Wear-resistant casting with good toughness and high strength

Abstract

The invention belongs to the technical field of castings, and particularly relates to a wear-resistant casting with good toughness and high strength, the wear-resistant casting is mainly formed by combining a high-chromium cast iron framework casting and a nodular cast iron panel casting, and the high-chromium cast iron framework casting is mainly composed of a high-chromium cast iron concave base plate, a center seat, a plurality of rib plates, an outer ring, an annular bulge and a plurality of reinforcing bottom ribs; the cast iron manhole cover is formed by combining a plurality of fan-shaped nodular cast iron panels and selecting high-chromium cast iron materials through a lost foam casting method, the nodular cast iron panel casting is formed by combining a center block and a plurality of fan-shaped nodular cast iron panels and is formed by casting the nodular cast iron materials through the lost foam casting method, and compared with an existing conventional cast iron manhole cover, the cast iron manhole cover has the advantages of being good in toughness and strength, good in corrosion resistance and good in corrosion resistance. The nodular cast iron fan-shaped panel of the manhole cover is simple in structure, high in impact resistance, not prone to being broken and damaged when being heavily pressed by a vehicle, good in abrasion resistance and better in use performance, in addition, when a certain nodular cast iron fan-shaped panel of the manhole cover is damaged, only the nodular cast iron fan-shaped panel is replaced, overall replacement is not needed, and daily use cost can be greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of casting technology, and specifically relates to a wear-resistant casting with good toughness and high strength. Background Technology

[0002] Castings are metal shaped objects obtained by various casting methods. This involves pouring, injecting, sucking, or other casting methods into a pre-prepared mold, cooling it, and then processing it through grinding and other methods to obtain an object with a specific shape, size, and properties. Based on the different metal materials used, castings are classified into cast steel, cast iron, cast copper, cast aluminum, cast magnesium, cast zinc, and cast titanium, among others. Castings have a wide range of applications in daily life. Many common items are manufactured using casting processes, such as door locks, cookware, pipe valves, and manhole covers; tools like wrenches, hammers, and hardware; and structural components, railings, and covers in construction.

[0003] Manhole covers, a common casting in daily life, are widely used in driveways, sidewalks, and other scenarios. They are facilities that cover the entrances to inspection wells for underground pipelines and cables in cities. Their main functions are to prevent falls and facilitate pipeline maintenance. According to the material, they can be divided into concrete, metal, resin, etc. Existing metal manhole covers are generally made of cast iron. However, conventional cast iron manhole covers are prone to rust, are brittle, and have weak impact resistance. They are easily broken and damaged under the pressure of vehicles, requiring frequent replacement, resulting in high maintenance costs and unsatisfactory performance. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a wear-resistant casting with good toughness and high strength. Compared with conventional cast iron manhole covers, it has better toughness and strength, stronger impact resistance, and is less prone to breakage under heavy vehicle pressure. It also has better wear resistance and superior performance. Furthermore, when a ductile iron fan-shaped panel of the manhole cover is damaged, only that panel needs to be replaced, eliminating the need for complete replacement and significantly reducing daily operating costs.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a wear-resistant casting with good toughness and high strength, comprising a high-chromium cast iron skeleton casting and a ductile iron panel casting;

[0006] The high-chromium cast iron skeleton casting includes a high-chromium cast iron concave base plate and center seat, ribs, outer ring, annular protrusion and reinforcing bottom ribs;

[0007] The high-chromium cast iron concave substrate has a central seat integrally formed at the middle of its upper end, and several ribs integrally formed around the central seat. An outer ring is integrally formed around the outer perimeter of the upper end of the high-chromium cast iron concave substrate. Several cavities are formed on the high-chromium cast iron concave substrate by the central seat, ribs, and outer ring. A drainage bottom hole I is integrally formed at the center of the high-chromium cast iron concave substrate. Several drainage bottom holes II are integrally formed around the bottom perimeter of the high-chromium cast iron concave substrate. An annular protrusion is integrally formed at the middle of the bottom end of the high-chromium cast iron concave substrate. Several reinforcing bottom ribs are integrally formed around the annular protrusion.

