Method for enhancing corrosion resistance of heterogeneous material inertia friction welding joint

Abstract

The invention provides a method for enhancing corrosion resistance of a heterogeneous material inertia friction welding joint, and belongs to the field of heterogeneous material connection. According to the method, high-quality connection of heterogeneous materials is achieved through an inertia friction welding method, and meanwhile high dislocation density and grain boundary density are introduced; in addition, grains are further refined through vibration impact strengthening, the dislocation density is improved, a compact and stable passive film is promoted to be generated on the surface of the connector, and the corrosion resistance of the connector is enhanced. According to the method provided by the invention, on the basis of not introducing other additional processes, high grain boundary density and dislocation density are introduced while rapid high-quality metallurgical bonding of heterogeneous materials is realized, enrichment and selective dissolution of elements are promoted, the compactness and stability of a surface passive film are favorably improved, and the corrosion resistance of a joint is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the field of heterogeneous material connection, and in particular relates to a method for enhancing the corrosion resistance of a heterogeneous material inertia friction welding joint. Background Art

[0002] Nickel-based superalloys have become key materials for the manufacture of hot-end components such as aircraft engine rotors due to their high strength, excellent corrosion resistance and fatigue resistance. However, the high production cost is currently the main factor limiting its application. Therefore, connecting nickel-based superalloys with alloy steel materials with similar performance and lower cost can effectively balance welding quality and economy. In complex service environments such as the ocean, hot-end components are subjected to mechanical loads such as high temperature and high pressure, coupled with corrosive environments such as high salt spray and high humidity, which can easily induce pitting and intergranular corrosion, seriously affecting the safety and reliability of welded structures, and placing more stringent requirements on the corrosion resistance of welded joints.

[0003] The existing technology mainly improves the corrosion resistance of materials by adjusting the chemical composition or regulating the microstructure. The literature "Effect of alloy elements on corrosion resistance and soft magnetic property of the designed ferritic stainless steel, YX Yao, YY Wei, HJ Li, et al., Applied Physics A, 2023, 129: 612." reported that increasing the content of Cr, Mn, Cu and Si elements can effectively improve the corrosion resistance of stainless steel, among which the addition of Cu element has the most significant effect on enhancing corrosion resistance. However, adding additional alloying elements will result in higher production costs, thus limiting its wide application in the industrial field. Therefore, improving the corrosion resistance of materials by adjusting the microstructure has more practical application value. The literature "Corrosion mechanism of additively manufactured 316L stainless steel in 3.5wt.%NaCl solution, JJNie, W.Liang, Y.Jiang, et al., Materials Today Communications, 2021, 26: 101648." 316 stainless steel was prepared by laser additive manufacturing technology, and it was found that it had a fine subgrain structure with a diameter of about 5μm, rich dislocations at the subgrain boundaries and Mo enrichment, which promoted the formation of a dense and stable passivation film on the surface, thereby improving the corrosion resistance of the material. The above study used an additional process to achieve the purpose of refining the grains and increasing the dislocation density, thereby enhancing the corrosion resistance of the material; the production process is relatively complex and cumbersome, resulting in a significant reduction in the overall production efficiency. Therefore, how to balance joint performance and production efficiency has become a key issue that needs to be urgently solved in the current research field.

[0004] It can be seen that in order to improve the corrosion resistance of inertia friction welding joints of heterogeneous materials, it is urgent to develop a new and efficient process method to achieve high-quality connection of heterogeneous materials through inertia friction welding technology, while introducing high dislocation density and grain boundary density. In addition, vibration impact strengthening can further refine the grains, increase the dislocation density, promote the formation of a dense and stable passivation film on the joint surface, and enhance the corrosion resistance of the joint. Summary of the invention

[0005] In response to the common problems of poor joint corrosion resistance and complicated processes in the above-mentioned prior art, the present invention provides a method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials. Through the synergistic effect of inertia friction welding technology and vibration impact strengthening, high-quality connection of heterogeneous assembly joints can be achieved, while the corrosion resistance of the joints is enhanced.

