A non-ferrous metal local annealing device and control method

Abstract

A non-ferrous metal local annealing equipment and control method, wherein the local annealing equipment comprises: a furnace body, wherein the furnace body is provided with a hot air circulation airway, a heater and a fan; the hot air circulation airway comprises an upper circulation airway, a lower circulation airway, a heating chamber and a fan chamber; the heater is arranged in the heating chamber, and the fan is arranged in the fan chamber; a container is arranged in the upper circulation airway and close to the furnace cover, and the container is a grille structure for airflow in and out; the furnace cover is covered on the furnace body, and is connected to the container through a height adjustment mechanism, and the furnace cover is provided with a plurality of jacks for passing the workpiece, and a part of the workpiece passes through the furnace cover into the container, and is locally annealed under the action of the heater and the fan. The present invention also includes a control method for a non-ferrous metal local annealing equipment. The present invention can ensure that the instrument temperature control accuracy reaches ±1°C, and the furnace temperature control accuracy reaches ±5°C; and air heating is adopted to avoid environmental pollution and quality problems such as spots that may exist after heating.

Description

Technical Field

[0001] The invention relates to a local annealing device, in particular to a non-ferrous metal local annealing device and a control method. Background Art

[0002] At present, the equipment used for local annealing in the heat treatment industry is mainly nitrate salt furnace, which specifically uses a 1:1 mixture of sodium nitrite and potassium nitrate as the heating medium. Since the workpiece is always heated in the salt solution, it has the advantages of fast heating speed and uniform temperature. At the same time, a layer of salt film will be attached to the surface of the workpiece when it comes out of the furnace, which has the effect of preventing the surface oxidation and decarburization of the workpiece. However, the nitrate salt furnace has the disadvantages of high pollution, high loss, and corrosiveness, which will cause damage to the operator's health.

[0003] In addition to the local annealing equipment of the nitrate furnace type, there is also an induction heating local annealing equipment, that is, a fixture is used to clamp the workpiece for local annealing. When there are multiple workpieces, multiple fixtures are required to clamp each workpiece at the same time, and the fixture plate is driven by a transmission chain to drive the workpiece to move until the workpiece enters the inductor at the designed speed for local annealing. However, this annealing method has the following defects: (1) In order to perform local heating annealing on the workpiece, it is mainly necessary to clamp it with a fixture. Once multiple workpieces are annealed at the same time, multiple workpieces need to be set up, and a drive chain drive is also required, which not only leads to a complex structure and increased costs, but also occupies a large area; (2) When using an inductor for annealing, on the one hand, inductor heating is radiant heat, which will cause uneven heating; on the other hand, it is necessary to pay attention to the influence of heat conduction during local annealing, so the design of the inductor is very critical. If it is not handled properly, the entire workpiece will be annealed and scrapped.

[0004] Furthermore, other annealing furnaces place non-ferrous metals in the furnace body for overall annealing, rather than local annealing, and therefore are different from the technical concept of the present invention. Summary of the invention

[0005] The object of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a non-ferrous metal local annealing device and a control method with simple structure, low cost and high annealing efficiency.

[0006] The technical solution of the present invention is:

[0007] A non-ferrous metal local annealing device of the present invention comprises:

[0008] The furnace body is provided with a hot air circulation duct, a heater and a fan; the hot air circulation duct includes an upper circulation duct, a lower circulation duct, a heating chamber and a fan chamber; the heater is arranged in the heating chamber, and the fan is arranged in the fan chamber;

[0009] A container is arranged in the upper circulating air duct and close to the furnace cover, and the container is a grille structure for air flow in and out;

[0010] A furnace cover is placed on the furnace body and connected to the container through a height adjustment mechanism. The furnace cover is provided with a plurality of insertion holes for passing the workpieces. A part of the workpiece passes through the furnace cover and enters the container, and is locally annealed under the action of the heater and the fan.

[0011] The control system is used to adjust the temperature of the heater and the air volume of the fan.

[0012] Furthermore, the container is designed to be universal, and the size of the socket of the furnace cover is adapted to the size of the workpiece. When in use, the container is combined with a matching furnace cover to perform local annealing of different workpieces.

[0013] Furthermore, the heating chamber is arranged between the upper circulation air duct and the lower circulation air duct, the fan chamber is arranged on one side, the size of the upper circulation air duct is larger than the lower circulation air duct, and a guide plate is provided between the upper circulation air duct and the container, and the guide plate is inclined toward the bottom surface of the container along the upper circulation air duct.

