A near-isothermal hot spinning forming method and a heat supplement method for a metal workpiece

Abstract

The application discloses a near-isothermal hot spinning forming method and a heat supplement method for a metal workpiece, and the forming method comprises the following steps: transferring and clamping a blank heated to a spinning preheating temperature on a workbench, the blank being located in an effective heat supplement area of a heat supplement system; and performing temperature measurement on the blank to determine whether the temperature of the blank meets the temperature before spinning of the blank, so as to determine whether the blank is heated in the heat supplement system and waits; then, near-isothermal hot spinning forming is completed in the heat supplement system according to a predetermined spinning program, the heat supplement system continuously heats the blank during spinning and performs real-time monitoring on the spinning temperature, and it is ensured that the fluctuation range of the spinning temperature is not more than + / -20 DEG C in the process from the beginning to the end of spinning deformation. The near-isothermal spinning forming process is a special hot spinning forming process for realizing deformation temperature control of difficult-to-deform metal materials such as high-temperature alloys and titanium alloys in a small fluctuation range in the spinning process by using a semi-closed active heat supplement system spinning equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot spinning forming, in particular to a near-isothermal hot spinning forming method and a heat supplement method for a metal workpiece. BACKGROUND

[0002] Difficult-to-deform alloy materials such as high-temperature alloys and titanium alloys have excellent characteristics such as high strength, good corrosion resistance, high-temperature resistance, high toughness, and good weldability. Parts such as casings made of such materials are widely used in aero-engines. At present, such parts are mainly manufactured by ring rolling forming ring blanks + machining, which generally has a large machining allowance, resulting in high raw material cost, and the large machining removal causes high processing cost and large residual stress, which leads to part deformation and other problems. Therefore, the development and application of near-net forming technology in the manufacture of difficult-to-deform metal ring forgings are very urgent.

[0003] Spinning forming process is a method of processing metal blanks into various rotationally symmetric hollow workpieces by rotating and locally pressing, which has the characteristics of high processing precision and efficiency, and the wall thickness of the prepared parts is relatively thin and close to the wall thickness during use, and has a small machining allowance. It is a near-net forming process widely used in the fields of aerospace, military equipment, and automobile parts. At present, the aero-engine casing parts are typical ring-shaped parts, which are very suitable for spinning forming. However, difficult-to-deform alloy materials also have the problems of poor plasticity at room temperature, high forming temperature, and narrow deformation temperature window. Therefore, higher requirements are put forward for the precise control of deformation temperature during hot spinning forming of difficult-to-deform metal material parts.

[0004] At present, the heating method of hot spinning forming process mainly uses flame heating, which uses flame to heat the blank and the spinning wheel, etc. This method has the advantages of simple heating method, high heating efficiency, and wide temperature range. However, this heating method belongs to open heating, and the flame can only cover part of the blank. Although the flame can cover all parts of the spinning blank by reciprocating scanning, the size of the flame, the heated area, and the distance between the flame and the blank are all adjusted manually, which has large fluctuation and randomness. In addition, the ambient temperature has a great influence on the heating temperature. In different seasons, the heating time and the size of the flame required for normal spinning of the blank are different, the heating temperature rising rate is different, and the temperature distribution of each area of the blank is also different. Since the forming temperature range of difficult-to-deform metal materials such as titanium alloys and high-temperature alloys is narrow, the deformation temperature range and temperature uniformity must be strictly controlled to ensure the forming quality. However, the flame heating method has the disadvantages of large heating temperature fluctuation, low heating precision, and low heating efficiency, which cannot realize the stability of the temperature, resulting in defects such as instability wrinkling, cracking, poor wall thickness uniformity, and mold holding during hot spinning forming of difficult-to-deform alloy materials, and even the mechanical properties do not meet the requirements.

[0005] In order to improve the accuracy and stability of temperature, a lot of research has been done, and in some research, the temperature of the blank is measured by temperature equipment, and feedback is given to the heating equipment to control heating, for example, patent documents CN103706716B, CN106964682A and CN111842603B. The patent document CN103706716B discloses a titanium alloy thin-walled component hot spinning precise temperature control method. In the hot spinning process, the infrared thermal imaging device is used to monitor the titanium alloy blank deformation zone in real time. According to the actual temperature of the titanium alloy blank deformation zone fed back by the infrared thermal imaging device, the local heating device is used to adjust the temperature of the titanium alloy blank deformation zone in real time, so that the temperature of the titanium alloy blank deformation zone is controlled within a certain range, that is, the titanium alloy thin-walled component hot spinning precise temperature control is realized, and the titanium alloy thin-walled component is obtained. Under the condition of open heating, the error of measuring the workpiece by using a multi-point infrared temperature measuring instrument is too large, and the actual temperature of the material deformation zone cannot be accurately obtained during the spinning process for adjustment and control, which cannot meet the requirements of temperature measurement accuracy.

[0006] Some researches use composite heating methods, such as patent CN109108139B, which discloses a titanium-based alloy material spinning forming method based on composite heating. First, a flame gun is used to preheat the blank, mandrel and spinning wheel, and then a follow-up induction heating coil is used to heat the blank to the spinning temperature. An infrared thermal imager is used to monitor the temperature during the spinning process, and a flame gun is used to heat the blank in the area that has been spun behind the spinning wheel. However, the forming temperature of the difficult-to-deform alloy material is high, the hot working window is narrow, and the temperature and strain rate are sensitive. The composite heating method is complex, and there is still a problem of poor temperature uniformity in different partitions, which cannot meet the manufacturing requirements of high-precision workpieces.

[0007] Therefore, in order to improve the deformation ability of the material and reduce the deformation resistance, improve the forming quality and forming efficiency, a new near-isothermal hot spinning forming method is needed for the manufacture of difficult-to-deform alloy material workpieces. SUMMARY

[0008] The purpose of the present application is to solve the problem that the existing hot spinning forming method of difficult-to-deform alloy material cannot accurately adjust and control the temperature of the material deformation zone, and the temperature uniformity is poor, which leads to the problem that the manufacturing requirements of workpieces cannot be met, and a near-isothermal hot spinning forming method of metal workpieces and a heat supplement method are provided.

[0009] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0010] A near-isothermal hot spinning forming method of metal workpieces, comprising the following steps:

[0011] heat the blank to the spinning preheating temperature;

[0012] The heated blank is transferred and clamped on a workbench rotating with the main shaft of the spinning equipment, the periphery of the workbench is provided with a heat supplement system, and the blank is located in an effective heat supplement area provided by the heat supplement system;

[0013] The temperature of the clamped and fixed blank is measured to determine the temperature T of the blank 坯 whether the temperature of the blank before spinning meets the process requirements If yes, the spinning equipment is started to spin; if not the heat supplement system is used to heat and supplement the temperature of the blank to meet the spinning equipment is started to spin again;

[0014] The blank is spun and formed in the spinning equipment by using a near-isothermal hot spinning process; during the near-isothermal hot spinning, the heat supplement system is used to actively heat and supplement the temperature of the blank, and the spinning temperature of the spinning deformation area of the blank is monitored in real time to ensure that the spinning temperature fluctuates within a range of ±20℃ during the process from the beginning to the end of the spinning deformation.

