Rolling forming method of C-shaped step section ring piece
By combining the core rollers and specific heat treatment processes, the serious wear of core rollers during the rolling process of large C-step cross-section rings is solved, and efficient and uniform forming and wear resistance are achieved, and production efficiency and service life of the rings are improved.
Patent Information
- Application Number
- CN202311839996.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2025-07-01
AI Technical Summary
In the rolling process of the large C-shaped step cross-section rings in the prior art, the core rollers are seriously worn, resulting in waste of mold materials and prolonged production cycle, and problems such as meat shortage and folding are prone to occur during forming.
The combined core roller is adopted, consisting of the core roller shaft and the combined groove, connected by a dovetail groove, and combined with a specific heat treatment process and blank heating method to achieve uniform forming and efficient production of the ring parts.
By replacing the combined groove instead of the entire core roller, the mold material is saved, the processing cycle is shortened, the production efficiency is improved, the uniformity and wear resistance of the ring parts are ensured, and the service life is extended.
Smart Images
Figure HDA0004638548690000011 
Figure HDA0004638548690000012
Abstract
Description
Technical Field
[0001] The present invention relates to a forming method, and particularly to a rolling forming method for a C-shaped stepped cross-section ring part. Background Art
[0002] A C-shaped stepped cross-section ring part is a special-shaped cross-section ring part with a boss on the inner diameter surface of the ring part, and is generally used as a bearing ring in fields such as wind power generation. Since such ring parts are in a high-load rotating environment for a long time, they must have strong wear resistance and good mechanical properties, so they are generally rolled by a ring rolling mill.
[0003] Large C-shaped stepped cross-section ring parts belong to inner convex special-shaped ring parts, with large outer diameter dimensions, large wall thickness, and large rolling deformation amount. However, the difference between the maximum wall thickness and the minimum wall thickness is not large, and generally a rectangular blank is directly used for forming. However, when a rectangular blank is formed into a C-shaped stepped cross-section ring part, a mutation will occur at the C-shaped step. At this point, the contact between the ring blank and the core roll is point / line contact, which causes great wear on the core roll. Therefore, the core roll needs to be frequently replaced, resulting in serious waste of die materials, and the core roll needs to be remade, which prolongs the production cycle and is not conducive to mass production. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a combined core roll to realize the rolling forming method for large C-shaped stepped cross-section ring parts.
[0005] To solve the above technical problem, the present invention provides a core roll and a rolling forming method for a large C-shaped stepped cross-section ring part, and its technical solution is as follows:
[0006] The core roll is characterized by comprising a core roll shaft and a combined groove.
[0007] Further, the core roll shaft and the combined groove are connected by a dovetail groove.
[0008] The rolling forming method for the large C-shaped stepped cross-section ring part comprises the following steps:
[0009] (1) Combine the core roll shaft and the combined groove into a core roll along the dovetail groove, and install it on the ring rolling mill. Adjust the parameters of the ring rolling mill and set it aside for use.
[0010] (2) Cut a cylindrical blank into a blank section with a length of L = (2 - 5)[B + (0.03 - 0.05)B s , where B is the height of the large C-shaped stepped cross-section ring part, and B s is the height of the C-shaped step. The diameter of the blank can be determined according to the condition that the volume of the large C-shaped stepped cross-section ring part is equal to the volume of the blank.
[0011] (3) Austenitize the blank by heating it to 1100 - 1150 °C, and upset and punch it within the temperature range of 850 °C - 1130 °C. Then load it into the ring rolling mill described in step (1) for rolling forming.
[0012] (4) The forged large C-shaped stepped cross-section ring is heat-treated by normalizing + tempering. First, heat the large C-shaped stepped cross-section ring to 780 - 800 °C and hold for 80 - 100 minutes, then raise the temperature to 930 - 950 °C and hold for 100 - 120 minutes, and air cool to room temperature; then heat the large C-shaped stepped cross-section ring to 240 - 280 °C and hold for 480 - 540 minutes, and air cool to room temperature.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0014] The rolling forming method of the C-shaped stepped cross-section ring described in the present invention involves a core roll, which is composed of a general core roll shaft and a special combined groove. During the rolling process, when the combined groove is severely worn due to point / line contact with the blank and needs to be replaced, or when the shape and size of the C-shaped step of the ring change and the core roll needs to be replaced, the entire core roll can be replaced by only replacing the combined groove, which saves a large amount of die materials and machining time, shortens the processing cycle, and improves production efficiency.
