Method and system for adjusting intensity of stirring for cooling of metal forgings

Abstract

The application discloses a metal forging cooling stirring intensity adjusting method and system, and belongs to the technical field of metal heat treatment. The method sets a specific jet stirring mechanism at the center of the bottom of a quenching tank and arranges a lateral auxiliary stirrer on the sidewall of the quenching tank. The spatial coordinate position of the core area of the upper end surface of the forging is calculated by acquiring the geometric parameters of the forging, the directional jet stirring mechanism is controlled to be aligned with the core cooling blind area of the upper end surface, the cooling liquid flow is obliquely impacted on the blind area and an effective vertical flow velocity component is formed, meanwhile, the lateral auxiliary stirrer is operated at an auxiliary intensity lower than the directional jet stirring intensity, the overall circulating flow in the quenching tank is maintained, the stirring intensity is dynamically adjusted in three stages according to the quenching cooling time sequence, and the temperature difference closed-loop feedback adjustment based on infrared temperature measurement is carried out. The application can accurately eliminate the cooling blind area of the core of the upper end surface of a large-diameter pie-shaped forging, realizes the uniform cooling of the whole forging, and significantly improves the quenching hardness consistency and the structure uniformity.

Description

Technical Field

[0001] This invention belongs to the field of metal heat treatment technology, and specifically relates to a method and system for adjusting the cooling stirring intensity of metal forgings. Background Technology

[0002] For large-diameter disc-shaped forgings (such as low-pressure rotor discs for nuclear power turbines, large flanges, and pressure vessel heads), the quenching and cooling process directly determines their final microstructure and mechanical properties during tempering heat treatment. In industrial settings, the disc-shaped forgings are typically placed horizontally on shims, heated to the austenitizing temperature in a furnace, and then hoisted into a quenching tank for cooling. To accelerate cooling and improve hardenability, the quenching tank is generally equipped with a stirring device that generates a circulating flow field through a propeller or bottom nozzle, enhancing convective heat transfer between the quenching medium and the forging surface.

[0003] However, existing quenching stirring systems have the following technical drawbacks:

[0004] First, the flow field generated by existing stirring devices is mainly characterized by circumferential circulation and vertical downward flow. For large-diameter disc-shaped forgings placed horizontally, the coolant flow is unlikely to form an effective vertical downward impact component in the core region of the upper end face (the upward-facing side) of the forging. Specifically, when the propeller agitator is installed on the tank wall or bottom, the circulating flow it generates mainly splits horizontally after reaching the upper surface of the forging. The vertical velocity component in the core region of the upper end face approaches zero, forming a significant quenching cooling blind zone. The cooling rate in this blind zone is much lower than that on the lower end face and the outer circumferential surface, resulting in insufficient hardness and substandard microstructure in the core region of the upper end face.

[0005] Second, existing technologies generally employ a uniform stirring intensity across the entire groove, which cannot provide localized strengthening for the specific blind area of ​​the core on the upper end face of the forging. Simply increasing the overall stirring intensity, while improving cooling in the blind area to some extent, will simultaneously exacerbate excessive cooling of the lower end face, leading to excessively rapid cooling and increased structural stress, which in turn induces quenching cracks.

[0006] Third, existing methods for adjusting stirring intensity largely rely on fixed-time programs (e.g., strong stirring for the first 30 seconds and weak stirring for the next 60 seconds), failing to consider the differentiated stirring intensity requirements of forgings at different quenching stages (film boiling, nucleation boiling, and convection cooling). In the film boiling stage, the forging surface is enveloped by a vapor film, requiring strong stirring to accelerate its rupture; in the nucleation boiling stage, excessive stirring can lead to excessively rapid local cooling; and in the convection cooling stage, only gentle circulation is needed to complete the microstructure transformation. Fixed programs cannot be synchronized with the physical state of the forging surface.

[0007] Fourth, in multi-batch continuous quenching scenarios, as the temperature of the quenching medium increases cumulatively, its cooling performance continuously declines, while the stirring intensity of the existing system remains unchanged, resulting in the actual cooling effect of subsequent batches of forgings deteriorating batch by batch, leading to poor quality consistency.

[0008] In summary, existing quenching stirring techniques cannot effectively address the cooling blind zone problem in the core area of ​​the upper surface of large-diameter disc-shaped forgings. There is an urgent need for a cooling stirring intensity adjustment method and system that can precisely cover the blind zone, consider overall circulation, and dynamically adjust according to the quenching stage. Summary of the Invention

[0009] The purpose of this invention is to provide a method and system for adjusting the cooling and stirring intensity of metal forgings. By combining bottom center directional spraying with lateral auxiliary stirring, and a timing control strategy that dynamically adjusts according to the quenching stage, the cooling blind zone in the core of the upper end face of the forging is precisely eliminated, while avoiding over-cooling in other areas, thereby improving the overall cooling uniformity of the forging and stabilizing the quenching quality.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a method for adjusting the cooling stirring intensity of metal forgings. The method is applied to large-diameter disc-shaped forgings that are horizontally placed on a pad in a quenching tank for quenching and cooling. A lifting and rotating directional spray stirring mechanism is provided at the center of the bottom of the quenching tank. The spray nozzle angle of the directional spray stirring mechanism is electrically adjustable. A lateral auxiliary stirrer is arranged on the side wall of the quenching tank.

[0012] The method includes the following steps:

[0013] Step S1: Before the forging is quenched in the groove, the geometric parameters of the forging are obtained, including the outer diameter, thickness and material information of the forging; the spatial coordinate position of the core area of ​​the upper end face of the forging is calculated according to the geometric parameters, wherein the core area of ​​the upper end face is a circular area with the center of the upper end face of the forging as the center.

