CN112877525B - Surface strengthening device and method for applying elastic stress field and thermal field to metal workpiece and assisting ultrasonic rolling - Google Patents

Abstract

The invention provides a surface strengthening device and a surface strengthening method for applying an elastic stress field and a thermal field to a metal workpiece and assisting ultrasonic rolling, wherein the metal workpiece is clamped between rotating output shafts of two spindle boxes, and the surface strengthening device is used for applying the elastic stress field, the thermal field and the ultrasonic rolling to the metal workpiece, so that the surface residual compressive stress level and the peak residual compressive stress level of the metal material are higher, the residual compressive stress influence layer is deeper, and the fatigue performance of the metal material is further improved.

Description

Surface strengthening device and method for applying elastic stress field and thermal field to metal workpiece and assisting ultrasonic rolling

technical field

The invention relates to the field of mechanical strengthening of metal surfaces, in particular to a surface strengthening device and method for applying elastic stress field and thermal field to metal workpieces and assisting ultrasonic rolling.

Background technique

One of the most important factors affecting the fatigue properties of metallic materials is residual stress. Among them, the residual compressive stress can partially or even fully offset the external tensile load, close micro-cracks, inhibit the formation of fatigue crack sources, and delay the expansion of fatigue cracks, thereby improving the fatigue performance of metal components. Ultrasonic rolling is an advanced mechanical surface strengthening method, which can generate residual compressive stress field on the surface of metal components and improve its fatigue performance. The important indicators of the surface residual compressive stress field generated by ultrasonic rolling include the surface residual compressive stress level, the peak residual compressive stress level and the residual compressive stress-affected layer depth.

The existing ultrasonic rolling strengthening method has certain limitations. The generated surface residual compressive stress and peak residual compressive stress are relatively low, and the residual compressive stress influence layer is shallow, which cannot maximize the fatigue performance of metal materials. Therefore, it is necessary to seek More perfect ultrasonic rolling surface strengthening method.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, and to provide a surface strengthening device and method for applying elastic stress field and thermal field to a metal workpiece and assisting ultrasonic rolling. The metal workpiece is a cylindrical workpiece, and the surface strengthening The device includes:

A dual-spindle synchronous rotation system, the dual-spindle synchronous rotation system includes two headstocks arranged symmetrically, and a synchronous motion base located between the two headstocks. The telescopic synchronizing shafts are connected, and a clamping device is arranged at the opposite end of the two output shafts, and the metal workpiece is fixed between the two clamping devices;

The ultrasonic rolling system is installed on the synchronous motion base and is located on one side of the metal workpiece. The synchronous motion base is used to drive the ultrasonic rolling system to make a feeding motion along the axial direction of the metal workpiece. The ultrasonic rolling system includes: There is an ultrasonic rolling head that can radially approach/far away from the metal workpiece;

The elastic stress field loading device includes a traverse drive system and an annular clamp fixed on the two clamping devices. The opposite ends of the two annular clamps are provided with mounting holes, and the two axial ends of the metal workpiece are fixed on the two clamps. In the installation hole of the ring clamp, the traverse drive system drives the first headstock to move horizontally away from the second headstock, and the metal workpiece is drawn according to the set stress level, and then the metal workpiece is subjected to a horizontal movement. elastic stress field;

A thermal field loading device, the thermal field loading device is provided with heaters located on both sides of the ultrasonic rolling head to heat the middle part of the metal workpiece, and the heater is connected to a feedback adjustment controller, which is used for real-time control of all workpieces. The heating power of the heater causes the heating part to heat up and maintain the specified temperature.

Further, a spindle servo motor for driving the retractable synchronous shaft to rotate is fixed on the first spindle housing.

Further, the traverse drive system is configured with a set of horizontal drive device connected to the first headstock, the horizontal drive device includes a hydraulic drive device and a piston rod, wherein the hydraulic drive device is provided with an oil pressure valve, and the hydraulic drive device passes through. The piston rod is connected with the first headstock;

Both headstocks are mounted on the slide rails of the bed.

Further, a third base is installed on the second headstock;

The heater is two sets of heating coil windings arranged on both sides of the ultrasonic rolling head and wound around the outer ring of the metal workpiece. The metal workpiece rotates and heats the metal workpiece, and the two series of heating coil windings are electrically connected with the feedback adjustment controller, and the heating coil windings and the feedback adjustment controller are installed on the third base through a bracket;

The feedback adjustment controller controls the heating power of the heater in real time according to the monitored temperature of the heating part of the metal workpiece, so that the heating part is heated and maintained at a specified temperature.

Further, the thermal field loading device further includes a temperature monitor connected to the feedback adjustment controller, for monitoring the heated surface temperature of the metal workpiece and feeding back to the feedback adjustment controller.

Further, the ultrasonic rolling head is close to/away from the metal workpiece along the radial direction of the metal workpiece.

Further, the clamping device is a claw plate,

The annular clamp is a sleeve with a "T"-shaped cross section, the front end is provided with the mounting hole, and the rear end is provided with a boss fixed in the center hole of the claw plate.

A method for surface strengthening of a metal workpiece by utilizing the above-mentioned device, comprising the steps of:

S1. Fix the ring clamps in the two clamping devices respectively, pass the metal workpiece through the two sets of heating coil windings of the heater, and then fix the metal workpiece axially between the two ring clamps;

S2. Use the traverse drive system to drive the first headstock to move horizontally away from the second headstock, so that the metal workpiece in the middle is drawn by the two ring clamps according to the set stress level, and then the metal workpiece is drawn. Apply an elastic stress field;

S3. Start the dual-spindle synchronous rotation system, the two clamping devices rotate synchronously, and drive the metal workpiece to rotate according to the set speed and direction;

S4. Start the thermal field loading device to heat the middle part of the metal workpiece to a specified temperature and then maintain the temperature;

S5. The operation of the synchronous motion base drives the ultrasonic rolling system to feed axially along the metal workpiece according to the set feed speed and direction;

S6. Start the ultrasonic rolling system, the ultrasonic rolling head of the ultrasonic rolling system is radially close to the metal workpiece, and continues to make a feeding motion along the axial direction of the metal workpiece, and the elastic stress field and heat are applied to the middle of the heating part of the rotating metal workpiece. Field-assisted ultrasonic rolling surface strengthening;

S7. After the ultrasonic rolling is finished, turn off the double-spindle synchronous rotation system, stop the rotation of the metal workpiece, stop the feeding movement of the ultrasonic rolling system along the axial direction of the metal workpiece, and then the ultrasonic rolling head is radially away from the metal workpiece;

S8. Turn off the heating field loading device and stop applying the heating field to the metal workpiece;

S9. Turn off the traverse drive system to make the metal workpiece elastically recover;

S10. Release the two clamping devices, remove the metal workpiece, and restore the temperature to room temperature.

Further, in steps S4-S6, the method further includes:

The temperature of the heating part of the metal workpiece is monitored in real time, and fed back to the feedback adjustment controller to control the temperature of the heating part of the metal workpiece in real time to maintain the specified temperature.

Further, in step S2, the required oil pressure is calculated according to the cross-sectional area of the metal workpiece, the cross-sectional area of the piston rod of the traverse drive system inside the hydraulic cylinder, and the preset elastic stress;

The strength of the applied elastic stress field shall not exceed the uniaxial tensile ratio limit of the material used for the metal workpiece.

In some embodiments, the metal workpiece is clamped between the rotating output shafts of the two headstocks, and the surface strengthening device is used to apply elastic stress field, thermal field and ultrasonic rolling to the metal workpiece, so as to make the surface residual pressure of the metal material. The stress level and peak residual compressive stress level are higher, and the residual compressive stress affects the layer deeper, thereby improving the fatigue performance of the metal material.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present invention. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Figure 1a shows a schematic diagram of a surface strengthening device that applies multiple physical fields to a metal workpiece and assists ultrasonic rolling;

Fig. 1b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 1a;

Figure 2a shows a schematic diagram of a device for applying an elastic stress field to a metal workpiece and assisting ultrasonic rolling;

Fig. 2b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 2a;

Figure 2c shows a schematic diagram of the two ends of the metal workpiece being clamped and fixed by the ring clamps installed on the two spindle boxes;

Figure 3a shows a schematic diagram of a device for applying a pulsed current field to a metal workpiece and assisting in ultrasonic rolling;

Fig. 3b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 3a;

Figure 3c shows a schematic diagram of a pulse current field loading device and an ultrasonic rolling system;

Figure 4a shows a schematic diagram of a strengthening device for applying a thermal field to a metal workpiece and assisting ultrasonic rolling;

Fig. 4b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 4a;

Figure 4c shows a schematic diagram of a thermal field loading device and an ultrasonic rolling system;

Figure 5a shows a schematic diagram of a device for applying a pulsed electromagnetic field to a metal workpiece and assisting in ultrasonic rolling;

Fig. 5b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 5a;

Figure 5c shows a schematic diagram of a pulsed electromagnetic field loading device and an ultrasonic rolling system;

Figure 6a shows a schematic diagram of a device for applying a cryogenic field to a metal workpiece and assisting in ultrasonic rolling;

