Method for connecting heterogeneous materials of solid hydrogen storage device

Abstract

The invention relates to the technical field of material welding, in particular to a solid hydrogen storage device heterogeneous material connecting method which comprises the steps that pretreatment is conducted; selecting an adaptive welding wire; welding parameters are set; assembling and welding; a good interface basis is provided for welding by means of cleaning and detection after welding and fine pretreatment on the welding surface, the defects of incomplete fusion, pseudo soldering and the like caused by uneven heat input in traditional welding are effectively overcome by combining the precise temperature control characteristic of laser wire feeding welding, the mechanical property of a welded joint is greatly improved, and the industrial use requirement is met.

Description

Technical Field

[0001] This invention relates to the field of material welding technology, specifically to a method for joining heterogeneous materials in a solid hydrogen storage device. Background Technology

[0002] In modern industrial production, heterogeneous materials (integrated materials composed of two metals with different structures) can fully integrate the performance advantages of metals with different structures, and meet the comprehensive performance requirements of products in terms of strength, corrosion resistance, and lightweight. Their application scope is constantly expanding and is widely involved in aerospace, automobile manufacturing, medical devices, electronic equipment and other fields.

[0003] However, welding of heterogeneous materials, specifically mesh metal materials and bulk metal materials, has always been a technical challenge in the industry. Mesh metal materials are characterized by being porous and loosely structured, while bulk metal materials exhibit dense and continuous structural features. The significant differences between the two structures lead to problems such as uneven heat conduction, difficulty in forming the molten pool, and difficulty in controlling weld filling during the welding process. Currently, there are relatively few methods suitable for welding such heterogeneous materials, and the application of mainstream traditional welding methods (such as arc welding and resistance welding) in this field is significantly limited. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for connecting heterogeneous materials in a solid hydrogen storage device to address the existing technical problems.

[0005] To address the problems of existing technologies, the technical solution adopted in this invention is: a method for connecting heterogeneous materials in a solid-state hydrogen storage device, characterized by comprising the following steps:

[0006] S1. Pre-treatment: Clean the welding surfaces of the mesh metal material and the block metal material respectively to remove impurities such as oil, oxide layer and rust. According to the type and thickness of the mesh metal material and the block metal material, process the welding surface to form a specific bevel shape.

[0007] S2. Selection of welding materials: Based on the melting point, thermal conductivity and chemical composition of the mesh metal material and the block structure, select a welding wire that can form a strong metallurgical bond with the two materials, reduce the formation of brittle phases and match the mechanical properties of the base material.

[0008] S3. Welding parameter settings: Based on the type and thickness of the two heterogeneous materials and the characteristics of the selected welding wire, set the parameters of the laser wire feeding welding equipment;

[0009] S4. Welding operation: Assemble and fix the pretreated mesh metal material and block material, start the welding equipment, focus the laser beam on the center of the welding interface, and complete the welding according to the set parameters.

[0010] S5. Post-weld treatment: After the weld has cooled to room temperature, clean the weld surface of slag, spatter and oxide scale, and perform macroscopic analysis, microscopic analysis and tensile strength test on the weld joint.

[0011] The beveling process described in S1 follows the following rules: I-type beveling is used when the material thickness is ≤3mm, V-type beveling is used when the material thickness is 3-8mm, and X-type beveling is used when the material thickness is >8mm.

[0012] The parameters of the laser wire feeding welding equipment described in S3 include laser power, welding speed and wire feeding speed. The laser power is set in the range of 80-800W, the welding speed is set in the range of 10-80mm / min, and the wire feeding speed is set in the range of 50-300mm / min.

[0013] The laser power is adjusted according to the material thickness. For every 1mm increase in material thickness, the laser power increases by 50-100W.

[0014] The welding speed is adjusted according to the wall thickness of the mesh metal material; the thinner the wall, the higher the welding speed.

[0015] The ratio of wire feeding speed to welding speed is controlled at 3-5:1.

[0016] Argon is used as the protective gas during welding as described in S4, with a gas flow rate of 10-20 L / min.

