Copper-based wear-resistant metal powder-cored wire and desulfurization mortar pump flow passage component surface strengthening method

Abstract

The invention relates to the technical field of metal material surface modification, in particular to a copper-based wear-resistant metal powder-cored wire and a desulfurization mortar pump flow passage component surface strengthening method.The method comprises the steps that an inner-layer metal powder-cored wire and an outer-layer metal powder-cored wire are prepared; cleaning the surface of the flow passage component of the desulfurization mortar pump and performing preheating treatment; preparing an inner cladding layer on the surface of the preheated flow passage component of the desulfurization mortar pump by using an inner-layer metal powder core welding wire; preparing an outer cladding layer on the surface of the inner cladding layer by using an outer-layer metal powder core welding wire; and carrying out welding-wire-free idle-walking cladding heating on the outer cladding layer along a welding bead, and applying ultrasonic treatment during the process. The inner cladding layer and the outer cladding layer sequentially cover the surface of the base body, so that the cladding layers have good hardness, wear resistance and impact toughness at the same time, and the overall quality of the cladding layers is improved.

Description

Technical Field

[0001] This invention relates to the field of surface modification technology for metallic materials, specifically to a method for strengthening the surface of copper-based wear-resistant metal powder-cored welding wire and flow components of desulfurization slurry pumps. Background Technology

[0002] The flow-through components (impeller, pump casing, etc.) of desulfurization slurry pumps, which continuously transport slurries containing hard particles and potentially corrosive substances, are subjected to severe wear, cavitation, and corrosion, making them the most vulnerable and critical components of the entire pump. These components are typically precision-manufactured using expensive wear-resistant materials such as high-chromium cast iron, resulting in high costs and long spare parts production cycles. Directly replacing these components is extremely costly, and the production losses due to downtime are even more substantial. Timely repair of worn areas, rather than complete replacement, can significantly reduce costs, drastically shorten downtime, and ensure production continuity. Furthermore, repairing and utilizing the original component substrate reduces resource consumption and waste, aligning with the requirements of a circular economy and sustainable development. Therefore, efficient repair of flow-through components is a key maintenance strategy for ensuring equipment operation, reducing costs and increasing efficiency, and practicing environmental protection.

[0003] Repairing with copper-based metal-cored wire offers significant advantages: the deposited copper alloy layer possesses excellent wear resistance, cavitation resistance, and good resistance to weak acid / seawater corrosion, effectively withstanding complex working conditions. The metal-cored wire process boasts high deposition efficiency, good forming quality, and controllable dilution rate, making it particularly suitable for rapid on-site or workshop repair of large-area wear areas. Repairing fully utilizes the component substrate, reducing resource consumption and waste, making it a key solution that balances high-efficiency production, significant cost reduction, and sustainability.

[0004] In existing technologies, using metal-cored welding wire for workpiece repair can significantly reduce costs and downtime, ensuring continuous production. The welded cladding layer typically possesses good hardness and wear resistance, but it is also brittle. Under severe or prolonged impact, the cladding layer is prone to cracking and may even detach from the workpiece surface. Therefore, this paper proposes a copper-based wear-resistant metal-cored welding wire and a method for surface strengthening of the flow components of a desulfurization slurry pump. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for strengthening the surface of copper-based wear-resistant metal powder core welding wire and desulfurization slurry pump flow components. An inner cladding layer and an outer cladding layer are sequentially covered on the substrate surface, so that the cladding layer simultaneously possesses good hardness, wear resistance, and impact toughness, thereby improving its overall quality.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a copper-based wear-resistant metal powder cored welding wire, comprising an inner metal powder cored welding wire and an outer metal powder cored welding wire, wherein the inner metal powder cored welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder cored welding wire is composed of an outer metal powder core and a welding wire sheath; The inner metal powder core comprises the following components by mass percentage: 15-25% Ni powder, 8-10% Ti powder, and the balance being Cu powder; The outer metal powder core comprises the following components by mass percentage: 15-25% Ni powder, 1-2.5% Si powder, 10-12% Cr powder, 8-10% Ti powder, 1-2% Nb powder, 10-20% TiC powder, and the balance being Cu powder.

