Forging process for large flat-head forge piece of transmission part of rolling mill equipment in steel mill
By adopting high-strength alloy steel ingots, segmented heating, multi-directional upsetting, magnetic field-assisted forming and other process steps in the forging process of large flat head forging, the problems of limited material performance, single heating methods and incomplete process steps in the existing technology are solved, and the high strength, high toughness and dimensional accuracy of the forging are achieved, and the operating performance and service life of the rolling mill equipment are improved.
Patent Information
- Application Number
- CN202510505217.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-06-27
AI Technical Summary
The existing large-scale flat-head forging forging process has shortcomings in the matching and control of raw material alloy elements, single heating method, unreasonable upset ratio control, unscientific drawing process, imperfect preforming and final forging processes, low edge cutting accuracy, and improper selection of heat treatment parameters, resulting in insufficient strength, poor toughness, and inaccurate dimensions of forgings, which affect the normal operation and service life of rolling mill equipment.
High-strength alloy steel ingots are used to ensure uniform heat receiving of materials, uniform internal tissue, strong plastic deformation ability, regular tissue structure and consistent performance through process steps such as segmented heating, multi-directional upsetting, magnetic field-assisted forming, ultrasonic deformation, isothermal forging, and fine heat treatment.
It significantly improves the mechanical properties of the forging, enhances strength and toughness, improves the plastic deformation ability of the material, reduces internal defects and residual stress, improves the quality and stability of the forging, makes its performance more consistent in different directions, and has also improved its adaptability and reliability.
Smart Images
Figure CN120205728A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of forging of transmission components, and particularly to a forging process for large flat-head forgings of transmission components of steel mill rolling mill equipment. Background Art
[0002] In steel mill rolling mill equipment, large flat-head forgings of transmission components play a crucial role. The large flat-head forgings are metal products made through a forging process and are mainly used as key components of various heavy machinery and equipment. The flat-head forgings are metal products with specific shapes and dimensions formed by plastic deformation of metal billets under external pressure. Such forgings are usually used in fields such as heavy machinery equipment, lifting equipment, metallurgy, chemical industry, engineering, and offshore shipbuilding. With the development of rolling mill equipment towards large-scale and high-performance, the demand for large flat-head forgings is increasing day by day, and higher requirements are also put forward for their quality and performance.
[0003] However, there are some deficiencies in the existing forging processes for large flat-head forgings. In terms of raw materials, some existing processes are not precise enough in the matching and control of alloying elements, resulting in certain limitations in material properties and making it difficult to meet the high requirements under complex working conditions. In the heating process, some heating methods are relatively single, and the control of the heating rate and holding time is not fine enough, easily causing uneven heating of the ingot, generating thermal stress and tissue defects. In the upsetting process, the control of the upsetting ratio is not reasonable or the technology adopted is relatively backward, affecting the metal flow and tissue density. In the drawing process, the settings of the reduction and feed are not scientific enough, and the lack of advanced auxiliary deformation technology makes the metal deformation effect poor and the internal quality difficult to guarantee. The pre-forming and final forging processes may not be perfect enough to effectively ensure the final structure and performance of the forgings. The trimming process may have problems with low precision, affecting the dimensional accuracy of the forgings. In the heat treatment process, the selection of parameters such as quenching temperature and tempering temperature is inappropriate, resulting in limited improvement in the comprehensive performance of the forgings.
[0004] The deficiencies of these existing processes seriously restrict the further improvement of the quality and performance of large flat-head forgings, and cannot fully meet the growing needs of steel mill rolling mill equipment. In practical applications, it may lead to problems such as insufficient strength, poor toughness, and inaccurate dimensions of the forgings, affecting the normal operation and service life of the rolling mill equipment. Therefore, there is an urgent need for a more advanced and perfect forging process for large flat-head forgings to overcome these deficiencies. Summary of the Invention
[0005] The purpose of the present invention is to solve the above problems and propose a forging process for large flat-head forgings of transmission components of steel mill rolling mill equipment.
[0006] To achieve the above purpose, the present invention adopts the following technical solutions: A forging process for a large flat-head forging of a transmission component of a rolling mill equipment in a steel plant, comprising the following steps: Raw material preparation: Select a high-strength alloy steel ingot; Heating: Place the steel ingot in a heating furnace for heating; Upsetting: Upset the heated steel ingot; Magnetic field-assisted forming: Perform magnetic field-assisted treatment on the upset blank to improve the formability of the material; Drawing out: Draw out the upset blank; Pre-forming: Pre-form the drawn-out blank through a die; Final forging: Place the pre-formed forging in a final forging die for final forging; Trimming: Trim the forging after final forging; Heat treatment: Perform heat treatment on the trimmed forging, including quenching and tempering.
