Method for producing a cladding alloy layer on concave and convex spherical mating surfaces and a support

Abstract

The application provides a preparation method of a cladding alloy layer on a concave-convex spherical surface matching surface and a support. The cladding alloy layer is formed by high-speed laser cladding on the concave-convex spherical surface matching surface to replace traditional stainless steel spherical surface cladding, so that the phenomenon of non-adhesion and cavity of stainless steel and a base material can be avoided. The preparation steps of the cladding alloy layer comprise the following steps: laser cladding of alloy powder on a matching surface on which the cladding alloy layer needs to be formed by a high-speed laser cladding device, so as to form the cladding alloy layer on the matching surface; then polishing the cladding alloy layer; during the laser cladding process, the flow rate of protective gas is controlled to be 2-20 L / min, the flow rate of powder feeding gas of the alloy powder is controlled to be 1-3 L / min, the power of laser is controlled to gradually increase from 20% to 90%, the powder feeding amount of the alloy powder is controlled to gradually increase from 1.5 g / min to 75 g / min; and the cladding height is controlled to be 15-25 mm.

Description

Preparation method of cladding alloy layer on concave and convex spherical mating surfaces and support Technical Field

[0001] This invention belongs to the field of bridge or building bearings, specifically relating to a method for preparing a cladding alloy layer on a concave or convex spherical mating surface and a bearing. Background Technology

[0002] As a crucial component in bridge and building construction, bearings serve two main functions: supporting the loads of the superstructure and sensitively transferring the loads and deformations of the superstructure to the substructure. They typically consist of an upper base connected to the superstructure, a lower base connected to the substructure, and a spherical cap located between the upper and lower bases. The basic structural forms of bearings are well-known in this field, and are described in documents such as CN2047030358U.

[0003] To reduce the resistance of the sliding surface, the support needs to have high wear resistance, low roughness, and a low coefficient of friction on the mating surface with the wear-resistant sliding plate. Typically, carbon steel clad with stainless steel is welded around the perimeter using argon arc welding. While this meets basic engineering requirements, some key issues remain to be addressed.

[0004] In practice, the stainless steel sheet covering the spherical crown needs to be pressed into a corresponding sphere using a spherical tool (the tooling size is slightly smaller than the spherical surface size). This spherical stainless steel sheet is then placed on the crown, and the two are joined by pressure and welding. This process involves multiple pressure applications to the stainless steel sheet, significantly reducing its wear resistance and surface finish. Furthermore, due to limitations in the pressing equipment, extra-large spherical crowns require splicing. The joints are welded using argon arc welding and then ground smooth, which cannot guarantee a smooth finish and contour, affecting the crown's performance. For convex or concave spherical workpieces, no matter how tightly the stainless steel is pressed, it will shrink after welding, and the bonding surface provides space for this shrinkage, causing the stainless steel to detach from the substrate. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing a cladding alloy layer on a mating surface of concave and convex spherical surfaces, as well as a support. This invention replaces traditional stainless steel spherical cladding by forming a cladding alloy layer on the mating surface of concave and convex spherical surfaces using high-speed laser cladding. This avoids the phenomenon of poor adhesion or gaps between the stainless steel and the substrate. The formed cladding alloy layer is metallurgically bonded to the concave or convex spherical surface, possessing excellent connection strength and ensuring stability and reliability.

[0006] To achieve its objective, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing a cladding alloy layer on a mating surface of concave and convex spherical surfaces, wherein the concave and convex spherical surfaces mate with each other, and a cladding alloy layer is formed on the mating surface of the concave spherical surface that mates with the convex spherical surface and / or on the mating surface of the convex spherical surface that mates with the concave spherical surface. The preparation steps of the cladding alloy layer include:

[0008] Alloy powder is laser-clad onto the mating surface where a cladding alloy layer needs to be formed using a high-speed laser cladding device, thereby forming the cladding alloy layer on the mating surface; then the cladding alloy layer is polished.

[0009] During the laser cladding process, the protective gas flow rate is controlled at 2-20 L / min, the alloy powder feeding gas flow rate is 1-3 L / min, the laser power is gradually increased from 20% of the preset power to 90% of the preset power, and the alloy powder feeding amount is gradually increased from 1.5 g / min to 75 g / min; the cladding height is controlled at 15-25 mm.