[0006] The present invention adopts the following technical solutions:

[0007] A method for enhancing the corrosion resistance of an inertia friction welding joint of heterogeneous materials comprises the following steps:

[0008] Step 1: Before welding, cut the workpiece to be welded and grind the surface to be welded step by step. Immerse the polished workpiece in anhydrous ethanol solution for ultrasonic cleaning and then dry it for use;

[0009] Step 2: Securely clamp the workpiece to be welded on the moving end and rotating end of the machine tool, and calibrate and adjust the concentricity of the workpiece to be welded; weld the workpiece to be welded;

[0010] Step 3: Remove the flash inside and outside the inertia friction welding joint after welding;

[0011] Step 4: After the weldment cools to room temperature, clamp it to the rotating end of the machine tool again, and make the vibrating rod directly above the center of the weld, and keep the bottom of the vibrating rod at the initial distance from the weld surface; start the machine tool and rotate the weldment, and after the weldment rotates smoothly, use the vibrating rod to vibrate and impact strengthen the center of the weld; after the weld center is strengthened, restore the vibrating rod to its initial position, and translate the vibrating rod to both sides of the weld, respectively, and perform vibration and impact strengthening on both sides of the weld. After the strengthening is completed, turn off the machine tool and remove the weldment.

[0012] As a supplement to the technical solution of the present invention, in step 2, the inertia friction welding process parameters are: initial speed of 300-1000r / min, welding pressure of 20-500MPa, moment of inertia of 30-500kg·m 2 .

[0013] As a supplement to the technical solution of the present invention, in step 4, the process parameters of vibration impact strengthening are: the impact force of the vibration rod on the weld area is 20 to 100 MPa, the vibration impact frequency is 20 to 80 Hz, and the vibration impact time is 5 to 20 s.

[0014] As a supplement to the technical solution of the present invention, in step 4, the rotation speed of the weldment is 100 to 500 r / min.

[0015] As a supplement to the technical solution of the present invention, in step 4, the distance between the bottom of the vibrating rod and the center surface of the weld is 0.5 to 5 mm.

[0016] As a supplement to the technical solution of the present invention, in step 4, the distance that the vibrating rod is translated toward both sides of the weld is 0.2 to 2 mm.

[0017] As a supplement to the technical solution of the present invention, in step 4, the end of the vibrating rod is spherical, and the diameter of the sphere is 1 to 5 mm.

[0018] As a supplement to the technical solution of the present invention, the heterogeneous materials include nickel-based high-temperature alloys and alloy steels.

[0019] As a supplement to the technical solution of the present invention, the nickel-based high-temperature alloy includes Inconel690, Inconel718, FGH98, FGH101, GH4065 or GH4169, etc.; the alloy steel includes 316LN stainless steel, 304 stainless steel or 201 stainless steel, etc.

[0020] As a supplement to the technical solution of the present invention, in step 1, the size of the workpiece to be welded after cutting is: inner diameter 10-100 mm, outer diameter 20-200 mm, and tube length 10-200 mm.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1) High-quality connection of heterogeneous materials is achieved through inertia friction welding technology. The joint interface is a composite connection mechanism of mechanical interlocking and metallurgical bonding, avoiding common defects such as element segregation, solidification and liquefaction cracks in fusion welding;

[0023] 2) Inertia friction welding technology is conducive to directly introducing high dislocation density and grain boundary density, reducing the energy barrier of electrochemical reaction, promoting element enrichment and selective dissolution and increasing element diffusion rate, which helps to form a dense and stable passivation film and enhance the corrosion resistance of the joint;

[0024] 3) Vibration impact strengthening is performed on the center area of ​​the weld to cause micro-plastic deformation on the weld surface and introduce a residual compressive stress layer. At the same time, the microstructure is optimized, the grains are further refined, the dislocation density is increased, and the corrosion resistance of the joint is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the device structure used in an embodiment of the present invention.

[0026] Figure 2 KAM statistical diagrams of the joints of the embodiments of the present invention: (a) Comparative Example 1; (b) Embodiment 1.

[0027] Figure 3 The joint geometry required for the embodiments of the present invention is the dislocation density distribution and average value: (a) Comparative Example 1; (b) Embodiment 1.

[0028] Figure 4 The corrosion current density, grain size and small-angle grain boundary ratio of the joint according to the embodiment of the present invention.

[0029] Figure 5 The corrosion morphologies of the joints according to the embodiments of the present invention are as follows: (a) Comparative Example 1; (b) Embodiment 1.