[0008] The ductile iron panel casting includes a center block and ductile iron fan-shaped panels;

[0009] The central block is fitted and fixed in the central seat. A drainage hole is integrally formed at the center of the central block, and the bottom end of the central block communicates with the drainage hole. The ductile iron fan-shaped panel is fitted and fixed in the cavity. A drainage hole is integrally formed at the center of the ductile iron fan-shaped panel, and the bottom end of the drainage hole communicates with the drainage hole.

[0010] As a preferred technical solution for a wear-resistant casting with good toughness and high strength according to the present invention, the ribs and reinforcing bottom ribs are distributed in a ring array.

[0011] As a preferred technical solution of the present invention for a wear-resistant casting with good toughness and high strength, one side of the outer ring is integrally formed with a protrusion, and two ductile iron fan-shaped panels near the protrusion are integrally formed with protrusions.

[0012] As a preferred technical solution for a wear-resistant casting with good toughness and high strength according to the present invention, the upper end of the ductile iron fan-shaped panel is integrally formed with a plurality of converging grooves, and the middle position of the upper end of the ductile iron fan-shaped panel is integrally formed with a guide groove. The guide groove is connected to the middle position of the plurality of converging grooves, and the middle position of the guide groove is connected to the upper end of the second drainage hole.

[0013] As a preferred technical solution for a wear-resistant casting with good toughness and high strength according to the present invention, the upper end of the ductile iron fan-shaped panel is integrally formed with several anti-slip protrusions.

[0014] As a preferred technical solution of the present invention for a wear-resistant casting with good toughness and high strength, the upper end surface of the central block and the upper end surface of the ductile iron fan-shaped panel are both coated with a wear-resistant coating.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. This invention is mainly composed of a high-chromium cast iron skeleton casting and a ductile iron panel casting. The high-chromium cast iron skeleton casting is mainly composed of a high-chromium cast iron concave base plate, a central seat, several ribs, an outer ring, annular protrusions, and several reinforcing bottom ribs. It is made of high-chromium cast iron and cast using the lost foam casting method. The ductile iron panel casting is composed of a central block and several ductile iron fan-shaped panels. It is made of ductile iron and cast using the lost foam casting method. The central block is embedded and fixed in the central seat on the high-chromium cast iron skeleton, and the ductile iron fan-shaped panels are embedded and fixed in the concave cavity on the high-chromium cast iron skeleton.

[0017] The manhole cover, composed of the aforementioned high-chromium cast iron skeleton casting and ductile iron panel casting, has better toughness and strength than existing conventional cast iron manhole covers. It has stronger impact resistance, is not easily broken or damaged under heavy vehicle pressure, and has better wear resistance and superior performance. In addition, if a ductile iron fan-shaped panel of the manhole cover is damaged, only that panel needs to be replaced, without the need for the entire cover, which can greatly reduce daily usage costs.

[0018] 2. The present invention provides drainage holes II, guide grooves, and several converging grooves and anti-slip protrusions on several ductile iron fan-shaped panels. This not only greatly increases the anti-slip effect of the ductile iron fan-shaped panel surface, making it more slip-resistant, but also facilitates the drainage of rainwater on the ductile iron fan-shaped panel by connecting the converging grooves, guide grooves and drainage holes II.

[0019] 3. The present invention further impregnates the surface of the ductile iron panel casting with a wear-resistant coating, which can further improve its wear resistance. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 for Figure 1 A schematic diagram of the structure viewed from below;

[0023] Figure 3 This is a cross-sectional structural diagram of the present invention;

[0024] Figure 4 for Figure 3 A schematic diagram of the structure viewed from below;

[0025] Figure 5 This is a schematic diagram showing the disassembled structure of the high-chromium cast iron skeleton and ductile iron panel of the present invention.

[0026] Figure 6 for Figure 5 A schematic diagram of the structure viewed from below;

[0027] Figure 7 for Figure 5 A schematic diagram of the cross-sectional structure;

[0028] Figure 8 for Figure 7 A schematic diagram of the structure viewed from below;

[0029] Figure 9 This is a schematic diagram of the high-chromium cast iron skeleton casting structure of the present invention;

[0030] Figure 10 for Figure 9 A schematic diagram of the structure viewed from below;

[0031] Figure 11 This is a schematic diagram of the ductile iron panel casting structure of the present invention;

[0032] Figure 12 for Figure 11 A schematic diagram of the structure viewed from below.

