A copper-cobalt alloy powder for laser cladding and its application

Abstract

This invention discloses a copper-cobalt alloy powder for laser cladding and its application. It comprises the following raw materials in the indicated mass percentages: 25-35% Cu, 0.1-1.0% C, 9.0-13.5% Cr, 1.0-1.3% Si, 0.1-0.5% Mo, 0.1-0.5% V, 0.1-0.8% Mn, 0.1-1.5% B, 0.1-0.8% ZrC, 0.2-1.5% CeC2, 0.2-1.5% LaC2, and the balance Co. The copper-cobalt alloy powder is used for laser cladding on the working surface of a continuous casting copper crystallizer to enhance its high-temperature wear resistance. The enhanced copper crystallizer exhibits high surface hardness, excellent overall thermal conductivity, excellent resistance to oxidation and corrosion, and possesses inherent lubricity and high thermal strength. The laser cladding layer on the continuous casting copper crystallizer surface shows low wear over a wide temperature range.

Description

Technical Field

[0001] This invention relates to the fields of powder materials and laser processing technology, specifically to a copper-cobalt alloy powder for laser cladding and its applications. Background Technology

[0002] Continuous casting copper crystallizers are key equipment used in the steel casting process to cool liquid metal and form solid steel billets. The surface properties of the continuous casting copper crystallizer directly affect the production efficiency of the casting process, the quality of the steel billets, and the service life of the crystallizer. Continuous casting copper crystallizers typically face problems such as high-temperature friction and wear, oxidation corrosion, and significant thermal cycling shock. Therefore, improving the high-temperature wear resistance, oxidation corrosion resistance, and thermal cycling shock resistance of the continuous casting copper crystallizer surface has become one of the key technologies for optimizing the continuous casting process.

[0003] Laser cladding, an advanced metal surface modification technology, utilizes a high-energy laser beam to melt alloy powder and rapidly clad it onto a metal surface. It allows for precise temperature control of the molten zone, preventing an excessively large heat-affected zone and thus avoiding deformation or performance degradation of the metal substrate. This results in a coating with special properties and a metallurgical bond with the metal substrate. However, when laser cladding is applied to copper alloy substrates, copper alloys possess characteristics such as high thermal conductivity, low melting point, easy oxidation, and high reflectivity. These properties make direct cladding with most metal materials prone to issues like mismatched coefficients of thermal expansion, poor interfacial fusion, or crack defects. Considering the metallurgical solid solution properties of dissimilar materials, nickel-based materials are typically chosen as the undercoat transition layer, or high-nickel content metal powders are directly used for laser cladding. This addresses, to some extent, the defects such as poor fusion or cracks that easily occur during the laser cladding process of copper alloys, and improves the interfacial bonding strength of dissimilar metals, the room temperature hardness of the copper alloy substrate, and its wear resistance. However, because the thermal conductivity and self-lubricating properties of the nickel-based undercoat or high-nickel content metal cladding layer are far lower than those of the copper alloy substrate, this severely affects the reliability of the metal coating prepared by laser cladding technology on the surface of continuously cast copper crystallizers under high-temperature conditions, including its wear resistance, oxidation corrosion resistance, and thermal cycling shock resistance. Therefore, selecting a suitable laser cladding process is crucial to improving the service performance of the surface of continuously cast copper crystallizers, and current technology has not yet made significant breakthroughs in this area. Summary of the Invention

[0004] To address the problems of low coating bonding strength, insufficient thermal conductivity, low resistance to oxidation and corrosion, poor high-temperature wear resistance, and short service life in existing laser cladding technology for continuous casting copper crystallizers, this invention provides a copper-cobalt alloy powder for laser cladding and its application. The copper-cobalt alloy powder is used to enhance the high-temperature wear resistance of the working surface of the continuous casting copper crystallizer through laser cladding. The enhanced copper crystallizer surface has high hardness, excellent overall thermal conductivity, excellent resistance to oxidation and corrosion, and excellent wear resistance. Furthermore, it possesses inherent lubricity and thermal strength, resulting in minimal wear on the surface of the laser cladding layer of the continuous casting copper crystallizer over a wide temperature range. This avoids the problem of premature failure of the copper crystallizer surface due to high-temperature wear during continuous casting, and is beneficial to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a copper-cobalt alloy powder for laser cladding, which is composed of the following elements by mass fraction:

[0007] 25-35% Cu, 0.1-1.0% C, 9.0-13.5% Cr, 1.0-1.3% Si, 0.1-0.5% Mo, 0.1-0.5% V, 0.1-0.8% Mn, 0.1-1.5% B, 0.1-0.8% ZrC, 0.2-1.5% CeC2, 0.2-1.5% LaC2 and the balance Co.

[0008] The copper-cobalt alloy powder is prepared by methods including, but not limited to, ball milling or acoustic resonance.

[0009] The prepared copper-cobalt alloy powder has a particle size of 53~150μm, an oxygen content of ≤200ppm, a sulfur content of ≤300ppm, and a flowability of ≤25 (s / 50g).

[0010] The copper-cobalt alloy powder is used on the surface of the continuous casting copper crystallizer, and a high-temperature wear-resistant coating is formed by laser cladding.

[0011] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished to a metallic luster with a grinding wheel, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0012] Laser cladding process parameters for copper-cobalt alloy powder: spot diameter: 6×20mm, laser power: 10000~15000W, scanning speed: 5~20mm / s, overlap rate: 50~70%, powder feeding speed: 40~70g / min, protective gas flow rate: 25~40L / min, cladding layer thickness: 1.0~3.0mm.

[0013] After laser cladding the copper-cobalt alloy powder, the laser-clad parts of the continuous casting copper crystallizer are air-cooled to room temperature and then tested and analyzed.