[0014] Step S2: Based on the spatial coordinates of the core area on the upper end face of the forging, control the directional spraying and stirring mechanism to rise or fall to the target height and rotate horizontally to the target azimuth angle so that the spray nozzle is aligned with the center of the core area on the upper end face; adjust the spray nozzle angle so that the sprayed coolant flow obliquely impacts the core area on the upper end face of the forging, forming a vertical velocity component in the core area on the upper end face.

[0015] Step S3: While the directional jet stirring mechanism is running, the lateral auxiliary stirrer is started. The lateral auxiliary stirrer operates at an auxiliary intensity lower than the directional jet stirring intensity to maintain the overall circulating flow in the quenching tank and prevent the local turbulence caused by the directional jet flow from interfering with the cooling of other areas of the forging.

[0016] Step S4: Dynamically adjust the intensity of directional jet stirring and lateral auxiliary stirring in three stages according to the quenching cooling sequence: Initial stage of quenching (film boiling stage): The surface temperature of the forging is higher than the boiling point of the medium, and the surface is wrapped with a vapor film, resulting in high heat exchange resistance. Directional jet stirring operates at the first intensity, utilizing the impact shearing effect of the high-speed directional jet to quickly break the vapor film in the core area of ​​the upper end face, allowing this area to enter the efficient nucleation boiling stage as early as possible; Mid-stage of quenching (nucleation boiling stage): The surface temperature of the forging drops below the boiling point of the medium, and directional jet stirring switches to the second intensity, which is lower than the first intensity, to maintain uniform cooling in the nucleation boiling stage and avoid structural stress caused by excessively strong stirring leading to excessively rapid local cooling; Late stage of quenching (convective cooling stage): Convection heat transfer dominates, and directional jet stirring switches to the third intensity, which is lower than the second intensity, to complete the remaining structural transformation through gentle circulation, focusing on reducing thermal stress and structural stress, and preventing deformation and cracking.

[0017] Furthermore, the directional jet stirring mechanism includes: a lifting column, a horizontal rotary table, a jet arm, a variable frequency water pump, and an angle adjustment motor; the lifting column is fixed to the center of the bottom of the quenching tank, the horizontal rotary table is installed on the top of the lifting column, the jet arm is horizontally installed on the horizontal rotary table, and a jet nozzle is installed at the end of the jet arm; the angle adjustment motor drives the jet nozzle to rotate around a horizontal axis, realizing electric adjustment of the jet nozzle angle within the range of 0° to 90°; the variable frequency water pump is connected to the jet arm through a high-pressure resistant hose, and the flow rate is continuously adjustable within the range of 5 to 120 m³ / h.

[0018] Furthermore, the method for obtaining the forging geometric parameters in step S1 includes: using a 3D laser scanner to perform a non-contact scan of the forging before it enters the slot to obtain the point cloud data of the forging's outer contour, and then calculating the outer diameter and thickness of the forging through fitting; or directly reading the forging design dimension parameters from the forging process card. The radius of the core region on the upper end face... Where D is the outer diameter of the forging; the spatial coordinates are established in a cylindrical coordinate system with the center of the bottom of the quenching tank as the origin, and the coordinates of the core center of the upper end face of the forging are (0, 0, ...). ),in H is the thickness of the forging. This refers to the height of the shim.

[0019] Furthermore, in step S2, the horizontal offset e of the injection nozzle is the distance between the projection of the injection nozzle on the horizontal plane and the center of the bottom of the quenching tank, satisfying the following condition: The vertical clearance g between the injection nozzle and the lower end face of the forging satisfies Target height of the directional jet mixing mechanism The target azimuth angle makes the horizontal projection direction of the injection nozzle point to the center of the core of the upper end face of the forging.

[0020] Furthermore, in step S2, the nozzle angle θ is the angle between the injection direction and the horizontal plane, satisfying... The lower limit angle To ensure that the jet stream does not directly impact the side of the forging; upper limit angle This ensures that the jet stream covers the outer edge of the core region on the upper surface. The vertical velocity component... The jet outlet velocity Q is the flow rate of the variable frequency water pump, and A is the cross-sectional area of ​​the injection nozzle; the vertical velocity component is not less than 0.3 m / s at the center of the core area on the upper end face of the forging.

[0021] Furthermore, in step S3, the intensity of the lateral auxiliary stirring is based on the total power of the propeller mixer motor. Characterized by the directional jet mixing intensity in terms of the variable frequency water pump motor power The two are characterized by a proportional relationship. The proportionality coefficient λ is based on the outer diameter D of the forging and the inner diameter of the quenching tank. The ratio is selected within the range of 0.25 to 0.45: when When λ=0.25; when When λ=0.35; when At this point, λ = 0.45. This ratio ensures that the lateral auxiliary stirring is sufficient to maintain the overall circulation without weakening the local enhancement effect of the directional injection in the blind zone.

[0022] Furthermore, in step S4, the second intensity Third intensity Duration of the initial quenching stage The theoretical value according to It is determined that the value should be taken within the range of 15~30s in engineering practice; the duration of the mid-stage quenching process. , The parameters are obtained by referring to a table based on the forging material, thickness, and medium parameters; the quenching process is initiated when the surface temperature of the forging is 20°C lower than the medium temperature, and continues until the surface temperature of the forging is 10°C lower than the medium temperature.