[0007] Preferably, the outer sheath of the welding wire is made of pure copper strip.

[0008] Preferably, the filling rate of both the inner and outer metal powder core welding wires is controlled at 20wt.%-25wt.%; and the diameter of both is controlled between 1.2-1.5mm.

[0009] The present invention also provides a method for surface strengthening of the flow components of a desulfurization slurry pump, comprising the following steps: S1. Weigh out the required raw materials for the inner metal core according to the proportion and mix them evenly. Use pure copper strip as the outer sheath of the welding wire to make the inner metal core welding wire. Weigh out the required raw materials for the outer metal core according to the proportion and mix them evenly. Use pure copper strip as the outer sheath of the welding wire to make the outer metal core welding wire. S2. Preheat the surface of the flow components of the desulfurization slurry pump; S3. Using inner metal core welding wire, based on MIG welding, a single-layer multi-pass welding cladding process is designed to prepare an inner cladding layer on the surface of the preheated desulfurization slurry pump flow parts, and then grind and clean the slag after cooling to room temperature. S4. Using outer metal core welding wire, based on MIG welding, design a multi-layer, multi-pass welding cladding process, prepare an outer cladding layer on the surface of the inner cladding layer, and grind and clean the slag after cooling to room temperature. S5. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead from step S4, and apply ultrasonic treatment during the process. S6. After cooling to room temperature, proceed with grinding and slag removal.

[0010] Preferably, in step S2, the preheating temperature is 220-250℃.

[0011] Preferably, in step S3, the thickness of the inner cladding layer is 0.5-0.8 mm, the inner cladding layer includes multiple parallel and overlapping weld beads, each weld bead is 5 mm wide, and the cladding overlap rate of adjacent weld beads is 45-50%.

[0012] Preferably, in step S4, the outer cladding layer has two layers, each with a thickness of 1-1.5 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each weld bead is 5 mm wide, and the cladding overlap coverage of adjacent weld beads is 45-50%.

[0013] Preferably, in steps S3-S4, the parameters for MIG welding are: welding current 110-140A, welding voltage 16-18V, welding speed 0.3m / min, and pure Ar as the shielding gas with a flow rate of 12L / min.

[0014] Preferably, in step S5, the parameters for TIG welding are: welding current 110-150A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, and pure Ar as the shielding gas with a flow rate of 12L / min.

[0015] Preferably, in step S5, the power of the ultrasonic treatment is 700-900W.

[0016] This invention provides a method for surface strengthening of copper-based wear-resistant metal powder-cored welding wire and flow components of desulfurization slurry pumps, which has the following advantages compared with the prior art: This invention sequentially covers the substrate surface with an inner cladding layer and an outer cladding layer, enabling the cladding layer to simultaneously possess good hardness, wear resistance, and impact toughness, thereby improving its overall quality. Specifically, the inner cladding layer adopts a Cu-Ni-Ti system to reduce hardness and brittleness while increasing toughness, while the outer cladding layer adds Cr, Ti, and TiC to ensure excellent hardness and wear resistance. Through the combination of the inner and outer cladding layers, the overall performance of the cladding layer can be improved, thereby extending the service life of the desulfurization slurry pump flow components.

[0017] This invention is based on arc cladding technology and designs a single-layer / multi-layer multi-pass welding cladding process. It is combined with secondary idle cladding heating, which makes the cladding layer and the flow parts of the desulfurization slurry pump more tightly bonded and free of defects such as cracks and pores. At the same time, ultrasonic treatment is applied during the secondary idle cladding heating to further refine the microstructure grains and improve the uniformity of the microstructure, so that the cladding layer has better mechanical properties. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a metallographic image of the outer cladding layer on the surface of the desulfurization slurry pump flow component in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the inner metal core welding wire and the outer metal core welding wire in this invention. Detailed Implementation

[0019] The following embodiments are provided to illustrate the implementation of this application in detail, so that the process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0020] Example 1 A copper-based wear-resistant metal powder cored welding wire includes an inner metal powder cored welding wire and an outer metal powder cored welding wire. The inner metal powder cored welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder cored welding wire is composed of an outer metal powder core and a welding wire sheath.