Fig. 6b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 6a;

Figure 6c shows a schematic diagram of a cryogenic field loading device and an ultrasonic rolling system;

Figure 7a shows a schematic diagram of a device for applying elastic stress field and pulsed current field to a metal workpiece and assisting ultrasonic rolling;

Fig. 7b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 7a;

Figure 7c shows a schematic diagram of a ring-shaped clamp for clamping a metal clamp, a pulsed current field loading device and an ultrasonic rolling system;

Figure 8a shows a schematic diagram of a device for applying elastic stress field and thermal field to a metal workpiece and assisting ultrasonic rolling;

Figure 8b shows a flow chart of a method for strengthening the surface of a metal workpiece based on the device of Figure 8a;

Figure 8c shows a schematic diagram of a ring clamp for clamping a metal clamp, a thermal field loading device and an ultrasonic rolling system;

Figure 9a shows a schematic diagram of a device for applying an elastic stress field and a pulsed electromagnetic field to a metal workpiece and assisting in ultrasonic rolling;

Fig. 9b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 9a;

Figure 9c shows a schematic diagram of a ring-shaped clamp for clamping a metal clamp, a pulsed electromagnetic field loading device and an ultrasonic rolling system;

Figure 10a shows a schematic diagram of a device for applying an elastic stress field and a cryogenic field to a metal workpiece and assisting ultrasonic rolling;

Fig. 10b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 10a;

Figure 10c shows a schematic diagram of a ring clamp for clamping a metal clamp, a cryogenic field loading device and an ultrasonic rolling system;

Figure 11a shows a schematic diagram of a device for applying elastic stress field, thermal field and cryogenic field to a metal workpiece and assisting ultrasonic rolling;

Fig. 11b shows a flow chart of a method for surface strengthening of a metal workpiece based on the device of Fig. 11a;

Figure 11c shows a schematic diagram of an annular clamp for clamping a metal clamp and a cryogenic field loading device, a thermal field loading device and an ultrasonic rolling system;

Figure 12a shows an exploded view of the elastic stress field loading device used to clamp both ends of the metal workpiece;

Figures 12b-1 to 12b-6 show the installation process diagrams of the elastic stress field loading device for fixing the metal workpiece;

Figure 13a is a comparison diagram of residual stress effect of ordinary ultrasonic rolling and application of elastic stress field-assisted ultrasonic rolling on the surface of a metal workpiece;

Figure 13b is a comparison diagram of the residual stress effect of ordinary ultrasonic rolling, applying pulsed current field assisted ultrasonic rolling, and applying elastic stress field-pulsed current field assisted ultrasonic rolling on the surface of a metal workpiece;

Figure 13c shows the residuals of ordinary ultrasonic rolling and thermal field-assisted ultrasonic rolling, elastic stress field-thermal-field-assisted ultrasonic rolling, and elastic-stress-thermal-cold-field-assisted ultrasonic rolling on the surface of the metal workpiece Stress effect comparison chart;

Figure 13d is a comparison diagram of the residual stress effect of ordinary ultrasonic rolling, applying pulsed electromagnetic field assisted ultrasonic rolling, and applying elastic stress field-pulsed electromagnetic field assisted ultrasonic rolling on the surface of a metal workpiece;

Figure 13e is a comparison diagram of residual stress effects of ordinary ultrasonic rolling, application of cryogenic field-assisted ultrasonic rolling, and elastic stress field-cryogenic field-assisted ultrasonic rolling on the surface of metal workpieces.

Detailed ways

In some of the following embodiments, one or more physical field-assisted ultrasonic rolling surface strengthening devices and methods for metal materials are provided, so that the surface residual compressive stress level and the peak residual compressive stress level generated on the surface of the metal material are higher, The residual compressive stress affects the layer deeper, thereby improving the fatigue performance of the metal material.

Among them, the in-situ TiB ₂ /2024Al composite material was selected, and the dumbbell-shaped round bar-shaped specimen recommended by "Standard for Force Controlled Constant Amplitude Axial Fatigue Test of Metal Materials" (ASTM E466-15) was used as an example.

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

Example 1

This embodiment is an application example corresponding to FIGS. 1a-1b, wherein FIG. 1a is a schematic diagram of a surface strengthening device 1000, and FIG. 1b is a flow chart of surface strengthening the metal workpiece by the surface strengthening device 1000.

As shown in Figure 1a, a physical field-assisted ultrasonic rolling surface strengthening device 1000 for metal materials is shown, including a dual-spindle synchronous rotation system 1, an ultrasonic rolling system 2, a metal workpiece 3, a traverse drive system 4 and a physical field Load system 5.

The dual-spindle synchronous rotation system 1 includes a first spindle box 1-1, a second spindle box 1-2, a first spindle 1-3, a second spindle 1-4, a spindle servo motor 1-5, and a spindle synchronous active belt 1 -6, retractable synchronous shaft 1-7, first main shaft synchronous driven belt 1-8, second main spindle synchronous driven belt 1-9, bed 1-10, synchronous motion base 1-11, ultrasonic rolling System base 1-12, second base 1-13, third base 1-14, first clamping device 1-15 and second clamping device 1-16.

Among them, the spindle servo motor 1-5 is located on the top of the first spindle box 1-1. The spindle servo motor 1-5 is connected with the retractable synchronous shaft 1-7 through the spindle synchronous active belt 1-6. The retractable synchronous shaft 1-7 is connected with the first main shaft 1-3 and the second main shaft 1-4 through the first main shaft synchronous driven belt 1-8 and the second main shaft synchronous driven belt 1-9, respectively. The top of the second headstock 1-2 is provided with a third base 1-14. The first spindle 1-3 and the second spindle 1-4 are respectively installed in the first spindle box 1-1 and the second spindle box 1-2; the first spindle box 1-1, the second spindle box 1-2 and the synchronization The motion bases 1-11 are respectively installed on the slide rails of the bed 1-10, and the synchronous motion base 1-11 can move along the slide rails of the bed 1-10 under the driving of the lead screw. One end of the synchronous motion base 1-11 is installed with an ultrasonic rolling system base 1-12, and the other end is installed with a second base 1-13; on the first clamping device 1-15 and the second clamping device 1-16 Claws are installed respectively; the front end of the claw is provided with boss teeth; the first clamping device 1-15 and the second clamping device 1-16 are respectively installed on the first spindle 1-3 and the second spindle 1-4 , so that the claws of the first clamping device 1-15 and the claws of the second clamping device 1-16 are facing opposite, and the metal workpiece 3 can be clamped.

Further, the ultrasonic rolling system 2 is installed on the ultrasonic rolling system base 1-12, and the ultrasonic rolling system base 1-12 is installed on the other side of the synchronous motion base 1-11 relative to the metal workpiece 3. side.

Further, the traverse drive system 4 includes a hydraulic drive device 4-1 and a piston rod 4-2. The hydraulic drive device 4-1 is installed with an oil pressure valve, and the hydraulic drive device 4-1 is connected to the first spindle box 1-1 through the piston rod 4-2, so that the hydraulic drive device 4-1 can drive the first spindle Box 1-1 moves along the slide rails of bed 1-10.

The physics loading system 5 includes one or more of a first physics loading system 501 , a second physics loading system 502 and a third physics loading system 503 . The first physical field loading system 501 may include an elastic stress field system 501a. The first physical field loading system 501 can be regarded as a traverse drive system 4, and the traverse drive system 4 drives the first headstock 1-1 to horizontally move away from the second headstock 1-2 to the metal workpiece 3 The drawing process is performed according to the set stress level, and then an elastic stress field is applied to the metal workpiece 3 . The second physics loading system 502 may include one or more of a pulsed electric current field system 502a, a thermal field system 502b, a pulsed electromagnetic field system 502c. The third physics loading system 503 may include a cryogenic field system 503a.

Further, the second physics field loading system 502 and the third physics field loading system 503 can be installed on the second base 1-13 or the third base 1-14 as a single system, or multiple systems can be installed on the base 1-14 at the same time. On the second base 1-13 and the third base 1-14, or multiple systems are simultaneously compactly installed on the second base 1-13 or the third base 1-14.

As shown in Fig. 1b, a physical field-assisted ultrasonic rolling surface strengthening method for metal materials is shown, which are sequentially clamping the workpiece, applying physical fields, applying rotation and feeding, ultrasonic rolling, stopping rotation and feeding, and unloading There are seven steps in physics and workpiece removal, and the sequence of steps needs to be adjusted according to different physics systems to obtain beneficial effects. The specific steps in this embodiment are as follows:

S1. Clamping the workpiece: Tighten the first clamping device 1-15 and the second clamping device 1-16, and clamp both ends of the metal workpiece 3 through the jaws.

S2, applying a physical field: start the physical field loading system 5, and apply physical fields including but not limited to the following physical fields to the metal workpiece 3: elastic stress field, pulsed current field, thermal field, pulsed electromagnetic field, cryogenic field.