[0023] Furthermore, the method also includes step S5: during the quenching and cooling process, the surface temperature of the core region of the upper end face is monitored in real time by a non-contact infrared thermometer array arranged directly above the core region of the upper end face of the forging. and the temperature at the position corresponding to the lower end face of the forging Compare; when temperature difference Exceeding the preset threshold At that time, the directional spray stirring intensity is automatically increased until the temperature difference drops below the threshold, realizing closed-loop regulation based on measured temperature feedback; the preset threshold is set in the range of 50℃~150℃ according to the forging material.

[0024] Furthermore, the spray nozzle is a fan-shaped nozzle installed at the end of the spray arm, with a fan-shaped diffusion angle of 30°~60°, and the fan-shaped plane is perpendicular to the rotation plane of the horizontal rotary table; the projection of the spray coverage area of ​​the fan-shaped nozzle on the upper end face of the forging is elliptical, with the major axis along the radial direction of the forging and the minor axis along the circumferential direction of the forging, and the length of the major axis is not less than 1.2 times the diameter of the core area on the upper end face of the forging.

[0025] Secondly, based on the same inventive concept, this invention provides a metal forging cooling and stirring intensity adjustment system for executing the method described in the first aspect. The system includes: a directional spray stirring mechanism, a lateral auxiliary stirrer, a forging parameter identification module, a spray control module, a stirring coordination module, and a cooling monitoring module. The directional spray stirring mechanism is installed at the center of the bottom of the quenching tank and includes a lifting column, a horizontal rotary table, a spray arm, a variable frequency water pump, and an angle adjustment motor, used to spray directional cooling liquid flow onto the core area of ​​the upper end face of the forging. The lateral auxiliary stirrer includes at least two sets of propeller stirrers symmetrically arranged on the sidewall of the quenching tank to maintain overall circulation within the quenching tank. The forging parameter identification module is used to acquire the geometric parameters of the forging before it enters the quenching tank and calculate the spatial coordinate position of the core area of ​​the upper end face of the forging. The spray control module is connected to the directional spray stirring mechanism and is used to adjust the cooling intensity according to the specified parameters. The spatial coordinate position controls the lifting height, horizontal azimuth angle, and nozzle angle of the directional jet stirring mechanism, and adjusts the flow rate of the variable frequency water pump; the stirring coordination module is connected to the directional jet stirring mechanism and the lateral auxiliary stirrer, and is used to dynamically adjust the directional jet stirring intensity and the lateral auxiliary stirring intensity in three stages according to the quenching and cooling sequence; the cooling monitoring module includes a non-contact infrared temperature measuring array arranged directly above the core area of ​​the upper end face of the forging, which is used to monitor the surface temperature of the core area of ​​the upper end face in real time and feed the temperature signal back to the jet control module to realize closed-loop regulation.

[0026] Compared with the prior art, the beneficial effects of this invention are:

[0027] This invention utilizes a liftable, rotatable, and adjustable-angle directional jetting and stirring mechanism to precisely and directionally deliver coolant to the core cooling blind zone on the upper end face of the forging, forming an effective vertical flow velocity component and fundamentally eliminating the blind zone. Lateral auxiliary stirring maintains overall circulation at a proportionally coordinated lower intensity, avoiding local turbulence interference and overcooling. Three-stage dynamic adjustment synchronizes the stirring intensity with the physical states of film boiling, nucleus boiling, and convective cooling on the forging surface. Closed-loop feedback based on infrared thermometry further ensures the quality consistency of multiple batches of continuous quenching, significantly improving the uniformity of quenching hardness and the stability of the microstructure of large-diameter disc-shaped forgings. Attached Figure Description

[0028] Figure 1 This is a flowchart of the method for adjusting the cooling and stirring intensity of metal forgings according to the present invention;

[0029] Figure 2 This is a schematic diagram showing the spatial relationship between the directional jet stirring mechanism and the forging of the present invention;

[0030] Figure 3 This is a time-series curve of the three-stage dynamic adjustment of stirring intensity according to the present invention;

[0031] Figure 4 This is a schematic diagram of the composition of the metal forging cooling and stirring intensity adjustment system of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] It should be noted that this invention is applicable to the quenching and cooling process of large-diameter disc-shaped forgings with an outer diameter of not less than 1.2m and a thickness of not less than 0.2m. These disc-shaped forgings include, but are not limited to, low-pressure rotor discs for nuclear power turbines, flanges for large pressure vessels, and turbine discs for gas turbines. When implementing this invention, the quenching tank should have sufficient space to install a directional jet stirring mechanism at the bottom center, and the liquid level in the tank should ensure that the liquid level is not lower than 200mm above the upper end face of the forging after it is completely submerged.

[0034] Example 1

[0035] like Figure 1 The diagram shown is a flowchart of the method for adjusting the cooling and stirring intensity of metal forgings according to the present invention. Taking a low-pressure rotor disc forging of a nuclear power turbine as an example, the method for adjusting the cooling and stirring intensity of metal forgings according to the present invention will be specifically described.

[0036] The wheel forging is made of SA-508Gr.3Cl.2 low-alloy steel, with an outer diameter D=2800mm, a thickness H=450mm, a quenching temperature of approximately 1020℃, and a target hardness of 250~290HBW. The quenching tank is cylindrical, with an inner diameter of... =5000mm, effective liquid depth 3500mm, quenching medium is 8% polyalkylene glycol polymer aqueous solution, medium boiling point is about 100℃, initial medium temperature is 35℃; the forging is placed horizontally on four shims, the height of the shims is... =300mm.