[0030] In the figure: 1-motor; 2-transmission shaft; 3-spindle; 4-brake; 5-flywheel; 6-rotating chuck; 7-workpiece to be welded; 8-vibrating rod; 9-moving workbench; 10-fixed chuck; 11-sliding system; 12-hydraulic cylinder. DETAILED DESCRIPTION

[0031] To facilitate the understanding of the technical solution, the present invention provides the following embodiments, specifically selecting Inconel690 nickel-based high-temperature alloy and 316LN stainless steel for welding, but not limited to the above grades. The method disclosed in the present invention is also applicable to enhancing the corrosion resistance of heterogeneous assembled joints of other grades of nickel-based high-temperature alloys and alloy steels.

[0032] The method described in the embodiment of the present invention is implemented by an inertia friction welding device, which includes a motor 1, a transmission shaft 2, a main shaft 3, a brake 4, a flywheel 5, a rotating chuck 6, a vibrating rod 8, a movable worktable 9, a fixed chuck 10, a sliding system 11 and a hydraulic cylinder 12; wherein the motor 1 is connected to one end of the main shaft 3 through the transmission shaft 2, the brake 4 is arranged on the main shaft 3, the other end of the main shaft 3 is connected to the flywheel 5, and the flywheel 5 is equipped with a rotating chuck 6 for clamping a workpiece 7 to be welded; the hydraulic cylinder 12 is connected to the sliding system 11, and the sliding system 11 is provided with a fixed chuck 10 for clamping another workpiece 7 to be welded; the movable worktable 9 is installed on a machine tool, and the vibrating rod 8 is installed on the movable worktable 9 and can be adjusted in position through the movable worktable 9.

[0033] Embodiment 1:

[0034] Step 1: Before welding, use wire cutting technology to process Inconel690 nickel-based high-temperature alloy and 316LN stainless steel into workpieces with an inner diameter of 70mm, an outer diameter of 107mm, and a tube length of 50mm. Then use sandpaper to finely grind the surface to be welded step by step, and immerse the workpiece to be welded in anhydrous ethanol solution for ultrasonic cleaning to remove surface oil and oxidation interlayer. After cleaning, blow dry the surface and dry it for use.

[0035] Step 2: Securely clamp the workpiece to be welded on the fixed chuck 10 and the rotating chuck 6, respectively, while ensuring that the axes of the two coincide with each other, and calibrate and adjust the concentricity of the workpiece to be welded. During the welding process, first set the inertia friction welding process parameters: initial speed of 760r / min, welding pressure of 170MPa, moment of inertia of 280kg·m 2. After the motor 1 drives the spindle 3 to drive the flywheel 5 to reach the predetermined speed, the spindle 3 is separated from the motor 1, and the welding energy is stored in the flywheel 5 in the form of kinetic energy. At the same time, the workpiece at the moving end is driven by the hydraulic servo to move toward the rotating end. After the workpieces come into contact, the surfaces to be welded rub against each other under the action of axial pressure to generate heat until they reach a high-temperature plastic state. The metal at the welding interface is gradually squeezed out to form flash. Under the continuous action of friction torque, the speed of the flywheel gradually decreases until it stops rotating. After maintaining pressure for 3s, it exits the moving end, and the welding process is completed.

[0036] Step 3: Use turning technology to remove the inner and outer flash of the inertia friction welding joint of heterogeneous materials by using the rotational motion of the weldment and the linear motion of the tool.

[0037] Step 4: After the weldment cools to room temperature, clamp it onto the rotary chuck 6 again, move the workbench 9 so that the vibrating rod 8 is located directly above the center of the weld, and the distance between the bottom of the vibrating rod 8 and the weld surface is 1mm. The vibrating rod 8 is made of 45# steel, and the end is spherical with a spherical diameter of 3mm. After starting the machine tool, rotate the weldment at a speed of 300r / min. After the weldment rotates smoothly, the vibrating rod 8 is subjected to vibration impact strengthening of the weld center of the weldment according to the process parameters of vibration impact force of 60MPa, frequency of 50Hz, and time of 10s. After the weld center is strengthened, restore the vibrating rod to its initial position, and translate 0.5mm to both sides of the weld center respectively. According to the above-mentioned vibration impact strengthening process parameters, vibration impact strengthening is performed on both sides of the weld respectively. After strengthening, the machine tool is turned off and the weldment is removed.