[0015] Adopt a cylindrical blank with a length of L = (2 - 5)[B + (0.03 - 0.05)B s of the material section, which can be more easily filled when forming the C-shaped step, and there will be no phenomena such as lack of material and folding. The blank is held at a temperature of 1100 - 1150 °C, so that alloying elements, carbides, nitrides, etc. in the alloy are completely dissolved into the austenite grains, preventing them from aggregating at the grain boundaries and precipitating during subsequent forging, which weakens its mechanical properties. Forging within the temperature range of 850 °C - 1130 °C can obtain a uniform and fine structure, improving the mechanical properties of the large C-shaped stepped cross-section ring. Adopt the method of normalizing + low-temperature tempering to obtain sufficient hardness, improve the wear resistance of the large C-shaped stepped cross-section ring, and extend its service life. Brief Description of the Drawings
[0016] The following further elaborates on the present invention in detail in conjunction with the drawings and specific embodiments.
[0017] Figure 1 is a schematic structural diagram of the core roll;
[0018] Figure 2 is Figure 1 the A - A sectional view of Specific Embodiments
[0019] The specific implementation method of the rolling forming method of the C-shaped stepped cross-section ring part of the present invention is as follows:
[0020] A mandrel roll described in the present invention is composed of a mandrel roll shaft and a combined groove, and is freely connected through a dovetail groove.
[0021] The rolling forming method of the large C-shaped stepped cross-section ring part of the present invention comprises the following steps:
[0022] (1) Combine the mandrel roll shaft and the combined groove into a mandrel roll along the dovetail groove, install it on the ring rolling mill, debug the parameters of the ring rolling mill, and reserve it for use.
[0023] (2) Cut the material. Select G20Cr2Ni4 bearing steel, and its main chemical element contents (by weight percentage) are: C content 0.17% - 0.23%, Mn content 0.30% - 0.60%, Si content 0.15% - 0.40%, S content ≤ 0.030%, P content ≤ 0.030%, Cr content 1.25% - 1.75%, Ni content 3.25% - 3.75%, Cu content ≤ 0.25, and the balance is Fe.
[0024] Cut the cylindrical G20Cr2Ni4 bearing steel billet into a material section with a length of L = 4[B + 0.04B s , where B is the height of the large C-shaped stepped cross-section ring part, and B s is the height of the C-shaped step. The diameter of the billet can be determined to be Φ600mm according to the condition that the volume of the large C-shaped stepped cross-section ring part is equal to the volume of the billet.
[0025] (3) Heat the billet to 1120°C for austenitization, and perform upsetting and punching on it within the range of 850°C - 1130°C. Then load it into the ring rolling mill described in step (1) for rolling forming.
[0026] (4) The large C-shaped stepped cross-section ring part after forging is heat-treated by normalizing + tempering. First, heat the large C-shaped stepped cross-section ring part to 780°C and hold for 80 minutes, then heat up to 940°C and hold for 100 minutes, and air-cool to room temperature; then heat the large C-shaped stepped cross-section ring part to 260°C and hold for 520 minutes, and air-cool to room temperature.
Claims
1. A rolling forming method for a C-shaped stepped cross-section ring, characterized in that, Including the following steps: (1) Combine the core roll shaft and the combined groove along the dovetail groove to form a core roll, install it on the ring rolling mill, and debug the parameters of the ring rolling mill for standby. (2) Cut the cylindrical blank into a blank section with a length of L = (2 - 5)[B + (0.03 - 0.05)B s , where B is the height of the large C-shaped stepped cross-section ring, and B s is the height of the C-shaped step. The diameter of the blank can be determined according to the condition that the volume of the large C-shaped stepped cross-section ring is equal to the volume of the blank. (3) Heat the blank to 1100 - 1150 °C for austenitization, and upset and punch it within the range of 850 °C - 1130 °C. Then load it into the ring rolling mill described in step (1) for rolling and forming. (4) The large C-shaped stepped cross-section ring after forging is heat-treated by normalizing + tempering. First, heat the large C-shaped stepped cross-section ring to 780 - 800 °C and hold for 80 - 100 minutes, then raise the temperature to 930 - 950 °C and hold for 100 - 120 minutes, and air-cool to room temperature; then heat the large C-shaped stepped cross-section ring to 240 - 280 °C and hold for 480 - 540 minutes, and air-cool to room temperature.
2. The rolling forming method of the C-shaped stepped cross-section ring according to claim 1, characterized in that In step (2), the length of the blank is L = 4[B + 0.04B s .