[0037] Step S1: Before the forging is quenched in the groove, the geometric parameters of the forging are obtained, including the outer diameter, thickness and material information of the forging; the spatial coordinate position of the core area of ​​the upper end face of the forging is calculated according to the geometric parameters, wherein the core area of ​​the upper end face is a circular area with the center of the upper end face of the forging as the center.

[0038] Specifically, the methods for obtaining the geometric parameters of the forging include: using a 3D laser scanner to perform a non-contact scan of the forging before it enters the slot to obtain the point cloud data of the forging's outer contour, and then calculating the outer diameter and thickness of the forging through fitting; or directly reading the design dimension parameters of the forging from the forging process card. The radius of the core region on the upper end face... Where D is the outer diameter of the forging; the spatial coordinates are established in a cylindrical coordinate system with the center of the bottom of the quenching tank as the origin, and the coordinates of the core center of the upper end face of the forging are (0, 0, ...). ),in H is the thickness of the forging. This refers to the height of the shim.

[0039] In this embodiment, before the forging is hoisted into the quenching tank, a 3D laser scanner fixed above the inlet of the quenching tank performs a non-contact scan of the forging to obtain the point cloud data of the forging's outer contour. After least-squares circle fitting, the outer diameter D = 2800 mm and the thickness H = 450 mm of the forging are obtained. The radius of the core region on the upper end face is: The coordinates of the core center of the upper end face of the forging are (0, 0, ...). ),in: ;

[0040] Step S2: Based on the spatial coordinates of the core area on the upper end face of the forging, control the directional spraying and stirring mechanism to rise or fall to the target height and rotate horizontally to the target azimuth angle so that the spray nozzle is aligned with the center of the core area on the upper end face; adjust the spray nozzle angle so that the sprayed coolant flow obliquely impacts the core area on the upper end face of the forging, forming a vertical velocity component in the core area on the upper end face.

[0041] like Figure 2 The diagram shows the spatial relationship between the directional spraying and stirring mechanism and the forging of the present invention. Specifically, the directional spraying and stirring mechanism includes: a lifting column, a horizontal rotary table, a spraying arm, a variable frequency water pump, and an angle adjustment motor. The lifting column is fixed to the center of the bottom of the quenching tank, the horizontal rotary table is installed on the top of the lifting column, the spraying arm is horizontally installed on the horizontal rotary table, and a spray nozzle is installed at the end of the spraying arm. The angle adjustment motor drives the spray nozzle to rotate around a horizontal axis, realizing electric adjustment of the spray nozzle angle within the range of 0° to 90°. The variable frequency water pump is connected to the spraying arm through a high-pressure resistant hose, and the flow rate is continuously adjustable within the range of 5 to 120 m³ / h. The horizontal offset e of the spray nozzle is the distance between the projection of the spray nozzle on the horizontal plane and the center of the bottom of the quenching tank, satisfying... The vertical clearance g between the injection nozzle and the lower end face of the forging satisfies The target height of the directional jet mixing mechanism The target azimuth angle makes the horizontal projection direction of the injection nozzle point to the center of the core of the upper end face of the forging.

[0042] Specifically, the nozzle angle θ is the angle between the injection direction and the horizontal plane, satisfying... The lower limit angle To ensure that the jet stream does not directly impact the side of the forging; upper limit angle This ensures that the jet stream covers the outer edge of the core region on the upper surface; the vertical velocity component The jet outlet velocity Q is the flow rate of the variable frequency water pump, and A is the cross-sectional area of ​​the injection nozzle; the vertical velocity component is not less than 0.3 m / s at the center of the core area on the upper end face of the forging. The injection nozzle is a fan-shaped nozzle installed at the end of the injection arm, with a fan-shaped diffusion angle of 30°~60°, and the fan-shaped plane is perpendicular to the rotation plane of the horizontal rotary table; the projection of the spray coverage area of ​​the fan-shaped nozzle on the upper end face of the forging is elliptical, with the major axis along the radial direction of the forging and the minor axis along the circumferential direction of the forging, and the length of the major axis is not less than 1.2 times the diameter of the core area on the upper end face of the forging.

[0043] In this embodiment, the horizontal offset of the injection nozzle e=0, meaning the injection nozzle is located directly above the center of the bottom of the quenching tank, satisfying e≤0.15×D=420mm; the vertical gap between the injection nozzle and the lower end face of the forging is set to g=350mm, falling within the range of 200mm~500mm. The target height of the directional injection stirring mechanism is: .

[0044] The horizontal rotary table is rotated to the target azimuth angle, so that the horizontal projection direction of the injection nozzle points to the center of the core on the upper end face of the forging. The upper and lower limits of the injection nozzle angle are calculated as follows:

[0045] ;

[0046] ;

[0047] θ = 38° is selected, which is between the upper and lower limits. The spray nozzle adopts a fan-shaped nozzle with a fan-shaped diffusion angle of 45°. The fan-shaped plane is perpendicular to the rotation plane of the horizontal rotary table. The projection of the spray coverage area on the upper end face of the forging is elliptical, with a major axis of about 1150 mm along the radial direction of the forging and a minor axis of about 580 mm along the circumferential direction of the forging. The length of the major axis is not less than 1.2 times the diameter of the core area of ​​the upper end face (934 mm) (i.e., not less than 1121 mm).

[0048] The variable frequency water pump flow rate is set to Q = 80 m³ / h, and the nozzle cross-sectional area is A = 0.012 m². Therefore, the nozzle outlet velocity is: The vertical velocity component formed at the center of the core region on the upper end face is: It is far higher than the minimum requirement of 0.3 m / s.

