A process for the production of a stainless steel bellows assembly

Abstract

This application relates to the field of corrugated pipe manufacturing technology, and more specifically, to a manufacturing process for a stainless steel corrugated pipe assembly, comprising the following steps: S1, applying brazing filler along the edge of the corrugated trough of the stainless steel corrugated pipe, then placing a support strip at the edge of the corrugated trough and filling it with brazing filler, the height of which is flush with the crest of the stainless steel corrugated pipe; then pushing it into the water tap joint connected to the water cooling plate, so that the crest of the stainless steel corrugated pipe abuts against the inner wall of the water tap joint, and then performing vacuum brazing to obtain the stainless steel corrugated pipe assembly. This application avoids wall thickness reduction, microcracks, and work hardening caused by plastic deformation of the thin-walled base material, eliminates residual tensile stress and high-temperature springback, eliminates stress concentration sources, and improves assembly accuracy, fatigue resistance, and long-term service reliability.

Description

Technical Field

[0001] This application relates to the field of corrugated pipe manufacturing technology, and more specifically, to a manufacturing process for a stainless steel corrugated pipe assembly. Background Technology

[0002] With the increasing integration of electronic devices such as AI servers, internal space is becoming increasingly compact, severely limiting the layout of heat dissipation systems. Miniature metal bellows, due to their excellent flexibility and foldability, can create flexible heat dissipation channels within confined spaces, making them a key functional component in the heat dissipation modules of increasingly thin and light devices. During the assembly of heat dissipation components, miniature metal bellows typically need to be connected to rigid connectors such as adapters to form a complete heat dissipation loop and improve overall heat dissipation efficiency.

[0003] Currently, the connection between miniature metal bellows and adapters generally adopts a vacuum brazing process. Specifically, the end of the bellows to be connected is first straightened mechanically to form a flat cylindrical section. Then, this flat section is inserted into the adapter, and the two are then metallurgically bonded through vacuum brazing to obtain the finished heat dissipation component.

[0004] However, the aforementioned existing technical solutions have many insurmountable defects, which severely restrict the assembly accuracy and long-term reliability of the products: First, the straightening process damages the corrugated pipe base material. The wall thickness of miniature metal corrugated pipes is typically 0.1mm-0.5mm. During mechanical straightening, the transition area between the crests and troughs is forced into plastic deformation. Due to the poor deformation coordination of thin-walled pipes, this transition area is highly susceptible to defects such as localized wall thinning, surface wrinkling, and even microcracks. Simultaneously, plastic deformation introduces significant lattice distortion and high dislocation density into the material, resulting in a pronounced work hardening effect and creating potential problems for subsequent processes.

[0005] Secondly, residual stress leads to high-temperature deformation and assembly failure. The straightening process introduces high residual tensile stress at the end of the bellows. During the subsequent high-temperature stage of vacuum brazing, this residual stress is released and drives the material to spring back. This deformation directly damages the assembly clearance between the straight section of the bellows and the adapter, as well as their coaxiality, resulting in out-of-tolerance geometric accuracy of the brazed assembly, which fails to meet the assembly requirements of precision heat dissipation modules. Furthermore, the residual stress, brazing thermal stress, and cooling shrinkage stress superimpose each other, forming a complex stress field in the transition area between the straight and bellows sections, which can easily induce cold cracks or thermal fatigue cracks.

[0006] Third, the base material undergoes corrosion and deterioration of mechanical properties. Straightening causes lattice distortion and increased dislocation density, significantly increasing the surface energy and chemical activity of the base material. This makes it more susceptible to wetting and dissolution by liquid brazing filler metal at high temperatures, leading to overheating or corrosion. This not only further thins the local wall thickness of the bellows but also significantly reduces its load-bearing strength, weakening the safety margin of the bellows as a pressure boundary.