[0014] The above technical solution is adopted:

[0015] The copper-cobalt alloy powder is mainly composed of Cu and Co. Cu provides the foundation for the material's overall high bonding strength and thermal conductivity. Cu allows the material to fuse well with the continuous casting copper crystallizer substrate during laser cladding, forming a good metallurgical interface between the cladding layer and the substrate, thus improving the metallurgical bond strength. Cu also significantly enhances the thermal conductivity of the cladding layer. Co, on the other hand, acts as the matrix structure of the coating during laser cladding, providing a high-temperature framework and a high-temperature strength matrix, inhibiting high-temperature softening of the coating, and laying the foundation for the material's overall high thermal strength. The limited solid solution of Co and Cu during the melting and solidification process forms a two-phase metallurgical intercalation structure. The high thermal conductivity of Cu in this structure refines the Co grains, significantly improving the hardness and strength of the cladding layer. The inherent lubricity of embedded Cu significantly improves the wear resistance of the cladding layer at high temperatures. Furthermore, C, Cr, Si, Mo, V, Mn, and B are reinforcing phase-forming elements that can form hard particles such as Cr7C3, SiC, MoC, VC, and B4C during the cladding layer's condensation process, greatly increasing the high-temperature hardness of the cladding layer. MoC and VC can also refine the grains, significantly improving the structural stability at high temperatures. Finally, the addition of ZrC, CeC2, and LaC2 carbides can improve the overall strength of the cladding layer during laser cladding. The synergistic effect of ZrC, CeC2, and LaC2 can reduce grain boundary corrosion sensitivity and prevent the diffusion of impurities such as O and S into the cladding layer, which is highly beneficial for maintaining the structural stability, oxidation resistance, and thermal strength of the cladding layer under wide temperature range conditions.

[0016] The present invention also provides an application of the above-mentioned copper-cobalt alloy powder for laser cladding, wherein the copper-cobalt alloy powder is used on the surface of a continuous casting copper crystallizer, and a high-temperature wear-resistant coating with high hardness, oxidation and corrosion resistance and excellent high-temperature friction and wear performance is formed by laser cladding.

[0017] Preferably, the Cu and Co elements in the copper-cobalt alloy powder form a dual-phase metallurgical intercalation structure, creating a heat-conducting network.

[0018] The copper-cobalt alloy powder is mainly composed of Cu and Co. During laser cladding, Co serves as the matrix structure of the coating, providing a high-temperature skeleton and a high-temperature strength matrix, and inhibiting high-temperature softening of the coating. The Cu element in the copper-cobalt alloy powder is almost insoluble in the Co matrix during laser cladding. Cu and Co form a dual-phase metallurgical intercalation structure, creating a thermally conductive network that ensures the thermal conductivity of the coating.

[0019] The Cu content is limited to 25-35 wt%. When the Cu content is less than 25 wt%, the thermal conductivity of the Cu-Co intercalation structure is low, and the accumulation of heat may cause local overheating of the Co group, which is not conducive to ensuring the overall thermal conductivity uniformity of the coating. When the Cu content is greater than 35 wt%, the thermal conductivity of the Cu-Co intercalation structure is too high, and the heat conduction may cause local undercooling, which is not conducive to ensuring the overall thermal conductivity uniformity of the coating.

[0020] Furthermore, the Cu element in the copper-cobalt alloy powder forms a metallurgical bridging structure with the CuCrZr matrix during laser cladding, thereby enhancing the bonding strength between the coating and the matrix.

[0021] When the Cu content is less than 25wt%, the local hardness of the metallurgical bridge formed with the CuCrZr substrate during laser cladding is too high, resulting in excessive internal stress, which is not conducive to ensuring the bonding strength between the coating and the substrate. When the Cu content is greater than 35wt%, the local hardness of the metallurgical bridge formed with the CuCrZr substrate during laser cladding is too low, resulting in excessive internal stress, which is not conducive to ensuring the bonding strength between the coating and the substrate.

[0022] Preferably, the C, Cr, Si, Mo, V, Mn, and B elements in the copper-cobalt alloy powder form Cr7C3, SiC, MoC, VC, and B4C carbide reinforcing particles during the laser cladding and condensation process, which significantly improves the high-temperature hardness of the cladding layer.

[0023] The Cr content in copper-cobalt alloy powder is limited to 9-13.5 wt%. During laser cladding, it reacts with C to form high-hardness Cr7C3 in situ, improving the coating's high-temperature hardness and wear resistance. When the Cr content is below 9 wt%, the insufficient in-situ formation of Cr7C3 during laser cladding results in inadequate hardness improvement, which is detrimental to enhancing the coating's wear resistance. Conversely, when the Cr content exceeds 13.5 wt%, excessive in-situ formation of Cr7C3 during laser cladding leads to excessive hardness and brittleness, which is also detrimental to improving the coating's wear resistance and reliability.

[0024] Preferably, the mass of Mo and V elements in the copper-cobalt alloy powder is limited to 0.1~0.5wt%, which, during laser cladding, form high-temperature stable MC-type carbides with C elements in situ, thereby improving the high-temperature stability of the coating.

[0025] When the mass percentages of Mo and V in the system are below 0.1%, the amount of high-temperature stable MC-type carbides such as MoC and VC formed in situ with C during laser cladding is insufficient, which is detrimental to improving the high-temperature stability of the coating. When the mass percentages of Mo and V are above 0.5%, the local segregation of MC-type carbides such as MoC and VC formed in situ with C during laser cladding leads to a decrease in high-temperature structural stability, which is also detrimental to improving the high-temperature stability of the coating.

[0026] Preferably, the CeC2 and LaC2 content in the copper-cobalt alloy powder is limited to 0.2~1.5wt%. During laser cladding, the molten pool can be purified and the grains refined, thereby further improving the high-temperature oxidation and corrosion resistance and thermal strength of the coating.

[0027] When the CeC2 and LaC2 masses in the system are below 0.2%, their effects on purifying the molten pool and refining grains during laser cladding are too small, which is detrimental to improving the high-temperature oxidation and corrosion resistance and thermal strength of the coating. When the CeC2 and LaC2 masses are above 1.5%, the excessive carbide content in the molten pool during laser cladding easily leads to local defects or stress corrosion, increasing the susceptibility to grain boundary corrosion, which is also detrimental to improving the high-temperature oxidation and corrosion resistance and thermal strength of the coating.