[0015] ​In the technical scheme of the present application, the blank is first heated to a spinning preheating temperature in a heating device, then transferred and clamped on the workbench of the spinning device, the workbench rotates with the main shaft of the spinning device, and can drive the blank to select for subsequent spinning; the spinning device is provided with a spinning system and a heat supplement system, the spinning system is used to realize local spinning deformation of the blank, and is used to form the shape of the workpiece and ensure the dimensional accuracy; the heat supplement system is installed on the periphery of the workbench, and the effective heat supplement area is formed, and the blank is located in the effective heat supplement area, that is, through the above-mentioned setting, the effective heat supplement area can envelope the entire blank, and the heat loss of the blank during the subsequent transfer, fixation and spinning process with the environment is supplemented, at the same time, the heat supplement system on the spinning device does not interfere with the movement of the spinning system in the radial and axial directions of the blank, and the synchronous realization of spinning and heating supplement during the workpiece forming process is ensured. The temperature of the clamped and fixed blank before spinning is measured, and it is judged whether the blank temperature meets the blank pre-spinning temperature required by the spinning process, if the blank temperature meets the blank pre-spinning temperature required by the spinning process at this time, the spinning device should be started to spin; if the blank temperature is lower than the blank pre-spinning temperature required by the spinning process at this time, the spinning device should be started after the blank is actively heated and supplemented to the blank pre-spinning temperature by the heat supplement system, that is, in this step, the heat supplement system is started to rapidly heat, and the effective heat supplement area of the heat supplement system continuously heats and supplements the blank, so as to prevent the temperature of the blank from continuing to lose, so that the temperature of the blank reaches the spinning condition required by the process, that is, reaches the pre-spinning temperature, and the spinning starts under the temperature condition that the temperature of the blank reaches the blank pre-spinning temperature; during the spinning process, the heat supplement system continues to heat and supplement the blank, and the deformation temperature in the deformation area of the blank, that is, the spinning temperature, is monitored and recorded in real time, so that the spinning temperature fluctuates by not more than ±20℃ from the beginning to the end of the spinning process, and at the same time, the maximum value and the minimum value of the spinning temperature T 旋 are located in the temperature fluctuation range required by the process, that is, the controllable heat supplement system is used to maintain the deformation temperature of the metal material in the forming process within a small fluctuation range, and then the near-isothermal spinning deformation is realized, which can reduce the deformation resistance of the difficult-to-deform metal material, keep the metal material in a high deformation capacity during the spinning process, improve the forming quality and forming efficiency, meet the workpiece manufacturing requirements, and at the same time, the product deformation parameter consistency and traceability of the hot spinning of the present technical scheme are good.

[0016] Through the above technical scheme, the spinning temperature is higher than the recrystallization temperature of the metal material, the spinning forming process of the present application is hot working, the metal material will undergo dynamic recrystallization, which is helpful to eliminate work hardening, thereby improving the plasticity and toughness of the metal material, the consistency of the formed workpiece product is good, and the manufacturing requirements of high-precision workpieces can be met, and the present technical scheme is suitable for difficult-to-deform metals with narrow forming temperature range, and is also suitable for non-difficult-to-deform metals.

[0017] In this invention, the effective heating zone refers to the area formed within the heating system that can heat and replenish the workpiece to reach the required temperature with uniform temperature distribution. The heating area that can achieve the heating and replenishing effect in the heating system may be larger than the effective heating zone. This is because some heating areas have lower temperatures or uneven temperature distribution due to the arrangement of heating elements, making them unsuitable for heating and replenishing the billet and temperature control. By rationally arranging the heating elements, the effective heating zone of the heating system is guaranteed, thus ensuring the quality of the workpiece.

[0018] billet temperature before spinning This is the starting temperature for spinning. When the billet temperature reaches the temperature before spinning, difficult-to-deform metal materials possess high deformation capacity, and it also provides a temperature basis for the spinning temperature fluctuation range to not exceed ±20℃ during near-isothermal hot spinning. The billet temperature before spinning is within the spinning temperature range and can be determined based on processing experience with metal materials. For new metal materials, the billet temperature before spinning can be obtained using numerical simulation software or calculation formulas.

[0019] Spinning temperature T 旋 Spinning temperature refers to the temperature of the workpiece's deformation zone after the spinning wheel contacts the workpiece and spinning pressure is applied. The spinning temperature is the instantaneous temperature during spinning and should be determined according to the specific material type, spinning conditions, and other factors within a range of deformation temperatures. In other words, the spinning temperature is not a fixed value but a temperature range with a certain fluctuation. In the near-isothermal hot spinning process of this invention, the spinning temperature fluctuation range is between the maximum and minimum values ​​required by the process, achieving strict control of the spinning temperature. This ensures sufficient plasticity of the metal material while avoiding spinning defects such as cracks and metal accumulation caused by excessively high or low temperatures. The spinning temperature T of the workpiece... 旋 Within a single spinning pass (i.e., from the start to the end of a single spinning pass), the temperature fluctuation range shall not exceed ±20℃, meaning that the highest spinning temperature T within a single spinning pass shall be [not specified]. 旋max and minimum value T 旋min The difference should not exceed 40℃. The spinning temperature can be obtained from the heat treatment diagram corresponding to the workpiece material. For a specific metal material, the spinning temperature is a range value, which can be obtained from the material handbook or thermal simulation test.

[0020] As a preferred embodiment of the present invention, the spinning preheating temperature is 300-1200°C. For different metal materials, the spinning preheating temperature of the billet is determined according to the spinning process.

[0021] As a preferred scheme of the present application, the time for transferring and clamping the heated blank on the worktable of the spinning device is defined as the transfer time, which is required to be less than 90s. In the above technical scheme, the blank heated to the spinning preheating temperature loses heat during the transferring process and the clamping process to the worktable, resulting in a temperature drop of the blank, which may cause the temperature of the blank to be lower than the allowable spinning starting temperature before spinning, and the hot spinning of the difficult-to-deform metal cannot be immediately performed. The spinning needs to be started after the blank is heated by the heating compensation system to meet the spinning condition, which results in a complicated process flow. Therefore, the transfer time is required to be as short as possible, which can reduce the heat loss of the blank during the transferring and clamping processes, reduce the temperature drop, and reduce the waiting time for the blank to be heated and compensated, and reduce the energy consumption. However, the shorter the transfer time is, the higher the flexibility of the transferring device and the clamping device is required. Considering comprehensively, the transfer time is in the range of 40-90s. For different metal materials, the transfer time is determined according to the spinning processing requirements, the equipment state and other factors. The shorter the transfer time is, the better.

[0022] As a preferred scheme of the present application, the spinning device comprises a machine body, a heating compensation system and a spinning roller system, the heating compensation system and the spinning roller system are arranged on the machine body, a worktable is arranged on the main shaft of the machine body, the spinning roller system comprises a spinning roller assembly, the heating compensation system comprises a furnace body and a temperature control system, the temperature control system comprises a furnace body temperature measurement module, a control module and a heating module, the heating module comprises a plurality of heating elements; a furnace cavity is formed in the furnace body, the heating elements are arranged on the inner wall of the furnace cavity for forming an effective heating compensation area in the furnace cavity; a spinning roller movement groove is arranged on the furnace body, the spinning roller assembly passes through the spinning roller movement groove for ensuring that the spinning roller assembly can freely move in the radial direction and the axial direction of the blank; the furnace body temperature measurement module is used for detecting the temperature of the effective heating compensation area, and the furnace body temperature measurement module and the heating module are electrically connected with the control module.

[0023] In the above technical solution, the spinning equipment integrates the heat supplement system and the spinning wheel system, the heat supplement system and the spinning wheel system are arranged on the machine body, the spinning wheel assembly of the spinning wheel system locally pressurizes the blank, and the shape and size of the workpiece can be formed; the furnace cavity is formed in the furnace body of the heat supplement system, the heating element is arranged in the furnace cavity wall, the uniform arrangement of the heating element forms an effective temperature compensation area in the furnace body, the blank is located in the effective temperature compensation area, and the blank can be heated and temperature compensated; at the same time, the furnace body of the heat supplement system is provided with a spinning wheel movement groove, the spinning wheel assembly passes through the spinning wheel movement groove and is located in the spinning wheel movement groove, and the arrangement ensures that the spinning wheel assembly can freely move in the radial and axial directions of the blank. The furnace body of the heat supplement system is a semi-closed structure, a semi-closed furnace cavity is formed in the furnace body, the heat supplement system on the spinning equipment does not interfere with the movement of the spinning system in the radial and axial directions of the blank, and synchronous implementation of spinning and heating temperature compensation in the workpiece forming process is ensured. The furnace body temperature measurement module of the temperature control system detects the temperature of the effective temperature compensation area and feeds back the temperature signal to the control module, the control module receives the temperature signal from the furnace body temperature measurement module, compares and processes the temperature signal according to the temperature compensation target temperature set by the temperature control system, and outputs the corresponding control signal to the heating module. The heating module is managed by the control module to adjust the heating power of the heating element according to the temperature signal fed back by the furnace body temperature measurement module, so as to keep the temperature stable near the temperature compensation target temperature. The connection between the furnace body temperature measurement module, the heating module and the control module of the temperature control system constitutes a temperature closed-loop control system for accurately monitoring and adjusting the temperature of the effective temperature compensation area. Through accurate temperature measurement of the furnace body temperature measurement module, temperature control of the control module and accurate regulation of the heating module, the temperature uniformity of the effective temperature compensation area is ± 15℃, and the temperature control accuracy is ± 1℃. The connection mode of the control module and the furnace body temperature measurement module or the heating module is field bus, industrial Ethernet and the like. These connection modes are connected in a manner understood by those skilled in the art, so as to realize data transmission and control signal reception.