[0014] Furthermore, the heater includes a transverse tubular heater arranged directly below the container and side tubular heaters arranged on both sides of the heating chamber; the vertical height of the side tubular heater from the bottom surface of the container is smaller than the vertical height of the transverse tubular heater from the bottom surface of the container.

[0015] Furthermore, the fan is a high-temperature fan, including a wind wheel, which is connected to the motor via a motor shaft. The wind wheel is arranged at the upper part of the fan room and is arranged in the same horizontal direction as the upper circulation air duct; the motor is arranged outside the furnace body, and the length of the motor shaft is not less than 200mm.

[0016] Furthermore, the furnace body, hot air circulation duct, container and furnace cover are all made of Cr25Ni20-3105 heat-resistant stainless steel.

[0017] Furthermore, the container is a material frame, the side walls and bottom of the material frame are grid structures, the upper part of the workpiece is exposed outside the furnace cover, and the lower part extends into the material frame, so that the height of the cavity formed by the furnace cover and the material frame is smaller than the height of the workpiece.

[0018] A control method for a non-ferrous metal local annealing device of the present invention comprises the following steps:

[0019] S1: Set process parameters and heating curve;

[0020] S2: Turn on the fan and adjust it to the target air volume;

[0021] S3: Select a furnace cover that matches the workpiece according to the workpiece model and install it on the furnace body;

[0022] S4: Turn on the heater, and the control system automatically calculates the temperature difference between the set target temperature and the actual heating temperature of the heater, outputs the heating output power control signal in different operating time periods, and adjusts the temperature;

[0023] S5: After reaching the target temperature, the workpiece is inserted into the container through the plug hole on the furnace cover. Under the action of the fan, hot air circulates into the container to perform local annealing on the workpiece;

[0024] S6: Annealing is completed and the product is taken out of the furnace.

[0025] Further, in step S4, when the temperature difference between the set temperature and the actual heating temperature is greater than 10-30°C, the output heating control power is 80%-100%; when the temperature difference is less than 10-30°C, the output heating control power is 0-30%.

[0026] Further, in step S5, when the hot air circulates, the hot air flows from the lower circulation air duct, enters the upper circulation air duct through the fan, and the hot air in the upper circulation air duct enters the inner cavity of the container from the side and bottom of the container under the action of the guide plate to perform local annealing on the workpiece, and enters the lower circulation air duct again through the heating chamber, and the cycle continues.

[0027] Beneficial effects of the present invention:

[0028] (1) By combining the container with the furnace cover, the material frame is designed to be universal, which is suitable for local annealing of all workpieces. When in use, it only needs to be combined with a matching furnace cover. The shape of the socket on the furnace cover can be designed according to different workpieces, which greatly improves the wide applicability and can achieve local annealing. Moreover, this design has a simple structure and does not require a drive chain to drive the workpiece to move, nor does it require multiple clamps to clamp the workpiece, which greatly reduces the floor space and reduces costs;

[0029] (2) By designing the sides and bottom of the container into a grid structure, hot air can enter the container along the grid to perform local annealing on the workpiece, greatly improving the annealing efficiency; a height adjustment mechanism is provided between the container and the furnace cover, which can be suitable for local annealing of different workpieces and can greatly reduce the loss caused by heat dissipation upwards;

[0030] (3) By providing a hot air circulation duct, not only the compactness of the structure is improved, but also a strong convection circulation can be performed, which greatly improves the efficiency of local annealing. In addition, guide plates are provided on both sides of the upper circulation duct, so that the airflow can be forced into the container under the guidance of the guide plates, further improving the annealing efficiency. Compared with the existing induction heating, the workpiece can be heated uniformly.

[0031] (4) The fan is designed to ensure that the motor will not be damaged by heat transfer, and the fan shaft is designed to be extended to facilitate heat dissipation and prevent the motor from being overheated, thereby greatly improving the service life of the fan;

[0032] (5) The control method of the present invention can ensure that the temperature control accuracy of the instrument reaches ±1°C and the temperature control accuracy of the furnace reaches ±5°C; and the use of air heating avoids environmental pollution and quality problems such as spots that may exist after heating; the production capacity is increased by 50%, the heating cost in the heating stage is reduced by 46.4%, the process parameters are more accurately controllable, and the quality control is more perfect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the furnace structure of an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of hot air circulation in an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the structure of the container and the furnace cover in the embodiment of the present invention;

[0036] Figure 4 Schematic diagram of the tubular structure of the heater according to the embodiment of the present invention;

[0037] Figure 5 is a schematic structural diagram of a sandwich composite thermal insulation layer according to an embodiment of the present invention;

[0038] Figure 6 It is a partial schematic diagram of the control system of the heater and the fan according to an embodiment of the present invention.