[0010] This invention employs a high-speed laser cladding method to laser clad alloy powder onto concave and / or convex spherical surfaces using the aforementioned process. This results in a dense and uniform cladding alloy layer, which is metallurgically bonded to the concave or convex spherical surface, exhibiting high bonding strength and excellent stability and reliability. The inventors have discovered that using the aforementioned protective gas flow rate during the high-speed laser cladding process not only protects the cladding head equipment but also significantly reduces the impact of the protective gas on the powder beam distribution. Excessive flow rate can easily disperse the powder, while insufficient flow rate makes it difficult to protect the cladding head. The aforementioned powder feeding gas flow rate ensures complete powder delivery from the powder feeder without causing powder splashing, thus facilitating a better cladding effect. Furthermore, using the aforementioned process parameters for laser power, powder feeding amount, and cladding height for high-speed laser cladding results in a cladding effect with better flatness and adhesion.

[0011] In a preferred embodiment, the preset power of the laser is 6000-12000W, and the power of the laser gradually increases from 20% of the preset power at a rate of 1200-2400W / h to 90% of the preset power.

[0012] The feed rate of the alloy powder gradually increases from 1.5 g / min to 75 g / min at a rate of 15-20 g / hour.

[0013] In a preferred embodiment, the cladding path used for laser cladding is a straight line or a spiral.

[0014] In a preferred embodiment, during the laser cladding process, the speed of the horizontal turntable of the high-speed laser cladding device is adjusted to keep the feed rate constant. This operation ensures a constant feed rate, reducing the impact of parameter variations on the cladding effect. The specific feed rate setting can be adjusted and determined by those skilled in the art based on actual process conditions such as workpiece size and laser power.

[0015] In some implementations, CNC polishing equipment is used to polish the cladding alloy layer to achieve the required profile and surface roughness.

[0016] Furthermore, after completing the preparation steps of the cladding alloy layer, the exposed parts other than the concave and convex spherical mating surfaces can be painted to achieve the purpose of corrosion prevention.

[0017] In a preferred embodiment, the alloy powder has a particle size of 20μm-120μm and a loose packing density ≥3.0g / cm³. 3 The fluidity is ≤30s / 50g; using alloy powder that meets the above requirements helps to ensure the fluidity of the alloy powder, avoids blockage during the laser cladding process, and helps to obtain better cladding results.

[0018] Preferably, the alloy powder is pre-baked under the following conditions: temperature 100-150℃, time 30-60 minutes. Baking removes moisture from the alloy powder.

[0019] Preferably, the alloy powder is selected from one or more of nickel-based, cobalt-based, and iron-based self-fluxing alloy powders. The alloy powder is commercially available, and specifically, for example, Ni2O powder, Ni60 powder, In625 powder, CoO6 powder, Co40 powder, FeO1 powder, FeO6 powder, or Fe31 powder can be used.

[0020] In some implementations, during the laser cladding process, the feeding method involves the rotation of a tooling, with the X / Y / Z axes of the cladding equipment working together; or the Y-axis of the cladding equipment robot rotates in conjunction with the X / Z axes, and the spherical cap is fixed in place.

[0021] Preferably, the laser cladding is performed using a pre-powder method or a synchronous powder feeding method;

[0022] Preferably, the powder feeding method for laser cladding is center-feeding or coaxial-feeding. Using the preferred powder feeding method improves powder utilization and cladding efficiency, and facilitates obtaining a cladding alloy layer with a smoother surface and fewer undulations.

[0023] In some embodiments, the thickness of the cladding alloy layer is 0.8-1.2 mm.

[0024] Furthermore, the concave spherical surface and the convex spherical surface are mating surfaces in bridge or building supports, wherein the convex spherical surface originates from the spherical cap in the support, and the concave spherical surface originates from the base that mats with the spherical cap. Furthermore, before laser cladding, the spherical cap and the base are shot-blasted to achieve a surface roughness of Rz 20μm-80μm, which improves the adhesion of subsequent paint treatments.