[0033] In the diagram: 1. High-chromium cast iron concave base plate; 2. Center seat; 3. Rib plate; 4. Outer ring; 5. Cavity; 6. convex frame; 7. Drainage bottom hole one; 8. Drainage bottom hole two; 9. Ring protrusion; 10. Reinforcing bottom rib; 11. Center block; 12. Drainage hole one; 13. Ductile cast iron fan-shaped panel; 14. Merging groove; 15. Guide groove; 16. Drainage hole two; 17. Anti-slip protrusion; 18. Protrusion; 19. Wear-resistant coating. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example

[0036] Please see Figure 1-12 The present invention provides the following technical solution: a wear-resistant casting with good toughness and high strength, comprising a high-chromium cast iron skeleton casting and a ductile iron panel casting.

[0037] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, the high-chromium cast iron skeleton casting further includes a high-chromium cast iron concave base plate 1, a center seat 2, a rib plate 3, an outer ring 4, an annular protrusion 9, and a reinforcing bottom rib 10.

[0038] High-chromium cast iron is a wear-resistant material with chromium as the main alloying element. The chromium content is typically between 11% and 30%. Its properties stem from its unique metal structure and alloy design. The microstructure of high-chromium cast iron is characterized by a martensitic matrix containing 12%-30% retained austenite. Carbides are predominantly M7C3 type (e.g., (Fe,Cr)7C3), distributed in hexagonal rod-like or lamellar shapes on the matrix. This structure significantly improves the material's continuity and wear resistance. Its microhardness can reach HV1200-1800, far exceeding that of ordinary white cast iron (HV840-1100), and the carbide volume fraction is typically 25%. %-35%; In terms of performance, high-chromium cast iron has the following advantages: high wear resistance: under abrasive wear conditions, its relative wear resistance can reach 1.5 times that of nickel-hard cast iron; good toughness and strength: impact toughness can reach 8-15J / cm², and compressive strength is not less than 800MPa; corrosion resistance and high temperature stability: in acidic media with pH=3, the corrosion rate is reduced by 60%, and a dense CQ oxide film can be formed at 600°C. Its oxidation resistance is better than that of ordinary cast iron. Compared with other materials, its wear resistance is far superior to that of ordinary white cast iron and alloy steel. At the same time, it has high toughness, high temperature strength and corrosion resistance, moderate cost and relatively mature production process;

[0039] A central seat 2 is integrally formed at the upper center of the high-gain cast iron concave substrate 1. Several ribs 3 are integrally formed around the central seat 2. An outer ring 4 is integrally formed around the upper outer perimeter of the high-gain cast iron concave substrate 1. Several cavities 5 are formed on the high-gain cast iron concave substrate 1 by the central seat 2, ribs 3, and outer ring 4. A protrusion 6 is integrally formed on one side of the outer ring 4. A drainage bottom hole 7 is integrally formed at the center of the high-gain cast iron concave substrate 1. The bottom end of the cover has several drainage holes 8 integrally formed around its perimeter. The bottom end of the high-gall cast iron concave base plate 1 has an annular protrusion 9 integrally formed in the middle position. Several reinforcing ribs 10 are integrally formed around the annular protrusion 9. The ribs 3 and the reinforcing ribs 10 are arranged in a ring array. The protrusion 6 on the high-gall cast iron skeleton casting is provided so that the cover can be positioned and connected to the mounting ring with a groove on the well opening. The drainage holes 7 and 8 are used to facilitate drainage of the cover.

[0040] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 11 and Figure 12 As shown, the ductile iron panel casting further includes a central block 11 and a ductile iron fan-shaped panel 13.