[0007] Fourth, the long-term reliability risks during the service phase are significant. The stress concentration zones formed by straightening and brazing (such as the straight-to-corrugated transition zone and brazed seam edges) are continuously subjected to the combined effects of pressure pulsation, thermal cycling, and mechanical vibration during equipment operation. Fatigue cracks will rapidly initiate and propagate, causing the components to fail far before their design life. Simultaneously, after cold working and high-temperature annealing, the balance between hardness, strength, and toughness of the corrugated pipe is disrupted, and its elastic compensation capacity is significantly reduced. Under thermal expansion and contraction or external displacement loads, it is more prone to fracture or leakage due to excessive stress.

[0008] Fifth, decreased corrosion resistance and potential safety hazards. For stainless steel bellows, the high-temperature brazing process easily induces sensitization. Combined with residual stress introduced by cold deformation, the material's corrosion resistance decreases, potentially leading to abnormal grain growth, intergranular corrosion, and stress corrosion cracking in the service environment. Furthermore, if metallurgical defects such as incomplete penetration, porosity, or slag inclusions exist within the brazed seam, under long-term high pressure and alternating loads, these defects will form penetrating leakage channels. This not only causes leakage of the heat dissipation medium and system shutdown but may also trigger more serious safety accidents.

[0009] In summary, the fundamental problem with existing methods for connecting metal bellows and adapters lies in the fact that the thin-walled bellows undergoes dual damage from forced cold deformation and high-temperature brazing, severely disrupting the microstructure integrity and macroscopic stress state of the material. Therefore, a new method is urgently needed that can reliably connect the metal bellows and adapter without forcibly straightening the bellows ends, thus ensuring both assembly accuracy and long-term service reliability. Summary of the Invention

[0010] To address the aforementioned issues, this application provides a manufacturing process for a stainless steel corrugated pipe assembly.

[0011] In a first aspect, this application provides a manufacturing process for a stainless steel corrugated pipe assembly, employing the following technical solution: A manufacturing process for a stainless steel corrugated pipe assembly includes the following steps: S1. Select a section of stainless steel corrugated pipe, apply a layer of brazing material along the edge of the trough of the stainless steel corrugated pipe, then place the support strip at the edge of the trough of the stainless steel corrugated pipe and fill it with brazing material. The height of the brazing material is level with the crest of the stainless steel corrugated pipe to obtain a pre-treated corrugated pipe. S2. Push the pre-treated corrugated pipe into the water tap joint that is connected to the water cooling plate, so that the crest of the stainless steel corrugated pipe abuts against the inner wall of the water tap joint, and obtain the pre-treated stainless steel corrugated pipe assembly. S3. Pre-treated stainless steel corrugated pipe assemblies are vacuum brazed to obtain stainless steel corrugated pipe assemblies.

[0012] By adopting the above technical solution, the forced straightening process at the end of the bellows is eliminated. The original crest and trough structure of the bellows is directly utilized. With the support strip and brazing filler filling the troughs to make the brazing filler height level with the crest, the bellows is pushed into the water tap joint and the crest abuts against the inner wall of the joint before vacuum brazing. This avoids the damage caused by forced plastic deformation of the thin-walled base material, such as wall thickness reduction, surface wrinkling, microcracks and work hardening. At the same time, it eliminates residual tensile stress and its springback deformation caused by the high temperature of brazing, ensuring the assembly gap and coaxiality between the bellows and the water tap joint. Because the bellows was not straightened, its lattice distortion and dislocation density were not artificially increased, and its surface chemical activity remained at a normal level. This effectively suppressed the overheating and corrosion of the base material during the brazing process, ensuring the integrity of the bellows wall thickness and its load-bearing strength. In addition, by utilizing the original corrugations of the bellows to abut against the inner wall of the water tap joint and filling with brazing filler, a reliable connection was achieved. This avoided the formation of stress concentration sources such as the straight section-corrugated transition zone, enabling the assembly to better withstand the combined effects of pressure pulsation, thermal cycling, and mechanical vibration during service. This improved fatigue resistance, elastic compensation capability, and corrosion resistance, thereby comprehensively improving the assembly accuracy and long-term service reliability of the stainless steel bellows assembly.

[0013] Preferably, the end of the water tap connector that contacts the corrugated pipe is made of 304, 304L, 316 or 316L stainless steel, and the end that contacts the water cooling plate is made of T2 copper, TP2 copper or copper-nickel alloy. The water tap connector and the adapter are integrally formed or welded together.

