High-strength reducing metal tee joint and preparation process thereof

Abstract

The invention relates to the technical field of reducing metal, and provides a high-strength reducing metal tee joint which comprises a large-diameter main pipe and a small-diameter branch pipe, the large-diameter main pipe and the small-diameter branch pipe are made of high-performance alloy materials, the small-diameter branch pipe communicates with the waist portion of the large-diameter main pipe, and the reducing tee joint is formed through a special connecting structure; the special connecting structure comprises a transition section, the transition section covers the connecting position of the large-diameter main pipe and the small-diameter branch pipe, the inner wall of the transition section is tightly welded to the connecting position of the large-diameter main pipe and the small-diameter branch pipe in an attached mode, the outer wall of the transition section is gradually reduced from the waist portion of the large-diameter main pipe to the far end of the small-diameter branch pipe, and the outer wall of the transition section is a smooth curved surface. And the length of the transition section is 0.5-0.8 time of the pipe diameter of the large-diameter main pipe. The special structural design and the creative preparation process are combined, the comprehensive performance such as strength, sealing performance and corrosion resistance of the reducing tee joint is remarkably improved, and the reducing tee joint can stably and reliably operate in various severe environments.

Description

Technical Field

[0001] The present invention relates to the technical field of different-diameter metals, and particularly to a high-strength different-diameter metal tee and its manufacturing process. Background Art

[0002] In the modern industrial field, as an important pipe connector, different-diameter metal tees are widely used in many industries. However, traditional different-diameter metal tees often have some deficiencies in actual use.

[0003] The structural design of traditional different-diameter tees may not be reasonable enough. When connecting pipes with different diameters, it is easy to have poor sealing performance, resulting in medium leakage and affecting the normal operation of the system. Its connection structure may not be able to effectively disperse stress, making the overall strength of the tee limited and difficult to withstand high pressure and impact force, resulting in a short service life.

[0004] In terms of the manufacturing process, previous processes may have problems such as limited material selection, low processing accuracy, and unstable welding quality. The performance of the materials may not meet the requirements of some harsh working conditions, and corrosion and other problems are likely to occur in complex environments. Due to improper process control during processing, large dimensional deviations may occur, affecting installation and use. The welding process may have defects such as poor weld quality and a large heat-affected zone, affecting the connection strength and reliability of the tee.

[0005] With the continuous development and progress of industrial technology, the performance requirements for different-diameter metal tees are getting higher and higher, including higher strength, better sealing performance, stronger corrosion resistance, and more excellent fluid transportation efficiency, etc. In order to overcome the defects of the existing technology and meet the growing needs of modern industry, it is necessary to develop a high-strength different-diameter metal tee and its innovative manufacturing process to achieve a comprehensive improvement in the performance of the tee and adapt to various complex and demanding application scenarios. Summary of the Invention

[0006] To overcome the defects of the existing technology, the purpose of the present invention is to provide a high-strength different-diameter metal tee and its manufacturing process.

[0007] To achieve the above object, the technical solution of the present invention is realized as follows: A high-strength reduced-diameter metal tee, including a large-diameter main pipe and a small-diameter branch pipe. The materials of the large-diameter main pipe and the small-diameter branch pipe are high-performance alloy materials. The small-diameter branch pipe is connected to the waist of the large-diameter main pipe, and a reduced-diameter tee is formed through a special connection structure. The special connection structure includes a transition section. The transition section covers the connection of the large-diameter main pipe and the small-diameter branch pipe. Its inner wall is closely attached and welded to the connection of the large-diameter main pipe and the small-diameter branch pipe. Its outer wall shows a gradually decreasing trend from the waist of the large-diameter main pipe to the distal end of the small-diameter branch pipe. The outer wall of the transition section is a smooth curved surface, and the length of the transition section is 0.5 times to 0.8 times the diameter of the large-diameter main pipe. This special connection structure can effectively disperse stress and improve the overall strength of the tee.

[0008] Preferably, the inner diameter of the large-diameter main pipe is 50 mm to 80 mm, and the outer diameter is 60 mm to 90 mm; the inner diameter of the small-diameter branch pipe is 20 mm to 40 mm, and the outer diameter is 30 mm to 50 mm.

[0009] Preferably, the radius of curvature of the inner wall curved surface of the transition section is 100 mm to 150 mm.

