Semi-solid closed precision extrusion-forging composite forming process for screw complex parts

Abstract

The application discloses a semi-solid closed precision extrusion-forging composite forming process of screw complex parts, and relates to the forming technical field of screw complex parts. 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 100 mm at room temperature, then carries out semi-solid isothermal treatment on the obtained stepped shaft radial forged bar to prepare a "stepped long shaft" semi-solid spherulitic material, and finally places the prepared "stepped long shaft" semi-solid spherulitic material in a lower die cavity, controls the mutual closing extrusion of the upper and lower dies, and then jointly forges left and right push rods, so that the semi-solid closed extrusion-forging composite forming of the screw complex parts can be realized. The application can prepare the screw complex parts with semi-solid spherulitic structure and forged deformation structure, and 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 components, and in particular to a semi-solid closed-loop precision extrusion forging composite forming process for complex screw components. 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 precision extrusion forging composite forming process for screw-type complex parts. This process enables the fabrication of high-performance screw-type complex parts that simultaneously possess both semi-solid spherulitic structures and forged deformation structures.

[0005] To achieve the above objectives, embodiments of this application provide a semi-solid closed-loop precision extrusion forging composite forming process for complex screw-type parts, including the following steps: S1, Radial forging strain-induced preparation of "stepped long axis" semi-solid spherulite material: S11, Prepare a 304 stainless steel bar with a length of 600 mm and a diameter of 100 mm; S12, Radial forge the 304 stainless steel bar to obtain a stepped axis radial forged bar with diameters of 45 mm at both ends and 50 mm in the middle; S13, Perform a semi-solid isothermal treatment on the stepped axis radial forged bar at 1420℃ for 10 min to obtain a "stepped long axis" semi-solid spherulite material with a grain size of 30-50 μm; S2, Semi-solid closed-loop extrusion forging composite forming: S21, Form the "stepped long axis" semi-solid spherulite material obtained in step S1 into a semi-solid spherulite material... S22. The crystalline material is placed into the lower mold cavity inside the lower mold; S23. The upper mold is controlled to descend at a speed of 10 mm / s and then come into close contact with the lower mold, completing the "radial extrusion" of the "stepped long axis" semi-solid spherulite material, forming a sealed upper and lower mold composite cavity, and obtaining a screw-like blank with an internal grain size of 30-50 μm and a near-spherical grain shape; S24. The left and right extrusion rods are controlled to perform semi-solid or solid "axial forging" on the screw-like blank at a speed of 10 mm / s, forcing the screw-like blank to undergo plastic deformation flow and completely fill the upper and lower mold composite cavity after being forged by the left and right extrusion rods in the upper and lower mold composite cavity, finally obtaining a screw-like complex part with a screw root diameter of 45 mm that simultaneously possesses a semi-solid spherulite structure and a forged deformation structure.

[0006] This application has the following advantages over the prior art:

[0007] 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 pollution-free. At the same time, this method can efficiently prepare "stepped long axis" semi-solid spherulite materials of different sizes.

[0008] 2. The "stepped 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.

[0009] 3. The embodiments of this application can not only realize the near-net-shape forming of screw by "extrusion forging" composite, which significantly improves the material utilization rate, but also have the advantages of high material density of formed parts, mechanical properties that are superior to those of traditional semi-solid formed parts, and the ability to further improve the performance of parts through heat treatment. Attached Figure Description

[0010] 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.

[0011] Figure 1 This is a process flow diagram of an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of the structure of the lower mold in the embodiment of this application;

[0013] 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

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] Reference Figure 1 The embodiments of this application provide a semi-solid closed-loop precision extrusion forging composite forming process for complex screw-type parts, including the following steps:

[0019] S1. Preparation of "stepped long axis" semi-solid spherulite material induced by radial forging strain:

[0020] S11. Prepare 304 stainless steel bars with a length of 600mm and a diameter of 100mm.

[0021] S12. The 304 stainless steel bar 11 is radially forged to obtain a stepped axial radial forged bar 12 with a diameter of 45 mm at both ends and a diameter of 50 mm in the middle.

[0022] S13. The stepped axial radial forged bar stock 12 is subjected to a semi-solid isothermal treatment at 1420℃ for 10 min to obtain a "stepped long axis" semi-solid spherulite material 13 with a grain size of 30-50μm.

[0023] S2, Semi-solid closed-loop extrusion forging composite forming. It should be noted that this step is completed based on the 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 rods 23 and 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.

[0024] S21. Place the “stepped long axis” semi-solid spherulite material 13 obtained in step S1 into the lower mold cavity inside the lower mold.

[0025] S22. After the upper mold 22 descends at a speed of 10 mm / s, it comes into close contact with the lower mold 21, completing the radial extrusion of the "stepped long axis" semi-solid spherulite material 13, forming a sealed upper and lower mold composite cavity 25, and obtaining a screw-like blank 26 with an internal grain size of 30-50 μm and a near-spherical grain shape.

[0026] S23. Control the left extrusion rod 23 and the right extrusion rod 24 to perform semi-solid or solid "axial forging" on the screw-like blank 26 at a speed of 10 mm / s. This forces the screw-like blank 26 to be forged by the left extrusion rod 23 and the right extrusion rod 24 in the upper and lower die composite cavity 25, resulting in plastic deformation flow of the material and complete filling of the upper and lower die composite cavity 25. Finally, a screw-like complex part 27 with a screw root diameter of 45 mm is obtained, which simultaneously possesses a semi-solid spherulitic structure and a forged deformation structure.

[0027] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes 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 precision extrusion-forging combined forming process for screw-like complex parts, characterized in that, The method comprises the following steps: S1, preparing a "ladder long axis" semi-solid spherulitic material by radial forging strain induction; S11, preparing a 304 stainless steel bar with a length of 600 mm and a diameter of 100 mm; S12, performing radial forging on the 304 stainless steel bar to obtain a ladder shaft type radial forged bar with a diameter of 45 mm at both ends and a diameter of 50 mm in the middle; S13, performing semi-solid isothermal treatment on the ladder shaft type radial forged bar at 1420 DEG C for 10 min to obtain a "ladder long axis" semi-solid spherulitic material with a grain size of 30-50 μm; S2, semi-solid closed extrusion and forging composite forming; S21, placing the "ladder long axis" semi-solid spherulitic material obtained in step S1 into a lower die cavity in a lower die; S22, controlling an upper die to tightly contact with the lower die after descending at a speed of 10 mm / s, completing "radial extrusion" on the "ladder long axis" semi-solid spherulitic material, forming a sealed upper and lower die composite cavity, and obtaining a screw type blank with an internal grain size of 30-50 μm and a nearly spherical grain shape; S23, controlling left and right extrusion rods to perform semi-solid or solid "axial forging" on the screw type blank at a speed of 10 mm / s, forcing the screw type blank to be forged by the left and right extrusion rods in the upper and lower die composite cavity, causing material plastic deformation flow and completely filling the upper and lower die composite cavity, and finally obtaining a screw type complex part with a screw root diameter of 45 mm, which simultaneously has semi-solid spherulitic structure and forged deformation structure.

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