[0014] Preferably, the brazing filler used in step S1 is composed of the following raw materials by weight percentage: Chromium 6.5-9.5%, boron 2.85-3.45%, silicon 4.2-4.8%, iron 2.6-3.4%, zinc 1.0-5.0%, rare earth elements 0.1-0.2%, aluminum 0.05-0.3%, carbon 0.1-0.8%, additives 15-20%, and the remainder is nickel.

[0015] By adopting the above technical solution, the synergistic effect of chromium, boron, and silicon lowers the melting point of the brazing filler and improves its fluidity, allowing it to fully fill the gap between the corrugated pipe and the inner wall of the water tap joint during vacuum brazing, forming a dense and defect-free metallurgical bond. The addition of zinc effectively improves the wettability of the brazing filler to stainless steel and copper alloys, promotes interfacial reaction and element diffusion, and enhances the connection strength. Trace amounts of rare earth elements and aluminum can purify the molten pool, refine the grains, reduce porosity and inclusions, and improve the density and corrosion resistance of the joint. Carbon and iron play a role in solid solution strengthening and stabilizing the microstructure, ensuring the stability of the brazed joint under high temperature and stress conditions. This formula not only has good metallurgical compatibility with stainless steel corrugated pipes and water-cooled plates, avoiding excessive corrosion of the corrugated pipes, but also endows the joint with excellent fatigue resistance, creep resistance, and resistance to media corrosion, thereby ensuring the reliability and safety of the miniature heat dissipation components during long-term service.

[0016] Preferably, the rare earth elements are composed of lanthanum and cerium in a weight ratio of 1:2.5-4.

[0017] By employing the above technical solutions, lanthanum effectively purifies grain boundaries, adsorbs impurities, and refines grains; while cerium significantly improves interfacial wettability and element diffusion capacity. The synergistic effect of these two elements not only improves the density and metallurgical bonding quality of the brazed joint, but also further enhances the joint's mechanical strength, corrosion resistance, and thermal fatigue resistance, ensuring the long-term reliability of the components under harsh operating conditions.

[0018] Preferably, the additives include solvents, thickeners, rheology modifiers and activators in a weight ratio of 20-30:1-2:0.5-1:0.3.

[0019] By employing the above technical solution, the solvent acts as a carrier to fully disperse the solid components of the brazing filler metal, adjusting the paste to a suitable viscosity for easy application to the troughs of the corrugated pipe; the thickener prevents the filler metal particles from settling and stratifying, ensuring uniform and stable composition during storage and coating; the rheology modifier imparts excellent thixotropic properties to the paste, making it easy to spread during application and maintain its shape without dripping after application, allowing for precise positioning in the trough areas; the activator effectively removes the oxide film on the surface of the base material during the brazing heating stage, improving the wetting and spreading performance of the filler metal on stainless steel and copper, and promoting metallurgical bonding. The four components work synergistically in the above proportions, giving the brazing paste excellent coating processability, storage stability, and brazing activity, ensuring a dense, defect-free, high-quality joint for vacuum brazing.

[0020] Preferably, the activator is composed of zinc chloride and zirconium oxide in a weight ratio of 1-3:0.5.

[0021] By employing the above technical solutions, zinc chloride effectively removes the oxide film on the surfaces of stainless steel and copper, reduces the surface tension of the brazing filler metal, and improves wettability and spreadability. Zirconia, as a high-temperature stable carrier, slows down the decomposition rate of zinc chloride, synergistically prolongs the activation time, and inhibits excessive corrosion. The combination of the two can ensure brazing activity while reducing residual corrosion in the brazing seam, and improving the joint's tightness and corrosion resistance.

[0022] Preferably, the brazing filler used in step S1 is composed of the following raw materials by weight percentage: Chromium 7.5%, boron 3.25%, silicon 4.5%, iron 2.8%, zinc 2.5%, rare earth elements 0.15%, aluminum 0.1%, carbon 0.3%, additives 17%, and the remainder is nickel.