[0028] Preferably, the hardness of the high-temperature wear-resistant coating exceeds 600 HV, and the high-temperature wear at 650°C is less than 20% of that of the CuCrZr substrate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The copper-cobalt alloy powder of this invention uses Cu and Co as the main components. Cu lays the foundation for the overall high bonding strength and thermal conductivity of the material. Cu enables the material to fuse well with the continuous casting copper crystallizer substrate during laser cladding, forming a good metallurgical interface between the laser cladding layer and the substrate, thus improving the metallurgical bonding strength between the cladding layer and the substrate. Cu also significantly enhances the thermal conductivity of the cladding layer. Co, on the other hand, acts as the matrix structure of the coating during laser cladding, providing a high-temperature skeleton and a high-temperature strength matrix, inhibiting high-temperature softening of the coating, and laying the foundation for the overall high thermal strength of the material. The limited solid solution of Co and Cu during the melting and solidification process forms a two-phase metallurgical intercalation structure of Co and Cu. The high thermal conductivity of Cu in this two-phase metallurgical intercalation structure refines the Co grains, significantly improving the hardness and strength of the cladding layer. The self-lubricating properties of Cu in the metallurgical intercalation structure significantly improve the wear resistance of the cladding layer at high temperatures. In addition, C, Cr, Si, Mo, V, Mn, and B are reinforcing phase forming elements, which can form hard particles such as Cr7C3, SiC, MoC, VC, and B4C during the cladding layer solidification process, greatly improving the high-temperature hardness of the cladding layer. MoC and VC can also refine the grains, which can significantly improve the microstructure stability at high temperatures. Finally, the addition of ZrC, CeC2, and LaC2 carbides can improve the overall strength of the cladding layer during laser cladding. Furthermore, the synergistic effect of ZrC, CeC2, and LaC2 can reduce the sensitivity to grain boundary corrosion and prevent impurities such as O and S from diffusing into the interior of the cladding layer. This is very beneficial for maintaining the microstructure stability, oxidation corrosion resistance, and thermal strength of the cladding layer under wide temperature range conditions.

[0031] This invention uses the aforementioned copper-cobalt alloy powder for laser cladding on the working surface of a continuous casting copper crystallizer to enhance its high-temperature wear resistance. The enhanced copper crystallizer has high surface hardness, excellent overall thermal conductivity, and excellent resistance to oxidation and corrosion. It also possesses intrinsic lubricity and thermal strength. The wear on the surface of the laser cladding layer of the continuous casting copper crystallizer is small over a wide temperature range, avoiding the problem of premature failure of the copper crystallizer surface due to high-temperature wear during continuous casting. This is very beneficial for improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions. Attached Figure Description

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] Figure 1 A schematic diagram of the layer structure of a high-temperature wear-resistant coating prepared by laser cladding process using the copper-cobalt alloy powder of the present invention on a continuous casting copper crystallizer;

[0034] Figure 2 These are macroscopic photographs of the copper crystallizer after laser cladding during the continuous casting process of Example 1 and Comparative Example 1, where a) is a macroscopic photograph of Example 1 after laser cladding and b) is a macroscopic photograph of Comparative Example 1 after laser cladding.

[0035] Figure 3 The images are cross-sectional metallographic photographs of the laser cladding layer formed on the surface of the copper crystallizer during the continuous casting process of Example 1 and Comparative Example 1, where a) is a cross-sectional metallographic photograph of the surface laser cladding layer of Example 1 and b) is a cross-sectional metallographic photograph of the surface laser cladding layer of Comparative Example 1.

[0036] Figure 4 The hardness curves of the cross section of the laser cladding layer formed in the copper crystallizer during the continuous casting process of Example 1 and Comparative Example 1 are shown.

[0037] Figure 5 The wear performance test results of the laser cladding layer formed on the copper crystallizer during the continuous casting process of Example 1 and Comparative Example 1 under the conditions of room temperature of 25°C, medium temperature of 400°C and high temperature of 650°C are shown in a), where a) is the wear performance test result of Example 1 and Comparative Example 1 under the condition of room temperature of 25°C, b) is the wear performance test result of Example 1 and Comparative Example 1 under the condition of medium temperature of 400°C, and c) is the wear performance test result of Example 1 and Comparative Example 1 under the condition of high temperature of 650°C.

[0038] Figure 6 These are macroscopic photographs of the copper crystallizer after laser cladding during the continuous casting process of Example 2 and Comparative Example 2, where a) is a macroscopic photograph of Example 2 after laser cladding and b) is a macroscopic photograph of Comparative Example 2 after laser cladding.

[0039] Figure 7The images are cross-sectional metallographic photographs of the laser cladding layer formed on the surface of the copper crystallizer during the continuous casting process of Example 2 and Comparative Example 2, where a) is a cross-sectional metallographic photograph of the surface laser cladding layer of Example 2 and b) is a cross-sectional metallographic photograph of the surface laser cladding layer of Comparative Example 2.

[0040] Figure 8 The hardness curves of the cross section of the laser cladding layer formed in the copper crystallizer during the continuous casting process of Example 2 and Comparative Example 2 are shown.

[0041] Figure 9 The wear performance test results of the laser cladding layer formed on the copper crystallizer during the continuous casting process of Example 2 and Comparative Example 2 under the conditions of room temperature of 25°C, medium temperature of 400°C and high temperature of 650°C are shown in a), where a) is the wear performance test result of Example 2 and Comparative Example 2 under the condition of room temperature of 25°C, b) is the wear performance test result of Example 2 and Comparative Example 2 under the condition of medium temperature of 400°C, and c) is the wear performance test result of Example 2 and Comparative Example 2 under the condition of high temperature of 650°C.

[0042] The specific reference numerals in the attached figures are as follows:

[0043] 1. Continuous casting copper crystallizer substrate; 2. Laser cladding layer; 3. Copper-cobalt dual-phase metallurgical intercalation structure; 4. Carbide-reinforced particles. Detailed Implementation

[0044] 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.

[0045] The laser cladding layer structure of the continuous casting copper crystallizer prepared in the embodiments of the present invention is as follows: Figure 1 As shown, a laser cladding layer 2 is formed on the surface of the continuous casting copper crystallizer substrate 1, and a copper-cobalt dual-phase metallurgical intercalation structure 3 is formed in the laser cladding layer 2; the substrate of the laser cladding layer 2 is a binary rare earth carbide-doped copper-cobalt alloy, which can be one layer or multiple layers; carbide reinforcing particles 4 are also formed in the laser cladding layer 2, and the number, size and shape of the carbide reinforcing particles can be selected according to actual needs.

[0046] Example 1

[0047] This embodiment provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 25% Cu, 0.6% C, 10.5% Cr, 1.1% Si, 0.2% Mo, 0.1% V, 0.3% Mn, 0.6% B, 0.1% ZrC, 0.2% CeC2, 0.2% LaC2 and the balance Co.

[0048] The copper-cobalt alloy powder mentioned above is obtained by ball milling and mixing the above components in the above proportions.

[0049] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 170ppm, a sulfur content of 215ppm, and a flowability of 20 (s / 50g).

[0050] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0051] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0052] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 10000W, scanning speed: 10mm / s, overlap rate: 60%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.0mm.

[0053] After laser cladding the aforementioned copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Specifically, the inspection included... Figure 2 As shown in a), no obvious defects such as oxidative corrosion pits, lack of fusion, or cracks were found on the surface of the cladding layer.