[0017] The welding surface cleaning described in S1 uses one or more of the following methods: mechanical grinding, chemical cleaning, or ultrasonic cleaning, and the water film on the welding surface is continuously and uniformly adhered after cleaning.

[0018] The mesh metal material and the block material described in S4 are assembled and fixed using a vise or a special positioning fixture.

[0019] The weld cleaning described in S5 uses a wire brush, sandpaper, or high-pressure air gun. The macroscopic analysis uses the naked eye or a magnifying glass to detect whether there are cracks, pores, or incomplete penetration defects in the weld. The microscopic analysis uses a microscope to observe the microstructure of the weld and the heat-affected zone.

[0020] The beneficial effects of this invention compared to the prior art are:

[0021] Firstly, the refined pretreatment of the welding surface (cleaning impurities and customizing the beveling) provides a good interface foundation for welding. Combined with the precise temperature control characteristics of laser wire feeding welding, it effectively avoids defects such as incomplete fusion and false welding caused by uneven heat input in traditional welding. The mechanical properties of the welded joint (such as tensile strength) are greatly improved, meeting the requirements of industrial use.

[0022] Secondly, laser wire feeding welding of mesh and block materials can not only produce effective and high-quality welds, but also better control the weld composition and improve the welding quality.

[0023] Third, laser wire feeding welding has a high degree of automation, with welding speeds reaching 10-80 mm / min. Compared to traditional arc welding (usually ≤30 mm / min), efficiency is increased by more than 30%. In addition, the welding wire utilization rate is high during the welding process (without excessive spatter waste), post-weld processing is simple, and subsequent process costs are reduced, making it of good industrial promotion value. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of heterogeneous materials;

[0025] Figure 2 This is a schematic diagram of heterogeneous materials during welding;

[0026] Figure 3 These are morphological images of the front and back sides of the heterogeneous materials after welding.

[0027] Figure 4 This is a graph showing the tensile properties of heterogeneous materials after welding.

[0028] The labels in the diagram are: 1. Block metal material; 2. Mesh metal material. Detailed Implementation

[0029] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0030] The method for connecting heterogeneous materials in the solid-state hydrogen storage device in this embodiment includes the following steps:

[0031] S1. Material Preparation and Pretreatment

[0032] S30408 ​​mesh stainless steel (size 50×30×2mm, mesh size 2mm, wire diameter 0.8mm) and S30408 ​​block stainless steel (size 50×30×2mm, surface roughness Ra≤1.6μm) are selected; the welding equipment is a fiber laser wire feeding welding machine, and the tooling fixture is a special stainless steel positioning fixture.

[0033] S2, Preprocessing

[0034] Surface cleaning: First, use ultrasonic cleaning (cleaning agent is neutral degreaser, temperature is 50℃, cleaning time is 15min) to remove oil and dust from the mesh and block stainless steel surfaces. Then rinse the surface with anhydrous ethanol and finally blow dry with compressed air to ensure that the water film on the welded surface is continuous and unbroken.

[0035] Beveling: Since both materials are 2mm thick, an I-bevel is machined on the welding surface using mechanical milling. The bevel depth is 0.5mm and the surface roughness Ra is ≤3.2μm.

[0036] S3. Selection of Welding Materials

[0037] Based on the compositional characteristics of S30408 ​​stainless steel, ER308 stainless steel welding wire (1.2mm in diameter) is selected. This welding wire contains Cr (19-21%) and Ni (9-11%), which has a high degree of matching with the composition of the base material and can form an austenitic weld, with both good corrosion resistance and crack resistance.

[0038] S4. Welding Parameter Settings and Welding Process

[0039] Parameter settings: laser power 450W, laser circular oscillation amplitude 0.6mm, oscillation frequency 150Hz, welding speed 35mm / min, wire feed speed 120mm / min, angle between wire feed nozzle and welding interface 45°, shielding gas is argon (flow rate 15L / min).

[0040] Assembly and welding: Align the pre-treated mesh stainless steel with the block stainless steel, control the welding gap to 0.5mm, and fix it with a positioning fixture; start the welding equipment, focus the laser beam on the center of the welding interface, and move it at a constant speed along the welding direction. Monitor the wire feed speed and laser power in real time during the welding process to ensure no abnormal fluctuations.