[0023] By adopting the above technical solution, the amount of brazing filler metal is optimized, and the filler metal is further able to fully fill the gaps between the troughs, resulting in a dense, low-corrosion, and high-strength brazed joint.

[0024] Preferably, in step S1, the distance between the trough of the stainless steel corrugated pipe and the support strip is 0.1mm-0.5mm.

[0025] By adopting the above technical solution, a precise physical space is provided for the capillary filling of the brazing filler metal, ensuring that the liquid brazing filler metal can fully wet and fill the gap between the corrugation trough and the support strip, forming a dense and defect-free metallurgical bonding layer. Secondly, this gap effectively avoids hard compression between the support strip and the bellows, protecting the thin-walled base material from mechanical damage and maintaining the original structural integrity and elasticity of the bellows.

[0026] Preferably, in step S2, the assembly gap between the crest of the stainless steel corrugated pipe and the inner wall of the faucet connector is 0.05mm-0.15mm.

[0027] By adopting the above technical solution, a positioning space is provided for the corrugated pipe's crest, eliminating the need for forced diameter expansion or compression when pushing it into the faucet connector. This effectively avoids local deformation, wall thinning, or residual stress in the thin-walled base material caused by mechanical extrusion, fully preserving the corrugated pipe's elastic compensation capability. Secondly, this gap is highly compatible with the vacuum brazing process, providing a channel for the capillary penetration of the brazing filler metal. This promotes the uniform spread of the brazing filler metal along the contact surface between the crest and the inner wall of the connector, forming a continuous, dense, and defect-free metallurgical bonding layer, improving the strength and sealing performance of the connection interface. Furthermore, it effectively alleviates the thermal stress generated during temperature rise and fall due to the difference in thermal expansion coefficients between stainless steel and the faucet connector material, preventing cracking of the brazing seam and thus ensuring the long-term sealing reliability and structural stability of the heat dissipation component under complex operating conditions.

[0028] Preferably, the brazing process in step S3 is as follows: Heat to 350-550℃ from room temperature, hold for 30-50 minutes, then heat to 850-870℃, hold for 30-40 minutes, then heat to 950-1050℃, hold for 15-20 minutes, with a vacuum degree of 10. -3 -10 -5 Pa.

[0029] By adopting the above technical solution, the orderly conduct of the brazing process and the formation of a high-quality joint were achieved. In the first stage of heat preservation, the brazing filler metal and residual substances on the corrugated pipe surface are fully decomposed and volatilized, purifying the welding interface. Subsequently, the temperature is raised to 850-870℃ and held to promote the full diffusion of reducing elements such as boron and silicon in the brazing filler metal, reducing liquid phase viscosity and optimizing wetting and spreading properties. Finally, heating to a high-temperature stage of 950-1050℃ allows the brazing filler metal to completely melt and fill the joint gap, achieving a dense metallurgical bond. The entire process takes 10 minutes. -3 -10 -5 The process is carried out under a high vacuum environment of Pa, which effectively prevents metal oxidation, promotes the discharge of interfacial gases, and reduces the generation of defects such as porosity and inclusions, thereby ensuring the high strength, high reliability and excellent corrosion resistance of the brazed joint.

[0030] Preferably, after step S3, step S4 is further included: a stainless steel protective sleeve is fitted onto the outer wall of the faucet connector, and the stainless steel protective sleeve is connected to the faucet connector by spot welding or brazing.

[0031] By adopting the above technical solution, the protective sleeve can form a rigid transition support between the joint and the bellows, effectively absorbing and dispersing external mechanical stress and bending moment during bending, and preventing deformation or fatigue damage to the bellows troughs and brazed seam edges due to direct force. The protective sleeve is firmly connected to the faucet joint through spot welding or brazing, ensuring that the protective sleeve remains in a stable protective position without loosening or displacement during repeated bending. This ensures the continuous effectiveness of the rigid transition support and uniform stress transmission, thereby enhancing the mechanical protection capability for the bellows troughs and brazed seam edges, and further extending the number of bends and the flexible service life of the bellows.

