Wing rail with multi-layer gradient coating structure

Abstract

The utility model discloses a wing rail with a multi-layer gradient coating structure. The wing rail comprises a wing rail base body, and a transition layer, a hardened layer, a tough-hard composite layer, a wear-resistant reinforced layer, a wear-resistant advanced layer and a low-friction protective layer which are sequentially cladded on the wing rail base body. And each layer is made of Q690D steel, M2 steel, Ni25, Metco 8224, Metco 420C and Ni30Cu, so that gradient hardness distribution is formed. According to the structure, the hardness, the wear resistance and the lubricating performance of the wing rail can be remarkably improved, thermal stress between the coating and a base body is effectively relieved, the binding force is enhanced, the service life is prolonged, and the maintenance cost is reduced. And through the laser cladding technology, it is ensured that all the layers are tightly combined, diversified application requirements are met, and wide application prospects are achieved.

Description

Technical Field

[0001] This application belongs to the field of wing rail surface protective coating preparation, and particularly relates to a wing rail with a multi-layer gradient coating structure. Background Technology

[0002] In railway transportation systems, wing rails, as a key component of the track structure, directly affect the safety and stability of train operation. Exposed to the complex and ever-changing outdoor environment for extended periods, wing rails are subjected to enormous impacts and friction from trains, making them highly susceptible to wear and fatigue. These problems not only reduce the service life of the wing rails but can also lead to serious safety accidents.

[0003] To address the protection issues of wing rails, the traditional approach is to coat the wing rail surface with a protective coating. However, this single-coat structure often fails to simultaneously meet the performance requirements of multiple aspects, including hardness, wear resistance, corrosion resistance, and lubricity. Furthermore, due to the mismatch in thermal expansion coefficients between the coating and the substrate, the coating is prone to failure during use, such as peeling and cracking. Therefore, developing a multi-layered gradient coating structure for wing rails with excellent comprehensive performance, mature manufacturing technology, and low maintenance costs is of great significance for improving the safety and reliability of railway transportation systems. Utility Model Content

[0004] Based on the above background, this utility model aims to improve the performance and reduce the cost of the protective coating on the airfoil surface by optimizing the composition and structural design of the coating and improving the coating preparation process.

[0005] To address the aforementioned technical problems, this utility model provides a multi-layer gradient coating structure for an airfoil, comprising: an airfoil substrate, a transition layer, a hardening layer, a tough-hard composite layer, a wear-resistant reinforcing layer, a wear-resistant advanced layer, and a low-friction protective layer. The transition layer is directly clad onto the upper part of the airfoil substrate; the hardening layer is clad onto the upper part of the transition layer; the tough-hard composite layer is directly clad onto the upper part of the hardening layer to jointly provide hardness support; the wear-resistant reinforcing layer is directly clad onto the upper part of the hardness-toughness bonding layer; the wear-resistant advanced layer is clad onto the upper part of the wear-resistant reinforcing layer to ensure wear performance; and the low-friction protective layer, as a surface layer, is clad onto the upper part of the wear-resistant advanced layer to further enhance the wear resistance of the coating.

[0006] Optionally, the transition layer is made of Q690D steel with a thickness of 0.1 to 0.2 mm.

[0007] Optionally, the hardened layer is made of M2 steel with a thickness of 0.2 to 0.3 mm.

[0008] Optionally, the tough composite layer is made of Ni25 with a thickness of 0.3 to 0.4 mm.

[0009] Optionally, the wear-resistant reinforcement layer is specifically made of Metco 8224 with a thickness of 0.4 to 0.5 mm.

[0010] Optionally, the wear-resistant advanced layer is specifically made of Metco 420C with a thickness of 0.5–0.6 mm.

[0011] Optionally, the low-friction protective layer is made of Ni30Cu with a thickness of 0.1 to 0.2 mm.

[0012] The technical solution of this utility model has the following advantages:

[0013] 1. The multi-layer gradient coating structure of the airfoil rail provided by this utility model offers more comprehensive performance optimization: the multi-layer gradient coating structure, through a progressively layered design, can be precisely optimized for different performance requirements of the airfoil rail. From the transition layer to the low-friction protective layer, each layer undertakes a specific function, thereby achieving a comprehensive improvement in hardness, wear resistance, and friction coefficient control.

[0014] 2. The multi-layer gradient coating structure of the airfoil provided by this utility model is more effective in relieving thermal stress: traditional single coatings or simple multi-layer structures often fail to effectively relieve thermal stress between the coating and the substrate. However, the multi-layer gradient coating structure, through the design of the transition layer, can significantly reduce thermal stress, prevent problems such as coating peeling or cracking during use, and improve the stability and service life of the coating.

