Screw complex semi-solid closed extrusion forming process

Abstract

The application discloses a screw complex semi-solid closed extrusion forming process and relates to the technical field of screw complex forming. The application first carries out cold radial forging plastic deformation on 304 stainless steel bars with a length of 600 mm and a diameter of 90 mm at room temperature, then carries out semi-solid isothermal treatment on the obtained radial forged bars to prepare "long shaft" semi-solid spherulitic materials, finally places the prepared "long shaft" semi-solid spherulitic materials in a lower die cavity, controls the mutual closing of an upper die and the lower die, then extrudes together through left and right push rods, and thus the radial forging strain induced semi-solid closed extrusion forming of the screw complex can be realized. Through the application, the screw complex with fine near-spherical microstructure can be prepared, and the application has the characteristics of simple process, small forming force, high material utilization rate, high product compactness and good mechanical properties.

Description

Technical Field

[0001] This application relates to the field of manufacturing technology for complex screw parts, and in particular to a semi-solid closed extrusion forming process for complex screw parts. Background Technology

[0002] Basic mechanical components are an indispensable part of the equipment manufacturing industry, directly determining the performance, quality, and reliability of major equipment and main products, and are key to the transformation of my country's equipment manufacturing industry. With the development of modern industrial technology, screw-type machinery such as screw pumps, screw compressors, screw vacuum pumps, and screw extruders are widely used in many fields such as aerospace, rail transportation, marine engineering, petrochemicals, and new energy vehicles. It is evident that my country has a huge demand for basic components such as screw-type machinery.

[0003] As a key core component of screw-type machinery, the screw's processing method, manufacturing precision, and quality have a significant impact on the overall performance of the machinery. Currently, the main production method for complex screw-type parts involves using expensive, high-controllability specialized equipment to perform multiple milling or grinding operations on the bar stock. This method offers advantages such as integrated manufacturing and a short process flow. However, over 60% of the material is wasted during milling, resulting in low material utilization. Furthermore, milling cuts through the metal fiber structure, leading to reduced mechanical properties and a lengthy production cycle, thus significantly limiting the improvement of product performance and production efficiency for complex screw-type parts. Summary of the Invention

[0004] To address the aforementioned technical problems, embodiments of this application provide a semi-solid closed-loop extrusion forming process for screw-type complex parts, which enables the preparation of screw-type complex parts with non-dendritic, fine, and uniform spherulitic structures.

[0005] To achieve the above objectives, embodiments of this application provide a semi-solid closed extrusion forming process for complex screw-type parts, including the following steps: S1, radial forging strain induced semi-solid material preparation: S11, preparing 304 stainless steel bars with a length of 600mm and a diameter of 90mm;

[0006] S12. The 304 stainless steel bar is radially forged to obtain a radially forged bar with a diameter of 45 mm; S13. The radially forged bar is subjected to a semi-solid isothermal treatment at 1420℃ for 10 min to obtain a "long-axis" semi-solid spherulite material with a grain size of 30-50 μm.

[0007] S2, Semi-solid closed extrusion molding: S21, The "long-axis" semi-solid spherulite material obtained in step S1 is placed into the lower mold cavity inside the lower mold; S22, The upper mold is controlled to descend at a speed of 10 mm / s and then contact the lower mold, completing the "radial mold closing" of the upper and lower molds to form a sealed upper and lower mold composite cavity; S23, The left extrusion rod and the right extrusion rod are controlled to perform "axial extrusion" on the "long-axis" semi-solid spherulite material in the upper and lower mold composite cavity at a speed of 10 mm / s, forcing the "long-axis" semi-solid spherulite material to fill and solidify in the upper and lower mold composite cavity, thereby forming the required screw-like complex part with a screw root diameter of 45 mm.

[0008] This application has the following advantages over the prior art:

[0009] 1. The radial forging strain induced semi-solid material preparation process in this application embodiment does not involve oxidation and the introduction of impurity phases caused by high-temperature overheating liquid during the preparation of other semi-solid slurries. The prepared semi-solid material is pure and free of pollution. At the same time, this method can efficiently prepare "long-axis" semi-solid spherulite materials of different sizes.