[0032] In summary, this application has the following beneficial effects: 1. This application eliminates the forced straightening of the corrugated pipe ends and uses the original crest and trough structure in conjunction with brazing filler to achieve connection, avoiding wall thickness reduction, micro-cracks, work hardening and residual tensile stress caused by plastic deformation of thin-walled base material, eliminating high-temperature springback deformation, and ensuring assembly clearance and coaxiality.

[0033] 2. By utilizing the abutment fit between the original corrugations of the corrugated pipe and the inner wall of the water tap joint, and with the brazing filler filling the troughs to form a dense metallurgical bond, stress concentration sources such as the straight section-corrugated transition zone are eliminated, enabling the component to better withstand the combined effects of pressure pulsation, thermal cycling and mechanical vibration, and improving fatigue resistance, elastic compensation ability and corrosion resistance.

[0034] 3. In the brazing alloy formulation, chromium, boron, and silicon work together to lower the melting point and improve fluidity, zinc improves wettability, rare earth elements and aluminum purify the molten pool and refine the grains, and carbon and iron stabilize the microstructure, enabling the brazing alloy to fully fill the gaps to form a dense joint. This gives the joint excellent creep resistance and resistance to media corrosion, ensuring long-term service reliability. Detailed Implementation Example

[0035] Example 1

[0036] A manufacturing process for a stainless steel corrugated pipe assembly includes the following steps: S1. Select a section of stainless steel corrugated pipe, apply a layer of brazing material along the edge of the trough of the stainless steel corrugated pipe, then place the support strip at the edge of the trough of the stainless steel corrugated pipe and fill it with brazing material. The height of the brazing material is level with the crest of the stainless steel corrugated pipe to obtain a pre-treated corrugated pipe. The stainless steel corrugated pipe is made of 304 stainless steel, with a wall thickness of 0.1mm, a corrugation pitch of 1.5mm, and a corrugation height of 0.5mm. The end of the faucet connector that contacts the bellows is made of 304 stainless steel, and the faucet connector and the water cooling plate are integrally formed. The solder used in step S1 consists of the following raw materials by weight percentage: Chromium 6.5g, Boron 2.8g, Silicon 4.2g, Iron 2.6g, Zinc 1.0g, Rare Earth Elements 0.1g, Aluminum 0.05g, Carbon 0.1g, Additives 15g, Nickel 67.6g; Rare earth elements are composed of lanthanum and cerium in a weight ratio of 1:2.5; The additives include solvent (deionized water), thickener (hydroxyethyl cellulose), rheology modifier (hydrogenated castor oil), and activator, in a weight ratio of 20:1:0.5:0.3; The activator is composed of zinc chloride and zirconium oxide in a weight ratio of 1:0.5; In step S1, the distance between the trough of the stainless steel corrugated pipe and the support strip is 0.1 mm; The support belt is a steel ring. When in use, the steel ring is divided into two parts and fitted onto the edge of the corrugated stainless steel pipe. S2. Push the pre-treated corrugated pipe into the water tap joint that is connected to the water cooling plate, so that the crest of the stainless steel corrugated pipe abuts against the inner wall of the water tap joint, and obtain the pre-treated stainless steel corrugated pipe assembly. In step S2, the assembly gap between the crest of the stainless steel bellows and the inner wall of the faucet connector is 0.05 mm. S3. Pre-treated stainless steel corrugated pipe assembly is vacuum brazed to obtain stainless steel corrugated pipe assembly. The brazing process in step S3 is as follows: Heat to 350℃ from room temperature and hold for 30 minutes, then heat to 850℃ and hold for 30 minutes, then heat to 950℃ and hold for 15 minutes, with a vacuum degree of 10. -3 Pa.

[0037] The difference between Examples 2-3 and Example 1 lies in the types and amounts of raw materials used, as well as the parameters. Specific differences are shown in Table 1. Table 1. Types, amounts, and parameters of raw materials used in the preparation.

[0038] In Example 2, the rare earth elements consist of lanthanum and cerium in a weight ratio of 1:3.5; The additives include solvent (deionized water), thickener (hydroxyethyl cellulose), rheology modifier (hydrogenated castor oil), and activator, in a weight ratio of 25:1.5:0.8:0.3; The activator is composed of zinc chloride and zirconium oxide in a weight ratio of 2:0.5.