[0010] Preferably, a preparation process for a high-strength reduced-diameter metal tee includes the following steps:

[0011] Material selection: Select a titanium alloy blank, and its chemical composition conforms to Ti-6Al-4V;

[0012] Pretreatment: Clean the surface of the titanium alloy blank to remove oil and impurities on the surface;

[0013] Forming of the large-diameter main pipe: Heat the pretreated titanium alloy blank to 950 °C, and use a hot extrusion process to extrude the blank into the preliminary shape of the large-diameter main pipe. The extrusion speed is 20 mm / s;

[0014] Forming of the small-diameter branch pipe: Use the same process as the forming of the large-diameter main pipe to extrude another part of the titanium alloy blank into the preliminary shape of the small-diameter branch pipe, but its heating temperature is 900 °C, and the extrusion speed is 15 mm / s to meet the size and performance requirements of the small-diameter branch pipe;

[0015] Machining: Use numerical control machining equipment to further machine the large-diameter main pipe and the small-diameter branch pipe to make their sizes and precisions meet the design requirements. During the machining process, coolant is used for cooling, and the temperature of the coolant is 20 °C;

[0016] Connection preparation: Grind the connection part of the waist of the large-diameter main pipe and the small-diameter branch pipe to remove the surface oxide layer, and then clean it with acetone to improve the surface quality of the connection part;

[0017] Transition section manufacturing: Use the same material as the large-diameter main pipe and the small-diameter branch pipe to manufacture the transition section, making its inner wall shape match the shape of the connection between the large-diameter main pipe and the small-diameter branch pipe, and the inner wall can be closely fitted and welded to the connection;

[0018] Connection: Place the transition section at the connection of the large-diameter main pipe and the small-diameter branch pipe, and use electron beam welding technology for welding. The acceleration voltage during welding is 60 kV, the electron beam current is 20 mA, the welding speed is 10 mm / s, and argon is used for protection during the welding process to prevent the weld from oxidizing;

[0019] Reinforcement treatment: After welding is completed, perform ultrasonic impact treatment on the weld and the surrounding area. The ultrasonic impact frequency is 20 kHz, and the impact time is 15 minutes. Further refine the grains through ultrasonic impact to enhance the strength of the connection part;

[0020] Heat treatment: Perform heat treatment on the welded reducing metal tee. Heat it to 600 °C, hold for 2 hours, and then cool it to room temperature at a rate of 8 °C / min to eliminate welding residual stress and improve the strength and stability of the tee;

[0021] Surface treatment: Perform sandblasting on the surface of the reducing metal tee. The particle size of the sand used for sandblasting is 80 mesh, and the sandblasting pressure is 0.5 MPa to improve the surface roughness and corrosion resistance;

[0022] Post-treatment: Perform low-temperature aging treatment on the reducing metal tee after surface treatment. Place it in an environment of -50 °C for 3 hours to further improve the structural strength and stability.

[0023] Preferably, in the hot extrusion process, the preheating temperature of the extrusion die is 300 °C.

[0024] Preferably, in the electron beam welding technology, the welding part needs to be preheated before welding, and the preheating temperature is 200 °C.

[0025] Preferably, during the heat treatment process, the heating rate of the heating equipment is 5 °C / min.

[0026] Preferably, after the surface treatment, the reducing metal tee is pickled. The pickling solution is a 10% nitric acid solution, and the pickling time is 15 minutes.

[0027] Preferably, after the pickling treatment, the reducing metal tee is passivated. The passivation solution is a 5% potassium dichromate solution, and the passivation time is 10 minutes.

[0028] The beneficial effects of the present invention are reflected in:

[0029] In terms of structure, the setting of the special connection structure, including the transition section and its unique design, enables the tee to not only achieve a tight fit during welding when connecting the large-diameter main pipe and the small-diameter branch pipe, effectively preventing medium leakage and ensuring good sealing performance, but also the smooth curved surface design on its outer wall can significantly reduce fluid resistance and improve fluid transportation efficiency. At the same time, the length design of the transition section and the range of the curvature radius of the inner wall curved surface can effectively disperse stress, greatly enhancing the overall strength of the tee, enabling it to withstand high pressure and impact force, and extending its service life.