[0024] As a more preferred scheme of the present application, the workbench of the machine body is provided with a quick clamping structure of the blank, the bottom of the furnace body is connected with the workbench, the workbench is used for supporting the blank, and the clamping structure is used for fixing the blank on the workbench.

[0025] As a preferred scheme of the present application, the control module of the heat supplement system is provided with a temperature compensation target temperature, and the temperature compensation target temperature ranges from 300 to 1200℃. The control module includes a user interface, such as a display screen and a control panel, which allows the user to set the temperature compensation target temperature, monitor the real-time temperature and other parameters, and the temperature control accuracy and temperature measurement mode of the heat supplement system meet the standard requirements.

[0026] As a preferred scheme of the present application, the furnace body temperature measuring module comprises a plurality of temperature measuring sensors, the installation position and insertion depth of the plurality of temperature measuring sensors on the furnace body are designed to be able to reflect the real temperature of the effective temperature compensation zone. The temperature measuring sensor is a thermocouple, a sensor for temperature measurement based on thermoelectric effect.

[0027] As a preferred scheme of the present application, the spinning wheel assembly comprises an inner spinning wheel and an outer spinning wheel, the entire structure of the inner spinning wheel and part of the structure of the outer spinning wheel are located in the effective temperature compensation zone of the heat compensation system when the spinning wheel assembly is working, the inner spinning wheel is located at the inner side of the blank and can abut against the inner wall of the workpiece blank, the outer spinning wheel is located at the outer side of the blank and can abut against the outer wall of the workpiece blank, the inner spinning wheel and the outer spinning wheel pass through and are located in the spinning wheel movement groove, so as to ensure that the inner spinning wheel and the outer spinning wheel can independently and freely move along the radial direction and the axial direction of the blank.

[0028] In the above technical scheme, the entire inner spinning wheel and part of the outer spinning wheel are located in the effective temperature compensation zone, the effective temperature compensation zone can preheat the inner spinning wheel and the outer spinning wheel, reduce the temperature difference between the inner spinning wheel, the outer spinning wheel and the blank, further reduce the temperature drop of the workpiece in the spinning process, and be more conducive to controlling the spinning temperature of the blank in the near-isothermal hot spinning process; the inner spinning wheel is located at the inner side of the blank, the outer spinning wheel is located at the outer side of the blank, the inner spinning wheel and the outer spinning wheel pass through and are located in the spinning wheel movement groove, so as to ensure that the inner spinning wheel and the outer spinning wheel can independently move in the radial direction and the axial direction of the workbench, and perform space spinning according to the spinning track required by the process, and the diameter and width of the spinning wheel movement groove should be greater than the diameter of the inner spinning wheel and the outer spinning wheel, so as to prevent interference in the spinning process; in the spinning process, the inner spinning wheel and the outer spinning wheel abut against the inner wall and the outer wall of the blank respectively, and locally press the blank, and under the rotation of the blank, the inner spinning wheel and the outer spinning wheel move along the radial direction and the axial direction of the blank to spin and form the blank. The movement between the inner spinning wheel and the outer spinning wheel does not affect the working of the heat compensation system, and the spinning process and the heat compensation process do not interfere with each other, and the realization of spinning and heating temperature compensation in the workpiece forming process is ensured.

[0029] Further, the spinning wheel movement groove is arranged on the top surface and the side surface of the furnace body, so as to ensure that the spinning wheel assembly can independently and freely move along the radial direction and the axial direction of the blank.

[0030] As a preferred scheme of the present application, the furnace body comprises furnace body one and furnace body two, the furnace body one and the furnace body two are oppositely arranged, a furnace cavity one is formed in the furnace body one, a furnace cavity two is formed in the furnace body two, the furnace cavity one and the furnace cavity two form the furnace cavity of the furnace body, the furnace body one and the furnace body two can be close to or away from the workbench, the furnace body one and the furnace body two are closed after being close to each other to form the furnace cavity, so that the blank is located in the effective temperature compensation zone; a first rotating wheel movement groove is arranged on the furnace body one, a second rotating wheel movement groove is arranged on the furnace body two, and the first rotating wheel movement groove and the second rotating wheel movement groove form the rotating wheel movement groove.

[0031] In the above technical scheme, the furnace body structure of the heat compensation system is a semi-closed movable split type structure; the furnace body one and the furnace body two can be close to or away from the workbench, facilitating the taking or placing of the workpiece blank; when the blank is to be placed on the workbench or taken out of the workbench after spinning is completed, the furnace body one and the furnace body two are away from the workbench, at this time, the furnace body is in an open state; after the blank is fixed on the workbench of the spinning equipment, the furnace body one and the furnace body two are close to the workbench, the furnace body is in a closed state, the furnace cavity one and the furnace cavity two form the furnace cavity, the first rotating wheel movement groove and the second rotating wheel movement groove form the rotating wheel movement groove, the rotating wheel assembly passes through and is located in the rotating wheel movement groove, an effective temperature compensation zone is arranged in the furnace cavity, the blank is located in the effective temperature compensation zone when the furnace body is closed, and the heat compensation system can accurately monitor and adjust the temperature of the effective temperature compensation zone through closed loop control among the furnace body temperature measurement module, the heating module and the control module of the temperature control system, so that the effective temperature compensation zone provides a uniform temperature field to heat and compensate the blank.

[0032] As a more preferred scheme of the present application, the furnace body one and the furnace body two close the furnace body of the heat compensation system by being close to the workbench; the furnace body one and the furnace body two open the furnace body of the heat compensation system by being away from the workbench, the time for the furnace body to complete closing is controlled within 15 seconds, and the time for the furnace body to complete opening is controlled within 15 seconds. The furnace body structure of the heat compensation system is a semi-closed movable split type structure, the furnace body completes closing or opening by the furnace body one and the furnace body two being close to or away from the workbench respectively, and in the process of being close to or away from the workbench, the effective heating zone is open, which causes heat loss in the effective temperature compensation zone. Therefore, the time for completing closing or opening needs to be strictly controlled to avoid excessive loss of the ambient temperature in the effective temperature compensation zone due to the opening of the furnace body.

[0033] As a more preferred scheme of the present application, the maximum value of the target temperature after the furnace body is closed of the heat supplement system is consistent with the temperature before spinning required by the process. The set value of the target temperature should fully consider the temperature rise effect caused by the deformation heat of the spinning deformation zone, and the sum of the set spinning temperature value and the temperature rise caused by the deformation heat is the measured spinning temperature in the actual deformation process of the workpiece.

[0034] As a more preferred scheme of the present application, the furnace body one or the furnace body two is connected to the spinning equipment body through sliding components or hinged components, so that the furnace body one and the furnace body two can slide close to or away from the workbench, or the furnace body one and the furnace body two can rotate close to or away from the workbench. Through the above arrangement, a semi-closed effective temperature supplement zone is formed in the furnace body one and the furnace body two. Before the blank is transferred and clamped on the workbench, the furnace body one and the furnace body two are away from the workbench. After fixing is completed, the furnace body one and the furnace body two are close to the workbench to form an effective temperature supplement zone. The heat supplement system is used to heat and supplement the temperature of the blank to the spinning temperature of the blank.