[0049] Step S3: While the directional jet stirring mechanism is running, the lateral auxiliary stirrer is started. The lateral auxiliary stirrer operates at an auxiliary intensity lower than the directional jet stirring intensity to maintain the overall circulating flow in the quenching tank and prevent the local turbulence caused by the directional jet flow from interfering with the cooling of other areas of the forging.

[0050] Specifically, the lateral auxiliary agitator includes at least two sets of propeller agitators symmetrically arranged on the sidewall of the quenching tank, with the centerline of the propeller blades located near the height of the forging thickness mid-section; the lateral auxiliary agitation intensity is based on the total power of the propeller agitator motor. Characterized by the directional jet stirring intensity as measured by the power of the variable frequency water pump motor. Representation, both satisfy The proportionality coefficient λ is based on the outer diameter D of the forging and the inner diameter of the quenching tank. The ratio is selected when: When λ=0.25; when When λ=0.35; when At that time, λ=0.45.

[0051] In this embodiment, two sets of propeller agitators are symmetrically arranged on the sidewall of the quenching tank, with the centerline of the propeller blades located at the height of the midpoint of the forging thickness, i.e., from the bottom of the quenching tank. Place.

[0052] The ratio of the outer diameter of the forging to the inner diameter of the quenching tank is: The ratio is within the range of 0.5 to 0.7, therefore the proportionality coefficient λ = 0.35. The variable frequency water pump motor power is 45kW, then the lateral auxiliary stirring intensity is: The two sets of propeller agitators are each equipped with an 8kW motor, totaling 16kW, which covers the calculated value of 15.75kW. The speed is set at 120rpm to maintain the overall circulation flow in the quenching tank.

[0053] Step S4: The intensity of directional jet stirring and the intensity of lateral auxiliary stirring are dynamically adjusted in three stages according to the quenching cooling sequence: In the initial stage of quenching, the surface temperature of the forging is higher than the boiling point of the medium, and the directional jet stirring is operated at the first intensity to quickly break the vapor film in the core area of ​​the upper end face; In the middle stage of quenching, the surface temperature of the forging drops below the boiling point of the medium, and the directional jet stirring is switched to the second intensity, which is lower than the first intensity, to maintain uniform cooling in the nucleation boiling stage; In the later stage of quenching, the directional jet stirring is switched to the third intensity, which is lower than the second intensity, to gently cycle and complete the microstructure transformation and reduce microstructure stress.

[0054] Specifically, the second intensity The third strength ,in The first strength; the duration of the initial stage of quenching. The theoretical value according to Confirmed, among which This refers to the vertical velocity component formed in the core region of the upper end face during the initial stage of quenching. In engineering... The value is taken within the range of 15~30s; the duration of the intermediate stage of quenching. ,in The empirical time required for the forging to cool from the immersion temperature to the boiling point of the medium is obtained by referring to a table based on the forging material, thickness, and medium parameters; the later stage of quenching is initiated when the surface temperature of the forging is 20°C lower than the medium temperature, and continues until the surface temperature of the forging is 10°C lower than the medium temperature.

[0055] Figure 3 This is a time-series curve of the stirring intensity for the three-stage dynamic adjustment of the present invention. In this embodiment, based on the continuous cooling transformation curve (CCT curve) of SA-508Gr.3Cl.2 steel and the cooling characteristics of the polymer aqueous solution, the three-stage dynamic adjustment process is as follows:

[0056] Initial stage of quenching (film boiling stage): The forging immersion temperature is 1020℃, the medium boiling point is approximately 100℃, the forging surface temperature is higher than the medium boiling point, and the surface is covered by a vapor film. Directional jet stirring operates at its highest intensity, and the variable frequency water pump power... =45kW (full power), flow rate 80m³ / h, vertical velocity component =1.14 m / s, utilizing the impact shearing effect of a high-speed directional jet to rapidly break the vapor film in the core region of the upper end face. The theoretical duration is: .

[0057] Considering the heat capacity of the forging and the actual vapor film stability, in engineering, it is taken as follows: =25s, within the range of 15~30s; the side auxiliary stirrer runs synchronously at 120rpm.

[0058] Mid-stage quenching (nuclear boiling stage): When the surface temperature of the forging drops below 100℃, it enters the nucleation boiling stage, and the directional jet stirring switches to the second intensity. The corresponding flow rate is 40 m³ / h, and the vertical velocity component is reduced to about 0.57 m / s to maintain uniform cooling during the nuclear boiling stage.

[0059] The empirical time for cooling from the immersion temperature to the boiling point of the medium was obtained from a table based on the forging material, thickness, and medium parameters, using SA-508Gr.3Cl.2 steel, 450mm thickness, and 8% polymer aqueous solution. =180s, then the duration is: The side-assisted stirrer is maintained at 120 rpm.

[0060] Late quenching stage (convection cooling stage): When the surface temperature of the forging is 20°C lower than the medium temperature (i.e., lower than 35 + 20 = 55°C), this stage is initiated, and directional spray stirring is switched to the third intensity. The corresponding flow rate is 20 m³ / h, with gentle circulation to complete the remaining microstructure transformation, reducing thermal and structural stress; the lateral auxiliary stirrer is simultaneously reduced to 60 rpm. This stage continues until the surface temperature of the forging is 10°C below the medium temperature (i.e., below 45°C), with a total quenching time of approximately 420 s.

