implementation examples are as follows: Figure 1-6 As shown, a mold for a cast iron machine includes a forming cavity 1 for shaping cast iron. The upper end of the forming cavity 1 is provided with a guard 3, and the guard 3 is provided with a dovetail groove 4. In actual use, this dovetail groove 4 provides a stable installation position for the lifting lug steel core 5 to be installed later. During hoisting and handling, it can effectively prevent the lifting lug steel core 5 from accidentally falling off, ensuring operational safety and preventing dangerous situations caused by the loosening of the lifting lug steel core 5.

[0028] Lifting lugs 5 are provided at both ends of the molding cavity 1. The lifting lugs 5 are connected to the guard edge 3 through dovetail grooves 4. The outer side of the lifting lugs 5 is covered with a titanium alloy cladding layer 6, and its surface is also coated with WC-Co hard alloy, which enhances the strength, corrosion resistance, wear resistance and scratch resistance of the lifting lugs 5. In harsh working environments, the lifting lugs 5 can reduce the risk of damage caused by wear and scratches, extend the service life of the lifting lugs 5, and reduce the increased costs and production interruptions caused by frequent replacements.

[0029] Both the upper and lower sides of the lifting lug are provided with a brazing layer 8. This brazing layer 8 is an alloy brazing layer 8, which reduces the safety hazards caused by loose connections during use and helps to improve the overall structural stability of the mold.

[0030] The molding cavity 1 is provided with reinforcing ribs on both sides. The reinforcing ribs are connected to the guard edge 3 through the dovetail groove 4. The presence of the reinforcing ribs enhances the structural strength of the molding cavity 1, making it less prone to deformation when subjected to the pressure and impact of cast iron. This effectively ensures the dimensional accuracy and quality of cast iron products. The dovetail groove 4 connection method is stable and reliable, ensuring that the reinforcing ribs will not loosen or shift during operation, allowing the mold to maintain stable performance during long-term use.

[0031] The reinforcing ribs on both sides of the guard 3 and the lifting lugs at both ends form a rectangular frame, and the lifting lugs and the two ends of the reinforcing ribs are fixedly connected by welding. When the mold is subjected to heavy loads and complex stresses, it can effectively prevent deformation and strongly guarantee the shape accuracy and dimensional accuracy of the forming mold cavity 1, thereby improving the quality of cast iron products. Moreover, when the mold is subjected to external forces, the frame can evenly distribute the force to various parts, reduce local stress concentration, and extend the service life of the mold.

[0032] The brazing layer 8 is designed in the shape of a triangular pyramid, which can more effectively disperse stress and reduce local stress concentration when subjected to tensile and shear forces during hoisting, thereby improving the connection strength and durability of the brazing layer 8.

[0033] The connection points between the dovetail groove 4 and the reinforcing rib and the lifting lug steel core 5 are all frosted. The frosting treatment increases the surface roughness of the connection points, thereby increasing the friction and making the installation of the reinforcing rib and the lifting lug steel core 5 in the dovetail groove 4 more stable, less prone to sliding or displacement, and further improving the stability of the mold during use.

[0034] The cladding layer 6 is coated using a hot isostatic pressing process, which achieves a tight bond between the cladding layer 6 and the lifting lug steel core 5, eliminates interfacial porosity and defects, significantly improves the bonding strength and interfacial stability, and thus enhances the overall performance of the lifting lug steel core 5.

[0035] The alloy brazing layer 8 uses a Ni-Cr-B-Si alloy brazing filler metal, with a thickness of 0.5–1.5 mm. The Ni-Cr-B-Si alloy brazing filler metal exhibits good wettability and fluidity. This brazing layer 8 is positioned within a brazing groove 9, which has a triangular pyramidal groove structure. The brazing groove 9 is located at the connection joint where the reinforcing rib and lifting lug connect to the dovetail groove 4 on the guard edge 3. During brazing, it can fully fill the weld seam, forming a uniform, continuous, and defect-free brazed joint, significantly improving the sealing performance and strength of the connection. Choosing a brazing layer thickness of 0.5–1.5 mm provides sufficient connection strength while avoiding the increased cost and thermal stress concentration caused by an excessively thick brazing layer 8. A thinner brazing layer 8 helps reduce the size of the heat-affected zone and minimizes the impact on the base material's properties.

[0036] In actual production, the forming cavity 1 of the mold precisely shapes the required cast iron form. The dovetail groove 4 on the guard rim 3 securely mounts the lifting lug steel core 5, and during multiple lifting operations of heavy cast iron parts, the lifting lug steel core 5 has never loosened or fallen off. The titanium alloy cladding layer 6 and the WC-Co hard alloy coating effectively protect the lifting lug steel core 5, ensuring that it maintains good performance even after long-term use.

[0037] The reinforcing ribs on both sides of the forming cavity 1 and the guard edge 3 are tightly fitted together through the dovetail groove 4. When subjected to huge cast iron pressure, the forming cavity 1 does not deform, ensuring the dimensional accuracy of the cast iron parts. The rectangular frame formed by the reinforcing ribs on both sides of the guard edge 3 and the lifting lugs at both ends reduces the damage to the mold and the number of repairs.

[0038] The triangular pyramidal structure and thickness of the brazed layer 8 ensure a secure connection between the lifting lug steel core 5 and other components.

[0039] The above are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A mold for a cast iron machine, characterized in that, The device includes a molding cavity, with a protective rim at the upper end of the molding cavity and a dovetail groove on the protective rim; lifting lugs are provided at both ends of the molding cavity and are connected to the protective rim through the dovetail grooves; a cladding layer is provided on the outer side of the lifting lugs, the cladding layer is a titanium alloy layer, and a WC-Co hard alloy coating is provided on the surface of the titanium alloy layer; brazing layers are provided on both the upper and lower sides of the lifting lugs, the brazing layers are alloy brazing layers.

2. The mold for a casting iron machine according to claim 1, characterized in that, The molding cavity is provided with reinforcing ribs on both sides, and the reinforcing ribs are connected to the guard edge through dovetail grooves.

3. The mold for a casting iron machine according to claim 1, characterized in that, The reinforcing ribs on both sides of the guardrail and the lifting lugs at both ends form a rectangular frame, and the lifting lugs and the two ends of the reinforcing ribs are fixedly connected by welding.

4. A mold for a casting iron machine according to claim 1, characterized in that, The brazing layer is arranged in a triangular pyramidal structure.

5. A mold for a casting iron machine according to claim 1, characterized in that, The dovetail groove and the connection between the reinforcing rib and the lifting lug steel core are all sandblasted.

6. A mold for a casting iron machine according to claim 1, characterized in that, The coating layer is applied using a hot isostatic pressing process.

7. A mold for a casting iron machine according to claim 1, characterized in that, The alloy brazing layer uses Ni-Cr-B-Si alloy brazing filler metal, and the thickness of the brazing layer is 0.5-1.5 mm.

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