[0015] 3. The multi-layer gradient coating structure of the airfoil rail provided by this utility model has stronger bonding strength: the multi-layer gradient coating structure adopts an advanced manufacturing process to ensure a tight bond between each layer. This tight bond not only improves the overall strength of the coating, but also makes the coating more resistant to peeling and detachment when subjected to external impact, thereby extending the service life of the airfoil rail.

[0016] 4. Greater adaptability: Compared with traditional single coatings or simple multi-layer structures, multi-layer gradient coating structures are more adaptable. They can be customized to meet different application environments and requirements, thereby satisfying diverse application needs.

[0017] 5. Lower maintenance costs: Although the fabrication process of the multi-layer gradient coating structure is relatively complex, its excellent overall performance and stability reduce wear and corrosion during use, thereby lowering maintenance costs. Furthermore, because the coating further controls the coefficient of friction, it also reduces wear between friction pairs, further extending the service life of the airfoil and reducing maintenance costs.

[0018] In summary, multi-layer gradient coating wing rails offer significant advantages over traditional single or other multi-layer structures in terms of performance optimization, thermal stress relief, bonding strength, adaptability, and maintenance costs. These advantages make multi-layer gradient coating wing rails more promising and valuable for use in railway transportation systems. Attached Figure Description

[0019] Figure 1 A schematic diagram of a multi-layer gradient coating structure for an airfoil rail;

[0020] Figure 2 This is a hardness distribution diagram for Example 1;

[0021] Figure 3 This shows the wear rate in Example 1.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. Airfoil base; 2. Transition layer; 3. Hardened layer; 4. Tough and hard composite layer; 5. Wear-resistant reinforced layer; 6. Wear-resistant advanced layer; 7. Low friction protective layer. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] like Figure 1The diagram shows a multi-layer gradient coating structure for an airfoil, comprising: an airfoil substrate (1), a transition layer (2), a hardening layer (3), a tough-hard composite layer (4), a wear-resistant reinforcing layer (5), a wear-resistant advanced layer (6), and a low-friction protective layer (7). The transition layer (2) is directly clad onto the upper part of the airfoil substrate (1), the hardening layer (3) is clad onto the upper part of the transition layer (2), the tough-hard composite layer (4) is directly clad onto the upper part of the hardening layer (3) to provide hardness support, the wear-resistant reinforcing layer (5) is directly clad onto the upper part of the hardness-toughness bonding layer (4), the wear-resistant advanced layer (6) is clad onto the upper part of the wear-resistant reinforcing layer (5) to ensure wear performance, and the low-friction protective layer (7) serves as a surface layer, clad onto the upper part of the wear-resistant advanced layer (6) to further enhance the wear resistance of the coating. The transition layer (2) is made of Q690D steel, which has good toughness and resistance to thermal cracking, and can form a good metallurgical bond with the airfoil substrate (1), and effectively relieve the thermal stress between the coating and the substrate. The hardening layer (3) is made of M2 steel, which has high hardness and can significantly improve the wear resistance of the coating while maintaining toughness. The tough-hard composite layer (4) is made of Ni25 powder, which has excellent hardness and toughness bonding ability, and can improve the impact resistance of the coating while ensuring the hardness of the coating, and can balance the hardness and toughness of the coating to improve the overall performance of the coating. The wear-resistant strengthening layer (5) is made of Metco 8224, in which Cr and B particles provide high hardness, Ni as a binder phase improves the toughness and bonding of the coating, and Metco 8224 as the wear-resistant strengthening layer (5) can significantly improve the wear resistance of the coating and extend the service life of the airfoil. The wear-resistant advanced layer (6) uses Metco420C powder, which combines the high hardness and wear and corrosion resistance of Cr and Mo with the bonding ability of Fe and Ni between coatings, so that the coating has better wear resistance while maintaining good metallurgical bonding and high hardness. The low friction protective layer (7) uses Ni30Cu, which has good wear resistance and can significantly reduce the coefficient of friction between the coating and the friction pair, reduce wear and improve service life. In addition, nickel-coated copper can effectively reduce the large amount of reflection and decomposition of copper under high laser energy input.