[0035] As a more preferred scheme of the present application, the furnace body one and the furnace body two are semi-cylindrical cavity structures with a wall thickness of 50-100 mm.

[0036] As a preferred scheme of the present application, the temperature T of the clamped and fixed blank is measured 坯 , and compared with the temperature before spinning required by the process . If T , the heat supplement system is started to heat and supplement the temperature of the blank. The heat supplement system will increase the heating power of the heating element to increase the temperature rise rate of the temperature supplement, and actively compensate the heating of the blank in the heat supplement time to make the temperature of the blank reach the temperature before spinning. Then the spinning equipment is started to perform spinning of the workpiece according to the predetermined spinning program. If T , the heat supplement system is started to supplement the temperature of the blank, and the spinning equipment is started to perform spinning of the workpiece according to the predetermined spinning program. The heat supplement system will maintain the heating power of the heating element to maintain the temperature of the blank within the spinning temperature range.

[0037] In the above technical scheme, the heat of the blank heated to the spinning preheating temperature will be lost in the transfer process and the process of being fixed to the workbench, resulting in a decrease in the temperature of the blank. The temperature of the blank cannot reach the temperature before spinning , and near-isothermal hot spinning forming cannot be achieved. By measuring the temperature T of the blank 坯 , and comparing it with the temperature before spinning required by the process , it is determined whether the spinning is immediately started or the spinning is started after the temperature of the blank is supplemented to the temperature before spinning by the heat supplement system. If T 坯 is lower than the temperature before spinning required by the process The temperature of the blank decreases greatly during the transferring process and the process of being fixed to the workbench, and the temperature of the blank cannot meet the requirement of the start spinning temperature, so the heating system increases the heating power of the heating element, increases the temperature rising rate of the compensation heating, actively and quickly compensates and heats the blank within the specified compensation heating time, so as to offset the heat loss of the blank, and the temperature of the blank reaches the pre-spinning temperature. 坯 The temperature of the blank is higher than the pre-spinning temperature required by the process The temperature of the blank decreases slightly during the transferring process and the process of being fixed to the workbench, and the temperature of the blank can meet the requirement of the start spinning temperature, so the heating system maintains the heating power of the heating element, maintains the spinning temperature, and prevents the temperature of the blank from decreasing during the spinning process. Therefore, the heating system is started to compensate and heat the blank, and the spinning equipment is started to spin the workpiece according to the predetermined spinning program.

[0038] As a more preferred scheme of the present application, the temperature of the effective compensation heating area of the heating system is not higher than the pre-heating temperature of spinning; if The heating system is started to compensate and heat the blank, and the compensation heating time of the heating system is not more than 5 minutes. The spinning temperature of the workpiece made of different metal materials is different, and the corresponding compensation heating time is different. The compensation heating time is determined according to the processed metal material, so as to control the heating system. In the present application, the blank after being fixed is located in the effective compensation heating area of the heating system. The holding temperature of the effective compensation heating area before the heating system is started should be lower than the pre-heating temperature of spinning, so as to prevent the temperature of the blank from increasing and causing microstructure defects. Moreover, the compensation heating time is controlled to be not more than 5 minutes, so that the temperature rising rate of the compensation heating should be as fast as possible.

[0039] As a preferred scheme of the present application, the spinning equipment is further provided with a blank temperature measuring module for detecting the temperature of the blank located in the effective compensation heating area, so as to obtain the temperature T 坯 or the spinning temperature T 旋 of the blank.

[0040] In the above technical scheme, the temperature of the blank is detected by the blank temperature measuring module after being clamped, and the detected temperature of the blank is fed back to the heating system, so as to control the heating system to compensate and heat the blank. In addition, when the heating system comprises a furnace body and a temperature control system, the temperature control system comprises a furnace body temperature measuring module, a control module and a heating module. The furnace body temperature measuring module is used to detect the temperature of the effective compensation heating area. The furnace body temperature measuring module and the blank temperature measuring module cooperate with each other to respectively test the effective heating area and the temperature of the blank, so as to obtain the real-time temperature of the effective compensation heating area for compensating and heating the blank, provide a basis for the parameter adjustment of the heating system, stabilize the adjustment range of the heating system, and improve the stability and reliability of the heating system.

[0041] As a more preferred scheme of the present application, the blank temperature measuring module comprises at least one infrared temperature measuring sensor, the infrared temperature measuring sensor is non-contact with the temperature measuring target blank, the infrared temperature measuring sensor is located between the blank and the heating element, and the infrared temperature measuring sensor always points to the blank, and the installation of the infrared temperature measuring sensor does not affect the movement of the spinning assembly.

[0042] As a preferred scheme of the present application, for the blank of high-temperature alloy material, the spinning temperature is 900-1150℃. The blank of high-temperature alloy material includes but is not limited to one of Waspaloy, GH4169, IN718, GH3536, IN783, IN625, GH4698, and for different types of high-temperature alloy materials, the spinning temperature is different, and the spinning temperature range is determined according to the specific material grade, but is within 900-1150℃.

[0043] When spinning the high-temperature alloy material, the high-temperature alloy material is a difficult-to-deform alloy material, and attention should be paid to avoid grain growth due to excessively high temperature, which will affect the mechanical properties of the material, and excessively low forging temperature will increase the difficulty of spinning deformation, resulting in cracks in the workpiece, therefore, in the present application, the near-isothermal hot spinning process is adopted for the high-temperature alloy material, and in the spinning forming, a heating compensation system is used to heat and compensate the blank, so that the spinning temperature fluctuation range of the blank is controlled within ±20℃, and the maximum and minimum values of the spinning temperature are both within the spinning temperature range required by the process, which can ensure good deformation ability of the metal material in the spinning process, reduce the deformation resistance, improve the forming quality and forming efficiency, and meet the workpiece manufacturing requirements. Precise control of the temperature in the spinning process is the key to ensuring the quality of the high-temperature alloy forging.

[0044] In the spinning process, the spinning process parameters are controlled to optimize the forming performance of the workpiece and the final microstructure, and in addition, after forming, the cooling speed of the workpiece has a significant influence on the final microstructure and performance.

[0045] As a preferred scheme of the present application, for the blank of titanium alloy material, the spinning temperature is 700-900℃. The titanium-based alloy blank includes but is not limited to one of Ti6242, Ti64, TC11, TC4, TA12A, TA7, TA15, etc. For different types of titanium alloy materials, the spinning temperature is different, and the spinning temperature will be adjusted according to the phase transition temperature of the specific material grade to ensure that the plasticity of the titanium alloy is high and the deformation resistance is low at the spinning temperature.

[0046] In the spinning process, the initial spinning temperature of the titanium alloy material is generally higher than its beta transformation temperature to ensure that the titanium alloy has good plasticity in the beta phase region. At the same time, the spinning temperature before the end of spinning should be controlled in the alpha + beta two-phase region to ensure the organization and mechanical properties of the forging. In addition, the spinning temperature range of titanium alloy is narrow, which requires strict control of the heating and temperature compensation time of the blank by the heating and temperature compensation system during the spinning manufacturing process, so that the spinning temperature fluctuation range of the blank is controlled within ± 20℃, to avoid grain growth or other adverse organizational structure.

[0047] As a preferred scheme of the present application, in the near-isothermal hot spinning, the blank is heated and temperature compensated by the heating and temperature compensation system to ensure that the spinning temperature fluctuation range is not more than ± 10℃ during the process from the beginning to the end of spinning. The spinning temperature is more accurately controlled, the deformation coefficient of the metal material is smaller, and the consistency of the formed workpiece product is better.

[0048] As a preferred scheme of the present application, in the near-isothermal hot spinning process for spinning and forming the blank, the rotation speed of the blank is 50-300r / min; the spinning wheel feed ratio is 0.1-3cm / r; the spinning wheel corner radius is 0.3t-2.5t, where t is the wall thickness of the blank, mm; the thinning rate of each pass is 10-40%, and the thinning rate of each pass should be not greater than the ultimate thinning rate of the metal material.