[0061] This embodiment may further include: step S5, during the quenching and cooling process, monitoring the surface temperature of the core region of the upper end face in real time using a non-contact infrared thermometer array arranged directly above the core region of the upper end face of the forging. And the surface temperature is compared with the temperature of the corresponding position on the lower end face of the forging. Compare; when temperature difference Exceeding the preset threshold At that time, the intensity of directional spraying and stirring is automatically increased until the temperature difference drops below the threshold; the preset threshold is set in the range of 50℃~150℃ according to the material of the forging.

[0062] In this embodiment, a non-contact infrared temperature measurement array (4×4 dot matrix, covering an area with a diameter of 1000mm) is arranged 300mm directly above the core area of ​​the upper end face of the forging to monitor the surface temperature of the core area of ​​the upper end face in real time. Temperature at the corresponding position on the lower end face of the forging Measurements are taken using pre-embedded thermocouples; a preset temperature difference threshold is used. =80℃, within the range of 50℃~150℃. At the 90s stage of the mid-quenching process, the surface temperature of the core area on the upper end face was measured to be approximately 185℃, and the corresponding temperature on the lower end face was approximately 95℃, with a temperature difference of: When the temperature difference exceeds the preset threshold of 80℃, the injection control module automatically increases the directional injection stirring intensity from the second intensity of 22.5kW to 30kW (flow rate 53m³ / h). After 15 seconds, the temperature difference drops to 72℃, which is below the threshold, and the system returns to the second intensity.

[0063] After adopting the method of this invention, the hardness of the core area on the upper end face of the wheel forging is 268 HBW, the corresponding position on the lower end face is 275 HBW, and the hardness of the circumferential surface is 271 HBW, with a difference of only 7 HBW. In contrast, without the traditional full-groove uniform stirring process of this invention (side stirrer at 180 rpm, no directional spray), the hardness of the core area on the upper end face is only 231 HBW, a difference of 44 HBW from the lower end face, indicating a significant cooling blind zone. This invention effectively eliminates the cooling blind zone in the core area of ​​the upper end face, significantly improving the overall hardness uniformity of the forging.

[0064] Example 2

[0065] like Figure 4 The diagram shown is a schematic representation of the metal forging cooling and stirring intensity adjustment system of the present invention. This embodiment provides a metal forging cooling and stirring intensity adjustment system for executing the metal forging cooling and stirring intensity adjustment method described in Embodiment 1. The system includes: a directional spray stirring mechanism, a lateral auxiliary stirrer, a forging parameter identification module, a spray control module, a stirring coordination module, and a cooling monitoring module.

[0066] The directional spraying and stirring mechanism is installed at the center of the bottom of the quenching tank and includes a lifting column, a horizontal rotary table, a spraying arm, a variable frequency water pump, and an angle adjustment motor. It is used to spray directional cooling liquid into the core area of ​​the upper end face of the forging.

[0067] Specifically, the lifting column is fixed to the center of the bottom of the quenching tank, the horizontal rotary table is installed at the top of the lifting column, the spray arm is horizontally installed on the horizontal rotary table, and a spray nozzle is installed at the end of the spray arm; the angle adjustment motor drives the spray nozzle to rotate around the horizontal axis, realizing electric adjustment of the spray nozzle angle within the range of 0°~90°; the variable frequency water pump is connected to the spray arm through a high-pressure resistant hose, and the flow rate is continuously adjustable within the range of 5~120m³ / h. The spray nozzle is a fan-shaped nozzle installed at the end of the spray arm, with a fan-shaped diffusion angle of 30°~60°, and the fan-shaped plane is perpendicular to the rotation plane of the horizontal rotary table; the projection of the spray coverage area of ​​the fan-shaped nozzle onto the upper end face of the forging is elliptical, with the major axis along the radial direction of the forging and the minor axis along the circumferential direction of the forging, and the length of the major axis is not less than 1.2 times the diameter of the core area of ​​the upper end face of the forging.

[0068] The lateral auxiliary agitator includes at least two sets of propeller agitators symmetrically arranged on the side wall of the quenching tank to maintain the overall circulating flow in the quenching tank; the center line of the propeller agitator blades is located near the height of the forging thickness mid-section to avoid the blade flow field being directly blocked by the end face of the forging, thus ensuring the stability of the overall circulating flow in the tank.

[0069] The forging parameter identification module is used to obtain the geometric parameters of the forging before it is quenched in the groove, including the outer diameter, thickness and material information of the forging, and to calculate the spatial coordinate position of the core area on the upper end face of the forging.

[0070] Specifically, the forging parameter identification module includes a 3D laser scanner and a process card data interface: the 3D laser scanner is fixed above the quenching tank inlet and performs a non-contact scan of the forging before it enters the tank to obtain the point cloud data of the forging's outer contour. The outer diameter and thickness of the forging are then calculated through fitting. For batch production parts, the forging parameter identification module directly reads the forging design dimension parameters from the forging process card database through the process card data interface.

[0071] The injection control module is connected to the directional injection mixing mechanism and is used to control the lifting height, horizontal azimuth angle and injection nozzle angle of the directional injection mixing mechanism according to the spatial coordinate position, and to adjust the flow rate of the variable frequency water pump.

[0072] The spray control module includes a lifting drive unit, a slewing drive unit, an angle adjustment unit, and a flow rate adjustment unit: the lifting drive unit drives the lifting column to rise and fall, so that the center of the spray nozzle reaches the target height; the slewing drive unit drives the horizontal turntable to rotate to the target azimuth angle; the angle adjustment unit adjusts the spray nozzle angle to the set value through the angle adjustment motor; and the flow rate adjustment unit sets the spray flow rate by adjusting the working frequency of the variable frequency water pump.