[0038] Step 5: Perform microstructure analysis on the weld joint and take the weld interface as the center line to obtain a 6×6mm 2 The electrochemical test was carried out on the samples, and the electrochemical corrosion performance of the joint in 3.5wt.% NaCl solution was evaluated using an electrochemical workstation. Figure 2 As can be seen in (b), the KAM diagram of the joint is obviously yellow-green, indicating that there is a high dislocation density and plastic deformation. Figure 3 Middle (b), Figure 4 and Figure 5 As shown in (b), the average joint geometry requires a dislocation density of 6.3×10 13 m -2 , the current density is 1.138×10 -7 A / cm 2 , the grain size is 10.6μm, the proportion of small-angle grain boundaries is 18%, and the number of pitting holes in the joint is 2.

[0039] Embodiment 2:

[0040] Step 1: Before welding, use wire cutting technology to process Inconel690 nickel-based high-temperature alloy and 316LN stainless steel into workpieces with an inner diameter of 70mm, an outer diameter of 107mm, and a tube length of 50mm. Then use sandpaper to finely grind the surface to be welded step by step, and immerse the workpiece to be welded in anhydrous ethanol solution for ultrasonic cleaning to remove surface oil and oxidation interlayer. After cleaning, blow dry the surface and dry it for use.

[0041] Step 2: Securely clamp the workpiece to be welded on the fixed chuck 10 and the rotating chuck 6, respectively, while ensuring that the axes of the two coincide with each other, and calibrate and adjust the concentricity of the workpiece to be welded. During the welding process, first set the inertia friction welding process parameters: initial speed of 760r / min, welding pressure of 170MPa, moment of inertia of 280kg·m 2 . After the motor 1 drives the spindle 3 to drive the flywheel 5 to reach the predetermined speed, the spindle 3 is separated from the motor 1, and the welding energy is stored in the flywheel 5 in the form of kinetic energy. At the same time, the workpiece at the moving end is driven by the hydraulic servo to move toward the rotating end. After the workpieces come into contact, the surfaces to be welded rub against each other under the action of axial pressure to generate heat until they reach a high-temperature plastic state. The metal at the welding interface is gradually squeezed out to form flash. Under the continuous action of friction torque, the speed of the flywheel gradually decreases until it stops rotating. After maintaining pressure for 3s, it exits the moving end, and the welding process is completed.

[0042] Step 3: Use turning technology to remove the inner and outer flash of the inertia friction welding joint of heterogeneous materials by using the rotational motion of the weldment and the linear motion of the tool.

[0043] Step 4: After the weldment cools to room temperature, clamp it onto the rotary chuck 6 again, move the workbench 9 so that the vibrating rod 8 is located directly above the center of the weld, and the distance between the bottom of the vibrating rod 8 and the weld surface is 1mm. The vibrating rod 8 is made of 45# steel, and the end is spherical with a spherical diameter of 3mm. After starting the machine tool, rotate the weldment at a speed of 300r / min. After the weldment rotates smoothly, the vibrating rod 8 is used to perform vibration impact strengthening on the weld center of the weldment according to the process parameters of vibration impact force of 20MPa, frequency of 80Hz, and time of 10s. After the weld center is strengthened, restore the vibrating rod to its initial position, and translate 0.5mm to both sides of the weld center. Perform vibration impact strengthening on both sides of the weld according to the above-mentioned vibration impact strengthening process parameters. After the strengthening is completed, turn off the machine tool and remove the weldment.

[0044] Step 5: Perform microstructure analysis on the weld joint and take the weld interface as the center line to obtain a 6×6mm 2 The electrochemical test was carried out on the sample, and the electrochemical corrosion performance of the joint in 3.5wt.% NaCl solution was evaluated using an electrochemical workstation. The results obtained were the same as those in Example 1, except that the average geometric dislocation density of the joint was 6.0×10 13 m-2 , the current density is 1.245×10 -7 A / cm 2 , the grain size is 10.8μm, the proportion of small-angle grain boundaries is 17.2%, and the number of pitting holes in the joint is 3.

[0045] Embodiment 3:

[0046] Step 1: Before welding, use wire cutting technology to process Inconel690 nickel-based high-temperature alloy and 316LN stainless steel into workpieces with an inner diameter of 70mm, an outer diameter of 107mm, and a tube length of 50mm. Then use sandpaper to finely grind the surface to be welded step by step, and immerse the workpiece to be welded in anhydrous ethanol solution for ultrasonic cleaning to remove surface oil and oxidation interlayer. After cleaning, blow dry the surface and dry it for use.