[0021] By mass percentage, the inner metal powder core comprises the following components: 15% Ni powder, 9% Ti powder, and the balance being Cu powder; the outer metal powder core comprises the following components: 15% Ni powder, 1% Si powder, 10% Cr powder, 9% Ti powder, 2% Nb powder, 10% TiC powder, and the balance being Cu powder.

[0022] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: S1. Weigh out the required raw materials for the inner metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an inner metal core welding wire with a diameter of 1.5mm using a wire drawing machine. The filler content is 22wt.%. Weigh out the required raw materials for the outer metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an outer metal core welding wire with a diameter of 1.5mm using a wire drawing machine. The filler content is 22wt.%. S2. Use an angle grinder to clean the surface of the desulfurization slurry pump flow parts to remove surface oil, oxide scale and other impurities, and then preheat the surface of the desulfurization slurry pump flow parts at 220℃. S3. Using inner metal core welding wire, based on MIG welding, a single-layer multi-pass welding cladding process is designed. An inner cladding layer is prepared on the surface of the preheated desulfurization slurry pump flow component. The thickness of the inner cladding layer is 0.8mm. The inner cladding layer includes multiple parallel and overlapping weld beads. Each weld bead is 5mm wide and the cladding overlap rate of adjacent weld beads is 50%. After cooling to room temperature, the slag is removed by grinding. The parameters for the above-mentioned MIG welding are as follows: welding current 130A, welding voltage 17V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min. S4. Using outer metal core welding wire, based on MIG welding, design a multi-layer, multi-pass welding cladding process. Prepare an outer cladding layer on the surface of the inner cladding layer. There are two outer cladding layers, each with a thickness of 1.5 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each with a width of 5 mm. The cladding overlap coverage of adjacent weld beads is 50%. After cooling to room temperature, grind and remove slag. The parameters for the above-mentioned MIG welding are as follows: welding current 130A, welding voltage 17V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min. S5. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead from step S4, and apply ultrasonic treatment during the process, controlling the power to be 800W. The parameters for the TIG welding are as follows: welding current 150A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, pure Ar as shielding gas, and its flow rate 12L / min.

[0023] S6. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0024] Example 2 A copper-based wear-resistant metal powder cored welding wire includes an inner metal powder cored welding wire and an outer metal powder cored welding wire. The inner metal powder cored welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder cored welding wire is composed of an outer metal powder core and a welding wire sheath.

[0025] By mass percentage, the inner metal powder core comprises the following components: 20% Ni powder, 8% Ti powder, and the balance being Cu powder; the outer metal powder core comprises the following components: 20% Ni powder, 2% Si powder, 11% Cr powder, 8% Ti powder, 1.5% Nb powder, 15% TiC powder, and the balance being Cu powder.