[0039] In Example 3, the rare earth elements consist of lanthanum and cerium in a weight ratio of 1:4; The additives include solvent (deionized water), thickener (hydroxyethyl cellulose), rheology modifier (hydrogenated castor oil), and activator, in a weight ratio of 30:2:1:0.3; The activator is composed of zinc chloride and zirconium oxide in a weight ratio of 3:0.5.

[0040] Example 4 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that after step S3, step S4 is included: a stainless steel protective sleeve is fitted onto the outer wall of the faucet connector, and the stainless steel protective sleeve is connected to the faucet connector by spot welding or brazing.

[0041] Example 5 A manufacturing process for a stainless steel bellows assembly. The difference between this embodiment and Embodiment 1 is that the brazing filler used in step S1 is composed of the following raw materials by weight percentage: Chromium 7.5g, Boron 3.25g, Silicon 4.5g, Iron 2.8g, Zinc 2.5g, Rare Earth Elements 0.15g, Aluminum 0.1g, Carbon 0.3g, Additives 17g, Nickel 61.9g.

[0042] Example 6 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that the rare earth element is yttrium.

[0043] Example 7 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that the rare earth element is lanthanum.

[0044] Example 8 A manufacturing process for a stainless steel bellows assembly, the difference between this embodiment and Embodiment 1 is that chromium is replaced with copper.

[0045] Example 9 A manufacturing process for a stainless steel bellows assembly, the difference between this embodiment and Embodiment 1 is that boron is replaced with phosphorus.

[0046] Example 10 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that rare earth elements are omitted.

[0047] Example 11 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that the amount of silicon used is 1g.

[0048] Example 12 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that the amount of iron used is 1g.

[0049] Example 13 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that silver is used instead of zinc.

[0050] Example 14 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that, in step S2, the assembly gap between the crest of the stainless steel corrugated pipe and the inner wall of the faucet connector is 0.2 mm.

[0051] Comparative Example Comparative Example 1 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that a section of stainless steel corrugated pipe is selected, one end is straightened mechanically, a layer of brazing filler is applied, and it is placed inside the water nozzle connector that communicates with the water cooling plate. The remaining steps remain unchanged.

[0052] Comparative Example 2 A manufacturing process for a stainless steel corrugated pipe assembly. The difference between this embodiment and Embodiment 1 is that the support strip is not placed at the edge of the corrugated pipe trough in step S1.

[0053] Detection methods / test methods Bending times: Clamp the joint with a bench vise and perform bending tests by swinging it 90° to the left and right until the bellows breaks. Record the number of bending times. The bending speed is 1 second / bending. Tensile strength: Axial tension was applied. During clamping, the bellows end and the non-connected end of the faucet connector were fixed separately, ensuring the clamping position avoided the weld joint area to prevent damage to the connector from clamping force. The loading direction was consistent with the component axis to prevent eccentric force from distorting the test results. A uniform loading rate of 1 mm / min was used, continuously loading at a uniform rate until the connector broke or detached. The tensile strength was recorded. Corrosion resistance test: A salt solution with a concentration of 5%, pH 6.5, temperature of 35℃, and a spray rate of 2.0 ml / H was prepared. The welded area of ​​the stainless steel corrugated pipe assembly was tilted at a 45° angle to the salt spray outlet. After 96 hours, the substrate was removed every 8 hours and observed using a 10x magnifying glass. No corrosion or rust was observed. The experimental data are shown in Table 2. Table 2 Experimental data of Examples 1-14 and Comparative Examples 1-2

[0054] As can be seen from the above experimental data, this application eliminates the forced straightening process at the end of the corrugated pipe and directly utilizes the original crest and trough structure in conjunction with the support strip and brazing filler to achieve the connection, effectively solving the problems of wall thickness reduction, microcracks, work hardening and residual stress caused by cold deformation in the prior art.