[0041] Ductile iron is a type of cast iron material produced by spheroidizing graphite to form spheroids. Its properties stem from the smaller cutting effect of spheroidal graphite on the matrix, effectively inhibiting crack propagation. Ductile iron exhibits excellent mechanical properties, with tensile strength typically ranging from 420-1000 MPa and yield strength reaching 300-420 MPa.

[0042] MPa, elongation range of 2%-20%, fatigue strength is better than conventional cast iron, suitable for structural parts with high strength and toughness requirements;

[0043] A central block 11 is fitted and fixed in the central seat 2. A drainage hole 12 is integrally formed at the center of the central block 11, and the bottom end of the central block 11 communicates with a drainage bottom hole 7. A ductile iron fan-shaped panel 13 is fitted and fixed in the cavity 5. A drainage hole 16 is integrally formed at the center of the ductile iron fan-shaped panel 13, and the bottom end of the drainage hole 16 communicates with a drainage bottom hole 8. A plurality of converging grooves 14 are integrally formed at the upper end of the ductile iron fan-shaped panel 13. A guide groove 15 is integrally formed at the middle position of the upper end of the ductile iron fan-shaped panel 13. The guide groove 15 communicates with the middle position of the plurality of converging grooves 14, and the middle position of the guide groove 15 communicates with the upper end of the drainage hole 16. A plurality of anti-slip protrusions 17 are integrally formed at the upper end of the ductile iron fan-shaped panel 13. Two ductile iron fan-shaped panels 13 near the protrusion 6 are also integrally formed. The upper part of the manhole cover is integrally formed with protrusions 18. The upper end face of the central block 11 and the upper end face of the ductile iron fan-shaped panel 13 are both coated with wear-resistant coating 19. The protrusions 18 on the ductile iron fan-shaped panel 13 can be fitted and matched with the brackets 6 on the outer ring 4. The drainage hole 12 on the ductile iron fan-shaped panel 13 is used for drainage in the middle area of ​​the manhole cover. Through the confluence groove 14 and the guide groove 15 on the ductile iron fan-shaped panel 13, the rainwater on the manhole cover is introduced into the drainage hole 16 and discharged. The wear-resistant coating 19 on the central block 11 and the ductile iron fan-shaped panel 13 is a hot-dip galvanized coating. By immersing it in molten zinc at 450°C, a zinc-iron alloy layer is formed, which not only provides a physical barrier, but also has cathodic protection. The corrosion resistance can reach more than 20 years. The wear resistance comes from the dense alloy layer structure.

[0044] In this embodiment: the present invention is mainly composed of a high-chromium cast iron skeleton casting and a ductile iron panel casting. The high-chromium cast iron skeleton casting is mainly composed of a high-chromium cast iron concave base plate 1, a central seat 2, several ribs 3, an outer ring 4, annular protrusions 9, and several reinforcing bottom ribs 10. It is made of high-chromium cast iron and is cast by lost foam casting. The ductile iron panel casting is composed of a central block 11 and several ductile iron fan-shaped panels 13. It is made of ductile iron and is cast by lost foam casting. The central block 11 is embedded and fixed in the central seat 2 on the high-chromium cast iron skeleton, and the ductile iron fan-shaped panels 13 are embedded and fixed in the cavity 5 on the high-chromium cast iron skeleton.

[0045] The manhole cover, composed of the aforementioned high-chromium cast iron skeleton casting and ductile iron panel casting, has better toughness and strength than existing conventional cast iron manhole covers. It has stronger impact resistance, is not easily broken or damaged under heavy vehicle pressure, and has better wear resistance and superior performance. In addition, if a ductile iron fan-shaped panel 13 of the manhole cover is damaged, only that panel needs to be replaced, without the need for the entire cover, which can greatly reduce daily usage costs.

[0046] The present invention provides drainage holes 16, guide grooves 15, and several confluence grooves 14 and anti-slip protrusions 17 on several ductile iron fan-shaped panels 13. This not only greatly increases the anti-slip effect of the ductile iron fan-shaped panel 13, making it more slip-resistant, but also facilitates the drainage of rainwater on the ductile iron fan-shaped panel 13 by connecting the confluence grooves 14, guide grooves 15 and drainage holes 16, making it more efficient to drain water.