[0047] Step 2: Securely clamp the workpiece to be welded on the fixed chuck 10 and the rotating chuck 6, respectively, while ensuring that the axes of the two coincide with each other, and calibrate and adjust the concentricity of the workpiece to be welded. During the welding process, first set the inertia friction welding process parameters: initial speed of 760r / min, welding pressure of 170MPa, moment of inertia of 280kg·m 2 . After the motor 1 drives the spindle 3 to drive the flywheel 5 to reach the predetermined speed, the spindle 3 is separated from the motor 1, and the welding energy is stored in the flywheel 5 in the form of kinetic energy. At the same time, the workpiece at the moving end is driven by the hydraulic servo to move toward the rotating end. After the workpieces come into contact, the surfaces to be welded rub against each other under the action of axial pressure to generate heat until they reach a high-temperature plastic state. The metal at the welding interface is gradually squeezed out to form flash. Under the continuous action of friction torque, the speed of the flywheel gradually decreases until it stops rotating. After maintaining pressure for 3s, it exits the moving end, and the welding process is completed.

[0048] Step 3: Use turning technology to remove the inner and outer flash of the inertia friction welding joint of heterogeneous materials by using the rotational motion of the weldment and the linear motion of the tool.

[0049] Step 4: After the weldment cools to room temperature, clamp it on the rotary chuck 6 again, move the workbench 9 so that the vibrating rod 8 is located directly above the center of the weld, and the distance between the bottom of the vibrating rod 8 and the weld surface is 1mm. The material of the vibrating rod 8 is 45# steel, and the end is spherical with a spherical diameter of 3mm. After starting the machine tool, rotate the weldment at a speed of 300r / min. After the weldment rotates smoothly, the vibrating rod 8 is used to vibrate and impact strengthen the weld center of the weldment according to the process parameters of vibration impact force of 100MPa, frequency of 20Hz, and time of 10s. After strengthening the weld center, restore the vibrating rod to its initial position, and translate it 0.5mm to both sides of the weld center. According to the above vibration impact strengthening process parameters, vibration impact strengthen both sides of the weld. After strengthening, turn off the machine tool and remove the weldment.

[0050] Step 5: Perform microstructure analysis on the weld joint and take the weld interface as the center line to obtain a 6×6mm 2 The electrochemical test was carried out on the sample, and the electrochemical corrosion performance of the joint in 3.5wt.% NaCl solution was evaluated using an electrochemical workstation. The results obtained were the same as those in Example 1, except that the average geometric dislocation density of the joint was 5.6×10 13 m -2 , the current density is 1.35×10 -7 A / cm 2 , the grain size is 11.2μm, the proportion of small-angle grain boundaries is 16.5%, and the number of pitting holes in the joint is 3.

[0051] Comparative Example 1:

[0052] Step 1: Before welding, use wire cutting technology to process Inconel690 nickel-based high-temperature alloy and 316LN stainless steel into workpieces with an inner diameter of 70mm, an outer diameter of 107mm, and a tube length of 50mm. Then use sandpaper to finely grind the surface to be welded step by step, and immerse the workpiece to be welded in anhydrous ethanol solution for ultrasonic cleaning to remove surface oil and oxidation interlayer. After cleaning, blow dry the surface and dry it for use.

[0053] Step 2: Securely clamp the workpiece to be welded on the fixed chuck 10 and the rotating chuck 6, respectively, while ensuring that the axes of the two coincide with each other, and calibrate and adjust the concentricity of the workpiece to be welded. During the welding process, first set the inertia friction welding process parameters: initial speed of 760r / min, welding pressure of 170MPa, moment of inertia of 280kg·m 2 . After the motor 1 drives the spindle 3 to drive the flywheel 5 to reach the predetermined speed, the spindle 3 is separated from the motor 1, and the welding energy is stored in the flywheel 5 in the form of kinetic energy. At the same time, the workpiece at the moving end is driven by the hydraulic servo to move toward the rotating end. After the workpieces come into contact, the surfaces to be welded rub against each other under the action of axial pressure to generate heat until they reach a high-temperature plastic state. The metal at the welding interface is gradually squeezed out to form flash. Under the continuous action of friction torque, the speed of the flywheel gradually decreases until it stops rotating. After maintaining pressure for 3s, it exits the moving end, and the welding process is completed.