[0030] In the preparation process, titanium alloy blanks with high strength, low density, and good corrosion resistance are selected as materials, laying a foundation for the manufacture of high-performance tees. The pretreatment steps ensure the stability of subsequent processing and product quality. In the forming processes of the large-diameter main pipe and the small-diameter branch pipe, by precisely controlling the heating temperature and extrusion speed, the forming effect is ideal, meeting different size and performance requirements. The use of coolant during the machining process effectively reduces heat and improves machining accuracy. The connection preparation steps enhance the surface quality of the welding part and ensure reliable welding quality. The application of electron beam welding technology ensures connection strength and sealing performance, and the innovative strengthening treatment further refines grains, eliminates residual stress, and enhances the strength of the connection part. Heat treatment effectively eliminates welding residual stress, improves the material microstructure, and enhances the strength and toughness of the tee. The surface treatment steps improve surface roughness and corrosion resistance, and the subsequent low-temperature aging treatment further eliminates residual stress and improves dimensional stability and mechanical properties.

[0031] In summary, by combining the special structural design with the creative preparation process, the present invention significantly improves the comprehensive performance of the reducing tee, such as strength, sealing performance, and corrosion resistance, enabling it to operate stably and reliably in various harsh environments, having broad application prospects and important practical values, and providing strong technical support for the development of related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the drawings:

[0033] Figure 1 is a structural schematic diagram of the reducing metal tee of the present invention;

[0034] Figure 2 is a transverse semi-sectional structural schematic diagram of the reducing metal tee of the present invention;

[0035] Figure 3 is a process flow chart of the preparation process of the present invention;

[0036] Description of the reference numerals:

[0037] 1. Large-diameter main pipe; 2. Small-diameter branch pipe; 3. Special connection structure. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all of the embodiments. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Based on the embodiments of the invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the invention.

[0039] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the invention, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain specific posture (as shown in the accompanying drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0040] In addition, "a plurality of" means two or more. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the invention.

[0041] Please refer to the attached drawings of the specification Figures 1-3 , the present invention provides a high-strength reducing metal tee and its manufacturing process, and the specific content is as follows:

[0042] I. High-strength reducing metal tee

[0043] The high-strength reducing metal tee includes a large-diameter main pipe 1 and a small-diameter branch pipe 2, and the materials of the large-diameter main pipe 1 and the small-diameter branch pipe 2 are high-performance alloy materials. This high-performance alloy material has excellent strength and corrosion resistance, which can ensure the long-term stable operation of the tee in various harsh environments. The small-diameter branch pipe 2 is connected to the waist of the large-diameter main pipe 1, and a reducing tee is formed through a special connection structure 3.

[0044] The special connection structure 3 includes a transition section, and the transition section covers the connection between the large-diameter main pipe 1 and the small-diameter branch pipe 2. Its inner wall is closely welded to the connection between the large-diameter main pipe 1 and the small-diameter branch pipe 2, which can effectively prevent medium leakage and ensure the sealing performance of the tee. Its outer wall shows a gradually decreasing trend from the waist of the large-diameter main pipe 1 to the distal end of the small-diameter branch pipe 2, and the outer wall of the transition section is a smooth curved surface. This design can reduce the resistance of the fluid flowing inside the tee and improve the fluid transportation efficiency. And the length of the transition section is 0.5 times to 0.8 times the diameter of the large-diameter main pipe 1. The special connection structure 3 can effectively disperse stress, improve the overall strength of the tee, enable it to withstand higher pressure and impact force, and extend the service life of the tee.

[0045] Among them, the inner diameter of the large-diameter main pipe 1 is 50 mm to 80 mm, and the outer diameter is 60 mm to 90 mm; the inner diameter of the small-diameter branch pipe 2 is 20 mm to 40 mm, and the outer diameter is 30 mm to 50 mm. The radius of curvature of the inner wall surface of the transition section is 100 mm to 150 mm.

[0046] II. Preparation Process of High-Strength Reducing Metal Tee

[0047] Material Selection: Select a titanium alloy blank, and its chemical composition conforms to Ti-6Al-4V. This titanium alloy material has high strength, low density and good corrosion resistance, and is an ideal material for manufacturing high-performance tees.

[0048] Pretreatment: Clean the surface of the titanium alloy blank to remove the oil and impurities on the surface to ensure the smooth progress of the subsequent processing and the stability of the product quality.

[0049] Forming of the Large-Diameter Main Pipe 1: Heat the pretreated titanium alloy blank to 950 °C, and use the hot extrusion process to extrude the blank into the preliminary shape of the large-diameter main pipe 1, with an extrusion speed of 20 mm / s. In the hot extrusion process, the preheating temperature of the extrusion die is 300 °C, which can reduce the temperature difference between the blank and the die, reduce the thermal stress, and improve the forming quality.