[0054] The cladding cross section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed, such as... Figure 3 As shown in a), the laser cladding layer forms a good metallurgical bond with the CuCrZr continuous casting copper crystallizer matrix. During the solidification process, Co and Cu form a two-phase metallurgical interlocking structure. The reinforcing phase particles are highly dispersed in the cladding layer. No obvious defects such as oxidative corrosion pores, lack of fusion, or cracks were found in the cross section of the cladding layer.

[0055] Samples were taken from the laser-clad CuCrZr continuous casting copper crystallizer and longitudinal section microhardness tests were performed. The results are as follows: Figure 4 As shown, the hardness of the CuCrZr matrix is ​​about 70-85 Hv, and the hardness of the laser cladding layer matrix with Co and Cu metallurgical intercalation structure is about 600-620 Hv.

[0056] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature of 25℃ are as follows: Figure 5 As shown in a), the wear of the laser cladding layer is about 20% of that of the CuCrZr substrate, which significantly improves the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0057] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 400℃ are as follows: Figure 5 As shown in b), the wear of the laser cladding layer is about 25% of that of the CuCrZr substrate, which significantly improves the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0058] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃ are as follows: Figure 5 As shown in c), the wear of the laser cladding layer is about 18% of that of the CuCrZr substrate, which significantly improves the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0059] Example 2

[0060] This embodiment provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 30% Cu, 0.8% C, 12.3% Cr, 1.2% Si, 0.3% Mo, 0.5% V, 0.8% Mn, 1.0% B, 0.4% ZrC, 0.6% CeC2, 0.6% LaC2 and the balance Co.

[0061] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0062] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 165ppm, a sulfur content of 208ppm, and a flowability of 20 (s / 50g).

[0063] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0064] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0065] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: laser spot diameter: 6×20mm, laser power: 12000W, scanning speed: 12mm / s, overlap rate: 65%, powder feeding speed: 55g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.3mm.

[0066] After laser cladding the aforementioned copper-cobalt alloy powder, a macroscopic inspection of the laser-clad layer surface was performed, such as... Figure 6 As shown in a), no obvious defects such as oxidative corrosion pits, lack of fusion, or cracks were found on the surface of the cladding layer.

[0067] Samples were taken from the cladding section of the CuCrZr continuous casting copper crystallizer after laser cladding, and metallographic observation was performed. Figure 7 As shown in a), the laser cladding layer forms a good metallurgical bond with the CuCrZr continuous casting copper crystallizer matrix. During the solidification process, Co and Cu form a two-phase metallurgical interlocking structure. The reinforcing phase particles are highly dispersed in the cladding layer. No obvious defects such as oxidative corrosion pores, lack of fusion, or cracks were found in the cross section of the cladding layer.

[0068] Samples were taken from the laser-clad CuCrZr continuous casting copper crystallizer and longitudinal section microhardness tests were performed. The results are as follows: Figure 8 As shown, the hardness of the CuCrZr matrix is ​​about 70-85 Hv, and the hardness of the Co and Cu intercalation structure is about 600-625 Hv.

[0069] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature of 25℃ are as follows: Figure 9 As shown in a), the wear of the laser cladding layer is about 18% of that of the CuCrZr substrate, which significantly improves the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0070] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 400℃ are as follows: Figure 9 As shown in b), the wear of the laser cladding layer is about 21% of that of the CuCrZr substrate, which significantly improves the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0071] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃ are as follows: Figure 9 As shown in c), the wear of the laser cladding layer is about 13% of that of the CuCrZr substrate, which significantly improves the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0072] Example 3

[0073] This embodiment provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 35% Cu, 1% C, 13.5% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0074] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0075] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 168ppm, a sulfur content of 207ppm, and a flowability of 20 (s / 50g).

[0076] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0077] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0078] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 13000W, scanning speed: 15mm / s, overlap rate: 70%, powder feeding speed: 60g / min, protective gas flow rate: 32L / min, and cladding layer thickness: 2.5mm.

[0079] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection of the cladding layer surface revealed no obvious defects such as oxidative corrosion pits, incomplete fusion, or cracks.

[0080] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. A good metallurgical bond was formed between the laser cladding layer and the CuCrZr continuous casting copper crystallizer matrix. Co and Cu formed a two-phase metallurgical intercalation structure during the solidification process. The dispersion of the reinforcing phase particles in the cladding layer was high. No obvious defects such as oxidation corrosion pores, lack of fusion, or cracks were found in the cross-section of the cladding layer.

[0081] The CuCrZr continuous casting copper crystallizer after laser cladding was sampled and subjected to longitudinal section microhardness test. The hardness of the CuCrZr matrix was about 70-85 Hv, and the hardness of the dual-phase metallurgical intercalation structure of Co and Cu was about 610-625 Hv.

[0082] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 20% of that of the CuCrZr substrate, significantly improving the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0083] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 22% of that of the CuCrZr substrate, which significantly improved the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0084] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 17% of that of the CuCrZr substrate, significantly improving the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0085] Example 4

[0086] This embodiment provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 32% Cu, 0.4% C, 9% Cr, 1.3% Si, 0.1% Mo, 0.3% V, 0.5% Mn, 0.1% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0087] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0088] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 160ppm, a sulfur content of 200ppm, and a flowability of 20 (s / 50g).

[0089] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0090] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0091] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 14000W, scanning speed: 18mm / s, overlap rate: 70%, powder feeding speed: 60g / min, protective gas flow rate: 35L / min, and cladding layer thickness: 2.8mm.

[0092] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection of the cladding layer surface revealed no obvious defects such as oxidative corrosion pits, incomplete fusion, or cracks.

[0093] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. A good metallurgical bond was formed between the laser cladding layer and the CuCrZr continuous casting copper crystallizer matrix. Co and Cu formed a two-phase metallurgical intercalation structure during the solidification process. The dispersion of the reinforcing phase particles in the cladding layer was high. No obvious defects such as oxidation corrosion pores, lack of fusion, or cracks were found in the cross-section of the cladding layer.

[0094] The CuCrZr continuous casting copper crystallizer after laser cladding was sampled and subjected to longitudinal section microhardness test. The hardness of the CuCrZr matrix was about 70-85 Hv, and the hardness of the dual-phase metallurgical intercalation structure formed by Co and Cu was about 605-620 Hv.

[0095] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 12% of that of the CuCrZr substrate, significantly improving the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0096] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 15% of that of the CuCrZr substrate, significantly improving the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0097] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 17% of that of the CuCrZr substrate, significantly improving the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0098] Example 5

[0099] This embodiment provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 28% Cu, 0.1% C, 11% Cr, 1.0% Si, 0.5% Mo, 0.5% V, 0.1% Mn, 1.0% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0100] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0101] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 190ppm, a sulfur content of 200ppm, and a flowability of 20 (s / 50g).