[0007] Further, in the raw material preparation, the selected high-strength alloy steel ingot contains the following components and mass percentages: carbon (C) 0.35% - 0.45%, silicon (Si) 0.2% - 0.35%, manganese (Mn) 1.2% - 1.5%, chromium (Cr) 1.0% - 1.3%, molybdenum (Mo) 0.4% - 0.6%, niobium (Nb) 0.03% - 0.05%, vanadium (V) 0.1% - 0.15%, titanium (Ti) 0.02% - 0.03%, and the balance is iron (Fe) and unavoidable impurities, and the contents of impurity elements such as sulfur (S) and phosphorus (P) do not exceed 0.02%.
[0008] Further, in the heating step, the heating temperature is controlled between 1150°C and 1250°C, and heat preservation is carried out for a certain time to make the steel ingot uniformly heated; during the heating process, a segmented heating method is adopted. First, the steel ingot is heated to 800°C at a heating rate of 10°C / h to 15°C / h, and after a short heat preservation, it is then heated to the final temperature at a heating rate of 20°C / h to 25°C / h to reduce the thermal stress during the heating process.
[0009] Further, in the upsetting step, the upsetting ratio is controlled between 2.0 and 2.5; during the upsetting process, a multi-directional upsetting technology is adopted to make the steel ingot receive uniform pressure in multiple directions, further improving the uniformity of the internal structure.
[0010] Further, in the magnetic field-assisted forming step, the upset blank is placed in a special magnetic field generating device that can generate an alternating magnetic field with a strength of 1.5 Tesla and a frequency of 50 Hertz; When performing magnetic field assisted treatment, first place the blank steadily in the central area of the magnetic field generating device to ensure that the entire blank can be evenly covered by the magnetic field. Set the treatment time to 3 hours. After the treatment is completed, carefully take out the blank and prepare for the next step of upsetting operation.
[0011] Furthermore, in the upsetting step, during the upsetting process, a combination of multiple light presses and heavy presses is adopted to control the reduction per pass and the feed per pass, so that the shape and size of the blank gradually approach the requirements of the flat head forging; during the upsetting process, ultrasonic assisted deformation technology is introduced. Through the vibration of ultrasonic waves, the deformation resistance is reduced and the plastic deformation ability of the material is improved. The reduction per light press is controlled between 10% and 15%, the reduction per heavy press is controlled between 20% and 25%, and the feed per pass is controlled between 0.5 times and 0.8 times the thickness of the blank.
[0012] Furthermore, in the final forging step, the final forging temperature is controlled between 850 °C and 950 °C; during final forging, isothermal forging technology is adopted to make the forging deform at a constant temperature, reducing the residual stress caused by temperature changes.
[0013] Furthermore, in the heat treatment step, the quenching temperature is controlled between 880 °C and 920 °C, the tempering temperature is controlled between 550 °C and 650 °C, the quenching medium is oil, and the tempering time is 2 hours to 3 hours.
[0014] Furthermore, the magnetic field intensity of the magnetic field generating device is precisely controlled by adjusting the current magnitude, and the frequency is set through relevant control circuits.
[0015] Compared with the prior art, the present invention provides a forging process for large flat head forgings of transmission components of steel mill rolling mill equipment, having the following beneficial effects: In the forging process of the present invention, a magnetic field assisted forming step is added, which can promote the refinement and homogenization of grains inside the metal, making the grains of the forging finer and more evenly distributed, thus greatly improving the mechanical properties of the forging and significantly enhancing the strength and toughness; secondly, the magnetic field can improve the plastic deformation ability of the material, reduce the deformation resistance, making the blank more likely to undergo plastic deformation in subsequent processes, reducing the energy consumption and process difficulty during the deformation process, and being beneficial to improving production efficiency and reducing costs. Moreover, the magnetic field assisted treatment can effectively reduce the defects and residual stress inside the material, making the organizational structure more regular, improving the quality and stability of the forging. In addition, after the magnetic field assisted forming treatment, the anisotropy of the blank is improved, making the properties of the forging more consistent in different directions, enhancing its reliability and adaptability in practical applications.