[0050] Forming of the Small-Diameter Branch Pipe 2: Use the same process as the forming of the large-diameter main pipe 1 to extrude another part of the titanium alloy blank into the preliminary shape of the small-diameter branch pipe 2, but its heating temperature is 900 °C and the extrusion speed is 15 mm / s to meet the dimensional and performance requirements of the small-diameter branch pipe 2. By adjusting the heating temperature and extrusion speed, the organizational structure and performance of the branch pipe can be controlled to meet different usage requirements.

[0051] Machining: Use numerical control machining equipment to further process the large-diameter main pipe 1 and the small-diameter branch pipe 2 to make them reach the dimensions and accuracies required by the design. During the machining process, a coolant is used for cooling, and the temperature of the coolant is 20 °C, which can effectively reduce the heat during the machining process, reduce the thermal deformation, and improve the machining accuracy.

[0052] Connection Preparation: Grind the waist of the large-diameter main pipe 1 and the connection part of the small-diameter branch pipe 2 to remove the surface oxide layer, and then clean it with acetone to improve the surface quality of the connection part and ensure the reliability of the welding quality.

[0053] Manufacture of the Transition Section: Use the same material as the large-diameter main pipe 1 and the small-diameter branch pipe 2 to manufacture the transition section, so that the inner wall shape matches the shape at the connection of the large-diameter main pipe 1 and the small-diameter branch pipe 2, and the inner wall can be closely welded to the connection part. The design and manufacture of the transition section are the key links to ensure the strength and sealing performance of the tee.

[0054] Connection: Place the transition section at the connection between the large-diameter main pipe 1 and the small-diameter branch pipe 2, and use electron beam welding technology for welding. Before welding, the welding area needs to be preheated, and the preheating temperature is 200°C. The acceleration voltage during welding is 60 kV, the electron beam current is 20 mA, and the welding speed is 10 mm / s. Argon is used for protection during the welding process to prevent the weld from oxidizing. Electron beam welding technology has the advantages of fast welding speed, high weld quality, and small heat-affected zone, which can effectively improve the connection strength and sealing performance of the tee.

[0055] Innovative strengthening treatment: After welding, perform ultrasonic impact treatment on the weld and its surrounding area. The ultrasonic impact frequency is 20 kHz, and the impact time is 15 minutes. Further refine the grains through ultrasonic impact, eliminate the welding residual stress, enhance the strength of the connection part, and improve the overall performance of the tee.

[0056] Heat treatment: Perform heat treatment on the welded reducing metal tee. Heat it to 600°C, hold for 2 hours, and then cool it to room temperature at a rate of 8°C / min. Heat treatment can eliminate the welding residual stress, improve the microstructure of the material, and enhance the strength and toughness of the tee. During the heat treatment process, the heating rate of the heating equipment is 5°C / min to ensure uniform temperature rise and avoid generating thermal stress.

[0057] Surface treatment: Perform sandblasting on the surface of the reducing metal tee. The particle size of the sand used for sandblasting is 80 mesh, and the sandblasting pressure is 0.5 MPa to increase the surface roughness and corrosion resistance. After surface treatment, perform pickling on the reducing metal tee. The pickling solution is 10% nitric acid solution, and the pickling time is 15 minutes to remove the surface oxide layer and impurities. After pickling treatment, perform passivation on the reducing metal tee. The passivation solution is 5% potassium dichromate solution, and the passivation time is 10 minutes to form a dense oxide film and improve the corrosion resistance of the tee.

[0058] Post-treatment: Perform low-temperature aging treatment on the reducing metal tee after surface treatment. Place it in an environment of -50°C for 3 hours. Low-temperature aging treatment can further eliminate the residual stress, improve the dimensional stability and mechanical properties of the tee, and further enhance the structural strength and stability.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0060] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0061] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-strength reducing metal tee, characterized in that: The invention comprises a large-diameter main pipe (1) and a small-diameter branch pipe (2), wherein the large-diameter main pipe (1) and the small-diameter branch pipe (2) are made of high-performance alloy material, and the small-diameter branch pipe (2) is connected to the waist of the large-diameter main pipe (1), and a reducing tee is formed through a special connection structure (3); the special connection structure (3) comprises a transition section, and the transition section covers the connection between the large-diameter main pipe (1) and the small-diameter branch pipe (2), and the inner wall of the transition section is tightly welded to the connection between the large-diameter main pipe (1) and the small-diameter branch pipe (2), and the outer wall thereof shows a trend of gradually decreasing from the waist of the large-diameter main pipe (1) to the distal end of the small-diameter branch pipe (2), and the outer wall of the transition section is a smooth curved surface, and the length of the transition section is 0.5 to 0.8 times the diameter of the large-diameter main pipe (1); the special connection structure (3) can effectively disperse stress and improve the overall strength of the tee.