[0049] In the above technical scheme, in order to ensure the mechanical properties and machining precision of the workpiece, the spinning process parameters are controlled during the spinning process, the main shaft of the spinning equipment drives the workbench and the blank to rotate, the rotation speed of the blank is reasonably selected within the range of 50-300r / min, the spinning wheel feed ratio is reasonably selected within the range of 0.1-3mm / r; the spinning wheel corner radius is reasonably selected within the range of 0.3t-2.5t; the thinning rate of each pass should be not greater than the ultimate thinning rate, which is generally reasonably selected within the range of 10-40%, and the blank is spun to the design requirements of the workpiece after at least one spinning pass. If the thinning rate of one pass is not more than the ultimate thinning rate of the material then single-pass spinning can make the blank meet the wall thickness and size requirements, and the spinning forming is completed; if the single-pass thinning rate exceeds the ultimate thinning rate then the spinning should be divided into two passes, and the thinning rate of the first pass can be set to the ultimate thinning rate If the second-pass thinning rate also exceeds the ultimate thinning rate The thickness of the workpiece still does not meet the requirements, and the spinning should be divided into three passes, and so on, until the thickness of the workpiece after the last spinning pass meets the process requirements. In the spinning process, the spinning process parameters are controlled to optimize the forming performance and final organizational structure of the workpiece.

[0050] As a preferred scheme of the present application, the spinning wheel assembly of the spinning equipment adopts staggered or non-staggered distance, when the staggered distance is adopted, the radial and axial staggered distances are selected according to the spinning process and the material of the workpiece; the spinning wheel mode adopts positive spinning or reverse spinning.

[0051] The present application also provides a metal workpiece, which is prepared by the near-isothermal hot spinning forming method.

[0052] As a preferred scheme of the present application, the workpiece cross section includes but is not limited to one suitable for the spinning process in rectangular workpieces, flange workpieces, I-shaped workpieces, L-shaped workpieces, long cylindrical workpieces, conical workpieces, special-shaped workpieces, etc.

[0053] The present application also provides a heating method for a heating system in near-isothermal hot spinning forming, which comprises the following steps: after the heated blank is transferred and clamped on the workbench rotating with the main shaft of the spinning equipment, the blank is located in the effective heating area of the heating system, the blank is heated and tempered by the heating system, the heating target temperature T 补 and the heating rate v of the heating system are set, so that the blank temperature T 坯 of the blank reaches the spinning pre-temperature required by the process The spinning pre-temperature is calculated according to the following formula:

[0054]

[0055] Wherein T 旋 is the measured spinning temperature in the spinning deformation zone during the spinning process of the workpiece, in ℃; ΔT is the temperature rise caused by the spinning deformation heat, in ℃;

[0056] After the blank temperature T 坯 of the blank reaches the spinning pre-temperature required by the process , the spinning equipment is started to spin according to the predetermined spinning program, and the blank is heated and tempered by the heating system to control the spinning temperature within the range required by the process, and the fluctuation range is not more than ±20℃ during the spinning deformation process.

[0057] As a preferred scheme of the present application, the calculation formula of ΔT is as follows:

[0058]

[0059] Wherein Q is the heat generated by plastic deformation, in J; m is the mass of the blank, in kg; C is the specific heat capacity of the blank material, in J / (kg·℃).

[0060] As a preferred scheme of the present application, the calculation formula of the heat Q generated by plastic deformation is as follows:

[0061]

[0062] Wherein, theta is the coefficient of thermal deformation effect, generally 0.9 in metal plastic deformation; Equivalent stress at deformation temperature, the yield strength of the material at deformation temperature can be taken as the equivalent stress for the convenience of calculation; Equivalent strain rate of spinning deformation; the calculation formula of equivalent strain rate is as follows:

[0063]

[0064] Wherein, n is the rotating speed of the spinning spindle, and the unit is r / min; Spinning thinning rate, t0, tf respectively are the thickness of the blank before and after spinning, and the unit is mm.

[0065] Compared with the prior art, the beneficial effects of the present application are:

[0066] 1. The hot spinning forming method provided by the present application places the blank in the effective temperature compensation zone, measures the temperature of the clamped and fixed blank before spinning and judges whether the blank temperature meets the pre-spinning blank temperature required by the spinning process, if the blank temperature meets the pre-spinning blank temperature required by the process at this time, the spinning equipment is started to spin, if the blank temperature is lower than the pre-spinning blank temperature required by the process at this time, the spinning is started after the blank is heated and compensated to the pre-spinning blank temperature by the heating compensation system, the blank is heated and compensated by the effective temperature compensation zone of the heating compensation system to prevent the temperature of the blank from continuing to lose, so that the temperature of the blank meets the spinable condition required by the process, that is, the pre-spinning temperature, the spinning is started under the temperature condition that the temperature of the blank meets the pre-spinning blank temperature, in the spinning process, the blank is continuously heated and compensated by the heating compensation system, so that the spinning temperature of the blank fluctuates in the range of not more than ±20℃ from the start to the end of spinning, that is, the deformation temperature of the metal material in the forming process is maintained in a small fluctuation range by using the measurable and controllable heating compensation system, such setting can ensure that the deformation ability of the metal material is good and the deformation resistance is reduced in the spinning process, the forming quality and forming efficiency are improved, the consistency of the formed workpiece product is good, and the manufacturing requirements of high-precision workpieces can be met, the technical scheme of the present application is suitable for difficult-to-deform metals with narrow forming temperature range, and is also suitable for non-difficult-to-deform metals.

[0067] 2. The spinning equipment of the present application integrates a heat supplement system and a spinning wheel system, the heat supplement system and the spinning wheel system are arranged on the machine body, the spinning wheel assembly of the spinning wheel system locally pressurizes the blank, and can shape the shape and size of the workpiece; the furnace body of the heat supplement system is of a semi-closed structure, a furnace cavity is formed in the furnace body, and a heating element is arranged in the furnace cavity, the heating element is arranged in the furnace body to form an effective heat supplement area, and the blank is located in the effective heat supplement area to heat and supplement the temperature of the blank; at the same time, the furnace body of the heat supplement system is provided with a spinning wheel movement groove, the spinning wheel assembly passes through and is located in the spinning wheel movement groove, so that the spinning wheel assembly can independently move in the radial and axial directions of the workbench, the spinning process and the heat supplement process do not interfere with each other, and the realization of spinning and heat supplement during the shaping process of the workpiece is ensured respectively.

[0068] 3. The heat supplement system furnace body and the temperature control system of the present application, the temperature control system comprises a furnace body temperature measurement module, a control module and a heating module, the connection between the furnace body temperature measurement module, the heating module and the control module of the temperature control system constitutes a temperature closed-loop control system, through accurate temperature measurement of the furnace body temperature measurement module, temperature control of the control module and accurate regulation and control of the heating module, the temperature uniformity of the effective heat supplement area is ± 15℃, the temperature control accuracy is ± 1℃, and the equipment foundation for realizing accurate control of the spinning temperature during the spinning process is provided.

[0069] 4. In the spinning forming process, the heat supplement system is used to heat and supplement the temperature of the blank, the near-isothermal hot spinning process is realized, the deformation compatibility of the blank is improved, the forming quality and production efficiency of the workpiece are improved, and the results of the embodiments show that the near-isothermal hot spinning method of the present application is used for spinning forming of high-temperature alloy or titanium alloy, the wall thickness of the obtained spinning workpiece is uniform, the workpiece is prevented from cracking during multi-pass spinning, the forming quality is good, defects such as instability and wrinkling do not occur during the spinning process, and the generation of cracks and the risk of polishing are also reduced; the mechanical properties of the workpiece obtained by spinning meet the performance requirements of the parts, and the uniformity of the workpiece is improved, and the grain size can reach 7-9 levels.

[0070] 5. The near-isothermal hot spinning forming method of the present application can realize the forming of thin-walled workpieces by controlling the temperature and spinning process parameters, the process flow is simple and can be realized, material is saved and processing cost is reduced, the temperature during the spinning deformation process is controllable and measurable, and the quality consistency and stability of the workpiece are effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 A blank cross section prepared for Example 1.