[0026] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: S1. Weigh out the required raw materials for the inner metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an inner metal core welding wire with a diameter of 1.2 mm using a wire drawing machine. The filler content is 25 wt.%. Weigh out the required raw materials for the outer metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an outer metal core welding wire with a diameter of 1.2 mm using a wire drawing machine. The filler content is 25 wt.%. S2. Use an angle grinder to clean the surface of the desulfurization slurry pump flow parts to remove surface oil, oxide scale and other impurities, and then preheat the surface of the desulfurization slurry pump flow parts at 250℃. S3. Using inner metal core welding wire, based on MIG welding, a single-layer multi-pass welding cladding process is designed. An inner cladding layer is prepared on the surface of the preheated desulfurization slurry pump flow component. The thickness of the inner cladding layer is 0.6 mm. The inner cladding layer includes multiple parallel and overlapping weld beads. Each weld bead is 5 mm wide and the cladding overlap rate of adjacent weld beads is 45%. After cooling to room temperature, the slag is removed by grinding. The parameters for the above MIG welding are: welding current 110A, welding voltage 16V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min; S4. Using outer metal core welding wire, based on MIG welding, design a multi-layer, multi-pass welding cladding process. Prepare an outer cladding layer on the surface of the inner cladding layer. There are two outer cladding layers, each with a thickness of 1 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each with a width of 5 mm. The cladding overlap coverage of adjacent weld beads is 45%. After cooling to room temperature, grind and remove slag. The parameters for the above MIG welding are: welding current 110A, welding voltage 16V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min; S5. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead from step S4, and apply ultrasonic treatment during the process, controlling the power to be 900W. The parameters for the above TIG welding are: welding current 120A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, pure Ar as shielding gas, and its flow rate 12L / min; S6. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0027] Example 3 A copper-based wear-resistant metal powder cored welding wire includes an inner metal powder cored welding wire and an outer metal powder cored welding wire. The inner metal powder cored welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder cored welding wire is composed of an outer metal powder core and a welding wire sheath.

[0028] By mass percentage, the inner metal powder core comprises the following components: 25% Ni powder, 10% Ti powder, and the balance being Cu powder; the outer metal powder core comprises the following components: 25% Ni powder, 2.5% Si powder, 12% Cr powder, 10% Ti powder, 2% Nb powder, 20% TiC powder, and the balance being Cu powder.

[0029] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: S1. Weigh out the required raw materials for the inner metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an inner metal core welding wire with a diameter of 1.5mm using a wire drawing machine. The filler content is 20wt.%. Weigh out the required raw materials for the outer metal core according to the specified ratio and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an outer metal core welding wire with a diameter of 1.5mm using a wire drawing machine. The filler content is 20wt.%. S2. Use an angle grinder to clean the surface of the desulfurization slurry pump flow parts to remove surface oil, scale and other impurities, and then preheat the surface of the desulfurization slurry pump flow parts at 230℃. S3. Using inner metal core welding wire, based on MIG welding, a single-layer multi-pass welding cladding process is designed. An inner cladding layer is prepared on the surface of the preheated desulfurization slurry pump flow component. The thickness of the inner cladding layer is 0.5mm. The inner cladding layer includes multiple parallel and overlapping weld beads. Each weld bead is 5mm wide and the cladding overlap rate of adjacent weld beads is 50%. After cooling to room temperature, the slag is removed by grinding. The parameters for the above MIG welding are: welding current 140A, welding voltage 18V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min; S4. Using outer metal core welding wire, based on MIG welding, design a multi-layer, multi-pass welding cladding process. Prepare an outer cladding layer on the surface of the inner cladding layer. There are two outer cladding layers, each with a thickness of 1.5 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each with a width of 5 mm. The cladding overlap coverage of adjacent weld beads is 50%. After cooling to room temperature, grind and remove slag. The parameters for the above MIG welding are: welding current 140A, welding voltage 18V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min; S5. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead from step S4, and apply ultrasonic treatment during the process, controlling the power to 700W. The parameters for the above-mentioned TIG welding are as follows: welding current 110A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, pure Ar as shielding gas, and its flow rate 12L / min. S6. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0030] Comparative Example 1 A copper-based wear-resistant metal powder cored welding wire includes an outer metal powder cored welding wire, which is composed of an outer metal powder core and a welding wire sheath.

[0031] By mass percentage, the outer metal powder core comprises the following components: 15% Ni powder, 1% Si powder; 10% Cr powder, 9% Ti powder, 2% Nb powder, 10% TiC powder, with the balance being Cu powder.