[0054] Step 3: Use turning technology to remove the inner and outer flash of the inertia friction welding joint of heterogeneous materials by using the rotational motion of the weldment and the linear motion of the tool.

[0055] Step 4: Perform microstructure analysis on the weld joint and take the weld interface as the center line to obtain a 6×6mm 2 The electrochemical test was carried out on the samples, and the electrochemical corrosion performance of the inertia friction welding joint in 3.5wt.%NaCl solution was evaluated using an electrochemical workstation. Figure 2As can be seen in (a), the color of the joint KAM diagram is relatively dark, and the green is mainly concentrated at the weld interface, and the dislocation density is small. Figure 3 Middle (a), Figure 4 and Figure 5 As shown in (a), the average joint geometry requires a dislocation density of 3.4×10 13 m -2 , the current density is 2.256×10 -7 A / cm 2 The average grain size is 12.9 μm, the proportion of small-angle grain boundaries is 10%, and the number of pitting holes in the joint is 6.

[0056] By comparing Comparative Example 1 and Example 1, it can be found that the inertia friction welding technology proposed by the present invention can achieve rapid metallurgical bonding of nickel-based alloy and stainless steel heterogeneous materials while introducing high grain boundary density and dislocation density. The synergistic effect of vibration impact strengthening further refines the grains and increases the dislocation density, which helps to enhance the compactness and stability of the surface passivation film. In addition, the corrosion current density of each joint is positively correlated with the grain size and negatively correlated with the proportion of low-angle grain boundaries. With the refinement of grains and the increase of dislocation density and low-angle grain boundary proportion, the number of pitting holes in the joint is reduced, and the corrosion resistance of the joint is significantly enhanced.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials, characterized in that: The following steps are involved: Step 1: Before welding, cut the workpiece to be welded and grind the surface to be welded step by step. Immerse the polished workpiece in anhydrous ethanol solution for ultrasonic cleaning and then dry it for use; Step 2: Securely clamp the workpiece to be welded on the moving end and rotating end of the machine tool, and calibrate and adjust the concentricity of the workpiece to be welded; weld the workpiece to be welded; Step 3: Remove the flash inside and outside the inertia friction welding joint after welding; Step 4: After the weldment cools to room temperature, clamp it to the rotating end of the machine tool again, and make the vibrating rod directly above the center of the weld, and keep the bottom of the vibrating rod at the initial distance from the weld surface; start the machine tool and rotate the weldment, and after the weldment rotates smoothly, use the vibrating rod to vibrate and impact strengthen the center of the weld; after the weld center is strengthened, restore the vibrating rod to its initial position, and translate the vibrating rod to both sides of the weld, respectively, and perform vibration and impact strengthening on both sides of the weld. After the strengthening is completed, turn off the machine tool and remove the weldment.

2. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 1, characterized in that: In step 2, the inertia friction welding process parameters are: initial rotation speed of 300-1000 r / min, welding pressure of 20-500 MPa, moment of inertia of 30-500 kg·m 2 .

3. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 1 or 2, characterized in that: In step 4, the process parameters of vibration impact strengthening are: the impact force of the vibration rod on the weld area is 20-100 MPa, the vibration impact frequency is 20-80 Hz, and the vibration impact time is 5-20 s.

4. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 3, characterized in that: In step 4, the rotation speed of the weldment is 100 to 500 r / min.

5. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 4, characterized in that: In step 4, the distance between the bottom of the vibrating rod and the center surface of the weld is 0.5 to 5 mm.

6. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 5, characterized in that: In step 4, the distance that the vibrating rod moves toward both sides of the weld is 0.2 to 2 mm.

7. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 6, characterized in that: In step 4, the end of the vibrating rod is spherical, and the diameter of the sphere is 1 to 5 mm.

8. The method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 7, characterized in that: The heterogeneous materials include nickel-based high-temperature alloys and alloy steels.

9. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 8, characterized in that: The nickel-based high-temperature alloy includes Inconel690, Inconel718, FGH98, FGH101, GH4065 or GH4169; the alloy steel includes 316LN stainless steel, 304 stainless steel or 201 stainless steel.

10. A method for enhancing the corrosion resistance of inertia friction welding joints of heterogeneous materials according to claim 9, characterized in that: In step 1, the size of the workpiece to be welded after cutting is: inner diameter 10-100 mm, outer diameter 20-200 mm, and tube length 10-200 mm.

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