[0010] 2. The "long shaft" semi-solid material prepared in the embodiments of this application can be directly placed into the mold cavity for screw forming. Compared with traditional cutting processing, it can shorten the process flow, save production costs, and improve production efficiency.

[0011] 3. The embodiments of this application can not only achieve near-net-shape forming of screws and significantly improve material utilization, but also have the advantages of high material density of formed parts, mechanical properties comparable to forgings, and further improved part performance through heat treatment. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a process flow diagram of an embodiment of this application;

[0014] Figure 2 This is a schematic diagram of the structure of the lower mold in the embodiment of this application;

[0015] Figure 3 This is a schematic diagram of the structure of a complex screw-like component manufactured according to an embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0019] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] Reference Figure 1 The embodiments of this application provide a semi-solid closed-loop extrusion forming process for complex screw-type parts, including the following steps:

[0021] S1. Preparation of semi-solid materials induced by radial forging strain:

[0022] S11. Prepare 304 stainless steel bars 11 with a length of 600mm and a diameter of 90mm.

[0023] S12. Radial forging is performed on the 304 stainless steel bar 11 to obtain a radially forged bar 12 with a diameter of 45mm.

[0024] S13. The radial forged bar stock 12 is subjected to a semi-solid isothermal treatment at 1420℃ for 10 min to obtain a semi-solid spherulite material 13 with a grain size of 30-50 μm.

[0025] S2, Semi-solid closed-circuit extrusion molding. It should be noted that this step is performed using a mold. (Refer to...) Figures 1 to 3 The mold includes a lower mold 21, an upper mold 22, a right extrusion rod 23, and a right extrusion rod 24. The right extrusion rods 23 and 24 are both located between the lower mold 21 and the upper mold 22. The lower mold 21, the upper mold 22, the right extrusion rod 23, and the right extrusion rod 24 together form a composite mold cavity 25. The shape of the composite mold cavity 25 is adapted to the shape of the screw-like complex part 26 with a screw root diameter of 45mm to be prepared.

[0026] S21. Place the “long-axis” semi-solid spherulite material 13 obtained in step S1 into the lower mold cavity 211 inside the lower mold 21.

[0027] S22. After the upper mold 22 descends at a speed of 10mm / s, it contacts the lower mold 21, completing the "radial mold closing" of the upper mold 22 and the lower mold 21, forming a sealed upper and lower mold composite cavity 25.

[0028] S23, control the right extrusion rod 23 and the right extrusion rod 24 to perform "axial extrusion" on the "long axis" semi-solid spherulite material 13 in the upper and lower mold composite cavity 25 at a speed of 10 mm / s, so as to force the "long axis" semi-solid spherulite material 13 to fill and solidify in the upper and lower mold composite cavity 25, thereby forming the screw-like complex part 26 with a screw root diameter of 45 mm.

[0029] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A semi-solid closed-loop extrusion forming process for complex screw-type parts, characterized in that, Includes the following steps: S1. Preparation of semi-solid materials induced by radial forging strain: S11. Prepare 304 stainless steel bars with a length of 600mm and a diameter of 90mm; S12. The 304 stainless steel bar is radially forged to obtain a radially forged bar with a diameter of 45mm. S13. The radial forged bar is subjected to a semi-solid isothermal treatment at 1420℃ for 10 min to obtain a "long-axis" semi-solid spherulite material with a grain size of 30-50 μm. S2, Semi-solid closed extrusion molding: S21. Place the "long-axis" semi-solid spherulite material obtained in step S1 into the lower mold cavity inside the lower mold. S22. After the upper mold descends at a speed of 10mm / s, it contacts the lower mold, completing the "radial mold closing" of the upper and lower molds and forming a sealed upper and lower mold composite cavity; S23. Control the left and right extrusion rods to perform "axial extrusion" on the "long-axis" semi-solid spherulite material in the upper and lower mold composite cavity at a speed of 10 mm / s, forcing the "long-axis" semi-solid spherulite material to fill and solidify in the upper and lower mold composite cavity, thereby forming the required screw-type complex part with a screw root diameter of 45 mm.

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