[0032] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: S1. Weigh the required raw materials for the outer metal core according to the proportion and mix them evenly. Use T2 pure copper strip as the outer sheath of the welding wire and draw it into an outer metal core welding wire with a diameter of 1.5mm through a wire drawing machine. Its filler content is 22wt.%. S2. Use an angle grinder to clean the surface of the desulfurization slurry pump flow parts to remove surface oil, oxide scale and other impurities, and then preheat the surface of the desulfurization slurry pump flow parts at 220℃. S3. Using outer metal core welding wire, based on MIG welding, a multi-layer, multi-pass welding cladding process is designed to prepare an outer cladding layer on the surface of the desulfurization slurry pump flow component. There are two outer cladding layers, each with a thickness of 1.5 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each with a width of 5 mm. The cladding overlap coverage of adjacent weld beads is 50%. After cooling to room temperature, the slag is removed by grinding. The parameters for the above MIG welding are: welding current 130A, welding voltage 17V, welding speed 0.3m / min, using pure Ar as the shielding gas with a flow rate of 12L / min; S4. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead in step S4, and apply ultrasonic treatment during the process, with the power controlled at 800W. The parameters for the above TIG welding are: welding current 150A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, pure Ar as shielding gas, and its flow rate 12L / min; S5. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0033] Comparative Example 2 A copper-based wear-resistant metal powder-cored welding wire, identical to that in Example 1.

[0034] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: Steps S1-S4 are the same as in Example 1; S5. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0035] Comparative Example 3 A copper-based wear-resistant metal powder-cored welding wire, identical to that in Example 1.

[0036] A method for surface strengthening of the flow components of a desulfurization slurry pump includes the following steps: Steps S1-S4 are the same as in Example 1; S5. Using TIG welding, heat the outer cladding layer without feeding welding wire by running it along the weld bead from step S4. The parameters for the above TIG welding are: welding current 150A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, pure Ar as shielding gas, and its flow rate 12L / min; S6. After cooling to room temperature, grind and clean the workpiece to achieve the required smoothness to meet the requirements of its use.

[0037] Comparative Example 4 A copper-based wear-resistant metal powder cored welding wire includes an inner metal powder cored welding wire and an outer metal powder cored welding wire. The inner metal powder cored welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder cored welding wire is composed of an outer metal powder core and a welding wire sheath.

[0038] By mass percentage, the inner metal powder core comprises the following components: 15% Ni powder, 9% Ti powder, and the balance being Cu powder; the outer metal powder core comprises the following components: 15% Ni powder, 1% Si powder, 10% Cr powder, 9% Ti powder, 2% Nb powder, and the balance being Cu powder.

[0039] A method for surface strengthening of the flow components of a desulfurization slurry pump is the same as in Example 1.

[0040] Performance testing The welded desulfurization slurry pump flow components from Examples 1-3 and Comparative Examples 1-4 were used as samples for testing.

[0041] 1. Hardness test: The hardness of the outer cladding layer of the sample was tested using a micro Vickers hardness tester. The specific test results are shown in Table 1.

[0042] 2. Wear performance test: A high-vacuum tribological tester was used. The wear test was conducted at room temperature, with air wear for 40 minutes, a sliding angular velocity of 750 r / min, and a load of 20 N. The specific test results are shown in Table 1.

[0043] 3. Impact toughness test: The specimens were tested at -20℃ according to the standard of GB / T229-2020. The specific test results are shown in Table 2.

[0044] Table 1 Hardness and Wear

[0045] As shown in Table 1, compared with Example 1, no inner cladding layer was used in Comparative Example 1, but it had no effect on the hardness and wear resistance of the sample; TIG welding was not performed on the outer cladding layer in Comparative Example 2, and ultrasonic treatment was not performed during TIG welding in Comparative Example 3, which resulted in a reduction in the hardness and wear resistance of the sample; TiC powder was not added in Comparative Example 4, which significantly reduced the hardness and wear resistance of the sample.