[0016] The forging process of the present invention provides an important guarantee for the preparation of large flat-head forgings with high performance and high quality, has great application value and broad market prospects, and is of great significance for promoting the manufacturing technology progress of the transmission components of steel mill rolling mill equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] To better understand the technical solution of the present invention, the following will be described in detail in conjunction with relevant drawings. It should be understood that the following specific embodiments are not intended to limit the specific implementation modes of the technical solution of the present invention, but only the implementation modes that the technical solution of the present invention can adopt. It should be noted first that the description of the positional relationship between components herein, such as component A is located above component B, is based on the relative positions of the components in the drawings and is not intended to limit the actual positional relationship between the components. Embodiment 1
[0019] See Figure 1 , Figure 1 A schematic diagram of the process of the forging process of a large flat-head forging of the transmission component of a steel mill rolling mill equipment of the present invention is drawn. As shown in the figure, the forging process of a large flat-head forging of the transmission component of a steel mill rolling mill equipment involved in this Embodiment 1 includes the following contents: Raw material preparation: Select high-strength alloy steel ingots, which contain the following components and mass percentages: carbon (C) 0.35%, silicon (Si) 0.2%, manganese (Mn) 1.2%, chromium (Cr) 1.0%, molybdenum (Mo) 0.4%, niobium (Nb) 0.03%, vanadium (V) 0.1%, titanium (Ti) 0.02%, and the balance is iron (Fe) and unavoidable impurities, and the contents of impurity elements such as sulfur (S) and phosphorus (P) do not exceed 0.02%.
[0020] Heating: Put the steel ingot into a heating furnace and adopt a segmented heating method. First, heat the steel ingot to 800°C at a heating rate of 10°C / h, after a short holding time, then heat it to 1150°C at a heating rate of 20°C / h and hold for a certain time to make the steel ingot evenly heated.
[0021] Upsetting: The upsetting ratio is controlled at 2.0, and multi-directional upsetting technology is adopted to make the steel ingot receive uniform pressure in multiple directions, further improving the uniformity of the internal structure.
[0022] Magnetic field-assisted forming: Place the upset billet in a special magnetic field generating device that can produce an alternating magnetic field with a strength of 1.5 Tesla and a frequency of 50 Hertz. First, place the billet steadily in the central area of the magnetic field generating device to ensure that the entire billet is evenly covered by the magnetic field. The treatment time is set to 3 hours. After the treatment is completed, carefully remove the billet; The action of the magnetic field can promote the refinement and homogenization of grains inside the metal. Through the interaction between the magnetic field and metal atoms and crystal structures, the original grain growth pattern is broken, making the grains finer and more evenly distributed, thus effectively improving the mechanical properties of the forging, such as increasing strength and toughness.
[0023] Secondly, the magnetic field can improve the plastic deformation ability of the material, reduce the deformation resistance of the material, make the billet more likely to undergo plastic deformation in subsequent processes such as drawing, and reduce the energy consumption and process difficulty during the deformation process.
[0024] Furthermore, magnetic field-assisted treatment reduces defects and residual stresses inside the material. The uniform magnetic field can make the internal organizational structure of the material more regular, reduce the generation of micro-defects, eliminate or homogenize the existing residual stresses to a certain extent, and improve the quality and stability of the forging.
[0025] In addition, after magnetic field-assisted forming treatment, the anisotropy of the billet is improved, making the properties of the forging more consistent in different directions, and enhancing its reliability and adaptability in practical applications.
[0026] Drawing: Adopt a combination of multiple light presses and heavy presses during the drawing process. The reduction amount of each light press is controlled at 10%, the reduction amount of each heavy press is controlled at 20%, and the feed amount is controlled at 0.5 times the thickness of the billet. During the drawing process, introduce ultrasonic-assisted deformation technology. Through the vibration of ultrasonic waves, reduce the deformation resistance and improve the plastic deformation ability of the material.
[0027] Pre-forming: Pre-form the drawn billet through a die.
[0028] Final forging: Control the final forging temperature at 850 °C. During final forging, adopt isothermal forging technology to make the forging deform at a constant temperature, reducing the residual stresses caused by temperature changes.
[0029] Trimming: Trim the forging after final forging.
[0030] Heat treatment: Control the quenching temperature at 880 °C, and the quenching medium is oil. Control the tempering temperature at 550 °C, and the tempering time is 2 hours. Example 2
[0031] The forging process of a large flat-head forging for the transmission components of a steel mill rolling mill equipment involved in this Embodiment 2 includes the following content: Raw material preparation: Select high-strength alloy steel ingots, which contain the following components and mass percentages: carbon (C) 0.40%, silicon (Si) 0.30%, manganese (Mn) 1.35%, chromium (Cr) 1.15%, molybdenum (Mo) 0.5%, niobium (Nb) 0.04%, vanadium (V) 0.125%, titanium (Ti) 0.025%, and the balance is iron (Fe) and unavoidable impurities, where the contents of impurity elements such as sulfur (S) and phosphorus (P) do not exceed 0.02%.