[0025] The present invention also provides a bridge or building support, the support comprising a spherical cap and a base that mates with the spherical cap, wherein the spherical cap comprises at least one convex spherical surface, and a concave spherical surface adapted to the convex spherical surface is formed on the base that mates with the convex spherical surface; a cladding alloy layer formed by the preparation method described above is formed on the convex spherical surface and / or the concave spherical surface.

[0026] The technical solution provided by this invention has the following beneficial effects:

[0027] The high-speed laser cladding process of this invention forms a cladding alloy layer on a concave or convex spherical surface to replace the traditional stainless steel cladding. The cladding alloy layer and the substrate are metallurgically bonded, and the resulting cladding alloy layer and substrate have better connection strength. The cladding alloy layer and the substrate form an integral structure, which can ensure stability and reliability. Compared with cladding stainless steel plates, it avoids the problem of "two layers of skin" that are not tightly adhered and have gaps.

[0028] This invention employs a high-speed laser cladding process, which achieves a higher linear speed compared to traditional cladding technology, and its overall efficiency is 3-4 times that of traditional cladding technology.

[0029] The cladding layer obtained by the preparation method of the present invention is flat and can be directly ground and polished without turning, which greatly saves materials and processing costs.

[0030] High-speed laser cladding forms the alloy layer with minimal heat input and thermal deformation to the workpiece. Furthermore, it allows for higher power density and the use of high-melting-point alloy powder materials. Attached Figure Description

[0031] Figure 1 is a schematic diagram of forming a cladding alloy layer on the convex surface of a spherical crown in one embodiment;

[0032] Figure 2 is a schematic diagram of forming a cladding alloy layer on the concave spherical surface of a base that mates with a spherical crown in one embodiment. Detailed Implementation

[0033] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0035] Where specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps or conditions in this technical field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0036] As mentioned earlier, the structure of bridge or building bearings includes an upper base, a lower base, and a spherical cap located between the upper and lower bases. The specific structure of the bearing is conventional in this technical field and will not be elaborated further. The spherical cap includes at least one convex spherical surface, as shown in Figure 1. This spherical cap 1 includes one convex spherical surface; however, in some bearings, the spherical cap may also include two convex spherical surfaces. Correspondingly, the base 2, which mates with the spherical cap 1 in the bearing, has a concave spherical surface adapted to fit the convex spherical surface of the spherical cap 1, as shown in Figure 2. In existing applications of bearings, a wear-resistant sliding plate is also provided between the concave and convex spherical surfaces. In the prior art, a stainless steel plate is used to cover the spherical surface to improve the wear resistance, reduce roughness, and lower coefficient of friction of the mating surface with the wear-resistant sliding plate. The main improvement of this invention over existing supports lies in forming a cladding alloy layer 3 on the mating surfaces of the concave spherical surface and / or the convex spherical surface, replacing the aforementioned stainless steel plate covering. Other structural features of the support can adopt conventional forms in the art, and will not be elaborated upon. In this invention, the mating of the concave and convex spherical surfaces covers indirect mating situations, such as when other intermediate components are provided between them, such as the wear-resistant sliding plate mentioned earlier.

[0037] In some preferred embodiments of the present invention, the main steps of forming the cladding alloy layer on the concave spherical surface of the base 2 and / or the convex spherical surface of the crown 1 include:

[0038] 1) Use particles with a size of 20μm-120μm and a loose packing density ≥3.0g / cm³. 3 For alloy powders with a flowability ≤30s / 50g, the alloy powders are pre-baked at a temperature of 100-150℃ for 30-60min.

[0039] 2) The above alloy powder is laser-clad onto the mating surfaces on which the cladding alloy layer needs to be formed in a high-speed laser cladding device, namely the aforementioned mating concave or convex spherical surfaces;

[0040] The laser cladding process conditions include: controlling the protective gas flow rate to 2-20 L / min, the alloy powder feeding gas flow rate to 1-3 L / min, the preset laser power to 6000-12000 W, and controlling the laser power to gradually increase from 20% to 90% of the preset power, with an optimal increase rate of 1200-2400 W / h; gradually increasing the alloy powder feeding rate from 1.5 g / min to 75 g / min, with an optimal increase rate of 15-20 g / h; during the cladding process, the height of the cladding head is continuously reduced, while ensuring a cladding height of 15-25 mm; the protective gas can be argon or nitrogen, etc., and the powder feeding gas can be argon or nitrogen, etc.