[0047] The present invention further impregnates the surface of the ductile iron panel casting with a wear-resistant coating 19, which can further improve its wear resistance.

[0048] Lost foam casting is a modern green casting technology that uses foam plastic to create a solid model that perfectly matches the shape of the casting. High-temperature molten metal is poured into the model, causing it to vaporize and disappear, thus accurately replicating complex shapes. Its core steps include: high-precision foam pattern fabrication, using expandable polystyrene (EPS) and other materials through foaming or CNC machining; module integration, bonding the pattern to the gating system to form a cluster for clustered production; refractory coating and drying, applying a 0.5-2mm thick coating to the model surface to resist molten metal erosion and allow gas to escape; dry sand vibration molding, filling with binder-free dry sand and compacting it through vibration to ensure clear contours; negative pressure pouring and displacement, pouring molten metal under sealed negative pressure, causing the model to vaporize instantly and the molten metal to fill the space; and sand removal and cleaning, recovering the dry sand after the casting cools, removing the gating gate, and shot blasting the casting.

[0049] In addition, all content not described in detail in this embodiment falls within the scope of existing technology and common knowledge.

[0050] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wear-resistant casting with good toughness and high strength, characterized in that: Including high-chromium cast iron skeleton castings and ductile iron panel castings; The high-chromium cast iron skeleton casting includes a high-chromium cast iron concave base plate (1), a center seat (2), a rib plate (3), an outer ring (4), an annular protrusion (9), and a reinforcing bottom rib (10). The high-gain cast iron concave substrate (1) has a central seat (2) integrally formed at the middle position of its upper end. The central seat (2) has several ribs (3) integrally formed around its perimeter. The high-gain cast iron concave substrate (1) has an outer ring (4) integrally formed around its upper outer perimeter. The high-gain cast iron concave substrate (1) has several cavities (5) formed around its central seat (2), ribs (3), and outer ring (4). The high-gain cast iron concave substrate (1) has a drainage bottom hole (7) integrally formed at its center position. The high-gain cast iron concave substrate (1) has several drainage bottom holes (8) integrally formed around its bottom perimeter. The high-gain cast iron concave substrate (1) has an annular protrusion (9) integrally formed at the middle position of its bottom end. The annular protrusion (9) has several reinforcing bottom ribs (10) integrally formed around its perimeter. The ductile iron panel casting includes a center block (11) and a ductile iron fan-shaped panel (13). The central block (11) is fitted and fixed in the central seat (2). A drainage hole (12) is integrally formed at the center of the central block (11), and the bottom end of the central block (11) is connected to the drainage bottom hole (7). The ductile iron fan-shaped panel (13) is fitted and fixed in the cavity (5). A drainage hole (16) is integrally formed at the center of the ductile iron fan-shaped panel (13), and the bottom end of the drainage hole (16) is connected to the drainage bottom hole (8).

2. The wear-resistant casting with good toughness and high strength according to claim 1, characterized in that: The ribs (3) and the reinforcing bottom ribs (10) are both arranged in a ring array.

3. The wear-resistant casting with good toughness and high strength according to claim 1, characterized in that: One side of the outer ring (4) is integrally formed with a protrusion (6), and two ductile iron fan-shaped panels (13) near the protrusion (6) are integrally formed with protrusions (18).

4. The wear-resistant casting with good toughness and high strength according to claim 1, characterized in that: The upper end of the ductile iron fan-shaped panel (13) is integrally formed with several confluence grooves (14), and the middle position of the upper end of the ductile iron fan-shaped panel (13) is integrally formed with a guide groove (15). The guide groove (15) is connected to the middle position of the several confluence grooves (14), and the middle position of the guide groove (15) is connected to the upper end of the second drain hole (16).

5. A wear-resistant casting with good toughness and high strength according to claim 1, characterized in that: The upper end of the ductile iron fan-shaped panel (13) is integrally formed with several anti-slip protrusions (17).

6. A wear-resistant casting with good toughness and high strength according to claim 1, characterized in that: The upper surface of the central block (11) and the upper surface of the ductile iron fan-shaped panel (13) are both coated with a wear-resistant coating (19).

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