[0039] Description of the accompanying drawings:

[0040] 1. Furnace body; 2. Furnace cover; 3. Container; 4. Hot air circulation duct; 5. Heater; 6. Fan; 7. Height adjustment mechanism; 8. Workpiece; 9. Guide plate; 10. Sandwich composite insulation layer; 21. Socket; 41. Upper circulation duct; 42. Lower circulation duct; 43. Heating chamber; 44. Fan chamber; 45. Upper exhaust port; 46. Lower air intake port; 71. Support rod; 72. Screw; 73. Adjusting nut; 74. Locking nut; 101. Polycrystalline mullite fiberboard; 102. Aluminum silicate fiber felt. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1 to Figure 3As shown: a non-ferrous metal local annealing equipment, including a furnace body 1, a furnace cover 2, a container 3 and a control system. Among them, the furnace body is provided with a hot air circulation airway 4, a heater 5 and a fan 6; the container 3 is arranged in the hot air circulation airway 4 and close to the furnace cover 2, and the container 3 is a grille structure for airflow in and out; the furnace cover 2 covers the furnace body 1, and is connected to the container 3 through a height adjustment mechanism 7, and the furnace cover 2 is provided with a plurality of plug holes 21 for passing the workpiece, and a part of the workpiece 8 passes through the furnace cover 2 into the container 3, and is locally annealed under the action of the heater 5 and the fan 6; the control system is used to adjust the temperature of the heater and the air volume of the fan.

[0043] Specifically, in this embodiment, the furnace body, hot air circulation duct, grille container and furnace cover are all made of Cr25Ni20-3105 heat-resistant stainless steel, which are cut into predetermined sizes by laser and then welded with 3105 heat-resistant stainless steel high-temperature welding rods. Since 3105 heat-resistant stainless steel has good oxidation resistance, high high-temperature strength, good dimensional stability, and can work at 1100°C for a long time, it effectively avoids heating deformation during work, making the equipment have a longer service life. It is expected that the service life of the main structure can reach at least 20 years.

[0044] In this embodiment, the hot air circulation air duct 4 includes an upper circulation air duct 41, a lower circulation air duct 42, a heating chamber 43 and a fan chamber 44 which are interconnected. The heating chamber 43 is arranged between the upper circulation air duct 41 and the lower circulation air duct 42, and the fan chamber 44 is arranged on one side. The container 3 is arranged in the upper circulation air duct 41, and the fan 6 is arranged in the upper part of the fan chamber 44, and is arranged in the same horizontal direction as the upper circulation air duct 41. An upper exhaust port 45 is arranged on the side of the upper circulation air duct, and a lower air intake port 46 is arranged on the side of the lower circulation air duct. Both the upper exhaust port and the lower air intake port are connected to the outside. Among them, the spatial size of the upper circulation air duct is larger than the spatial size of the lower circulation air duct, so as to facilitate the installation of the container in the upper circulation air duct. The specific structure of the hot air circulation air duct is: a U-shape opening to one side is formed between the upper circulation air duct, the lower circulation air duct and the fan chamber, and the open space is designed as a heating chamber. The present invention designs a hot air circulation for the furnace body, which, on the one hand, can greatly improve the compactness of the structure, that is, by arranging the positions of the heater, the fan and the container, can fully utilize the airway space and save the volume of the furnace body; on the other hand, the fan performs a strong convection circulation on the hot air, which greatly improves the local annealing efficiency of the workpiece; and the air enters from the bottom and exits from the top, the airflow flows from the bottom to the top, then flows through the container toward the heater, and then enters the bottom, such a cycle can greatly improve the hot air circulation effect, and the hot air enters the container so that the workpiece is heated evenly, and will not be directly radiated by the heater, which greatly improves the temperature uniformity.