[0055] As shown in Example 1 and Comparative Examples 1-2, the bending count, tensile strength, and corrosion resistance of Comparative Examples 1-2 are all reduced. This indicates that eliminating the forced straightening process at the end of the bellows can avoid wall thinning, microcracks, and work hardening caused by plastic deformation of the thin-walled base material, and eliminate the springback deformation caused by residual tensile stress at the high temperature of brazing. The support strip plays a key role in maintaining the corrugated structure, providing space for brazing filler, and preventing the loss of fine powder materials, which can improve tensile strength, bending count, and corrosion resistance. The synergistic effect of both ensures the assembly clearance, coaxiality, and tightness of the brazed joint between the bellows and the faucet connector, and improves the fatigue resistance, load-bearing strength, and corrosion resistance of the component.

[0056] As can be seen from Examples 1 and 5-13, by optimizing the composition and amount of brazing filler metal, it is beneficial to improve tensile strength, bending cycles and corrosion resistance, so that the bellows assembly can obtain high strength, high corrosion resistance and excellent fatigue resistance.

[0057] As can be seen from Examples 1 and 4, adding a stainless steel protective sleeve to the outer wall of the water tap connector and fixing it by spot welding or brazing can effectively absorb bending stress, protect the corrugated pipe trough and brazing edge, and extend the number of bends and the service life of the component.

[0058] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A manufacturing process for a stainless steel corrugated pipe assembly, characterized in that, The preparation steps include the following: S1. Select a section of stainless steel corrugated pipe, apply a layer of brazing material along the edge of the trough of the stainless steel corrugated pipe, then place the support strip at the edge of the trough of the stainless steel corrugated pipe and fill it with brazing material. The height of the brazing material is level with the crest of the stainless steel corrugated pipe to obtain a pre-treated corrugated pipe. S2. Push the pre-treated corrugated pipe into the water tap joint that is connected to the water cooling plate, so that the crest of the stainless steel corrugated pipe abuts against the inner wall of the water tap joint, and obtain the pre-treated stainless steel corrugated pipe assembly. S3. Pre-treated stainless steel corrugated pipe assemblies are vacuum brazed to obtain stainless steel corrugated pipe assemblies.

2. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 1, characterized in that, The solder used in step S1 consists of the following raw materials by weight percentage: Chromium 6.5-9.5%, boron 2.85-3.45%, silicon 4.2-4.8%, iron 2.6-3.4%, zinc 1.0-5.0%, rare earth elements 0.1-0.2%, aluminum 0.05-0.3%, carbon 0.1-0.8%, additives 15-20%, and the remainder is nickel.

3. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 2, characterized in that: The rare earth elements consist of lanthanum and cerium in a weight ratio of 1:2.5-4.

4. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 2, characterized in that: The additives include solvents, thickeners, rheology modifiers and activators, in a weight ratio of 20-30:1-2:0.5-1:0.

3.

5. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 2, characterized in that: The activator is composed of zinc chloride and zirconium oxide in a weight ratio of 1-3:0.

5.

6. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 2, characterized in that: The solder used in step S1 consists of the following raw materials by weight percentage: Chromium 7.5%, boron 3.25%, silicon 4.5%, iron 2.8%, zinc 2.5%, rare earth elements 0.15%, aluminum 0.1%, carbon 0.3%, with the remainder being nickel.

7. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 4, characterized in that: In step S1, the distance between the trough of the stainless steel corrugated pipe and the support strip is 0.1mm-0.5mm.

8. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 1, characterized in that: In step S2, the assembly gap between the crest of the stainless steel corrugated pipe and the inner wall of the faucet connector is 0.05mm-0.15mm.

9. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 1, characterized in that, The brazing process in step S3 is as follows: Heat to 350-550℃ from room temperature, hold for 30-50 minutes, then heat to 850-870℃, hold for 30-40 minutes, then heat to 950-1050℃, hold for 15-20 minutes, with a vacuum degree of 10. -3 -10 -5 Pa.

10. The manufacturing process of the stainless steel corrugated pipe assembly according to claim 1, characterized in that: After step S3, step S4 is also included: installing a stainless steel protective sleeve on the outer wall of the faucet connector, and connecting the stainless steel protective sleeve to the faucet connector by spot welding or brazing.

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