S3. Apply rotation and feed: start the dual-spindle synchronous rotation system 1, set the speed, and the spindle servo motor 1-5 is driven by the spindle synchronous active belt 1-6, the retractable synchronous shaft 1-7, and the first spindle synchronously driven The belt 1-8 and the second main shaft synchronous driven belt 1-9 drive the first main shaft 1-3 and the first clamping device 1-15 and the second main shaft 1-4 and the second clamping device 1-16 to rotate synchronously, Then, the metal workpiece 3 is driven to rotate at the set rotational speed; the synchronous motion bases 1-11 run to drive the ultrasonic rolling system 2 and the second and/or third physical field loading devices 502 installed on the second bases 1-13 , 503 according to the set feed speed and direction along the metal workpiece 3 axial feed movement.

S4. Ultrasonic rolling: The ultrasonic rolling head of the ultrasonic rolling system 2 is radially close to the metal workpiece 3, and continues to make a feeding motion along the axial direction of the metal workpiece 3, and the rotating metal workpiece 3 is subjected to ultrasonic waves assisted by an elastic stress field. Rolling surface strengthening is to carry out ultrasonic rolling surface strengthening assisted by the physical field on the metal workpiece 3 .

S5. Stop rotation and feed: turn off the dual-spindle synchronous rotation system 1, stop the rotation of the metal workpiece 3, stop the ultrasonic rolling system 2 and the second and/or third physical fields installed on the second base 1-13 The loading devices 502 and 503 are fed along the axial direction of the metal workpiece 3 , and then the ultrasonic rolling head is radially away from the metal workpiece 3 .

S6, unloading the physical field: after the ultrasonic rolling is finished, the physical field loading system 5 is turned off, and the physical field is stopped to be applied to the metal workpiece 3 .

S7. Remove the workpiece: loosen the first clamping device 1-15 and the second clamping device 1-16, thereby removing the metal workpiece 3.

In particular, depending on the physical field system, applying or unloading the physical field before or after the ultrasonic rolling step can further increase the level and depth of residual compressive stress on the surface layer generated by ultrasonic rolling, which is further illustrated in the following examples .

Embodiment 2

As shown in FIG. 2a, another metal material physics-assisted ultrasonic rolling surface strengthening device 2000 is shown, wherein the adopted physics-field loading system 5 is a first physics-field loading system 501, and the first physics-field loading system 501 is an elastic stress field system 501a. The elastic stress field system 501a includes annular clamps respectively fixed on two clamping devices, namely the first clamp 501a-1 and the second clamp 501a-2 in Figure 2a. One end of the metal workpiece 3 can be inserted into and fixed to one end of the first fixture 501a-1, and the other end of the first fixture 501a-1 is provided with a cylindrical boss; the other end of the metal workpiece 3 can be inserted into and fixed to the second fixture 501a One end of -2, the other end of the second clamp 501a-2 is provided with a cylindrical boss. The material of the metal workpiece 3 is an in-situ TiB ₂ /2024Al composite material, numbered as A-2.

As shown in Fig. 2b, the surface strengthening method of the corresponding device 2000 is shown, in order: clamping the workpiece, applying the physical field, applying rotation and feeding, ultrasonic rolling, stopping the rotation and feeding, unloading the physical field and removing the workpiece Seven steps. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The step of applying the physical field is to apply the elastic stress field, and the step of unloading the physical field is to unload the elastic stress field.

In particular, the step of clamping the workpiece is as follows: the two ends of the metal workpiece 3 are respectively inserted into one end of the first clamp 501a-1 and one end of the second clamp 501a-2 and fixed, and then clamped with the first clamping device 1-15 and the second clamp The jaws of the devices 1-16 clamp the other ends of the first clamp 501a-1 and the second clamp 501a-2, respectively, as shown in FIG. 2c. In particular, after clamping, the tooth surfaces of the boss teeth of the jaws must be in good contact with the cylindrical surfaces of the first clamp 501a-1 and the second clamp 501a-2 to ensure the coaxiality of the entire device; The inner side elevations of the boss teeth of the jaws are in good contact with the inner side elevations of the cylindrical bosses at the other ends of the first clamp 501a-1 and the second clamp 501a-2 to ensure that the hydraulic drive device 4-1 provides The hydraulic load is accurately applied to the metal workpiece 3 via the piston rod 4-2, the first headstock 1-1, the first spindle 1-3, the first clamping device 1-15, and the first clamp 501a-1.

The steps of applying the elastic stress field are: according to the cross-sectional area of the metal workpiece 3 and the piston rod 4-2 and the preset elastic stress, calculate the required oil pressure, and the applied elastic stress field strength does not exceed the uniaxial strength of the material used in the metal workpiece 3 The limit value of the stretching ratio; start the hydraulic drive device 4-1, adjust the oil pressure through the oil pressure valve, and drive the first spindle box 1-1, the first spindle 1-3, and the first clamping device 1 through the piston rod 4-2 The -15 moves laterally along the slide rail of the bed 1-10 away from the second headstock 1-2, so as to apply a preset uniaxial tensile elastic stress field to the metal workpiece 3.

The steps of unloading the elastic stress field are: closing the hydraulic drive device 4-1, unloading the oil pressure in the traverse drive system 4, so that the metal workpiece 3 is elastically restored.

In particular, applying an elastic stress field before the ultrasonic rolling step and unloading the elastic stress field after the ultrasonic rolling step can induce elastic stress superposition and resultant force-resultant moment rebalance in the metal workpiece 3, thereby further improving the efficiency of ultrasonic rolling The level and depth of the resulting surface residual compressive stress.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 2b are carried out in sequence.

In this embodiment, the parameters of each step are: firstly clamp the A-2 workpiece, then apply a 150MPa uniaxial tensile elastic stress field to the A-2 workpiece, and then make the A-2 workpiece rotate at a speed of 200r/min , and then carry out ultrasonic rolling surface strengthening on the A-2 workpiece. The rolling conditions are as follows: the rolling head is a Φ14mm tungsten carbide ball, the static load pressure is 180N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, and the axial feed rate is 0.1mm/r, stop the workpiece rotation and axial feed after ultrasonic rolling, unload the uniaxial tensile elastic stress field, and finally remove the workpiece.

Embodiment 3

As shown in FIG. 3a, another metal material physics-assisted ultrasonic rolling surface strengthening device 3000 is shown, wherein the adopted physics loading system 5 is a second physics loading system 502, the second physics loading system 502 is a pulsed current field system 502a, and the workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered as A-3.

As shown in Fig. 3b, the surface strengthening method corresponding to the shown device 3000 is shown, which are clamping workpiece, applying physical field, applying rotation and feeding, ultrasonic rolling, stopping rotation and feeding, unloading physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The step of applying the physical field is applying a pulsed current field, and the step of unloading the physical field is unloading the pulsed current field.

In particular, the workpiece clamping step is as follows: covering both ends of the metal workpiece 3 with insulating rubber sleeves, respectively, and then using the first clamping device 1-15 and the second clamping device 1-16 to clamp both ends of the metal workpiece 3 respectively.

The step of applying the pulsed current field is: adjust the positions of the first electrode 502a-1 and the second electrode 502a-2 on the arc-shaped support 502a-3 to be in the same plane as the rolling head at the tip of the ultrasonic rolling system 2, so as to ensure The rolling head is on the current path between the electrodes, as shown in Figure 3c; the first electrode 502a-1 and the second electrode 502a-2 are kept in good contact with the surface of the metal workpiece 3, and then the power source 502a-5 is turned on and adjusted to With preset pulse current parameters, pulse current is applied to the metal workpiece 3 through the wire 502a-4, the first electrode 502a-1 and the second electrode 502a-2.

Metal materials are good conductors of electricity, and the pulsed Joule heating effect will be generated under the action of the pulsed current field, and the thermal activation and thermal expansion caused by the thermal activation and thermal expansion can effectively reduce the deformation resistance of the metal workpiece 3 during the ultrasonic rolling process. In addition, the skin effect generated by the high-frequency pulse current will increase the current density on the surface of the material, making the Joule heating effect more concentrated on the surface of the material.

In particular, by applying a pulsed current field before the ultrasonic rolling step and unloading the pulsed current field after the ultrasonic rolling step, the electroplastic effect, skin effect and Joule heating effect can be induced in the metal workpiece 3, reducing the ultrasonic rolling deformation resistance, improve the plastic flow characteristics of the surface material, thereby further increasing the level and depth of the surface residual compressive stress generated by ultrasonic rolling.

The steps of unloading the pulse current field are: turning off the power supply 502a-5, and stopping the pulse current flow to the metal workpiece 3.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 3b are carried out in sequence.

In this embodiment, the parameters of each step are: firstly clamp the A-3 workpiece, and then apply a pulse frequency of 20000 Hz, a pulse width of 1 μs, a duty cycle of 50%, and a peak current density of 30 A/mm ² to the A-3 workpiece. Pulse current field, and then make A-3 workpiece rotate at a speed of 200r/min, and finally carry out ultrasonic rolling surface strengthening on A-3 workpiece. The rolling conditions are, the rolling head is Φ14mm tungsten carbide ball, static The load pressure is 180N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, and the axial feed rate is 0.1mm/r. After the ultrasonic rolling is finished, the rotation and axial feed of the workpiece are stopped, the pulse current field is unloaded, and the workpiece is finally removed.