2. A high-strength reducing metal tee according to claim 1, characterized in that: The inner diameter of the large-diameter main pipe (1) is 50 mm to 80 mm, and the outer diameter is 60 mm to 90 mm; the inner diameter of the small-diameter branch pipe (2) is 20 mm to 40 mm, and the outer diameter is 30 mm to 50 mm.

3. The high-strength reducing metal tee according to claim 1, characterized in that: The curvature radius of the inner wall curved surface of the transition section is 100 mm to 150 mm.

4. A preparation process for a high-strength reducing metal tee, characterized in that: The following steps are involved: Material selection: Select titanium alloy billet, whose chemical composition conforms to Ti-6Al-4V; Pretreatment: Clean the surface of the titanium alloy billet to remove oil and impurities on the surface; Forming of the large diameter main pipe (1): heating the pretreated titanium alloy billet to 950° C. and extruding the billet into a preliminary shape of the large diameter main pipe (1) by a hot extrusion process at an extrusion speed of 20 mm / s; Forming of the small-diameter branch pipe (2): using the same process as the forming of the large-diameter main pipe (1), another part of the titanium alloy billet is extruded into the preliminary shape of the small-diameter branch pipe (2), but the heating temperature is 900° C. and the extrusion speed is 15 mm / s to meet the size and performance requirements of the small-diameter branch pipe (2); Machining: CNC machining equipment is used to further process the large diameter main pipe (1) and the small diameter branch pipe (2) to achieve the size and accuracy required by the design. During the machining process, coolant is used for cooling, and the temperature of the coolant is 20° C.; Connection preparation: grinding the waist of the large diameter main pipe (1) and the connection part of the small diameter branch pipe (2) to remove the surface oxide layer, and then cleaning with acetone to improve the surface quality of the connection part; Fabrication of the transition section: the same material as that of the large-diameter main pipe (1) and the small-diameter branch pipe (2) is used to fabricate the transition section, so that the shape of its inner wall matches the shape of the connection between the large-diameter main pipe (1) and the small-diameter branch pipe (2), and the inner wall can be welded tightly to the connection; Connection: The transition section is placed at the connection between the large diameter main pipe (1) and the small diameter branch pipe (2), and the electron beam welding technology is used for welding. The acceleration voltage during welding is 60 kV, the electron beam current is 20 mA, and the welding speed is 10 mm / s. Argon gas is used for protection during the welding process to prevent the weld from oxidation; Strengthening treatment: After welding, the weld and surrounding areas are subjected to ultrasonic impact treatment. The ultrasonic impact frequency is 20kHz and the impact time is 15 minutes. The ultrasonic impact is used to further refine the grains and enhance the strength of the connection. Heat treatment: Heat the welded reducing metal tee to 600°C, keep it warm for 2 hours, and then cool it to room temperature at a rate of 8°C / min to eliminate welding residual stress and improve the strength and stability of the tee. Surface treatment: The surface of the reducing metal tee is sandblasted with a particle size of 80 mesh and a sandblasting pressure of 0.5 MPa to improve the surface roughness and corrosion resistance; Post-treatment: The surface treated reducing metal tees are subjected to low-temperature aging treatment and placed in a minus 50°C environment for 3 hours to further improve the structural strength and stability.

5. The process for preparing a high-strength reducing metal tee according to claim 1, characterized in that: In the hot extrusion process, the preheating temperature of the extrusion die is 300°C.

6. The process for preparing a high-strength reducing metal tee according to claim 1, characterized in that: In the electron beam welding technology, the welding part needs to be preheated before welding, and the preheating temperature is 200°C.

7. The process for preparing a high-strength reducing metal tee according to claim 1, characterized in that: During the heat treatment process, the heating rate of the heating equipment is 5°C / min.

8. The process for preparing a high-strength reducing metal tee according to claim 1, characterized in that: After the surface treatment, the reducing metal tee is pickled with a 10% nitric acid solution for 15 minutes.

9. The process for preparing a high-strength reducing metal tee according to claim 1, characterized in that: After the pickling treatment, the different-diameter metal tee is passivated, the passivation solution is 5% potassium dichromate solution, and the passivation time is 10 minutes.

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