[0045] In addition, a guide plate 9 is provided between the upper circulation air duct 41 and the container 3, and the guide plate 9 is inclined toward the bottom surface of the container 3 along the upper circulation air duct 41, so that the hot air can quickly enter the container 3 under the guidance of the guide plate 9, and most of the air flow is forced to pass through the container, which greatly improves the local annealing efficiency of the workpiece. Specifically, the inclination angle of the guide plate 9 is 60°.

[0046] In this embodiment, the fan 6 includes a fan wheel, a motor and an extended motor shaft, all of which are made of 3105 heat-resistant stainless steel to increase their service life. The fan wheel is arranged in the fan room, and the motor is arranged outside the furnace body; the motor shaft is extended to 240mm to facilitate heat dissipation and prevent the motor temperature from being too high. The motor is wound with high-temperature resistant wire and an aluminum shell is used to facilitate heat dissipation. The fan power is 1.5KW, the exhaust volume is 2800m / h, and the wind pressure can reach up to 1140Pa, which can fully meet the production requirements.

[0047] In this embodiment, the heater 5 includes a transverse tube heater disposed directly below the container and a side tube heater disposed on both sides of the heating chamber. Figure 4 As shown: The tubular heater of this embodiment is mainly composed of 12 3KW heating tubes. The tube body of the heating tube is made of heat-resistant titanium alloy, and the internal heating element is made of imported HRE-1400℃ high-temperature resistant electric heating wire. It has the advantages of rapid heating, low energy consumption, and long service life. The heating tubes are evenly distributed and tightly fixed on the heat-resistant steel plate inside the furnace body, which can quickly and evenly conduct the heat generated by the heating tubes to the furnace body plate surface and the space inside the furnace body, and under the circulation of strong convection air, effectively prevent the heating tube from overheating, improve the service life, and make the furnace temperature uniform. Specifically, the distribution of the 12 heating tubes of this embodiment is as follows: there are 2 to 4 heating tubes for the side tubular heater and 4 to 8 heating tubes for the transverse tubular heater; and the vertical height of the side tubular heater from the bottom of the container is less than the vertical height of the transverse tubular heater from the bottom of the container, that is, the transverse tubular heater is closer to the container, which can make the workpiece more evenly heated in the forward direction.

[0048] like Figure 5 As shown: In this embodiment, a sandwich composite insulation layer 10 is provided between the outside of the hot air circulation airway and the furnace shell of the furnace body 1, and a polycrystalline mullite fiberboard 101 is laid on both the inner and outer surfaces, and a high-density aluminum silicate fiber felt 102 is filled in the middle. The polycrystalline mullite fiberboard has high heat resistance, and the aluminum silicate fiber felt has a certain heat storage capacity and low thermal conductivity. After the composite structure is laid, its thermal insulation performance is more than 2 times higher than that of refractory bricks, which effectively reduces heat loss.

[0049] like Figure 3As shown: In this embodiment, the container 3 is a material frame, and the side walls and bottom surface of the material frame are both grid structures. The upper part of the workpiece is exposed to the outside of the furnace cover, and the lower part extends into the material frame, so that the height of the cavity formed by the furnace cover 2 and the material frame is less than the height of the workpiece. The furnace cover 2 and the material frame are detachably connected through a height adjustment mechanism 7. Among them, there are four groups of height adjustment mechanisms, which are respectively arranged at the four corners of the material frame. The height adjustment mechanism includes a support rod 71, a screw rod 72, an adjustment nut 73 and a locking nut 74. The support rod 71 is connected to the vertical rods at the four corners of the material frame, or the vertical rods at the four corners of the material frame are directly extended to form a support rod. The screw rod is inserted into the support rod and can move up and down in the support rod and is locked by the adjustment nut; the furnace cover is provided with a connecting hole at a position corresponding to the screw rod. When the connecting hole of the furnace cover 2 is inserted into the screw rod 72, it is fastened by the locking nut 74. By setting up a height adjustment mechanism, it is possible to adapt to the height dimensions of different workpieces and meet the local annealing of different workpieces; and it is also possible to reduce the loss caused by the upward dissipation of heat to a great extent.

[0050] In this embodiment, when different workpieces need to be replaced, it is only necessary to replace the furnace cover with different sockets, that is, the material frame is universal and can be suitable for local annealing of all workpieces. When used, it only needs to be combined with a matching furnace cover, and the shape of the sockets on the furnace cover can be designed according to different workpieces.