Embodiment 4

As shown in Fig. 4a, another metal material physics-assisted ultrasonic rolling surface strengthening device 4000 is shown, wherein the adopted physics-field loading system 5 is a second physics-field loading system 502, the second physics-field loading system 502 is a thermal field system 502b, and the workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered as A-4.

As shown in Fig. 4b, the surface strengthening method corresponding to the shown device 4000 is shown, which are clamping workpiece, applying physical field, applying rotation and feeding, ultrasonic rolling, stopping rotation and feeding, unloading physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The step of applying a physical field is applying a thermal field, and the step of unloading the pulsed current field is unloading the thermal field.

In particular, the steps of applying the heat field are: starting the power supply 502b-1, adjusting the output voltage and current of the controller 502b-3, and energizing the heater 502b-4 through the support 502b-2 with wires inside to heat the metal workpiece 3, such as As shown in FIG. 4c ; the temperature of the metal workpiece 3 is monitored in real time by the temperature monitor 502b-5 and the voltage and current output by the controller 502b-3 are adjusted feedback, so that the middle part of the metal workpiece 3 is heated to the preset temperature. In particular, during the heating process, the temperature of the middle heating part of the metal workpiece 3 needs to be monitored in real time, and fed back to the feedback adjustment controller 502b-3 to control the temperature of the heating part of the metal workpiece 3 in real time to maintain the specified temperature, and the metal The heating temperature of the middle part of the workpiece 3 does not exceed the precipitation temperature of the second phase of the material used for the metal workpiece 3 .

The step of unloading the thermal field is: turning off the heater 502b-4, and stopping applying the thermal field to the metal workpiece 3.

The steps of removing the workpiece are: loosening the first clamping device 1-15 and the second clamping device 1-16, thereby removing the metal workpiece 3, and then allowing the metal workpiece 3 to stand still to restore its temperature to room temperature.

In particular, applying a thermal field before the ultrasonic rolling step and unloading the thermal field after the ultrasonic rolling step can induce thermal activation and thermal expansion in the metal workpiece 3, reduce the ultrasonic rolling deformation resistance, and improve the plastic flow properties of the surface material, thereby Further increase the level and depth of surface residual compressive stress generated by ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 4b are carried out in sequence.

In this embodiment, the parameters of each step are: firstly clamp the A-4 workpiece, then apply a thermal field to heat the workpiece to 150 °C, then rotate the A-4 workpiece at a speed of 200 r/min, and then apply a heat field to the A-4 workpiece. The workpiece of No. 1 is subjected to ultrasonic rolling surface strengthening. The rolling conditions are as follows: the rolling head is a Φ14mm tungsten carbide ball, the static load pressure is 180N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, the axial feed rate is 0.1mm/r, and the rolling After pressing, stop the workpiece rotation and axial feed, unload the thermal field, make the temperature return to room temperature, and finally remove the workpiece.

Embodiment 5

As shown in FIG. 5a, another metal material physics-assisted ultrasonic rolling surface strengthening device 5000 is shown, wherein the adopted physics-field loading system 5 is a second physics-field loading system 502, and the second physics-field loading system 502 is a pulsed electromagnetic field system 502c, and the workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered as A-5.

As shown in Fig. 5b, the surface strengthening methods corresponding to the shown device 5000 are shown, which are clamping workpiece, applying physical field, applying rotation and feeding, ultrasonic rolling, stopping rotation and feeding, unloading physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The step of applying the physical field is applying a pulsed electromagnetic field, and the step of unloading the physical field is unloading the pulsed electromagnetic field.

In particular, the step of applying the pulsed electromagnetic field is as follows: start the controller 502c-4, adjust the preset pulsed electromagnetic parameters, and energize the induction coil 502c-1 connected to the bracket 502c-2 through the wire 502c-3; pass the induction coil 502c -1 Apply a pulsed electromagnetic field to the metal workpiece 3. In particular, the induction coil 502c-1 should be composed of double coils arranged in parallel, and the distance between the two coils is equal to the coil radius, as shown in FIG.

The step of unloading the pulsed magnetic field is: turning off the controller 502c-4, and stopping the application of the pulsed electromagnetic field to the metal workpiece 3.

In particular, applying the pulsed electromagnetic field before the ultrasonic rolling step and unloading the pulsed electromagnetic field after the ultrasonic rolling step can induce a magnetostrictive effect in the metal workpiece 3, reduce the deformation resistance of ultrasonic rolling, and improve the plastic flow characteristics of the surface material, thereby Further increase the level and depth of surface residual compressive stress generated by ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in Fig. 5b are carried out in sequence.

In this embodiment, the parameters of each step are: firstly clamp the workpiece A-5, then apply a pulsed electromagnetic field with a pulse frequency of 200 Hz, a pulse width of 5ms, and a peak magnetic induction intensity of 3T to the workpiece A-5, and then apply a pulsed electromagnetic field to the workpiece A-5. The workpiece No. 1 rotates at a speed of 200r/min, and then the surface of the workpiece No. A-5 is ultrasonically rolled for surface strengthening. The amplitude is 10μm, and the axial feed rate is 0.1mm/r. After the rolling, the workpiece rotation and axial feed are stopped, the pulsed magnetic field is unloaded, and the workpiece is finally removed.

Embodiment 6

As shown in Fig. 6a, another metal material physics-assisted ultrasonic rolling surface strengthening device 6000 is shown, wherein the adopted physics loading system 5 is a third physics loading system 503, the third physics loading system 503 is a cryogenic field system 503a, and the workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered A-6.

As shown in Fig. 6b, the surface strengthening method corresponding to the shown device 6000 is shown, which are clamping workpiece, applying rotation and feeding, ultrasonic rolling, applying physical field, stopping rotation and feeding, unloading physical field and taking Seven steps under the workpiece. Wherein, except for the sequence of steps, the following steps are the same as the surface strengthening method in Embodiment 1:

The step of applying the physical field is applying a cryogenic field, and the step of unloading the physical field is unloading the cryogenic field.

In particular, the step of clamping the workpiece is: fixing the two axial ends of the metal workpiece 3 between the two clamping devices, and making the metal workpiece 3 be on the spray intersection line of the two groups of spray heads 503a-1;

The steps of applying the cryogenic field are: start the controller 503a-4, adjust to the preset cryogenic medium ejection flow, and immediately pass through the tank body 503a-5, the conduit 503a-3 and be fixed on the bracket 503a- after the end of the ultrasonic rolling. The spray head 503a-1 on the 2 sprays the cryogenic medium to the metal workpiece 3 for a preset period of time.

The steps of unloading the cryogenic field are: turn off the controller 503a-4, and stop spraying the cryogenic medium to the metal workpiece 3.

During the ultrasonic rolling process of metal materials, the friction between the material surface and the rolling head will generate a lot of heat. After the rolling is completed, the metal workpiece 3 is quickly put into a cryogenic medium atmosphere, which can quickly cool the workpiece. Since the temperature gradient of the surface layer of the metal workpiece 3 is higher than that of the interior, the rapid cooling process can significantly increase the level and depth of residual compressive stress on the surface layer of the metal workpiece 3 .

In particular, by sequentially applying and unloading the cryogenic field after the ultrasonic rolling step, a huge temperature drop gradient can be generated on the surface layer of the metal workpiece 3, thereby further increasing the level and layer depth of the surface residual compressive stress generated by ultrasonic rolling.

The steps of removing the workpiece are as follows: remove the metal workpiece 3 and let it stand to restore its temperature to room temperature.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 6b are carried out in sequence.

In this embodiment, the parameters of each step are: firstly clamp the A-5 workpiece, then rotate the A-6 workpiece at a rotational speed of 200 r/min, and then perform ultrasonic rolling surface strengthening on the A-6 workpiece, rolling The conditions are that the rolling head is a Φ14mm tungsten carbide ball, the static load pressure is 180N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, the axial feed rate is 0.1mm/r, and the ultrasonic rolling is performed at a flow rate of 1L/min. The workpiece is sprayed with cryogenic medium for 5 minutes, then the cryogenic field is unloaded, and finally the workpiece is removed to restore its temperature to room temperature.

Embodiment 7

As shown in Figure 7a, another metal material physics-assisted ultrasonic rolling surface strengthening device 7000 is shown, wherein the adopted physics-field loading system 5 is a first physics-field loading system 501 and a second physics-field loading system 502 , the first physical field loading system 501 is an elastic stress field system 501a, and the second physical field loading system 502 is a pulse current field system 502a. The workpiece material is in-situ TiB ₂ /2024Al composite material, numbered A-7.

As shown in Fig. 7b, the surface strengthening method corresponding to the shown device 7000 is shown, in order: clamping the workpiece, applying the physical field, applying rotation and feeding, ultrasonic rolling, stopping the rotation and feeding, unloading the physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The steps of applying the physical field are sequentially applying an elastic stress field and applying a pulsed current field; the steps of unloading the physical field are sequentially unloading the pulsed current field and unloading the elastic stress field.