[0102] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0103] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0104] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 15000W, scanning speed: 20mm / s, overlap rate: 70%, powder feeding speed: 70g / min, protective gas flow rate: 40L / min, and cladding layer thickness: 3.0mm.

[0105] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection of the cladding layer surface revealed no obvious defects such as oxidative corrosion pits, incomplete fusion, or cracks.

[0106] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. A good metallurgical bond was formed between the laser cladding layer and the CuCrZr continuous casting copper crystallizer matrix. Co and Cu formed a two-phase metallurgical intercalation structure during the solidification process. The dispersion of the reinforcing phase particles in the cladding layer was high. No obvious defects such as oxidation corrosion pores, lack of fusion, or cracks were found in the cross-section of the cladding layer.

[0107] The CuCrZr continuous casting copper crystallizer after laser cladding was sampled and subjected to longitudinal section microhardness test. The hardness of the CuCrZr matrix was about 70-85 Hv, and the hardness of the dual-phase metallurgical intercalation structure of Co and Cu was about 615-630 Hv.

[0108] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 5% of that of the CuCrZr substrate, significantly improving the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0109] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 12% of that of the CuCrZr substrate, which significantly improved the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0110] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 15% of that of the CuCrZr substrate, significantly improving the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0111] Comparative Example 1

[0112] This comparative example provides a cobalt-based alloy powder, which is composed of the following elements in mass percentage: 20% Ni, 0.6% C, 10.5% Cr, 1.1% Si, 0.2% Mo, 0.1% V, 0.3% Mn, 0.6% B and the balance Co.

[0113] The cobalt-based alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0114] The cobalt-based alloy powder has a particle size of 150-270 mesh, an oxygen content of 160 ppm, a sulfur content of 192 ppm, and a flowability of 20 (s / 50g).

[0115] The cobalt-based alloy powder described above was used to prepare a laser cladding coating on a CuCrZr continuous casting copper crystallizer.

[0116] Before laser melting the cobalt-based alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0117] The laser cladding process parameters for the above cobalt-based alloy powder are as follows: spot diameter: 6×20mm, laser power: 10000W, scanning speed: 10mm / s, overlap rate: 60%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.0mm.

[0118] After laser cladding the aforementioned cobalt-based alloy powder, a macroscopic inspection of the laser-clad layer surface was performed, such as... Figure 2 As shown in b), several obvious oxidative corrosion holes were found on the surface of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0119] The cladding cross section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed, such as... Figure 3 As shown in b), several obvious oxidative corrosion pores were found in the cross-section of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0120] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding, and longitudinal section microhardness tests were performed. The results are as follows: Figure 4 As shown, the hardness of the CuCrZr matrix is ​​approximately 70-85 Hv, and the hardness of the laser cladding layer matrix is ​​approximately 385-415 Hv.

[0121] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature of 25℃ are as follows: Figure 5 As shown in a), the wear of the laser cladding layer is about 40% of that of the CuCrZr substrate, which improves the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface to a certain extent.

[0122] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 400℃ are as follows: Figure 5 As shown in b), the wear of the laser cladding layer is about 120% of that of the CuCrZr substrate, which significantly reduces the mid-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0123] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃ are as follows: Figure 5 As shown in c), the wear of the laser cladding layer is about 175% of that of the CuCrZr substrate, which significantly reduces the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0124] In Comparative Example 1, no binary rare earth carbide-doped copper-cobalt alloy powder or reinforcing phase-forming elements were selected between the laser cladding layer and the CuCrZr matrix. Therefore, the high thermal conductivity, intrinsic lubrication, and high wear resistance of the Co-Cu dual-phase metallurgical intercalation structure were not achieved, nor were the synergistic effects of the oxidation corrosion resistance and thermal strength of ZrC, CeC2, and LaC2 carbides produced. Figure 5 As shown, the wear performance of the cladding layer is significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate. Therefore, it cannot effectively improve the wear resistance and reliability of the cladding layer under medium and high temperature conditions, which is not conducive to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0125] Comparative Example 2

[0126] This comparative example provides a high-nickel-cobalt-based alloy powder, which is composed of the following elements in mass percentage: 30% Ni, 0.8% C, 12.3% Cr, 1.2% Si, 0.3% Mo, 0.5% V, 0.8% Mn, 1.0% B and the balance Co.

[0127] The above-mentioned high-nickel cobalt-based alloy powder can be obtained by ball milling and mixing the above-mentioned components in the above-mentioned proportions.

[0128] The high-nickel cobalt-based alloy powder has a particle size of 150-270 mesh, an oxygen content of 170 ppm, a sulfur content of 213 ppm, and a flowability of 20 (s / 50g).

[0129] Laser cladding coatings were prepared on CuCrZr continuous casting copper crystallizers using the aforementioned high-nickel cobalt-based alloy powder.

[0130] Before laser melting the high-nickel cobalt-based alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0131] The laser cladding process parameters for the above-mentioned high-nickel cobalt-based alloy powder are as follows: spot diameter: 6×20mm, laser power: 12000W, scanning speed: 12mm / s, overlap rate: 65%, powder feeding speed: 55g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.3mm.

[0132] After laser cladding the aforementioned high-nickel-cobalt-based alloy powder, a macroscopic inspection of the laser-clad layer surface was performed, such as... Figure 6 As shown in b), several obvious oxidative corrosion holes were found on the surface of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0133] Samples were taken from the cladding section of the CuCrZr continuous casting copper crystallizer after laser cladding, and metallographic observation was performed. Figure 7 As shown in b), several obvious oxidative corrosion pores were found in the cross-section of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0134] Samples were taken from the laser-clad CuCrZr continuous casting copper crystallizer and longitudinal section microhardness tests were performed. The results are as follows: Figure 8 As shown, the hardness of the CuCrZr matrix is ​​approximately 70-85 Hv, and the hardness of the laser cladding layer matrix is ​​approximately 310-340 Hv.

[0135] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature of 25℃ are as follows: Figure 9 As shown in a), the wear of the laser cladding layer is about 42% of that of the CuCrZr substrate, which improves the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface to a certain extent.