[0072] Figure 2 A workpiece cross section prepared for Example 1.

[0073] Figure 3The structure schematic diagram of the heat supplement system and the spinning wheel system of the spinning equipment.

[0074] Figure 4 The opening and closing state profile schematic diagram of the heat supplement system of the spinning equipment.

[0075] Figure 5 The top view schematic diagram of the heat supplement system and the spinning wheel system of the spinning equipment.

[0076] Figure 6 The blank cross section schematic diagram prepared in the embodiment 2.

[0077] Figure 7 The workpiece cross section schematic diagram prepared in the embodiment 2.

[0078] The figure mark: 1-machine body, 2-workbench, 31-furnace body one, 32-furnace body two, 41-outer spinning wheel, 42-inner spinning wheel, 5-blank, 6-workpiece. DETAILED DESCRIPTION

[0079] In order to more clearly describe the invention purpose, technical scheme and technical effect advantage in the specific implementation case of the present application, the scheme in the specific embodiment will be described in detail in combination with the drawings of the present application. The specific technical scheme involved in the following specific embodiment is only for clearly and completely describing the innovative technical scheme of the present application, and it is only a part of the specific implementation scheme of the present application, not all the embodiments, and should not be understood as the limitation of the innovative scheme of the present application. Any scheme adopting the same inventive concept of the present application should be included in the protection scope of the present application.

[0080] Secondly, the related description of the drawings in the specific embodiment of the present application is only for facilitating the technical personnel to understand the present application scheme, and part of the details in the drawings is exhibited for facilitating the clear presentation of the technical scheme, and should not be considered that all the technical features in the drawings must be included in the specific implementation case, and more cannot be considered as the additional limitation of the innovative technical scheme of the present application. The components in each embodiment described and exhibited in the drawings can be combined and arranged in different configurations, and these combination and arrangement changes should be considered as a part of the all embodiments of the innovative scheme of the present application, and should be included in the protection scope of the present application.

[0081] In summary, the scheme or description presented in the specific embodiment and the drawings of the present application is not intended to limit the protection scope, but only represents the selected embodiment / case for helping the technical personnel to understand the related innovative scheme. Based on these embodiments, all other equivalent or parallel embodiments obtained by the technical personnel in the art without making creative labor belong to the protection scope of the present application.

[0082] It should be noted that, in the description of the embodiments of the present application, the terms of orientation or position relationship such as "upper", "lower", "left", "right", "center", "inner", "outer", and the like, are expressed based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product / device / apparatus of the present application is usually placed. These terms of orientation or position relationship are only for the convenience of describing the present application or simplifying the description in the embodiments, and for the convenience of the skilled person to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present application.

[0083] In addition, in the description of the technical scheme of the present application, unless otherwise specified / limited / limited, the terms "provided", "mounted", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected, which can be welding, riveting, bolting, screwing, etc. The connection means commonly used in the art. The connection can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the communication between two elements.

[0084] Example 1

[0085] The blank material is high-temperature alloy GH4169, and the initial wall thickness of the blank 5 before spinning is 15 mm, as shown in Figure 1 , the designed minimum wall thickness of the workpiece 6 after spinning is 10.5 mm, as shown in Figure 2 , the spinning thinning rate is 30%, according to the experience of hot spinning production of nickel-based high-temperature alloy, the single-pass ultimate thinning rate is generally 50-60%, the maximum thinning rate of the workpiece is less than the ultimate thinning rate, and single-pass spinning forming can be used. The spinning design adopts one-pass spinning to 10.5 mm, the deformation amount is 30%, the spinning segment length is increased from 145 mm to 200 mm, the spinning of the workpiece adopts near-isothermal hot spinning, and the spinning is performed in a spinning equipment.

[0086] As shown in Figure 3 , Figure 4As shown, the spinning equipment integrates a heat supplement system and a spinning roller system, a workbench 2 is installed on a spindle of a spinning equipment body 1, the spindle can drive the workbench 2 to rotate, the heat supplement system comprises a furnace body and a temperature control system, the temperature control system comprises a furnace body temperature measurement module, a control module and a heating module, the heating module comprises a plurality of heating rods; the furnace body is of a semi-closed movable split structure, a furnace cavity is formed in the furnace body, the heating rods are arranged on the inner wall of the furnace cavity for forming an effective heat supplement area in the furnace cavity, the furnace body comprises a furnace body one 31 and a furnace body two 32, and is of a semi-cylindrical cavity structure, the furnace body one 31 and the furnace body two 32 are oppositely arranged, and the furnace body one 31 and the furnace body two 32 can be close to or away from the workbench 2, a furnace cavity one is formed in the furnace body one 31, and a furnace cavity two is formed in the furnace body two 32, and the blank 5 is located in the effective heat supplement area when the furnace body one 31 and the furnace body two 32 are close to the workbench 1; a first spinning roller movement groove is arranged on the furnace body one 31, a second spinning roller movement groove is arranged on the furnace body two 32, and the first spinning roller movement groove and the second spinning roller movement groove form a spinning roller movement groove, the spinning roller system comprises an inner spinning roller 42 and an outer spinning roller 41, when the spinning roller assembly is working, the entire structure of the inner spinning roller 42 and part of the structure of the outer spinning roller 41 are located in the effective heat supplement area of the heat supplement system, the inner spinning roller 42 is located at the inner side of the blank 5 and can abut against the inner wall of the workpiece blank 5, the outer spinning roller 41 is located at the outer side of the blank 5 and can abut against the outer wall of the workpiece blank 5, the inner spinning roller 42 and the outer spinning roller 41 pass through and are located in the spinning roller movement groove, and the inner spinning roller 42 and the outer spinning roller 41 can freely move in the radial direction and the axial direction of the blank, the radial direction of the blank refers to the direction perpendicular to the center axis of the blank, the axial direction of the blank refers to the direction parallel to the center axis of the blank, the diameter and the width of the spinning roller movement groove should be greater than the diameters of the inner spinning roller and the outer spinning roller, and the spinning roller movement groove is C-shaped, as shown in the figure, so as to prevent interference during the spinning process. Figure 5

[0087] The spinning equipment is provided with a control system for controlling the operation of the heat supplement system and the spinning system. The spinning equipment is also provided with a blank temperature measurement module which is externally arranged on the heat supplement system, and the blank temperature measurement module is an infrared temperature measurement sensor for detecting the temperature of the blank located in the effective heat supplement area to obtain the blank temperature T 坯 or the spinning temperature T 旋 .

[0088] In the spinning process, the blank temperature needs to reach the spinning pre-temperature required by the process before spinning is started, the spinning pre-temperature is obtained according to experience or by using a calculation formula, and the spinning pre-temperature T is calculated according to the following formula:

[0089]

[0090] wherein T 旋 ​The spinning temperature measured in the spinning deformation zone during the spinning process of the workpiece is in ℃, and the spinning temperature can be obtained according to the corresponding hot working diagram of the workpiece material. The spinning temperature for a specific metal material is a range value, which can be obtained through a material manual or a thermal simulation test; ΔT is the temperature rise caused by the spinning deformation heat, in ℃, and the calculation formula of ΔT is as follows:

[0091]

[0092] Wherein Q is the heat generated by plastic deformation, in J; m is the mass of the blank, in kg; C is the specific heat capacity of the blank material, in J / (kg·℃), and the calculation formula of the heat Q generated by plastic deformation is as follows:

[0093]

[0094] Wherein θ is the deformation heat effect coefficient, generally taken as 0.9 in metal plastic deformation; is the equivalent stress at the deformation temperature, which can be taken as the yield strength σs of the material at the deformation temperature for convenience; is the equivalent strain rate of spinning deformation;

[0095]

[0096] Wherein n is the spinning spindle speed, in r / min; is the spinning thinning rate, t0,tf are the thicknesses of the blank before and after spinning, respectively, in mm.