In particular, the step of applying the elastic stress field is the same as the step of applying the elastic stress field in the surface strengthening method in the second embodiment;

The step of applying the pulsed current field is the same as the step of applying the pulsed current field of the surface strengthening method in the third embodiment;

The step of unloading the pulsed current field is the same as the step of unloading the pulsed current field of the surface strengthening method in the third embodiment;

The step of unloading the elastic stress field is the same as the step of unloading the elastic stress field of the surface strengthening method in the second embodiment.

In particular, the step of clamping the workpiece is as follows: the annular clamps 501a-1 and 501a-2 are respectively fixed on the two clamping devices, and then the metal workpiece 3 with insulating sleeves sleeved at both ends is axially fixed on the two clamping devices. between two ring clamps, as shown in Figure 7c.

As shown in Fig. 7c, applying the pulsed current field before the ultrasonic rolling step and unloading the pulsed current field after the ultrasonic rolling step can induce electroplastic effect, skin effect and Joule heating effect in the metal workpiece 3, reducing the ultrasonic rolling The compressive deformation resistance improves the plastic flow characteristics of the surface material, thereby further increasing the level and depth of the residual compressive stress on the surface produced by ultrasonic rolling.

In particular, applying the elastic stress field before the step of applying the pulsed current field and unloading the elastic stress field after the step of unloading the pulsed current field can induce elastic stress superposition and resultant force-resultant moment rebalancing within the metal workpiece 3, thereby further improving the The level and depth of surface residual compressive stress generated by current-field-assisted ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 7b are carried out in sequence.

In a specific application example, the parameters of each step are: firstly clamp the A-7 workpiece, then apply a 150MPa elastic stress field to the A-7 workpiece, and then apply a pulse frequency of 20000 Hz and a pulse width of 1 μs to the A-7 workpiece. , a pulse current field with a duty ratio of 50% and a peak current density of 30A/mm ² , and then the A-7 workpiece is rotated at a speed of 200r/min, and then the A-7 workpiece is subjected to ultrasonic rolling surface strengthening, rolling conditions The rolling head is a Φ14mm tungsten carbide ball, the static load pressure is 180N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, and the axial feed rate is 0.1mm/r. After the rolling, the workpiece rotation and axial feed are stopped. Then unload the pulse current field and the elastic stress field in turn, and finally remove the workpiece.

Embodiment 8

As shown in FIG. 8a, another metal material physics-assisted ultrasonic rolling surface strengthening device 8000 is shown, wherein the adopted physics loading system 5 is a first physics loading system 501 and a second physics loading system 502 , the first physical field loading system 501 is an elastic stress field system 501a, and the second physical field loading system 502 is a thermal field system 502b. The workpiece material is in-situ TiB ₂ /2024Al composite material, numbered A-8.

As shown in Fig. 8b, the surface strengthening method corresponding to the shown device 8000 is shown, which are clamping workpiece, applying physical field, applying rotation and feeding, ultrasonic rolling, stopping rotation and feeding, unloading physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The steps of applying a physical field are sequentially applying an elastic stress field and applying a thermal field; the steps of unloading the physical field are sequentially unloading the thermal field and unloading the elastic stress field.

In particular, the step of applying the elastic stress field is the same as the step of applying the elastic stress field in the surface strengthening method in the second embodiment;

The step of applying a thermal field is the same as the step of applying a thermal field in the surface strengthening method in Embodiment 4;

The step of unloading the thermal field is the same as the step of unloading the thermal field of the surface strengthening method in Embodiment 4;

The step of unloading the elastic stress field is the same as the step of unloading the elastic stress field of the surface strengthening method in the second embodiment.

In particular, the step of clamping the workpiece is as follows: fixing the ring clamps 501a-1 and 501a-2 on the two clamping devices respectively, passing the metal workpiece 3 through the two sets of heating coil windings of the heater 502b-4, The workpiece 3 is axially fixed between two annular clamps;

As shown in Fig. 8c, applying a thermal field before the ultrasonic rolling step and unloading the thermal field after the ultrasonic rolling step can induce thermal activation and thermal expansion in the metal workpiece 3, reduce the ultrasonic rolling deformation resistance, and improve the plastic flow of the surface material Therefore, the level and depth of surface residual compressive stress generated by ultrasonic rolling are further improved.

In particular, applying the elastic stress field before the step of applying the thermal field and unloading the elastic stress field after the step of unloading the thermal field can induce the superposition of elastic stress and the rebalance of the resultant force-resultant moment in the metal workpiece 3, thereby further improving the efficiency of the thermal field by the thermal field. The level and depth of surface residual compressive stress generated by assisted ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 8b are carried out in sequence.

In a specific application example, the parameters of each step are: firstly clamp the A-8 workpiece, then apply a 150MPa elastic stress field to the A-8 workpiece, and then apply a thermal field to heat the workpiece to 150 ° C, and then make the A-8 workpiece. The No. 8 workpiece is rotated at a speed of 200 r/min, and then the surface of the No. 8 workpiece is ultrasonically rolled for surface strengthening. The rolling conditions are as follows: the rolling head is a Φ14mm tungsten carbide ball, the static load pressure is 180N, and the ultrasonic frequency is 28KHz. , ultrasonic amplitude 10μm, axial feed rate 0.1mm/r, stop the workpiece rotation and axial feed after rolling, then unload the thermal field, and restore the workpiece temperature to room temperature, then unload the elastic stress field, and finally Remove the workpiece.

Embodiment 9

As shown in Fig. 9a, another metal material physics-assisted ultrasonic rolling surface strengthening device 9000 is shown, wherein the adopted physics loading system 5 is a first physics loading system 501 and a second physics loading system 502 , the first physical field loading system 501 is an elastic stress field system 501a, the second physical field loading system 502 is a pulsed electromagnetic field system 502c The workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered A-9.

As shown in Fig. 9b, the surface strengthening methods corresponding to the shown device 9000 are shown, in order: clamping the workpiece, applying the physical field, applying rotation and feeding, ultrasonic rolling, stopping the rotation and feeding, unloading the physical field and taking Seven steps under the workpiece. Wherein, except for the following steps, it is the same as the surface strengthening method in Embodiment 1:

The steps of applying the physical field are sequentially applying an elastic stress field and applying a pulsed electromagnetic field; and the steps of unloading the physical field are sequentially unloading the pulsed electromagnetic field and unloading the elastic stress field.

In particular, the step of applying the elastic stress field is the same as the step of applying the elastic stress field in the surface strengthening method in the second embodiment;

The step of applying the pulsed electromagnetic field is the same as the step of applying the pulsed electromagnetic field of the surface strengthening method in the fifth embodiment;

The step of unloading the elastic stress field is the same as the step of unloading the elastic stress field of the surface strengthening method in the second embodiment;

The step of unloading the pulsed electromagnetic field is the same as the step of unloading the pulsed electromagnetic field of the surface strengthening method in the fifth embodiment.

In particular, the step of clamping the workpiece is as follows: the annular clamps 501a-1 and 501a-2 are respectively fixed on the two clamping devices, and then the metal workpiece 3 is axially passed through the two sets of induction coils 502c- 1, and fix both ends of the metal workpiece 3 in the axial direction between the two ring clamps;

As shown in Figure 9c, applying a pulsed electromagnetic field before the ultrasonic rolling step and unloading the pulsed electromagnetic field after the ultrasonic rolling step can induce a magnetostrictive effect in the metal workpiece 3, reduce the ultrasonic rolling deformation resistance, and improve the plastic flow of the surface material Therefore, the level and depth of surface residual compressive stress generated by ultrasonic rolling are further improved.

In particular, applying the elastic stress field before the step of applying the pulsed electromagnetic field, and unloading the elastic stress field after the step of unloading the pulsed electromagnetic field can induce elastic stress superposition and resultant force-resultant moment rebalancing in the metal workpiece 3, thereby further improving the efficiency of the pulsed electromagnetic field. The level and depth of surface residual compressive stress generated by assisted ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 9b are carried out in sequence.

In a specific application example, the parameters of each step are: firstly clamp the workpiece No. A-9, then apply a 150MPa elastic stress field to the workpiece No. A-9, then apply a pulse frequency of 200Hz to the workpiece No. A-9, and a pulse width of 5ms. , a pulsed electromagnetic field with a peak magnetic induction intensity of 3 T, and then the A-9 workpiece is rotated at a speed of 200r/min, and then the surface of the A-9 workpiece is subjected to ultrasonic rolling surface strengthening. The rolling conditions are, the rolling head is Φ14mm tungsten carbide Carbide ball, static load pressure 180N, ultrasonic frequency 28KHz, ultrasonic amplitude 10μm, axial feed rate 0.1mm/r, stop the workpiece rotation and axial feed after rolling, and then unload the pulsed electromagnetic field and elastic stress in turn field, and finally remove the workpiece.

Embodiment ten

As shown in FIG. 10a, another metal material physics-assisted ultrasonic rolling surface strengthening device 10000 is shown, wherein the adopted physics loading system 5 is a first physics loading system 501 and a third physics loading system 503 , the first physical field loading system 501 is an elastic stress field system 501a, and the third physical field loading system 503 is a cryogenic field system 503a The workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered A-10.