[0032] Heating: Place the steel ingot in a heating furnace and adopt a segmented heating method. First, heat the steel ingot to 800°C at a heating rate of 12.5°C / h, conduct a short-term heat preservation, and then heat it to 1200°C at a heating rate of 22.5°C / h and keep it warm for a certain period of time to make the steel ingot evenly heated.
[0033] Upsetting: Control the upsetting ratio at 2.25 and adopt multi-directional upsetting technology to make the steel ingot receive uniform pressure in multiple directions, further improving the uniformity of the internal structure.
[0034] Magnetic field-assisted forming: Place the upset billet in a special magnetic field generating device, which can generate an alternating magnetic field with a strength of 1.5 Tesla and a frequency of 50 Hertz. First, place the billet stably in the central area of the magnetic field generating device to ensure that the whole billet can be evenly covered by the magnetic field, and set the treatment time to 3 hours. After the treatment, carefully take out the billet.
[0035] Drawing out: Adopt a combination of multiple light presses and heavy presses during the drawing out process. The reduction amount of each light press is controlled at 12.5%, the reduction amount of each heavy press is controlled at 22.5%, and the feeding amount is controlled at 0.65 times the thickness of the billet. During the drawing out process, introduce ultrasonic-assisted deformation technology. Through the vibration of ultrasonic waves, reduce the deformation resistance and improve the plastic deformation ability of the material.
[0036] Pre-forming: Pre-form the drawn billet through a die.
[0037] Final forging: Control the final forging temperature at 900°C. During final forging, adopt isothermal forging technology to make the forging deform at a constant temperature, reducing the residual stress caused by temperature changes.
[0038] Trimming: Trim the forging after final forging.
[0039] Heat treatment: Control the quenching temperature at 900°C, and the quenching medium is oil. Control the tempering temperature at 600°C, and the tempering time is 2.5 hours. Embodiment 3
[0040] The forging process of a large flat-head forging for the transmission components of a steel mill rolling mill equipment involved in this Embodiment 3 includes the following contents: Raw material preparation: Select high-strength alloy steel ingots, which contain the following components and mass percentages: carbon (C) 0.45%, silicon (Si) 0.35%, manganese (Mn) 1.5%, chromium (Cr) 1.3%, molybdenum (Mo) 0.6%, niobium (Nb) 0.05%, vanadium (V) 0.15%, titanium (Ti) 0.03%, and the balance is iron (Fe) and inevitable impurities, where the contents of impurity elements such as sulfur (S) and phosphorus (P) do not exceed 0.02%.
[0041] Heating: Put the steel ingot into a heating furnace and adopt a segmented heating method. First, heat the steel ingot to 800 °C at a heating rate of 15 °C / h, conduct a short-term heat preservation, and then heat it to 1250 °C at a heating rate of 25 °C / h and keep it warm for a certain time to make the steel ingot evenly heated.
[0042] Upsetting: Control the upsetting ratio at 2.5 and adopt multi-directional upsetting technology to make the steel ingot receive uniform pressure in multiple directions, further improving the uniformity of the internal structure.
[0043] Magnetic field-assisted forming: Place the upset blank in a special magnetic field generating device that can generate an alternating magnetic field with a strength of 1.5 Tesla and a frequency of 50 Hertz. First, place the blank stably in the central area of the magnetic field generating device to ensure that the whole blank can be evenly covered by the magnetic field, and set the treatment time to 3 hours. After the treatment, carefully take out the blank.
[0044] Drawing out: Adopt a combination of multiple light presses and heavy presses during the drawing out process. The reduction amount of each light press is controlled at 15%, the reduction amount of each heavy press is controlled at 25%, and the feeding amount is controlled at 0.8 times the thickness of the blank. During the drawing out process, introduce ultrasonic-assisted deformation technology. Through the vibration of ultrasonic waves, reduce the deformation resistance and improve the plastic deformation ability of the material.
[0045] Pre-forming: Pre-form the drawn blank through a die.
[0046] Final forging: Control the final forging temperature at 950 °C. During final forging, adopt isothermal forging technology to make the forging deform at a constant temperature, reducing the residual stress caused by temperature changes.