[0051] like Figure 6 As shown: In this embodiment, the control system includes a temperature controller, a frequency converter and a frequency controller. The temperature controller has the functions of compiling a heating process curve, over-temperature alarm, heating anti-dive, PID automatic calculation and control output. It can automatically calculate according to the temperature difference between the set temperature and the actual heating temperature, and output the heating output power control signal in different operating times (such as: when starting to work, due to the large temperature difference between the set temperature and the actual heating temperature, the output heating control power is 80%-100%, and the output is 0-30% when the temperature difference is less), so that the heating control is more accurate and the temperature fluctuation is effectively reduced. The frequency controller is used to control the output current size through the thyristor according to the output control signal size of the temperature controller, and the opening degree can be adjusted arbitrarily from 0 to 100%, so that the heating temperature control is more accurate, which not only reduces the interference impact on the power grid, but also can perform over-current short-circuit protection. The frequency converter is used to adjust the speed of the fan, using Schneider ATV series, with an adjustment range of 20-60HZ, and a wide range of fan speed adjustment.

[0052] The control method of the non-ferrous metal local annealing equipment of this embodiment includes the following steps:

[0053] S101: Setting process parameters and heating curve.

[0054] Specifically, the process parameters include but are not limited to the heating target temperature, heating rate, fan speed, etc.; a heating curve is formed according to the heating temperature during the heating process, so as to facilitate viewing the temperature changes of the entire process and facilitate subsequent temperature optimization and adjustment.

[0055] S102: Turn on the fan and adjust it to the target air volume.

[0056] Specifically, the fan is turned on first, and according to the set fan speed, the frequency converter controls the fan to run at the set speed. By turning on the fan first, the present invention can facilitate the testing and air volume adjustment of the hot air circulation airway, and carry out strong convection air circulation through the cooperation of the optimal air volume and the airway.

[0057] S103: Select a furnace cover that matches the workpiece according to the workpiece model and install it on the furnace body.

[0058] Specifically, since the container itself is placed in the furnace body, the selection of the workpiece mainly depends on the matching of the furnace cover. By selecting furnace covers with different socket sizes, it is suitable for workpieces of different models, and the distance between the furnace cover and the material frame is adjusted through the height adjustment mechanism to perform annealing according to the height size of the workpiece that requires local annealing.

[0059] S104: Turn on the heater, and the control system automatically calculates the temperature difference between the set target temperature and the actual heating temperature of the heater, outputs the heating output power control signal in different operating time periods, and adjusts the temperature.

[0060] Specifically, after the lower part of the workpiece enters the material frame, the heater is turned on, and the temperature controller automatically calculates the temperature difference between the set temperature and the actual heating temperature, and outputs the heating output power control signal at different operating times. When the temperature difference between the set temperature and the actual heating temperature is greater than 10°C, the output heating control power is 80%-100%; when the temperature difference is less than 10°C, the output heating control power is 0-30%. The temperature controller sends the heating output power control signal to the frequency controller, and the thyristor of the frequency controller controls the current of the output heater, making the heating temperature control more accurate.

[0061] S105: After reaching the target temperature, the workpiece is inserted into the container through the insertion hole on the furnace cover. Under the action of the fan, hot air circulates into the container to perform local annealing on the workpiece.

[0062] Specifically, hot air flows from the lower circulation air duct and enters the upper circulation air duct through the fan. The hot air in the upper circulation air duct enters the material frame under the action of the guide plate to perform local annealing on the workpiece, and enters the lower circulation air duct again through the heating chamber. This cycle is repeated to achieve local annealing of the workpiece, and the generated exhaust gas is discharged through the upper exhaust port.

[0063] S106: After annealing, take out of the furnace after keeping warm.

[0064] It can be said that the non-ferrous metal local annealing equipment of the present invention can ensure that the instrument temperature control accuracy reaches ±1°C, and the temperature control accuracy in the furnace reaches ±5°C; and the use of air heating avoids environmental pollution and quality problems such as spots that may exist after heating; the production capacity is increased by 50%, the heating cost in the heating stage is reduced by 46.4%, the process parameters are more accurately controllable, and the quality control is more perfect. Moreover, by combining the container and the furnace cover structure with the hot air circulation, the present invention can not only simplify the structure, reduce costs, and reduce the floor space, but also improve the local annealing efficiency and annealing quality, and ensure that the workpiece is heated evenly.