As shown in Fig. 10b, the surface strengthening method corresponding to the shown device 10000 is shown, which are clamping the workpiece, applying the first physical field, applying rotation and feeding, ultrasonic rolling, applying the second physical field, and unloading the second physical field. Nine steps of physics, stopping rotation and feeding, unloading the first physics and removing the workpiece. The specific steps in this embodiment are as follows:

S1. Clamping the workpiece: Insert the two ends of the metal workpiece 3 into one end of the first clamp 501a-1 and the second clamp 501a-2 respectively and fix them, and then use the first clamping device 1-15 and the second clamping device 1- The jaws of 16 clamp the other ends of the first clamp 501a-1 and the second clamp 501a-2 respectively, as shown in FIG. 2c. In particular, after clamping, the tooth surfaces of the boss teeth of the jaws must be in good contact with the cylindrical surfaces of the first clamp 501a-1 and the second clamp 501a-2 to ensure the coaxiality of the entire device; The inner side elevations of the boss teeth of the jaws are in good contact with the inner side elevations of the cylindrical bosses at the other ends of the first clamp 501a-1 and the second clamp 501a-2 to ensure that the hydraulic drive device 4-1 provides The hydraulic load is accurately applied to the metal workpiece 3 via the piston rod 4-2, the first headstock 1-1, the first spindle 1-3, the first clamping device 1-15, and the first clamp 501a-1, and The metal workpiece 3 is placed on the spray intersection line of the two sets of spray heads 503a-1.

S2. Apply elastic stress field: Calculate the required oil pressure according to the cross-sectional area of the metal workpiece 3 and the piston rod 4-2 and the preset elastic stress, and the applied elastic stress field strength does not exceed the single axis of the material used for the metal workpiece 3 The limit value of the stretching ratio; start the hydraulic drive device 4-1, adjust the oil pressure through the oil pressure valve, and drive the first spindle box 1-1, the first spindle 1-3, and the first clamping device 1 through the piston rod 4-2 -15 moves laterally along the slide rail of the bed 1-10 away from the second headstock 1-2, so as to apply a preset uniaxial tensile elastic stress field to the metal workpiece 3.

S3. Apply rotation and feed: start the dual-spindle synchronous rotation system 1, set the speed, and the spindle servo motor 1-5 is driven by the spindle synchronous active belt 1-6, the retractable synchronous shaft 1-7, and the first spindle synchronously driven The belt 1-8 and the second main shaft synchronous driven belt 1-9 drive the first main shaft 1-3 and the first clamping device 1-15 and the second main shaft 1-4 and the second clamping device 1-16 to rotate synchronously, Then, the metal workpiece 3 is driven to rotate at the set rotational speed; the synchronous motion bases 1-11 run to drive the ultrasonic rolling system 2 and the second and/or third physical field loading devices 502 installed on the second bases 1-13 , 503 according to the set feed speed and direction along the metal workpiece 3 axial feed movement.

S4. Ultrasonic rolling: The ultrasonic rolling head of the ultrasonic rolling system 2 is radially close to the metal workpiece 3, and continues to make a feeding motion along the axial direction of the metal workpiece 3, and the rotating metal workpiece 3 is subjected to ultrasonic waves assisted by an elastic stress field. Rolling surface strengthening is to carry out ultrasonic rolling surface strengthening assisted by the physical field on the metal workpiece 3 .

S5. Apply a cryogenic field: start the controller 503a-4, adjust to the preset cryogenic medium ejection flow, and immediately pass through the tank body 503a-5, the conduit 503a-3 and the bracket 503a- after the end of the ultrasonic rolling. The spray head 503a-1 on the 2 sprays the cryogenic medium to the metal workpiece 3 for a preset period of time.

S6, unloading the cryogenic field: turn off the controller 503a-4, and stop spraying cryogenic medium to the metal workpiece 3.

S7. Stop rotation and feed: turn off the dual-spindle synchronous rotation system 1, stop the rotation of the metal workpiece 3, stop the ultrasonic rolling system 2 and the second and/or third physical fields installed on the second base 1-13 The loading devices 502 and 503 are fed along the axial direction of the metal workpiece 3 , and then the ultrasonic rolling head is radially away from the metal workpiece 3 .

S8. Unload the elastic stress field: turn off the hydraulic drive device 4-1, unload the oil pressure in the traverse drive system 4, and make the metal workpiece 3 elastically recover.

S9. Removing the workpiece: loosen the first clamping device 1-15 and the second clamping device 1-16, thereby removing the metal workpiece 3 and returning it to room temperature.

As shown in Figure 10c, sequentially applying and unloading the cryogenic field after the ultrasonic rolling step can generate a huge temperature drop gradient on the surface layer of the metal workpiece 3, thereby further increasing the level and layer depth of the surface residual compressive stress generated by ultrasonic rolling .

In particular, applying an elastic stress field before the ultrasonic rolling step and unloading the elastic stress field after the step of unloading the cryogenic field can induce elastic stress superposition and resultant force-resultant moment rebalancing in the metal workpiece 3, thereby further improving the efficiency of the cryogenic field The level and depth of surface residual compressive stress generated by assisted ultrasonic rolling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 10b are carried out in sequence.

In a specific application example, the parameters of each step are: firstly clamp the A-10 workpiece, then apply a 150MPa elastic stress field to the A-10 workpiece, then make the A-10 workpiece rotate at a rotational speed of 200 r/min, and then The surface of A-10 workpiece is strengthened by ultrasonic rolling. The rolling conditions are as follows: the rolling head is Φ14mm tungsten carbide ball, the static load pressure is 180 N, the ultrasonic frequency is 28KHz, the ultrasonic amplitude is 10μm, and the axial feed rate is 0.1 mm/r, after the rolling, stop the axial feed and spray the cryogenic medium to the workpiece after ultrasonic rolling at a flow rate of 1L/min for 5 minutes, then unload the cryogenic field, stop the rotation of the workpiece, and then unload the elastic stress field , and finally remove the workpiece and let its temperature return to room temperature.

Embodiment 11

As shown in FIG. 11a, another metal material physics-assisted ultrasonic rolling surface strengthening device 11000 is shown, wherein the adopted physics loading system 5 is a first physics loading system 501 and a second physics loading system 502 and a third physics field loading system 503, the first physics field loading system 501 is an elastic stress field system 501a, the second physics field loading system 502 is a thermal field system 502b, and the third physics field loading system 503 is a cryogenic field system 503a, the workpiece material is an in-situ TiB ₂ /2024Al composite material, numbered A-11.

As shown in FIG. 11b, the surface strengthening method corresponding to the shown device 11000 is shown, in order: clamping the workpiece, applying the first physical field, applying the second physical field, applying rotation and feeding, ultrasonic rolling, and unloading the second Eleven steps of physics, applying third physics, unloading third physics, stopping rotation and feeding, unloading first physics and removing workpiece. The specific steps in this embodiment are as follows:

S1, clamping the workpiece: passing the metal workpiece 3 through the two sets of heating coil windings of the heater 502b-4, and inserting both ends of the metal workpiece 3 into one end of the first fixture 501a-1 and the second fixture 501a-2 and fixing them , and then use the jaws of the first clamping device 1-15 and the second clamping device 1-16 to clamp the other ends of the first clamp 501a-1 and the second clamp 501a-2, respectively, as shown in FIG. 2c. In particular, after clamping, the tooth surfaces of the boss teeth of the jaws must be in good contact with the cylindrical surfaces of the first clamp 501a-1 and the second clamp 501a-2 to ensure the coaxiality of the entire device; The inner side elevations of the boss teeth of the jaws are in good contact with the inner side elevations of the cylindrical bosses at the other ends of the first clamp 501a-1 and the second clamp 501a-2 to ensure that the hydraulic drive device 4-1 provides The hydraulic load is accurately applied to the metal workpiece 3 via the piston rod 4-2, the first headstock 1-1, the first spindle 1-3, the first clamping device 1-15, and the first clamp 501a-1, and The metal workpiece 3 is placed on the spray intersection of the two groups of spray heads 503a-1;

S2. Apply elastic stress field: Calculate the required oil pressure according to the cross-sectional area of the metal workpiece 3 and the piston rod 4-2 and the preset elastic stress, and the applied elastic stress field strength does not exceed the single axis of the material used for the metal workpiece 3 The limit value of the stretching ratio; start the hydraulic drive device 4-1, adjust the oil pressure through the oil pressure valve, and drive the first spindle box 1-1, the first spindle 1-3, and the first clamping device 1 through the piston rod 4-2 -15 moves laterally along the slide rail of the bed 1-10 away from the second headstock 1-2, so as to apply a preset uniaxial tensile elastic stress field to the metal workpiece 3.

S3. Applying a heat field: start the power supply 502b-1, adjust the output voltage and current of the controller 502b-3, and energize the heater 502b-4 through the bracket 502b-2 with wires inside to heat the metal workpiece 3, as shown in Figure 4c The temperature of the metal workpiece 3 is monitored in real time by the temperature monitor 502b-5, and the voltage and current output by the controller 502b-3 are adjusted feedback, so that the middle part of the metal workpiece 3 is heated to the preset temperature. In particular, during the heating process, the temperature of the middle heating part of the metal workpiece 3 needs to be monitored in real time, and fed back to the feedback adjustment controller 502b-3 to control the temperature of the heating part of the metal workpiece 3 in real time to maintain the specified temperature, and the metal The heating temperature of the middle part of the workpiece 3 does not exceed the precipitation temperature of the second phase of the material used for the metal workpiece 3 .