[0041] S5. Post-welding treatment and quality inspection

[0042] Post-weld treatment: After welding, allow the weld to cool naturally to room temperature. Use a wire brush to remove the weld slag from the weld surface, and then use sandpaper to polish the weld and surrounding area to make the surface smooth.

[0043] Quality Inspection:

[0044] Macroscopic analysis: The weld surface is continuous and smooth, without defects such as cracks, porosity, or incomplete penetration;

[0045] Microscopic analysis: The microstructure of the weld and heat-affected zone was observed using a microscope;

[0046] Tensile test: The tensile strength of the welded joint is 520MPa (fracture at the mesh area, 165.3MPa), while the tensile strength of the S30408 ​​stainless steel substrate is 510MPa. The weld strength is slightly higher than that of the substrate. When the fracture location is on the blocky stainless steel substrate (non-weld area), it proves that the welded joint is of reliable quality.

[0047] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for connecting heterogeneous materials in a solid-state hydrogen storage device, characterized in that, Includes the following steps: S1. Pretreatment: Clean the welding surfaces of the mesh metal material (2) and the block metal material (1) respectively, remove impurities such as oil, oxide layer and rust from the surfaces of the two, and process the welding surfaces according to the type and thickness of the mesh metal material (2) and the block metal material (1) to form a specific bevel shape. S2. Selection of welding materials: Based on the melting point, thermal conductivity and chemical composition of the mesh metal material (2) and the block structure, select a welding wire that can form a strong metallurgical bond with the two materials, reduce the generation of brittle phases and match the mechanical properties of the base material. S3. Welding parameter settings: Based on the type and thickness of the two heterogeneous materials and the characteristics of the selected welding wire, set the parameters of the laser wire feeding welding equipment; S4. Welding operation: Assemble and fix the pretreated mesh metal material (2) with the block material, start the welding equipment, focus the laser beam on the center of the welding interface, and complete the welding according to the set parameters. S5. Post-weld treatment: After the weld has cooled to room temperature, clean the weld surface of slag, spatter and oxide scale, and perform macroscopic analysis, microscopic analysis and tensile strength test on the weld joint.

2. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, The beveling process described in S1 follows the following rules: I-type beveling is used when the material thickness is ≤3mm, V-type beveling is used when the material thickness is 3-8mm, and X-type beveling is used when the material thickness is >8mm.

3. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, The parameters of the laser wire feeding welding equipment described in S3 include laser power, welding speed and wire feeding speed. The laser power is set in the range of 80-800W, the welding speed is set in the range of 10-80mm / min, and the wire feeding speed is set in the range of 50-300mm / min.

4. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 3, characterized in that, The laser power is adjusted according to the material thickness. For every 1mm increase in material thickness, the laser power increases by 50-100W.

5. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 3, characterized in that, The welding speed is adjusted according to the wall thickness of the mesh metal material (2). The thinner the wall thickness, the higher the welding speed.

6. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 3, characterized in that, The ratio of wire feeding speed to welding speed is controlled at 3-5:

1.

7. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, Argon is used as the protective gas during welding as described in S4, with a gas flow rate of 10-20 L / min.

8. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, The welding surface cleaning described in S1 adopts one or more of the following methods: mechanical grinding, chemical cleaning, or ultrasonic cleaning, and the water film on the welding surface is continuously and uniformly adhered after cleaning.

9. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, The mesh metal material (2) described in S4 is assembled and fixed with the block material using a vise or a special positioning fixture.

10. The method for connecting heterogeneous materials in a solid-state hydrogen storage device according to claim 1, characterized in that, The weld cleaning described in S5 uses a wire brush, sandpaper, or high-pressure air gun. The macroscopic analysis uses the naked eye or a magnifying glass to detect whether there are cracks, pores, or incomplete penetration defects in the weld. The microscopic analysis uses a microscope to observe the microstructure of the weld and the heat-affected zone.

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