[0073] The stirring coordination module is connected to the directional jet stirring mechanism and the lateral auxiliary stirrer, and is used to dynamically adjust the intensity of directional jet stirring and lateral auxiliary stirring in three stages according to the quenching and cooling sequence.

[0074] The stirring coordination module stores a quenching stage timing parameter table corresponding to each steel grade and thickness specification. In the initial stage of quenching, it controls the directional jet stirring mechanism to operate at the first intensity. In the middle stage of quenching, it controls it to switch to the second intensity. In the later stage of quenching, it controls it to switch to the third intensity. It also synchronously adjusts the rotation speed of the lateral auxiliary stirrer so that the intensity of the lateral auxiliary stirring is always coordinated with the intensity of the directional jet stirring.

[0075] The cooling monitoring module includes a non-contact infrared temperature measurement array arranged directly above the core area of ​​the upper end face of the forging, which is used to monitor the surface temperature of the core area of ​​the upper end face in real time and feed the temperature signal back to the injection control module to realize closed-loop regulation.

[0076] Specifically, the cooling monitoring module also includes a pre-embedded thermocouple set at a corresponding position on the lower end face of the forging, used to measure the temperature of the lower end face of the forging; the spray control module compares the surface temperature of the core area of ​​the upper end face measured by the infrared temperature measuring array with the temperature of the lower end face measured by the pre-embedded thermocouple. When the temperature difference between the two exceeds a preset threshold, the directional spray stirring intensity is automatically increased until the temperature difference drops below the threshold.

[0077] In this embodiment, the system modules are connected via an industrial Ethernet bus, employing a modular design. The modules communicate through standard interfaces, providing good scalability and maintainability. Each module has an independent configuration file and logging system, facilitating system deployment, debugging, and maintenance. The system's operation is the same as the execution process of the method described in Embodiment 1, and will not be repeated here.

[0078] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adjusting the intensity of cooling and stirring of metal forgings, characterized in that, The method is applied to large-diameter disc-shaped forgings that are placed horizontally on a pad in a quenching tank for quenching and cooling; a lifting and rotating directional spraying and stirring mechanism is provided at the center of the bottom of the quenching tank, and the spray nozzle angle of the directional spraying and stirring mechanism is electrically adjustable. The sidewall of the quenching tank is equipped with a lateral auxiliary stirrer; The method includes the following steps: Step S1: Before the forging is quenched in the groove, the geometric parameters of the forging are obtained, including the outer diameter, thickness and material information of the forging; the spatial coordinate position of the core area of ​​the upper end face of the forging is calculated according to the geometric parameters, wherein the core area of ​​the upper end face is a circular area with the center of the upper end face of the forging as the center. Step S2: Based on the spatial coordinates of the core area on the upper end face of the forging, control the directional spraying and stirring mechanism to rise or fall to the target height and rotate horizontally to the target azimuth angle so that the spray nozzle is aligned with the center of the core area on the upper end face; adjust the spray nozzle angle so that the sprayed coolant flow obliquely impacts the core area on the upper end face of the forging, forming a vertical velocity component in the core area on the upper end face. Step S3: While the directional jet stirring mechanism is running, the lateral auxiliary stirrer is started. The lateral auxiliary stirrer runs at an auxiliary intensity lower than the directional jet stirring intensity to maintain the overall circulation flow in the quenching tank and prevent the local turbulence caused by the directional jet flow from interfering with the cooling of other areas of the forging. Step S4: The intensity of directional jet stirring and the intensity of lateral auxiliary stirring are dynamically adjusted in three stages according to the quenching cooling sequence: In the initial stage of quenching, the surface temperature of the forging is higher than the boiling point of the medium, and the directional jet stirring is operated at the first intensity to quickly break the vapor film in the core area of ​​the upper end face; In the middle stage of quenching, the surface temperature of the forging drops below the boiling point of the medium, and the directional jet stirring is switched to the second intensity, which is lower than the first intensity, to maintain uniform cooling in the nucleation boiling stage; In the later stage of quenching, the directional jet stirring is switched to the third intensity, which is lower than the second intensity, to gently cycle and complete the microstructure transformation and reduce microstructure stress.

2. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 1, characterized in that, The directional jet stirring mechanism includes: a lifting column, a horizontal rotary table, a jet arm, a variable frequency water pump, and an angle adjustment motor; the lifting column is fixed to the center of the bottom of the quenching tank, the horizontal rotary table is installed on the top of the lifting column, the jet arm is horizontally installed on the horizontal rotary table, and a jet nozzle is installed at the end of the jet arm; the angle adjustment motor drives the jet nozzle to rotate around a horizontal axis, realizing electric adjustment of the jet nozzle angle within the range of 0° to 90°; the variable frequency water pump is connected to the jet arm through a high-pressure resistant hose, and the flow rate of the variable frequency water pump is continuously adjustable within the range of 5 to 120 m³ / h.

3. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 2, characterized in that, The methods for obtaining the geometric parameters of the forging in step S1 include: using a 3D laser scanner to perform a non-contact scan of the forging before it enters the slot to obtain the point cloud data of the forging's outer contour, and then calculating the outer diameter and thickness of the forging through fitting; or directly reading the design dimension parameters of the forging from the forging process card; the radius of the core region of the upper end face. Where D is the outer diameter of the forging; the spatial coordinates are established in a cylindrical coordinate system with the center of the bottom of the quenching tank as the origin, and the coordinates of the core center of the upper end face of the forging are (0, 0, ...). ),in H is the thickness of the forging. This refers to the height of the shim.

4. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 3, characterized in that, In step S2, the horizontal offset e of the injection nozzle of the directional injection stirring mechanism is the distance between the projection of the injection nozzle on the horizontal plane and the center of the bottom of the quenching tank, satisfying the following condition: The vertical clearance g between the injection nozzle and the lower end face of the forging satisfies The target height of the directional jet stirring mechanism is the vertical distance between the center of the jet nozzle and the center of the bottom of the quenching tank, satisfying the following conditions: The target azimuth angle makes the horizontal projection direction of the injection nozzle point to the center of the core of the upper end face of the forging.

5. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 4, characterized in that, In step S2, the nozzle angle θ is the angle between the injection direction and the horizontal plane, satisfying the following conditions: The lower limit angle To ensure that the jet stream does not directly impact the side of the forging; upper limit angle This ensures that the jet stream covers the outer edge of the core region on the upper surface; the vertical velocity component The jet outlet velocity Q is the flow rate of the variable frequency water pump, and A is the cross-sectional area of ​​the injection nozzle; the vertical velocity component is not less than 0.3 m / s at the center of the core area on the upper end face of the forging.

6. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 5, characterized in that, In step S3, the lateral auxiliary stirrer includes at least two sets of propeller stirrers symmetrically arranged on the sidewall of the quenching tank, with the centerline of the propeller blades located near the height of the forging thickness mid-section; the lateral auxiliary stirring intensity is based on the total power of the propeller stirrer motor. Characterized by the directional jet stirring intensity as measured by the power of the variable frequency water pump motor. Representation, both satisfy The proportionality coefficient λ is based on the outer diameter D of the forging and the inner diameter of the quenching tank. The ratio is selected when: When λ=0.25; when When λ=0.35; when At that time, λ=0.

45.

7. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 6, characterized in that, In step S4, the second strength The third strength ,in The first strength; the duration of the initial stage of quenching. The theoretical value according to Confirmed, among which This refers to the vertical velocity component formed in the core region of the upper end face during the initial stage of quenching. In engineering... The value is taken within the range of 15~30s; the duration of the intermediate stage of quenching. ,in The empirical time required for the forging to cool from the immersion temperature to the boiling point of the medium is obtained by referring to a table based on the forging material, thickness, and medium parameters; the later stage of quenching is initiated when the surface temperature of the forging is 20°C lower than the medium temperature and continues until the surface temperature of the forging is 10°C lower than the medium temperature.

8. The method for adjusting the cooling and stirring intensity of metal forgings according to claim 7, characterized in that, The method further includes step S5: during the quenching and cooling process, the surface temperature of the core region of the upper end face is monitored in real time by a non-contact infrared thermometer array arranged directly above the core region of the upper end face of the forging. And the surface temperature is compared with the temperature of the corresponding position on the lower end face of the forging. Compare; when temperature difference Exceeding the preset threshold At that time, the intensity of directional spraying and stirring is automatically increased until the temperature difference drops below the threshold; the preset threshold is set in the range of 50℃~150℃ according to the material of the forging.

9. The method for adjusting the cooling stirring intensity of metal forgings according to claim 9, characterized in that, The spray nozzle is a fan-shaped nozzle installed at the end of the spray arm. The fan-shaped nozzle has a fan-shaped diffusion angle of 30° to 60°, and the fan-shaped plane is perpendicular to the rotation plane of the horizontal rotary table. The projection of the spray coverage area of ​​the fan-shaped nozzle onto the upper end face of the forging is elliptical. The major axis of the ellipse is along the radial direction of the forging, and the minor axis is along the circumferential direction of the forging. The length of the major axis of the elliptical projection is not less than 1.2 times the diameter of the core area on the upper end face of the forging.

10. A system for adjusting the intensity of cooling and stirring of metal forgings, used to perform the method for adjusting the intensity of cooling and stirring of metal forgings according to any one of claims 1-9, characterized in that, The system includes: a directional jet stirring mechanism, a lateral auxiliary stirrer, a forging parameter identification module, a jet control module, a stirring coordination module, and a cooling monitoring module; The directional spraying and stirring mechanism is installed at the bottom center of the quenching tank and includes a lifting column, a horizontal rotary table, a spraying arm, a variable frequency water pump and an angle adjustment motor, used to spray directional cooling liquid flow into the core area of ​​the upper end face of the forging; The lateral auxiliary agitator includes at least two sets of propeller agitators symmetrically arranged on the side wall of the quenching tank to maintain the overall circulating flow within the quenching tank. The forging parameter identification module is used to obtain the geometric parameters of the forging before it is quenched in the groove, including the outer diameter, thickness and material information of the forging, and to calculate the spatial coordinate position of the core area on the upper end face of the forging. The injection control module is connected to the directional injection mixing mechanism and is used to control the lifting height, horizontal azimuth angle and injection nozzle angle of the directional injection mixing mechanism according to the spatial coordinate position, and to adjust the flow rate of the variable frequency water pump. The stirring coordination module is connected to the directional jet stirring mechanism and the lateral auxiliary stirrer, and is used to dynamically adjust the directional jet stirring intensity and the lateral auxiliary stirring intensity in three stages according to the quenching and cooling sequence. The cooling monitoring module includes a non-contact infrared temperature measurement array arranged directly above the core area of ​​the upper end face of the forging, which is used to monitor the surface temperature of the core area of ​​the upper end face in real time and feed the temperature signal back to the injection control module to realize closed-loop regulation.

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