S4. Apply rotation and feed: start the dual-spindle synchronous rotation system 1, set the speed, and the spindle servo motor 1-5 will be driven by the spindle synchronous active belt 1-6, the retractable synchronous shaft 1-7, and the first spindle synchronously. The belt 1-8 and the second main shaft synchronous driven belt 1-9 drive the first main shaft 1-3 and the first clamping device 1-15 and the second main shaft 1-4 and the second clamping device 1-16 to rotate synchronously, Then, the metal workpiece 3 is driven to rotate at the set rotational speed; the synchronous motion bases 1-11 run to drive the ultrasonic rolling system 2 and the second and/or third physical field loading devices 502 installed on the second bases 1-13 , 503 according to the set feed speed and direction along the metal workpiece 3 axial feed movement.

S5. Ultrasonic rolling: The ultrasonic rolling head of the ultrasonic rolling system 2 is radially close to the metal workpiece 3, and continues to make a feeding motion along the axial direction of the metal workpiece 3, and the rotating metal workpiece 3 is subjected to ultrasonic waves assisted by an elastic stress field. Rolling surface strengthening is to carry out ultrasonic rolling surface strengthening assisted by the physical field on the metal workpiece 3 .

S6, unloading the thermal field: turn off the heater 502b-4, and stop applying the thermal field to the metal workpiece 3.

S7. Apply a cryogenic field: start the controller 503a-4, adjust to the preset cryogenic medium ejection flow, and immediately pass through the tank 503a-5, the conduit 503a-3 and the support 503a- after the end of the ultrasonic rolling. The spray head 503a-1 on the 2 sprays the cryogenic medium to the metal workpiece 3 for a preset period of time.

S8, unloading the cryogenic field: turn off the controller 503a-4, and stop spraying cryogenic medium to the metal workpiece 3.

S9. Stop rotation and feed: turn off the dual-spindle synchronous rotation system 1, stop the rotation of the metal workpiece 3, stop the ultrasonic rolling system 2 and the second and/or third physical fields installed on the second base 1-13 The loading devices 502 and 503 are fed along the axial direction of the metal workpiece 3 , and then the ultrasonic rolling head is radially away from the metal workpiece 3 .

S10. Unload the elastic stress field: turn off the hydraulic drive device 4-1, unload the oil pressure in the traverse drive system 4, and make the metal workpiece 3 elastically recover.

S11. Removing the workpiece: loosen the first clamping device 1-15 and the second clamping device 1-16, thereby removing the metal workpiece 3 and returning it to room temperature. As shown in Fig. 11c, applying a thermal field before the ultrasonic rolling step and unloading the thermal field after the ultrasonic rolling step can induce thermal activation and thermal expansion in the metal workpiece 3, reduce the ultrasonic rolling deformation resistance, and improve the plastic flow of the surface material Therefore, the level and depth of surface residual compressive stress generated by ultrasonic rolling are further improved.

In particular, the sequential application and unloading of the cryogenic field after the step of unloading the thermal field can generate a huge temperature drop gradient on the surface layer of the metal workpiece 3, thereby further increasing the level and layer of residual compressive stress on the surface layer generated by the ultrasonic rolling assisted by the thermal field. deep.

In particular, applying the elastic stress field before the step of applying the thermal field and unloading the elastic stress field after the step of unloading the cryogenic field can induce the superposition of elastic stress and the rebalance of the resultant force-resultant moment in the metal workpiece 3, thereby further improving the The level and depth of surface residual compressive stress generated by ultrasonic rolling is aided by the cold field-hot field coupling.

In particular, the above-mentioned beneficial effects can only be obtained when the steps shown in FIG. 11b are carried out in sequence.

In a specific application example, the parameters of each step are: firstly clamp the A-11 workpiece, then apply a 150MPa elastic stress field to the A-11 workpiece, and then apply a thermal field to heat the workpiece to 150 ° C, and then make the A-11 workpiece. The No. 11 workpiece rotates at a speed of 200 r/min, and then a thermal field is applied to heat the workpiece to 150 ° C, and then the surface of the A-11 workpiece is ultrasonically rolled to strengthen the surface. The rolling conditions are that the rolling head is Φ14mm tungsten carbide carbide Ball, static load pressure 180N, ultrasonic frequency 28 KHz, ultrasonic amplitude 10μm, axial feed rate 0.1mm/r, stop the axial feed after rolling, then unload the heat field, and then flow to 1L/min. After ultrasonic rolling, the workpiece is sprayed with cryogenic medium for 5 minutes, then the cryogenic field is unloaded, the rotation of the workpiece is stopped, the elastic stress field is unloaded, and the workpiece is finally removed to restore its temperature to room temperature.

Embodiment 12

This embodiment is basically the same as the device and the surface strengthening method described in the second embodiment. In particular, in the step of clamping the workpiece in the surface strengthening method of the second embodiment, the two ends of the metal workpiece 3 are respectively penetrated into the first There are various ways to fix one end of the clamp 501a-1 and the second clamp 501a-2, such as screw connection, snap connection and so on. In particular, another metal workpiece 3-a and another elastic stress field system 501a-a are provided on the basis of the device 2000, and a new metal workpiece 3-a on the elastic stress field system 501a-a is provided. Fixed way, as shown in Figure 12a.

Wherein, one end of the metal workpiece 3-a is provided with a single pin hole, and the other end is provided with two pin holes; the coaxiality within the entire length of the metal workpiece 3-a is less than or equal to 0.01.

The elastic stress field system 501a-a includes a first clamp 501a-a-1, a second clamp 501a-a-2, a limit block 501a-a-3, a first tension threaded pin 501a-a-4, a second Tension threaded pins 501a-a-5, limit threaded pins 501a-a-6 and nuts 501a-a-7. The diameters of the hollow parts of the first fixture 501a-a-1 and the second fixture 501a-a-2 are in clearance fit with the diameters of both ends of the metal workpiece 3-a, the maximum clearance is ≤0.05mm, and the minimum clearance is ≥0mm; the first fixture 501a -a-1 is provided with a group of pin holes, the positions of the group of pin holes correspond to the single pin holes at one end of the metal workpiece 3-a, and the size of the group of pin holes is the same as the size of the single pin hole at one end of the metal workpiece 3-a , the first tension threaded pin 501a-a-4 is inserted into the set of pin holes, and the first tension threaded pin 501a-a-4 maintains clearance fit with the set of pin holes, the maximum clearance is ≤ 0.05mm, and the minimum clearance is ≥ 0mm; The stop block 501a-a-3 can be inserted into the groove on the second clamp 501a-a-2; the stop block 501a-a-3 and the second clamp 501a-a-2 are integrally formed with two sets of pin holes , wherein the first group of pin holes completely pass through the second clamp 501a-a-2, the second group of pin holes pass through the second clamp 501a-a-2 and the limit block 501a-a-3 respectively; two groups of pin holes The position of the metal workpiece 3-a corresponds to the two pin holes at the other end of the metal workpiece 3-a, and the size of the two groups of pin holes is the same as the size of the two pin holes at the other end of the metal workpiece 3-a; The second tension threaded pins 501a-a-5, the second tension threaded pins 501a-a-5 are in clearance fit with the first group of pin holes, the maximum clearance is less than or equal to 0.05mm, and the minimum clearance is greater than or equal to 0mm; Insert the limiting threaded pins 501a-a-6, and the limiting threaded pins 501a-a-6 maintain clearance fit with the second group of pin holes, the maximum clearance is ≤0.05mm, and the minimum clearance is ≥0mm; the first tension threaded pins 501a-a -4. Nuts 501a-a-7 are screwed on the ends of the second tension threaded pin 501a-a-5 and the limit threaded pin 501a-a-6 respectively.

Compared with fixing methods such as screw connection and snap connection, the new fixing method of the metal workpiece 3-a on the elastic stress field system 501a-a can make the metal workpiece 3-a, elastic stress field system 501a-a and double The whole composed of the spindle synchronous rotation system 1 has better coaxiality; further, the clamping and dismounting of the metal workpiece 3-a can be made simpler and more convenient, without the need to move the first headstock back and forth through the traverse drive system 4 1-1; Further, since the metal workpiece 3-a is in close contact with the hollow parts of the first jig 501a-a-1 and the second jig 501a-a-2 with a small gap, the first tension threaded pin 501a-a- 4. The second tension threaded pin 501a-a-5 and the limit threaded pin 501a-a-6 are on the first clamp 501a-a-1, the second clamp 501a-a-2 and the limit block 501a-a-3 The pin holes of the pinholes are kept in close contact with a small gap, and the stability of the elastic stress field can also be improved.