[0041] The optimal scanning speed is 0.2-12 m / min.

[0042] Laser cladding can be performed using either a pre-placed powder method or a synchronous powder feeding method. The preferred powder feeding method is either center powder feeding or coaxial powder feeding.

[0043] During laser cladding, the cladding path can be a straight line or a spiral.

[0044] During laser cladding, the speed of the horizontal turntable of the high-speed laser cladding device is adjusted to keep the feed speed constant. The feeding method during laser cladding involves either tool rotation with the X / Y / Z axes of the cladding equipment working in tandem, or the Y-axis rotation and X / Z-axis linkage of the robotic arm of the cladding equipment, with a fixed spherical cap.

[0045] 3) After laser cladding is completed, the laser cladding layer is polished.

[0046] The aforementioned alloy powder is preferably one or more of nickel-based, cobalt-based, and iron-based self-fluxing alloy powders. For example, Ni20 powder, Ni60 powder, In625 powder, Co06 powder, Co40 powder, Fe01 powder, Fe06 powder, or Fe31 powder can be used.

[0047] In the following examples, all alloy powders used meet the following requirements: particle size between 20 μm and 120 μm, and loose packing density ≥ 3.0 g / cm³. 3 Flowability ≤30s / 50g.

[0048] Unless otherwise specified in the following examples, please refer to the preceding text.

[0049] Example 1

[0050] Forming a cladding alloy layer on the concave spherical surface of the base, the steps include:

[0051] 1) The alloy powder is a nickel-based self-fluxing alloy powder (Ni20 powder). The alloy powder is pre-baked at a temperature of 120℃ for 40 minutes.

[0052] 2) The above alloy powder is laser-clad onto the concave spherical surface in a high-speed laser cladding device;

[0053] The process conditions for laser cladding include: controlling the protective gas flow rate to 15 L / min, the alloy powder feeding gas flow rate to 2 L / min, the preset laser power to 10000 W, and controlling the laser power to gradually increase from 20% to 90% of the preset power at an increase rate of 2000 W / h; gradually increasing the alloy powder feeding rate from 1.5 g / min to 75 g / min at an increase rate of 18 g / h; ensuring the cladding height is between 15-20 mm during the cladding process; and a scanning speed of 5 m / min.

[0054] Laser cladding employs a synchronous powder feeding method, with the powder feeding mechanism using a central powder feeding system.

[0055] During laser cladding, the cladding path is a straight line.

[0056] 3) After laser cladding is completed, the laser cladding layer is polished.

[0057] The thickness of the cladding alloy layer in this embodiment is 0.8 mm.

[0058] Experimental results: The profile of the cladding alloy layer is ≤0.2, and the connection strength is ≥160MPa.

[0059] Example 2

[0060] The steps for forming a cladding alloy layer on the convex surface of the spherical cap include:

[0061] 1) The alloy powder is a cobalt-based self-fluxing alloy powder (CoO6 powder). The alloy powder is pre-baked at a temperature of 140℃ for 50 minutes.

[0062] 2) The above alloy powder is laser-clad onto the convex spherical surface in a high-speed laser cladding device;

[0063] The process conditions for laser cladding include: controlling the protective gas flow rate to 15 L / min, the alloy powder feeding gas flow rate to 3 L / min, the preset laser power to 10000 W, controlling the laser power to gradually increase from 20% to 90% at an increase rate of 2000 W / h; gradually increasing the alloy powder feeding rate from 1.5 g / min to 75 g / min at an increase rate of 18 g / h; ensuring the cladding height is between 15-20 mm during the cladding process; and a scanning speed of 8 m / min.

[0064] Laser cladding employs a synchronous powder feeding method, with coaxial powder feeding as the feeding mechanism.

[0065] During laser cladding, the cladding path is a spiral.

[0066] 3) After laser cladding is completed, the laser cladding layer is polished.

[0067] The thickness of the cladding alloy layer in this embodiment is 1.0 mm.

[0068] Experimental results: The profile of the cladding alloy layer is ≤0.2, and the connection strength is ≥160MPa.