[0026] In this application, the various coatings interact and are closely connected, together forming an overall coating with excellent performance. The transition layer (2) alleviates the thermal stress between the substrate and the subsequent coating through the transition layer (2), improving the overall stability of the coating. At the same time, the transition layer (2) provides a good substrate for the hardening layer (3), allowing the hardening layer (3) to be deposited uniformly and stably on the transition layer (2). The presence of the transition layer (2) helps to reduce the difference in thermal stress between the hardening layer (3) and the airfoil substrate (1), thereby improving the overall thermal shock resistance of the coating. The hardening layer (3) provides a higher hardness base for the tough-hard composite layer (4), thereby improving the overall hardness of the coating. The tough-hard composite layer (4) can maintain a certain degree of toughness while improving hardness, thereby enhancing the impact resistance of the coating. The hardening layer (4) provides a solid support for the wear-resistant strengthening layer (5), allowing the wear-resistant strengthening layer (5) to better exert its wear resistance performance. The wear-resistant reinforcing layer (5) not only improves the wear resistance of the coating, but also further enhances the overall hardness of the coating. The tough composite layer (4) maintains high hardness while also possessing a certain degree of toughness, which can alleviate the brittleness caused by the high hardness of the wear-resistant reinforcing layer (5). The wear-resistant reinforcing layer (5) not only improves the wear resistance of the coating, but also forms a good bond with the tough composite layer (4), enhancing the overall performance of the coating. The wear-resistant advanced layer (6) has extremely high hardness and wear resistance, providing solid protection for the low-friction protective layer (7). The low-friction protective layer (7) can reduce the coefficient of friction between the coating and the friction pair, reduce wear, and improve service life. At the same time, the presence of the low-friction protective layer (7) can further enhance the overall performance of the coating, making it more adaptable to the needs of use in extreme environments. The multi-layer gradient coating structure of the airfoil rail forms a coating structure with a gradient hardness distribution by rationally selecting the materials and thicknesses of each layer. This structure can significantly improve the comprehensive performance of the coating, such as hardness and wear resistance. The gradient structure can also alleviate the thermal stress difference between the coating and the substrate, improving the overall stability and service life of the coating.

[0027] Example 1

[0028] This example uses a wing rail as the base material, and the material is U75V. U75V rail is a pearlitic steel with C, Si and Mn as the main components. After heat treatment, the microstructure of U75V rail is normal, making it an ideal material for important components such as railway tracks and wing rails.

[0029] Step 1: Preheat the airfoil base (1) at 600°C for one hour to remove surface oxides and other impurities, and then polish it.

[0030] Step 2: Conduct a cladding experiment on the transition layer (2) to prepare a coating with a thickness of 0.1 to 0.2 mm.

[0031] Step 3: Conduct a cladding experiment on the hardened layer (3) to prepare a coating with a thickness of 0.2 to 0.3 mm.

[0032] Step 4: Conduct a cladding experiment on the tough composite layer (4) to prepare a coating with a thickness of 0.3 to 0.4 mm.

[0033] Step 5: Conduct a cladding experiment on the wear-resistant reinforcement layer (5) to prepare a coating with a thickness of 0.4 to 0.5 mm.

[0034] Step 6: Conduct a cladding experiment on the wear-resistant advanced layer (6) to prepare a coating with a thickness of 0.5-0.6 mm.

[0035] Step 7: Conduct a cladding experiment on the low friction protective layer (7) to prepare a coating with a thickness of 0.2 mm.

[0036] Step 8: Cut the cooled sample into blocks and characterize its mechanical properties. The hardness distribution is as follows: Figure 2 As shown. The wear resistance of the coating is significantly improved compared to the airfoil base material, with a wear rate as... Figure 3 As shown.

Claims

1. A multi-layer gradient coating structure for a wing rail, characterized in that... include: The airfoil base (1), transition layer (2), hardening layer (3), tough composite layer (4), wear-resistant reinforcing layer (5), wear-resistant advanced layer (6) and low friction protection layer (7); the transition layer (2) is directly clad on the upper part of the airfoil base (1), the hardening layer (3) is clad on the upper part of the transition layer (2), the tough composite layer (4) is directly clad on the upper part of the hardening layer (3), the wear-resistant reinforcing layer (5) is directly clad on the upper part of the tough composite layer (4), the wear-resistant advanced layer (6) is clad on the upper part of the wear-resistant reinforcing layer (5), and the low friction protection layer (7) is a surface layer clad on the upper part of the wear-resistant advanced layer (6).

2. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The transition layer (2) is made of Q690D steel.

3. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The hardened layer (3) is made of M2 steel.

4. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The tough composite layer (4) is made of Ni25.

5. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The wear-resistant reinforcement layer (5) is made of Metco 8224.

6. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The wear-resistant advanced layer (6) adopts Metco 420C.

7. The airfoil rail with a multi-layer gradient coating structure according to claim 1, characterized in that, The low-friction protective layer (7) is made of Ni30Cu.

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