[0136] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 400℃ are as follows: Figure 9 As shown in b), the wear of the laser cladding layer is about 135% of that of the CuCrZr substrate, which significantly reduces the mid-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0137] The wear performance test results of the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃ are as follows: Figure 9 As shown in c), the wear of the laser cladding layer is about 183% of that of the CuCrZr substrate, which significantly reduces the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0138] In Comparative Example 2, no binary rare earth carbide-doped copper-cobalt alloy powder or reinforcing phase-forming elements were selected between the laser cladding layer and the CuCrZr matrix. Therefore, the high thermal conductivity, intrinsic lubrication, and high wear resistance of the Co-Cu dual-phase metallurgical intercalation structure were not achieved, nor was the synergistic effect of the oxidation corrosion resistance and thermal strength of ZrC, CeC2, and LaC2 carbides produced. Figure 9 As shown, the wear performance of the cladding layer is significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate. Therefore, it cannot effectively improve the wear resistance and reliability of the cladding layer under medium and high temperature conditions, which is not conducive to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0139] Comparative Example 3

[0140] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 20% Cu, 0.6% C, 10.5% Cr, 1.1% Si, 0.2% Mo, 0.1% V, 0.3% Mn, 0.6% B, 0.1% ZrC, 0.1% CeC2, 0.1% LaC2 and the balance Co.

[0141] The copper-cobalt alloy powder mentioned above is obtained by ball milling and mixing the above components in the above proportions.

[0142] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 170ppm, a sulfur content of 215ppm, and a flowability of 20 (s / 50g).

[0143] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0144] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0145] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 13000W, scanning speed: 15mm / s, overlap rate: 70%, powder feeding speed: 60g / min, protective gas flow rate: 32L / min, and cladding layer thickness: 2.5mm.

[0146] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0147] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Several obvious oxidative corrosion pores were found in the cross-section of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0148] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 340-380 Hv.

[0149] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature of 25°C. The wear amount of the laser cladding layer was approximately 150% of that of the CuCrZr substrate, significantly reducing the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0150] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 130% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0151] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 165% of that of the CuCrZr substrate, which significantly reduced the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0152] In Comparative Example 3, the Cu content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr matrix was 20 wt%, lower than the specified range of 25-35%. Defects such as oxidative corrosion pits, incomplete fusion, and cracks occurred within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr matrix. Therefore, the high thermal conductivity, intrinsic lubrication, and high wear resistance of the Co-Cu dual-phase metallurgical intercalation structure were not achieved. The wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer matrix, thus failing to effectively improve the wear resistance and reliability of the cladding layer under room temperature and medium-high temperature conditions, which is detrimental to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0153] Comparative Example 4

[0154] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 42% Cu, 1% C, 13.5% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0155] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0156] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 165ppm, a sulfur content of 190ppm, and a flowability of 20 (s / 50g).

[0157] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0158] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0159] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 14000W, scanning speed: 18mm / s, overlap rate: 70%, powder feeding speed: 60g / min, protective gas flow rate: 35L / min, and cladding layer thickness: 2.8mm.

[0160] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0161] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Several obvious oxidative corrosion pores were found in the cross-section of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0162] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 270-300 Hv.

[0163] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 212% of that of the CuCrZr substrate, significantly reducing the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0164] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 236% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0165] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 220% of that of the CuCrZr substrate, significantly reducing the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0166] In Comparative Example 4, the Cu content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr matrix was 42 wt%, exceeding the specified range of 20-35%. Defects such as oxidative corrosion pits, incomplete fusion, and cracks occurred within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr matrix. Therefore, the high thermal conductivity, intrinsic lubrication, and high wear resistance of the Co-Cu dual-phase metallurgical intercalation structure were not achieved. The wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer matrix, thus failing to effectively improve the wear resistance and reliability of the cladding layer under room temperature and medium-high temperature conditions, which is detrimental to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0167] Comparative Example 5

[0168] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 35% Cu, 1% C, 8% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0169] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0170] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 188ppm, a sulfur content of 197ppm, and a flowability of 20 (s / 50g).

[0171] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0172] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0173] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 15000W, scanning speed: 20mm / s, overlap rate: 70%, powder feeding speed: 70g / min, protective gas flow rate: 40L / min, and cladding layer thickness: 3.0mm.

[0174] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion pores were found on the surface of the cladding layer, but no defects such as incomplete fusion or cracks were found.

[0175] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Several obvious oxidation corrosion pores were found in the cross-section of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0176] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 500-550 Hv.

[0177] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 115% of that of the CuCrZr substrate, significantly reducing the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0178] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 110% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0179] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 130% of that of the CuCrZr substrate, significantly reducing the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0180] In Comparative Example 5, the Cr content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr substrate was selected to be 8 wt%, which is lower than the specified range of 9-13.5%. During laser cladding, the insufficient in-situ production of Cr7C3 with C resulted in inadequate hardness enhancement. Consequently, the high thermal conductivity, intrinsic lubrication, and high wear resistance of the Co-Cu dual-phase metallurgical intercalation structure were not achieved, which is detrimental to improving the coating's wear resistance. The wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate. Therefore, it could not effectively improve the wear resistance and reliability of the cladding layer under room temperature and medium-high temperature conditions, which is detrimental to improving the service performance and service life of the continuous casting copper crystallizer under a wide temperature range.

[0181] Comparative Example 6

[0182] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 35% Cu, 1% C, 15% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0183] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0184] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 160ppm, a sulfur content of 200ppm, and a flowability of 20 (s / 50g).

[0185] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0186] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0187] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 15000W, scanning speed: 20mm / s, overlap rate: 70%, powder feeding speed: 70g / min, protective gas flow rate: 40L / min, and cladding layer thickness: 3.0mm.

[0188] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0189] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Several obvious oxidative corrosion pores were found in the cross-section of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0190] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 650-680 Hv.

[0191] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 130% of that of the CuCrZr substrate, significantly reducing the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0192] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 150% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0193] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 160% of that of the CuCrZr substrate, which significantly reduced the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0194] In Comparative Example 6, the Cr content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr substrate was 15 wt%, exceeding the specified range of 9-13.5%. This resulted in defects such as oxidative corrosion pits, incomplete fusion, and cracks within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr substrate. Excessive in-situ formation of Cr7C3 during laser cladding led to excessive hardness and brittleness, further hindering the formation of a good metallurgical bond between the laser cladding layer and the CuCrZr substrate. This negatively impacted the coating's wear resistance and reliability, and the wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate. Therefore, it could not effectively improve the wear resistance and reliability of the cladding layer under room temperature and medium-high temperature conditions, thus hindering the improvement of the continuous casting copper crystallizer's service performance and service life over a wide temperature range.