[0097] The near-isothermal hot spinning forming method comprises the following steps:

[0098] (1) The blank is heated to a spinning preheating temperature of 1000℃ by using a heating device. During the heating process, the set heating temperature of the heating device is 1000℃, and the blank needs to be placed in the heating device for heat preservation. The heat preservation time is calculated according to the wall thickness of the blank at 0.4-0.8 min / mm, so that the temperature of the blank reaches 1000℃;

[0099] (2) The target temperature of the temperature compensation system after the furnace body is closed is consistent with the spinning temperature required by the process. Before the blank is placed on the workbench, the furnace body one and the furnace body two of the temperature compensation system are moved away from the workbench to a certain distance to open the furnace body. The opening time of the furnace body is controlled within 15s;

[0100] The mechanical arm quickly transfers and clamps the heated blank on the workbench of the spinning device. After clamping, the furnace body one and the furnace body two of the temperature compensation system are close to the workbench to quickly close the furnace body. The closing time of the furnace body is controlled within 15s;

[0101] (3) The infrared temperature sensor detects the temperature of the blank at this time, and the control system controls the temperature T 坯 and the calculated temperature before spinning In contrast, if The heating system is started to heat the blank, the heating system will increase the heating power of the heating element, increase the temperature rising rate of the heating, and increase the ambient temperature in the effective temperature zone of the heating system. In the heating time, the blank is actively compensated and heated to compensate for the temperature loss of the workpiece; if The heating system is started to heat the blank, and the spinning equipment is started to spin the workpiece according to the predetermined spinning program.

[0102] (4) The blank is spun and formed in the spinning equipment using the near-isothermal hot spinning process. The inner spinning wheel and the outer spinning wheel move along the pre-set motion trajectory through the pre-fabricated groove on the heating system furnace body to spin the spinning point. According to the pre-set spinning trajectory, hot spinning is started. In the spinning process, the heating system continues to heat the blank, and the deformation temperature in the spinning deformation zone of the blank, i.e. the spinning temperature, is monitored and recorded in real time, so that the spinning temperature fluctuates by no more than ±20℃ from the start to the end of the spinning process. The spinning process parameters are as follows: the rotation speed of the workbench driving the blank is 100 revolutions per minute; the spinning wheel feed ratio is 0.5-0.8 millimeters per revolution; the spinning wheel corner radius is 1t; the pass reduction rate is 30%, and the spinning wheel mode is positive spinning.

[0103] The formed part is detected, and the wall thickness of the formed workpiece is uniform without cracking defects. According to the mechanical property test standard, the mechanical properties of the workpiece meet the requirements in multiple test results, and the grain size of the formed workpiece can reach 7-9 levels according to the test, which shows that the forming precision of the forming method is very high, and the quality of the workpiece can be ensured, and the reliability and durability of the workpiece in various engineering applications can be met.

[0104] Example 2

[0105] The blank material is Ti64 titanium alloy, and the initial wall thickness of the blank 5 before spinning is 26mm, as shown in Figure 6 The designed wall thickness of the workpiece 6 after spinning is 15mm, and the workpiece is a flange workpiece, as shown in Figure 7 The spinning reduction amount is 42%, and the spinning design adopts two-pass spinning to 15mm. The spinning of the workpiece adopts near-isothermal hot spinning, and the spinning of this embodiment is carried out in the spinning equipment of example 1.

[0106] The spinning temperature of the Ti64 titanium alloy blank before spinning is obtained according to experience or calculated according to the relationship between the spinning deformation temperature and the deformation temperature rise. In this embodiment, the Ti64 alloy hot working diagram is consulted and combined with production experience, and the spinning temperature T 旋 30-50℃ below the phase transition point, T旋 900℃, the temperature of the blank before spinning is calculated as about 870℃, the near-isothermal hot spinning forming method comprises the following steps:

[0107] (1) The blank is heated to the preheating temperature of 900℃ by using a heating device. During the heating process, the set heating temperature of the heating device is 900℃, and the blank needs to be kept in the heating device. The holding time is calculated according to the wall thickness of the blank at 0.6-0.8 min / mm;

[0108] (2) The target temperature of the heating system after the furnace body is closed is consistent with the spinning temperature required by the process. Before the blank is placed on the workbench, the furnace body one and the furnace body two of the heating system are moved away from the workbench to a certain distance to open the furnace body. The opening time of the furnace body is controlled within 15 seconds;

[0109] The heated blank is quickly transferred and clamped and fixed on the workbench of the spinning device by the mechanical arm. After clamping, the furnace body one and the furnace body two of the heating system are moved close to the workbench to quickly close the furnace body. The closing time of the furnace body is controlled within 15 seconds;

[0110] (3) The temperature of the blank at this time is detected by the infrared temperature sensor, and the control system controls the temperature T 坯 of the blank to be consistent with the calculated temperature of the blank before spinning If the temperature of the blank is lower than the calculated temperature of the blank before spinning , the heating system is started to heat and compensate the temperature of the blank. The heating system will increase the heating power of the heating element to increase the temperature rising rate of the compensation, so that the ambient temperature in the effective temperature zone of the heating system is increased. The blank is actively compensated and heated within the compensation time to compensate for the temperature loss of the workpiece; if the temperature of the blank is higher than the calculated temperature of the blank before spinning , the heating system is started to compensate the temperature of the blank, and the spinning device is started to spin the workpiece according to the predetermined spinning program.

[0111] (4) The blank is spun and formed by using the near-isothermal hot spinning process in the spinning device. The inner spinning roller and the outer spinning roller move the spinning starting point through the groove preformed on the furnace body of the heating system according to the pre-set motion trajectory, and start hot spinning according to the pre-set spinning trajectory. During the spinning process, the heating system continues to heat and compensate the temperature of the blank, and the deformation temperature in the deformation zone of the blank, i.e. the spinning temperature, is monitored and recorded in real time, so that the spinning temperature fluctuates by no more than ±20℃ from the start to the end of the spinning. The spinning process parameters are as follows: the rotation speed of the workbench driving the blank is 180 revolutions per minute; the spinning roller feed ratio is 1-1.2 millimeters per revolution; the spinning roller round corner radius is 1t; the reduction rate of each pass is 20-25%; and the spinning roller mode is positive spinning.

[0112] The above steps are repeated to complete two passes of spinning until the blank reaches the design size of the workpiece. The titanium alloy material workpiece is tested according to the mechanical property test standard, and the mechanical properties of the workpiece meet the requirements in multiple test results, and the grain size of the formed workpiece can reach 7-9 levels.

[0113] For those skilled in the art, when understanding the scheme described in the embodiments of the present application, reference can be made to the conventional technical manuals in the art, and for the above-mentioned terms, appropriate understanding or adjustment can be made for reference, and the same or similar technical scheme implementation conditions can be derived without creative labor.

[0114] The above embodiments only describe the basic principles, main features and / or advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments. The above embodiments and the description in the summary of the application only describe the principles or specific cases of the present application. Without departing from the essence of the innovative idea of the present application, the innovative scheme of the present application can have various changes and improvements. These changes and improvements all fall within the scope of the present application.

Claims

1. A near-isothermal hot spin forming method for metal workpieces, characterized in that, Includes the following steps: Heat the billet to the spinning preheating temperature; The heated billet is transferred and clamped onto a worktable that rotates with the spindle of the spinning equipment. A heating system is installed around the worktable, and the billet is located within the effective heating zone set by the heating system. The spinning equipment includes a machine body, a heating system, and a spinning wheel system. The heating system includes a furnace body and a temperature control system. The temperature control system includes a furnace body temperature measuring module, a control module, and a heating module. The heating module includes several heating elements. A furnace cavity is formed inside the furnace body, and the heating elements are arranged on the inner wall of the furnace cavity to form an effective heating zone within the furnace cavity. The furnace body includes Furnace Body One and Furnace Body Two, which are arranged opposite to each other. Furnace Body One and Furnace Body Two can approach or move away from the worktable. When Furnace Body One and Furnace Body Two approach each other, they close to form a furnace cavity, so that the billet is located within the effective heating zone of the furnace cavity. The temperature of the billet after clamping and fixing is measured and the billet temperature T is determined. 坯 Does the billet temperature T before spinning meet the process requirements? b旋 If T 坯 ≥T b旋 Then the spinning equipment will be started for spinning; if T 坯 <T b旋 The heating system is used to heat the billet to a temperature that meets the T standard. 坯 ≥T b旋 Then restart the spinning equipment to perform spinning; In the spinning equipment, a near-isothermal hot spinning process is used to spin the billet. During near-isothermal hot spinning, a heating system is used to actively heat and replenish the temperature of the billet, and the spinning temperature in the spinning deformation zone of the billet is monitored in real time to ensure that the fluctuation range of the spinning temperature from the beginning to the end of the spinning deformation does not exceed ±20℃.