[0046] Table 2 Impact Toughness

[0047] As shown in Table 2, compared with Example 1, the impact toughness of the sample in Comparative Example 1 was significantly reduced because no inner cladding layer was used; the impact toughness of the samples in Comparative Example 2 and Comparative Example 3 was reduced; and the impact toughness of the sample in Comparative Example 4 was slightly reduced.

[0048] 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 variations 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-based wear-resistant metal powder-cored welding wire, characterized in that, It includes inner metal powder core welding wire and outer metal powder core welding wire. The inner metal powder core welding wire is composed of an inner metal powder core and a welding wire sheath, and the outer metal powder core welding wire is composed of an outer metal powder core and a welding wire sheath. The inner metal powder core comprises the following components by mass percentage: 15-25% Ni powder, 8-10% Ti powder, and the balance being Cu powder; The outer metal powder core comprises the following components by mass percentage: 15-25% Ni powder, 1-2.5% Si powder, 10-12% Cr powder, 8-10% Ti powder, 1-2% Nb powder, 10-20% TiC powder, and the balance being Cu powder.

2. The copper-based wear-resistant metal-cored welding wire according to claim 1, characterized in that, The outer sheath of the welding wire is made of pure copper strip.

3. The copper-based wear-resistant metal-cored welding wire according to claim 1, characterized in that, The filling rate of both the inner and outer metal powder core welding wires is controlled at 20wt.%-25wt.%; and the diameter of both is controlled between 1.2-1.5mm.

4. A method for surface strengthening of the flow-through components of a desulfurization slurry pump, comprising using the copper-based wear-resistant metal-cored welding wire as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Weigh out the required raw materials for the inner metal core according to the proportion and mix them evenly. Use pure copper strip as the outer sheath of the welding wire to make the inner metal core welding wire. Weigh out the required raw materials for the outer metal core according to the proportion and mix them evenly. Use pure copper strip as the outer sheath of the welding wire to make the outer metal core welding wire. S2. Preheat the surface of the flow components of the desulfurization slurry pump; S3. Using inner metal core welding wire, based on MIG welding, a single-layer multi-pass welding cladding process is designed to prepare an inner cladding layer on the surface of the preheated desulfurization slurry pump flow parts, and then grind and clean the slag after cooling to room temperature. S4. Using outer metal core welding wire, based on MIG welding, design a multi-layer, multi-pass welding cladding process, prepare an outer cladding layer on the surface of the inner cladding layer, and grind and clean the slag after cooling to room temperature. S5. Using TIG welding, heat the outer cladding layer without feeding the welding wire along the weld bead from step S4, and apply ultrasonic treatment during the process. S6. After cooling to room temperature, proceed with grinding and slag removal.

5. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In step S2, the temperature of the preheating treatment is 220-250℃.

6. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In step S3, the thickness of the inner cladding layer is 0.5-0.8 mm, and the inner cladding layer includes multiple parallel and overlapping weld beads, each weld bead is 5 mm wide, and the cladding overlap rate of adjacent weld beads is 45-50%.

7. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In step S4, the outer cladding layer consists of two layers, each with a thickness of 1-1.5 mm. Each outer cladding layer includes multiple parallel and overlapping weld beads, each weld bead being 5 mm wide, and the cladding overlap coverage of adjacent weld beads being 45-50%.

8. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In steps S3-S4, the parameters for MIG welding are: welding current 110-140A, welding voltage 16-18V, welding speed 0.3m / min, and pure Ar as the shielding gas with a flow rate of 12L / min.

9. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In step S5, the parameters for TIG welding are: welding current 110-150A, tungsten electrode extension length 3mm, welding speed 0.8m / min, nozzle height 6mm, and pure Ar as the shielding gas with a flow rate of 12L / min.

10. The surface strengthening method for the flow components of a desulfurization slurry pump according to claim 1, characterized in that, In step S5, the power of the ultrasonic treatment is 700-900W.

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