[0195] Comparative Example 7

[0196] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 20% Cu, 0.6% C, 10.5% Cr, 1.1% Si, 0.05% Mo, 0.05% V, 0.3% Mn, 0.6% B, 0.1% ZrC, 0.2% CeC2, 0.2% LaC2 and the balance Co.

[0197] The copper-cobalt alloy powder mentioned above is obtained by ball milling and mixing the above components in the above proportions.

[0198] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 170ppm, a sulfur content of 215ppm, and a flowability of 20 (s / 50g).

[0199] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0200] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0201] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 12000W, scanning speed: 12mm / s, overlap rate: 65%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.3mm.

[0202] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion pores were found on the surface of the cladding layer, but no defects such as incomplete fusion or cracks were found.

[0203] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Several obvious oxidation corrosion pores were found in the cross-section of the cladding layer, but no defects such as lack of fusion or cracks were found.

[0204] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 550-570 Hv.

[0205] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 85% of that of the CuCrZr substrate, which to some extent improved the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0206] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 125% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0207] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 170% of that of the CuCrZr substrate, significantly reducing the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0208] In Comparative Example 7, the content of Mo and V elements in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr substrate was selected to be 0.05 wt%, which is lower than the specified range of 0.1~0.5%. During laser cladding, the amount of high-temperature stable MC-type carbides such as MoC and VC formed in situ with C element mass is insufficient, which is not conducive to improving the high-temperature stability of the coating. The wear performance of the cladding layer is significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate. Therefore, it cannot effectively improve the wear resistance and reliability of the cladding layer under medium and high temperature conditions, and is not conducive to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0209] Comparative Example 8

[0210] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 35% Cu, 1% C, 13.5% Cr, 1.3% Si, 0.6% Mo, 0.6% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.5% CeC2, 1.5% LaC2 and the balance Co.

[0211] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0212] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 160ppm, a sulfur content of 195ppm, and a flowability of 20 (s / 50g).

[0213] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0214] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0215] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 12000W, scanning speed: 12mm / s, overlap rate: 65%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 2.3mm.

[0216] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0217] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. Local segregation of MC-type carbides such as MoC and VC was found in the cross-section of the cladding layer, indicating poor microstructure stability. Several obvious oxidative corrosion pores were also found, as well as defects such as incomplete fusion and cracks.

[0218] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 680-700 Hv.

[0219] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 70% of that of the CuCrZr substrate, which to some extent improved the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0220] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 150% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0221] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 185% of that of the CuCrZr substrate, which significantly reduced the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0222] In Comparative Example 8, the content of Mo and V elements in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr matrix was selected to be 0.6 wt%, which is higher than the limit range of 0.1~0.5%. Defects such as oxidative corrosion pits, incomplete fusion, and cracks occurred within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr matrix. During laser cladding, the in-situ formation of MC-type carbides such as MoC and VC during laser cladding led to local segregation, resulting in reduced high-temperature structural stability and hindering the improvement of the coating's high-temperature stability. The high-temperature wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer matrix, thus failing to effectively improve the wear resistance and reliability of the cladding layer under medium- and high-temperature conditions, and consequently, hindering the improvement of the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0223] Comparative Example 9

[0224] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 20% Cu, 0.6% C, 10.5% Cr, 1.1% Si, 0.2% Mo, 0.1% V, 0.3% Mn, 0.6% B, 0.1% ZrC, 0.1% CeC2, 0.1% LaC2 and the balance Co.

[0225] The copper-cobalt alloy powder mentioned above is obtained by ball milling and mixing the above components in the above proportions.

[0226] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 160ppm, a sulfur content of 205ppm, and a flowability of 20 (s / 50g).

[0227] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0228] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0229] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 11000W, scanning speed: 15mm / s, overlap rate: 60%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 1.8mm.

[0230] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion pores were found on the surface of the cladding layer, but no defects such as incomplete fusion or cracks were found.

[0231] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. The cross-section of the cladding layer showed coarsening of the grains, several obvious oxidation corrosion pores, and defects such as incomplete fusion and cracks.

[0232] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 500-520 Hv.

[0233] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 80% of that of the CuCrZr substrate, which to some extent improved the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0234] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 190% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0235] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 225% of that of the CuCrZr substrate, which significantly reduced the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0236] In Comparative Example 9, the CeC2 and LaC2 content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr substrate was selected to be 0.1%, which is less than the specified range of 0.2~1.5%. Defects such as oxidative corrosion pits, incomplete fusion, and cracks occurred within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr substrate. The laser cladding process had insufficient effect in purifying the molten pool and refining the grains, which was detrimental to improving the high-temperature oxidation corrosion resistance and thermal strength of the coating. The high-temperature wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate, thus failing to effectively improve the wear resistance and reliability of the cladding layer under medium- and high-temperature conditions, and consequently, hindering the improvement of the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0237] Comparative Example 10

[0238] This comparative example provides a copper-cobalt alloy powder composed of the following elements in mass percentage: 35% Cu, 1% C, 13.5% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B, 0.8% ZrC, 1.8% CeC2, 1.8% LaC2, and the balance Co.

[0239] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0240] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 162ppm, a sulfur content of 185ppm, and a flowability of 20 (s / 50g).

[0241] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0242] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0243] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 11000W, scanning speed: 15mm / s, overlap rate: 60%, powder feeding speed: 50g / min, protective gas flow rate: 30L / min, and cladding layer thickness: 1.8mm.

[0244] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0245] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. The cross-section of the cladding layer showed that the grain boundary corrosion sensitivity of the cladding layer was high, and several obvious oxidative corrosion pores were found. In addition, defects such as incomplete fusion and cracks were also found.

[0246] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 600-620 Hv.

[0247] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 75% of that of the CuCrZr substrate, which to some extent improved the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0248] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 223% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0249] Wear performance tests were conducted on the CuCrZr continuous casting copper crystallizer after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 245% of that of the CuCrZr substrate, which significantly reduced the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0250] In Comparative Example 10, the CeC2 and LaC2 content in the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr substrate was 0.8%, which is higher than the specified range of 0.2-1.5%. Defects such as oxidative corrosion pits, incomplete fusion, and cracks occurred within the cladding layer, preventing the laser cladding layer from forming a good metallurgical bond with the CuCrZr substrate. Excessive carbide content in the molten pool during laser cladding easily leads to localized defects or stress corrosion, increasing the susceptibility to grain boundary corrosion. This is detrimental to improving the high-temperature oxidation corrosion resistance and thermal strength of the coating. The high-temperature wear performance of the cladding layer is significantly lower than that of the CuCrZr continuous casting copper crystallizer substrate, thus failing to effectively improve the wear resistance and reliability of the cladding layer under medium- and high-temperature conditions, and is detrimental to improving the service performance and service life of the continuous casting copper crystallizer under a wide temperature range.