[0047] Trimming: Trim the forging after final forging.
[0048] Heat treatment: Control the quenching temperature at 920 °C and the quenching medium is oil. Control the tempering temperature at 650 °C and the tempering time is 3 hours.
[0049] In order to verify the effect of the forging process of the present invention, performance tests were carried out on the large flat-headed forgings prepared in Examples 1-3, and the test results are shown in the following table:
[0050] It can be seen from the test results that the large flat-headed forgings prepared by the forging process of the present invention have good mechanical properties and meet the usage requirements of the transmission components of the steel mill rolling mill equipment.
[0051] The above are only specific application examples of the present invention and do not constitute any limitation to the protection scope of the present invention. Any technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of the protection of the present invention.
Claims
1. A forging process for large flat head forgings of transmission parts of rolling mill equipment in a steel plant, characterized in that: The following steps are involved: Raw material preparation: Use high-strength alloy steel ingots; Heating: Put the steel ingot into the heating furnace for heating; Upsetting: Upsetting the heated steel ingot; Magnetic field assisted forming: The roughened blank is subjected to magnetic field assisted processing; Drawing: Drawing the roughened blank; Preforming: Preforming the drawn blank through a die; Final forging: Place the preformed forging into the final forging die for final forging; Trimming: Trimming the forgings after final forging; Heat treatment: Heat treatment is performed on the forgings after trimming, including quenching and tempering.
2. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the raw material preparation, the selected high-strength alloy steel ingot contains the following components and mass percentages: carbon (C) 0.35%~0.45%, silicon (Si) 0.2%~0.35%, manganese (Mn) 1.2%~1.5%, chromium (Cr) 1.0%~1.3%, molybdenum (Mo) 0.4%~0.6%, niobium (Nb) 0.03%~0.05%, vanadium (V) 0.1%~0.15%, titanium (Ti) 0.02%~0.03%, and the remainder is iron (Fe) and unavoidable impurities, among which the content of impurity elements such as sulfur (S) and phosphorus (P) does not exceed 0.02%.
3. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the heating step, the heating temperature is controlled between 1150°C and 1250°C, and is kept warm for a certain period of time so that the steel ingot is evenly heated; during the heating process, a segmented heating method is adopted, firstly the steel ingot is heated to 800°C at a heating rate of 10°C / h to 15°C / h, and after a short insulation, it is heated to the final temperature at a heating rate of 20°C / h to 25°C / h to reduce thermal stress during the heating process.
4. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the upsetting step, the upsetting ratio is controlled between 2.0 and 2.5; in the upsetting process, a multi-directional upsetting technology is used to make the steel ingot receive uniform pressure in multiple directions, thereby further improving the uniformity of the internal structure.
5. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the magnetic field assisted forming step, the upset blank is placed in a special magnetic field generating device, which can generate an alternating magnetic field with an intensity of 1.5 Tesla and a frequency of 50 Hz; When performing magnetic field-assisted processing, first place the blank steadily in the central area of the magnetic field generating device to ensure that the entire blank can be evenly covered by the magnetic field. The processing time is set to 3 hours. After the processing is completed, the blank is carefully taken out and prepared for the next step of stretching operation.
6. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the drawing step, a combination of multiple light and heavy pressing is used during the drawing process, and the pressing amount and feed amount are controlled each time, so that the shape and size of the blank gradually approach the requirements of the flat head forging; in the drawing process, ultrasonic assisted deformation technology is introduced to reduce the deformation resistance and improve the plastic deformation capacity of the material through the vibration of ultrasonic waves. The pressing amount of each light pressing is controlled at 10% to 15%, the pressing amount of each heavy pressing is controlled at 20% to 25%, and the feed amount is controlled at 0.5 to 0.8 times the thickness of the blank.
7. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the final forging step, the final forging temperature is controlled between 850° C. and 950° C. During the final forging, isothermal forging technology is used to deform the forging at a constant temperature to reduce residual stress caused by temperature changes.
8. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 1, characterized in that: In the heat treatment step, the quenching temperature is controlled between 880° C. and 920° C., the tempering temperature is controlled between 550° C. and 650° C., the quenching medium is oil, and the tempering time is 2 hours to 3 hours.
9. The forging process of a large flat head forging of a transmission component of a steel mill equipment according to claim 2, characterized in that: The magnetic field strength of the magnetic field generating device is precisely controlled by adjusting the current, and the frequency is set by a related control circuit.