Comparative ratio

As a comparison, ordinary ultrasonic rolling surface strengthening was carried out, and the materials and rolling conditions used were exactly the same as those of No. A-2 to A-11 workpieces, numbered No. B-1. Using an X-ray stress meter, an electrolytic polishing machine and a high-precision laser displacement sensor, the distribution of the residual stress on the surface of the workpiece along the depth direction perpendicular to the material surface in all embodiments is measured. Among them, the electrolytic polishing machine is used to peel off the affected layer, the high-precision laser displacement sensor is used to measure the depth of the affected layer at the peeled place, and the X-ray stress meter is used to measure the residual stress value of each affected layer. The residual stress measurements are shown in Figures 13a-13e, respectively.

The surface residual compressive stress level, the peak residual compressive stress level and the residual compressive stress-affected layer depth of the physical field-assisted ultrasonic rolling workpiece in Examples 2 to 11 are significantly higher than those of the ordinary ultrasonic rolling workpiece in the comparative example. of the above indicators. The measurement results show that compared with ordinary ultrasonic rolling, physics-assisted ultrasonic rolling can comprehensively improve the surface residual compressive stress level, peak residual compressive stress level, and residual compressive stress-affected layer depth, and significantly optimize the surface residual compressive stress distribution. It can effectively improve the fatigue performance of the workpiece.

To sum up, the device and method for strengthening the surface of metal materials assisted by the physical field of ultrasonic rolling provided by the present invention in the above-mentioned embodiments have the advantages of simple structure, low cost of use and maintenance, convenient operation of related methods, and mechanical surface strengthening of metal materials. It is of great practical value in improving fatigue performance.

The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in ordinary ways in the art; any person skilled in the art, without departing from the present invention Within the scope of the technical solution of the invention, many possible changes and modifications can be made to the technical solution of the present invention by using the methods and technical contents disclosed above, or modified into equivalent embodiments with equivalent changes, which does not affect the essence of the present invention. . Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the protection scope of the technical solutions of the present invention.

Claims (10)

1. A surface enhancing apparatus for applying elastic stress fields and thermal fields to a metal workpiece and assisting ultrasonic rolling, the metal workpiece (3) being a cylindrical workpiece, characterized in that the surface enhancing apparatus comprises:

the double-spindle synchronous rotation system (1) comprises two spindle boxes which are symmetrically arranged and a synchronous motion base (1-11) positioned between the two spindle boxes, output shafts of the two spindle boxes are connected with the same telescopic synchronous shaft (1-7) through synchronous belts, clamping devices are respectively configured at opposite ends of the two output shafts, and a metal workpiece (3) is fixed between the two clamping devices;

the ultrasonic rolling system (2) is arranged on the synchronous motion base (1-11) and is positioned on one side of the metal workpiece (3), the synchronous motion base (1-11) is used for driving the ultrasonic rolling system (2) to make feeding motion along the axial direction of the metal workpiece (3), and the ultrasonic rolling system (2) comprises an ultrasonic rolling head which can be radially close to/far away from the metal workpiece (3);

the elastic stress field loading device comprises a transverse moving driving system (4) and annular clamps fixed on two clamping devices, wherein mounting holes are formed in opposite ends of the two annular clamps, two axial ends of a metal workpiece (3) are fixed in the mounting holes of the two annular clamps, the transverse moving driving system (4) drives a first spindle box (1-1) to horizontally move away from a second spindle box (1-2), the metal workpiece (3) is subjected to drawing treatment according to a set stress level, and an elastic stress field is applied to the metal workpiece (3);

the device comprises a thermal field loading device (502b), wherein the thermal field loading device (502b-4) is provided with heaters (502b-4) which are positioned at two sides of an ultrasonic rolling head and used for heating the middle part of the metal workpiece (3), the heaters (502b-4) are connected with a feedback regulation controller (502b-3), the feedback regulation controller (502b-3) is used for controlling the heating power of the heaters (502b-4) in real time to enable the heating part to be heated and then maintained at a specified temperature, the heaters (502b-4) are two groups of heating coil windings which are arranged at two sides of the ultrasonic rolling head and wound on the outer ring of the metal workpiece (3), a gap which is not larger than the diameter of the workpiece is arranged between the heating coil windings and the outer diameter of the metal workpiece (3) so as not to influence the rotation of the metal workpiece (3) and heat the metal workpiece (3),

before the ultrasonic rolling step, a thermal field is applied by the thermal field loading device (502b), and the heating temperature of the middle part of the metal workpiece (3) does not exceed the second phase precipitation temperature of the material used by the metal workpiece (3).

2. A surface-enhancing apparatus as claimed in claim 1, wherein a spindle servo motor (1-5) for driving the telescopic synchronizing shafts (1-7) in rotation is fixed to the first headstock (1-1).

3. A surface-enhancing apparatus as claimed in claim 1, wherein the traverse driving system (4) is provided with a set of horizontal driving means connected to the first main spindle box (1-1), the horizontal driving means including a hydraulic driving means (4-1) and a piston rod (4-2), wherein the hydraulic driving means (4-1) is provided with an oil pressure valve, and the hydraulic driving means (4-1) is connected to the first main spindle box (1-1) through the piston rod (4-2);

the two main spindle boxes are both arranged on a slide rail of the lathe bed (1-10).

4. A surface-hardening arrangement according to claim 1, characterized in that a third base (1-14) is mounted on the second headstock (1-2);

two groups of heating coil windings connected in series are electrically connected with a feedback regulation controller (502b-3), and the heating coil windings and the feedback regulation controller (502b-3) are arranged on a third base (1-14) through a bracket;

the feedback regulation controller (502b-3) controls the heating power of the heater (502b-4) in real time according to the monitored temperature of the heating part of the metal workpiece (3) so that the heating part is heated and then maintained at the designated temperature.

5. The surface enhancement apparatus of claim 4, wherein the thermal field loading device (502b) further comprises a temperature monitor (502b-5) connected to the feedback conditioning controller (502b-3) for monitoring the surface temperature of the heated metal workpiece (3) and feeding back to the feedback conditioning controller (502 b-3).

6. The surface-strengthening device of claim 1, wherein the ultrasonic rolling head is close to/away from the metal workpiece (3) in a radial direction of the metal workpiece (3).

7. The surface enhancing apparatus of claim 1, wherein the clamping device is a claw disk,

the annular clamp is a sleeve with a T-shaped section, the front end of the annular clamp is provided with the mounting hole, and the rear end of the annular clamp is provided with a boss fixed in the central hole of the claw disc.

8. A method for surface strengthening a metal workpiece using the surface strengthening apparatus of any one of claims 1 to 7, comprising the steps of:

s1, fixing annular clamps on the two clamping devices respectively, enabling the metal workpiece (3) to pass through two groups of heating coil windings of the heater (502b-4), and then axially fixing the metal workpiece (3) between the two annular clamps;

s2, driving the first spindle box (1-1) to horizontally move away from the second spindle box (1-2) by using the transverse movement driving system (4), so that the metal workpiece (3) in the middle is drawn by the two annular clamps according to a set stress level, and an elastic stress field is applied to the metal workpiece (3);

s3, starting the double-spindle synchronous rotating system (1), and synchronously rotating the two clamping devices to drive the metal workpiece (3) to rotate according to the set rotating speed and the rotating direction;

s4, starting a thermal field loading device (502b), heating the middle part of the metal workpiece (3) to a specified temperature, and then maintaining the temperature;

s5, the synchronous motion base (1-11) operates to drive the ultrasonic rolling system (2) to axially feed along the metal workpiece (3) at a set feeding speed and direction;

s6, starting the ultrasonic rolling system (2), wherein an ultrasonic rolling head of the ultrasonic rolling system (2) is close to the metal workpiece (3) in the radial direction and continues to perform feed motion along the axial direction of the metal workpiece (3), and the ultrasonic rolling surface strengthening under the assistance of an elastic stress field and a thermal field is performed in the middle of a heating part of the rotating metal workpiece (3);

s7, after the ultrasonic rolling is finished, closing the double-spindle synchronous rotating system (1), stopping the rotation of the metal workpiece (3), stopping the axial feeding motion of the ultrasonic rolling system (2) along the metal workpiece (3), and then enabling the ultrasonic rolling head to be away from the metal workpiece (3) in the radial direction;

s8, closing the heating field loading device (502b), and stopping applying the thermal field to the metal workpiece (3);

s9, closing the transverse moving driving system (4) to enable the metal workpiece (3) to elastically recover;

s10, loosening the two clamping devices, taking down the metal workpiece (3) and enabling the temperature of the metal workpiece to be recovered to the room temperature.

9. The method of claim 8, wherein in steps S4-S6, the method further comprises:

and the temperature of the heating part of the metal workpiece (3) is monitored in real time and fed back to the feedback regulation controller (502b-3) to regulate and control the temperature of the heating part of the metal workpiece (3) to be maintained at a specified temperature in real time.

10. The method as claimed in claim 8, wherein in step S2, the required oil pressure is calculated based on the cross-sectional area of the metal workpiece (3) and the cross-sectional area of the piston rod (4-2) of the traverse drive system (4) inside the hydraulic cylinder and the magnitude of the predetermined elastic stress;

the strength of the applied elastic stress field does not exceed the limit value of the uniaxial stretching ratio of the material used for the metal workpiece (3).

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