2. The near-isothermal hot spinning forming method for metal workpieces according to claim 1, characterized in that, The time taken to transfer the heated billet and clamp it onto the worktable of the spinning equipment is called the transfer time, which must not exceed 90 seconds.

3. The near-isothermal hot spinning forming method for metal workpieces according to claim 1, characterized in that, A worktable is mounted on the main shaft of the machine body, and the rotary wheel system includes a rotary wheel assembly; a rotary wheel movement groove is provided on the furnace body, and the rotary wheel assembly passes through the rotary wheel movement groove to ensure that the rotary wheel assembly can move freely along the radial and axial directions of the billet; the furnace body temperature measuring module is used to detect the temperature of the effective heat compensation zone, and the furnace body temperature measuring module and the heating module are both electrically connected to the control module.

4. The near-isothermal hot spinning forming method for metal workpieces according to claim 3, characterized in that, The rotating wheel assembly includes an inner rotating wheel and an outer rotating wheel. When the rotating wheel assembly is working, the entire structure of the inner rotating wheel and part of the structure of the outer rotating wheel are located within the effective heating zone of the heating system. The inner rotating wheel is located inside the billet and can abut against the inner wall of the workpiece billet. The outer rotating wheel is located outside the billet and can abut against the outer wall of the workpiece billet. The inner rotating wheel and the outer rotating wheel pass through the rotating wheel movement groove and are located within the rotating wheel movement groove, ensuring that the inner rotating wheel and the outer rotating wheel can move independently and freely along the radial and axial directions of the billet.

5. A near-isothermal hot spinning forming method for metal workpieces according to claim 3, characterized in that, A first rotating wheel movement groove is provided on the first furnace body, and a second rotating wheel movement groove is provided on the second furnace body. The first rotating wheel movement groove and the second rotating wheel movement groove form the rotating wheel movement groove.

6. The near-isothermal hot spinning forming method for metal workpieces according to claim 5, characterized in that, The furnace body one and furnace body two close the furnace body of the heat replenishment system by approaching the workbench; the furnace body one and furnace body two open the furnace body of the heat replenishment system by moving away from the workbench. The time taken for the furnace body to complete closing is controlled within 15 seconds, and the time taken for the furnace body to complete opening is controlled within 15 seconds.

7. The near-isothermal hot spinning forming method for metal workpieces according to claim 1, characterized in that, The billet temperature T was measured after clamping and fixing. 坯 And the required spinning temperature T before spinning b旋 Comparison; if T 坯 <T b旋 The system is started and waits for the heating system to heat the billet. The heating system increases the heating power of the heating elements to improve the temperature rise rate. Within the specified heating time, the billet is actively heated to reach the pre-spinning temperature. Then, the spinning equipment is started to spin the workpiece according to the predetermined spinning program. If T 坯 ≥T b旋 The heating system is activated to replenish the temperature of the billet, and the spinning equipment is started to spin according to the predetermined spinning program. The heating system maintains the heating power of the heating element to keep the billet temperature within the spinning temperature range.

8. A near-isothermal hot spinning forming method for metal workpieces according to claim 7, characterized in that, The temperature of the effective heating zone of the heating system is not higher than the spinning preheating temperature; if T 坯 <T b旋 The heating system is activated to heat the billet, and the heating time of the heating system shall not exceed 5 minutes.

9. A near-isothermal hot spinning forming method for metal workpieces according to claim 1, characterized in that, The spinning equipment is also equipped with a billet temperature measuring module, which is used to detect the temperature of the billet located in the effective heat compensation zone to obtain the billet temperature or spinning temperature; the billet temperature measuring module is externally mounted on the heat compensation system or on the body of the spinning equipment.

10. A near-isothermal hot spinning forming method for metal workpieces according to claim 1, characterized in that, During near-isothermal hot spinning, a heating system is used to heat the billet to ensure that the spinning temperature fluctuates within ±10℃ from the start to the end of the spinning deformation process.

11. A near-isothermal hot spinning forming method for metal workpieces according to any one of claims 1-10, characterized in that, For high-temperature alloy blanks, the spinning temperature is 900–1150℃.

12. A near-isothermal hot spinning forming method for a metal workpiece according to any one of claims 1-10, characterized in that, For titanium alloy blanks, the spinning temperature is 700–900℃.

13. A near-isothermal hot spinning forming method for metal workpieces according to any one of claims 1-10, characterized in that, During the near-isothermal hot spinning process for spinning the billet, the billet rotation speed is 50-300 r / min; the spinneret feed ratio is 0.1-3 mm / r; the spinneret fillet radius is 0.3t-2.5t, where t is the billet wall thickness; the thinning rate per pass does not exceed the limit thinning rate of the billet material, and the thinning rate per pass is 10-40%.

14. A metal workpiece, characterized in that, The workpiece is prepared by a near-isothermal hot spinning forming method for metal workpieces as described in any one of claims 1-13.

15. A metal workpiece according to claim 14, characterized in that, The workpiece is one of the following: rectangular workpiece, flange workpiece, I-shaped workpiece, L-shaped workpiece, long cylindrical workpiece, conical workpiece, or irregular-shaped workpiece.

16. A method for supplementing the heat of a heat-supplementing system in near-isothermal hot spinning, characterized in that, The heat replenishment method includes: After the heated billet is transferred and clamped onto the worktable that rotates with the spindle of the spinning machine, the billet is located within the effective heating zone of the heating system. The heating system is used to heat and replenish the billet temperature. By setting the target temperature and heating rate of the heating system, the billet temperature T is maintained. 坯 The spinning temperature T before reaching the process requirements b旋 Temperature T before spinning b旋 The calculation formula is as follows: Where T 旋 The actual spinning temperature measured within the spinning deformation zone during the spinning process of the workpiece; The temperature rise is due to the heat generated by spinning deformation; billet temperature T 坯 The spinning temperature T before reaching the process requirements b旋 Then, the spinning equipment is started to spin according to the predetermined spinning program. At the same time, the heating system is started to heat the billet to keep the spinning temperature within the range required by the process, and the fluctuation range from the start to the end of the spinning deformation does not exceed ±20℃. The spinning equipment includes a machine body, a heating system, and a spinning wheel system. The heating system includes a furnace body and a temperature control system. The temperature control system includes a furnace body temperature measuring module, a control module, and a heating module. The heating module includes several heating elements. A furnace cavity is formed inside the furnace body. The heating elements are arranged on the inner wall of the furnace cavity to form an effective heating zone within the furnace cavity. The furnace body includes Furnace Body 1 and Furnace Body 2, which are arranged opposite to each other. Furnace Body 1 and Furnace Body 2 can be close to or far from the worktable. When Furnace Body 1 and Furnace Body 2 are close together, they close to form a furnace cavity, so that the billet is located within the effective heating zone of the furnace cavity.

17. The heat compensation method for a heat compensation system in near-isothermal hot spinning forming according to claim 16, characterized in that, The calculation formula is as follows: Where Q is the heat generated by plastic deformation; m is the mass of the billet; and C is the specific heat capacity of the billet material.

18. The heat compensation method for a heat compensation system in near-isothermal hot spinning according to claim 17, characterized in that, The formula for calculating the heat Q generated by plastic deformation is as follows: Where θ is the deformation thermal effect coefficient; The equivalent stress at the deformation temperature; is the equivalent strain rate of spinning deformation.

Images