[0251] Comparative Example 11

[0252] This comparative example provides a copper-cobalt alloy powder, which is composed of the following elements in mass percentage: 35% Cu, 1% C, 13.5% Cr, 1.3% Si, 0.5% Mo, 0.5% V, 0.8% Mn, 1.5% B and the balance Co.

[0253] The copper-cobalt alloy powder described above can be obtained by ball milling and mixing the above components in the above proportions.

[0254] The copper-cobalt alloy powder has a particle size of 53-150μm, an oxygen content of 160ppm, a sulfur content of 190ppm, and a flowability of 20 (s / 50g).

[0255] The aforementioned copper-cobalt alloy powder was used to prepare a laser-clad high-temperature wear-resistant coating on a CuCrZr continuous casting copper crystallizer.

[0256] Before laser melting the copper-cobalt alloy powder, the pre-melted cladding area on the surface of the continuous casting copper crystallizer is polished with a grinding wheel to a metallic luster, and the surface is wiped clean of oil, water and other contaminants with alcohol.

[0257] The laser cladding process parameters for the above copper-cobalt alloy powder are as follows: spot diameter: 6×20mm, laser power: 12000W, scanning speed: 10mm / s, overlap rate: 60%, powder feeding speed: 50g / min, protective gas flow rate: 35L / min, and cladding layer thickness: 2.5mm.

[0258] After laser cladding the copper-cobalt alloy powder, a macroscopic inspection was performed on the surface of the laser cladding layer (high-temperature wear-resistant coating) formed on the surface of the CuCrZr continuous casting copper crystallizer. Several oxidative corrosion holes were found on the surface of the cladding layer, as well as defects such as incomplete fusion and cracks.

[0259] The cross-section of the CuCrZr continuous casting copper crystallizer after laser cladding was sampled and metallographically observed. The cross-section of the cladding layer showed that the grains of the cladding layer were coarsened and the grain boundary corrosion sensitivity was high. Several obvious oxidative corrosion pores were found, as well as defects such as incomplete fusion and cracks.

[0260] Samples were taken from the CuCrZr continuous casting copper crystallizer after laser cladding and longitudinal section microhardness tests were performed. The hardness of the CuCrZr matrix was about 70-80 Hv, and the hardness of the laser cladding layer matrix was about 540-560 Hv.

[0261] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at room temperature (25°C). The wear amount of the laser cladding layer was approximately 80% of that of the CuCrZr substrate, which to some extent improved the room temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0262] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 400℃. The wear amount of the laser cladding layer was approximately 264% of that of the CuCrZr substrate, significantly reducing the medium-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0263] Wear performance tests were conducted on CuCrZr continuous casting copper crystallizers after laser cladding at 650℃. The wear amount of the laser cladding layer was approximately 285% of that of the CuCrZr substrate, significantly reducing the high-temperature wear resistance and reliability of the CuCrZr continuous casting copper crystallizer surface.

[0264] In Comparative Example 11, the copper-cobalt alloy powder formulation system between the laser cladding layer and the CuCrZr matrix did not contain ZrC, CeC2, or LaC2 components. Therefore, the synergistic effect of ZrC, CeC2, and LaC2 was not achieved, increasing the susceptibility of the cladding layer to grain boundary corrosion. Impurities such as O and S diffused into the cladding layer, causing defects such as oxidative corrosion pits, incomplete fusion, and cracks. During laser cladding, the overall strength of the cladding layer was poor, which was detrimental to maintaining the stability, oxidation resistance, and thermal strength of the cladding layer under wide temperature range conditions. The high-temperature wear performance of the cladding layer was significantly lower than that of the CuCrZr continuous casting copper crystallizer matrix. Therefore, it could not effectively improve the wear resistance and reliability of the cladding layer under medium- and high-temperature conditions, and was not conducive to improving the service performance and service life of the continuous casting copper crystallizer under wide temperature range conditions.

[0265] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A copper-cobalt alloy powder for laser cladding, characterized by, consists of the following elements by mass fraction: 25~35% of Cu, 0.1~1.0% of C, 9.0~13.5% of Cr, 1.0~1.3% of Si, 0.1~0.5% of Mo, 0.1~0.5% of V, 0.1~0.8% of Mn, 0.1~1.5% of B, 0.1~0.8% of ZrC, 0.2~1.5% of CeC2, 0.2~1.5% of LaC2, and the balance of Co.

2. The copper-cobalt alloy powder for laser cladding according to claim 1, characterized in that, The copper-cobalt alloy powder is prepared by a ball milling method or a sonic resonance method.

3. The copper-cobalt alloy powder for laser cladding according to claim 1, characterized in that, The copper-cobalt alloy powder has a particle size of 53~150μm, an oxygen content of ≤200ppm, a sulfur content of ≤300PPm, and a fluidity of ≤25(s / 50g).

4. Use of a copper-cobalt alloy powder for laser cladding according to any one of claims 1 to 3, characterized in that The copper-cobalt alloy powder is used for the surface of a continuous casting copper crystallizer to form a high-temperature wear-resistant coating by laser cladding.

5. Use of a copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The process parameters for laser cladding of the copper-cobalt alloy powder are as follows: laser power: 10000~15000W, scanning speed: 5~20mm / s, overlap rate: 50~70%, powder feeding speed: 40~70g / min, protective gas flow rate: 25~40L / min, and cladding layer thickness: 1.0~3.0mm.

6. The use of the copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The Cu element and the Co element in the copper-cobalt alloy powder form a dual-phase metallurgical intercalation structure to form a heat conduction network.

7. The use of the copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The Cu element in the copper-cobalt alloy powder forms a metallurgical bridging structure with a CuCrZr matrix during laser cladding.

8. The use of the copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The C, Cr, Si, Mo, V, Mn, and B elements in the copper-cobalt alloy powder form Cr7C3, SiC, MoC, VC, and B4C carbide strengthening particles during the laser cladding condensation process.

9. The use of the copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The Mo element and the V element in the copper-cobalt alloy powder generate in-situ high-temperature stable MC-type carbides with the C element during laser cladding.

10. The use of the copper-cobalt alloy powder for laser cladding according to claim 4, characterized in that, The high-temperature wear-resistant coating has a hardness of more than 600HV and a high-temperature wear amount at 650℃ of less than 20% of that of a CuCrZr matrix.

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