Claims

1. A non-ferrous metal local annealing equipment, characterized in that: include: A furnace body, wherein a hot air circulation duct, a heater and a fan are arranged in the furnace body; the hot air circulation duct comprises an upper circulation duct, a lower circulation duct, a heating chamber and a fan chamber; the heater is arranged in the heating chamber, and the fan is arranged in the fan chamber; A container is arranged in the upper circulating air duct and close to the furnace cover, and the container is a grille structure for air flow in and out; A furnace cover is covered on the furnace body and connected to the container through a height adjustment mechanism. The furnace cover is provided with a plurality of insertion holes for passing the workpiece. A part of the workpiece passes through the furnace cover and enters the container, and is locally annealed under the action of the heater and the fan. The container is designed to be universal. The insertion hole size of the furnace cover is adapted to the size of the workpiece. When in use, the container is combined with a matching furnace cover. By selecting furnace covers with different insertion hole sizes, it is adapted to workpieces of different models. The distance between the furnace cover and the material frame is adjusted by the height adjustment mechanism, so that annealing is performed according to the height size of the workpiece that needs to be locally annealed. The control system is used to adjust the temperature of the heater and the air volume of the fan.

2. The non-ferrous metal local annealing equipment according to claim 1, characterized in that: The heating chamber is arranged between the upper circulation air duct and the lower circulation air duct, the fan chamber is arranged on one side, the size of the upper circulation air duct is larger than the lower circulation air duct, and a guide plate is arranged between the upper circulation air duct and the container, and the guide plate is inclined toward the bottom surface of the container along the upper circulation air duct.

3. The non-ferrous metal local annealing equipment according to claim 1, characterized in that: The heater comprises a transverse tubular heater arranged directly below the container and side tubular heaters arranged on both sides of the heating chamber; the vertical height of the side tubular heater from the bottom surface of the container is smaller than the vertical height of the transverse tubular heater from the bottom surface of the container.

4. The non-ferrous metal local annealing equipment according to claim 1, characterized in that: The fan is a high-temperature fan, including a wind wheel, which is connected to the motor via a motor shaft. The wind wheel is arranged at the upper part of the fan room and is arranged in the same horizontal direction as the upper circulation air duct; the motor is arranged outside the furnace body, and the length of the motor shaft is not less than 200mm.

5. The non-ferrous metal local annealing equipment according to claim 1, characterized in that: The furnace body, hot air circulation duct, containers and furnace cover are all made of Cr25Ni20-3105 heat-resistant stainless steel.

6. The non-ferrous metal local annealing equipment according to claim 1, characterized in that: The container is a material frame, the side walls and bottom of the material frame are grid structures, the upper part of the workpiece is exposed outside the furnace cover, and the lower part extends into the material frame, so that the height of the cavity formed by the furnace cover and the material frame is smaller than the height of the workpiece.

7. A control method for the non-ferrous metal local annealing equipment according to claim 1, characterized in that: The following steps are involved: S1: Set process parameters and heating curve; S2: Turn on the fan and adjust it to the target air volume; S3: Select a furnace cover that matches the workpiece according to the workpiece model and install it on the furnace body; S4: Turn on the heater, and the control system automatically calculates the temperature difference between the set target temperature and the actual heating temperature of the heater, outputs the heating output power control signal in different operating time periods, and adjusts the temperature; S5: After reaching the target temperature, the workpiece is inserted into the container through the plug hole on the furnace cover. Under the action of the fan, hot air circulates into the container to perform local annealing on the workpiece; S6: Annealing is completed and the product is taken out of the furnace.

8. The control method of the non-ferrous metal local annealing equipment according to claim 7, characterized in that: In step S4, when the temperature difference between the set temperature and the actual heating temperature is greater than 10-30°C, the output heating control power is 80%-100%; When the temperature difference is less than 10-30°C, the output heating control power is 0-30%.

9. The control method of the non-ferrous metal local annealing equipment according to claim 7, characterized in that: In step S5, when the hot air circulates, the hot air flows from the lower circulation air duct and enters the upper circulation air duct through the fan. The hot air in the upper circulation air duct enters the inner cavity of the container from the side and bottom of the container under the action of the guide plate to perform local annealing on the workpiece, and then enters the lower circulation air duct again through the heating chamber, and the cycle continues.

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