[0069] Example 3

[0070] The steps for forming a cladding alloy layer on the convex surface of the spherical cap include:

[0071] This embodiment is based on Embodiment 2, with the main difference being that the alloy powder used is an iron-based self-fluxing alloy powder (FeO6 powder).

[0072] Experimental results: The profile of the cladding alloy layer is ≤0.2, and the connection strength is ≥160Mpa.

[0073] Comparative Example 1

[0074] The same procedure was followed as in Example 1, except that the power of the laser was gradually increased from 10% of the preset power to 80% of the preset power.

[0075] Experimental results: The profile of the cladding alloy layer is ≥0.25, and the connection strength is ≤155Mpa.

[0076] Comparative Example 2

[0077] The same procedure was followed as in Example 1, except that the amount of alloy powder fed was gradually increased from 1 g / min to 50 g / min, with an increase rate of 25 g per hour.

[0078] Experimental results: The profile of the cladding alloy layer is ≥0.3, and the connection strength is ≤150Mpa.

[0079] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a cladding alloy layer on a mating surface of concave and convex spherical surfaces, characterized in that, A concave spherical surface and a convex spherical surface are fitted together. A cladding alloy layer is formed on the mating surface of the concave spherical surface that mates with the convex spherical surface and / or on the mating surface of the convex spherical surface that mates with the concave spherical surface. The preparation steps of the cladding alloy layer include: laser cladding alloy powder onto the mating surface where the cladding alloy layer is to be formed using a high-speed laser cladding device, so as to form the cladding alloy layer on the mating surface; then polishing the cladding alloy layer; during the laser cladding process, the protective gas flow rate is controlled to be 2-20 L / min, the powder feeding gas flow rate of the alloy powder is controlled to be 1-3 L / min, the laser power is controlled to gradually increase from 20% of the preset power to 90% of the preset power, and the powder feeding amount of the alloy powder is gradually increased from 1.5 g / min to 75 g / min; the cladding height is controlled to be 15-25 mm.

2. The preparation method according to claim 1, characterized in that, The preset power of the laser is 6000-12000W, and the laser power gradually increases from 20% of the preset power at a rate of 1200-2400W / h to 90% of the preset power; the powder feeding rate of the alloy powder gradually increases from 1.5g / min at a rate of 15-20g / h to 75g / min.

3. The preparation method according to claim 1, characterized in that, The cladding path used for laser cladding is either a straight line or a spiral.

4. The preparation method according to any one of claims 1-3, characterized in that, During the laser cladding process, the speed of the horizontal turntable of the high-speed laser cladding device is adjusted to keep the feed speed constant.

5. The preparation method according to any one of claims 1-3, characterized in that, The alloy powder has a particle size of 20μm-120μm and a loose packing density of ≥3.0g / cm³. 3 Flowability ≤30s / 50g.

6. The preparation method according to claim 5, characterized in that, The alloy powder is pre-baked, and the baking conditions include a temperature of 100-150℃ and a time of 30-60 minutes.

7. The preparation method according to any one of claims 1-3, characterized in that, The alloy powder is selected from one or more of nickel-based, cobalt-based, and iron-based self-fluxing alloy powders.

8. The preparation method according to any one of claims 1-3, characterized in that, The laser cladding employs either a pre-placed powder method or a synchronous powder feeding method.

9. The preparation method according to claim 8, characterized in that, The powder feeding method for laser cladding is either center powder feeding or coaxial powder feeding.

10. The preparation method according to any one of claims 1-3, characterized in that, The thickness of the cladding alloy layer is 0.8-1.2 mm.

11. The preparation method according to any one of claims 1-3, characterized in that, The concave spherical surface and the convex spherical surface are mating surfaces in a bridge or building support, wherein the convex spherical surface originates from a spherical cap in the support, and the concave spherical surface originates from a base that mats with the spherical cap.

12. A bridge or building support, the support comprising a spherical cap and a base cooperating with the spherical cap, wherein the spherical cap comprises at least one convex spherical surface, and the base cooperating with the convex spherical surface has a concave spherical surface adapted to the convex spherical surface; characterized in that, A cladding alloy layer formed by the preparation method according to any one of claims 1-11 is formed on the convex spherical surface and / or the concave spherical surface.

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