Heat treatment process for improving mechanical property of casting

Abstract

The invention discloses a heat treatment process for improving the mechanical property of a casting, which comprises the following steps of: 1, pretreating a circular ring workpiece to eliminate dust impurities, greasy dirt impurities and an oxide layer on the surface of the circular ring workpiece; secondly, the circular ring is put into a heat treatment device to be subjected to heat treatment, meanwhile, uniform cooling treatment is conducted on the circular ring, stress concentration is avoided, and the overall strength is improved; thirdly, the workpiece is taken out, heat treatment deformation is corrected, the circular degree of the ring is ensured, and specifically, a special tool is used for conducting three-point or four-point pressure correction on the ring after tempering; and 4, uniformly taking 3-5 points on the annular section to test the hardness. When the heat treatment process is specifically used, in the heat treatment process of the circular-ring-shaped workpiece, the heat treatment effect is more uniform by utilizing rotation of the circular-ring-shaped workpiece to be matched with flowing of cooling liquid, and after heat treatment is completed, centrifugal force spin-drying can be utilized to be matched with air blowing, so that the cooling liquid on the surface can be removed, and subsequent treatment is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of casting heat treatment, in particular to a heat treatment process for improving the mechanical properties of castings. BACKGROUND

[0002] In the field of metal casting, due to its special structure, the circular ring-shaped castings are widely used in key components such as bearings, gears and transmission rings, and their mechanical properties directly affect the running stability and service life of the equipment. However, the traditional heat treatment process faces two major problems in improving the performance of circular ring-shaped castings. First, the uniformity of heat treatment is difficult to guarantee. During conventional quenching or tempering, the circular ring-shaped workpiece is usually placed statically in the heating furnace or cooling medium. Due to the difference in contact area and flow rate between the inner and outer walls of the ring-shaped structure and the cooling medium, it is easy to cause large temperature gradient in the cross section, leading to uneven organization (such as difference in martensite transformation rate) and residual stress concentration, and thus causing workpiece deformation, cracking or mechanical property fluctuation, limiting the application in high-precision scenarios. Second, the residual cooling liquid affects the subsequent process. After heat treatment, a large amount of cooling liquid (such as oil or water-based medium) is often attached to the surface of the workpiece. The traditional natural drying or manual wiping method is low in efficiency and easy to leave impurities, which interferes with the subsequent spraying, machining or detection links. SUMMARY

[0003] The purpose of the present application is to solve the problems existing in the prior art, and to provide a heat treatment process for improving the mechanical properties of castings. In specific use, the heat treatment process can make the circular ring-shaped workpiece rotate during heat treatment to cooperate with the flow of the cooling liquid, making the heat treatment effect more uniform, and after the heat treatment is completed, the surface cooling liquid can be removed by centrifugal drying and air blowing, facilitating subsequent processing.

[0004] In order to achieve the above purpose, the present application adopts the following technical scheme: A heat treatment process for improving the mechanical properties of castings: comprising the following steps: First step: pretreat the circular ring-shaped workpiece to remove dust, impurities, oil stains and oxidation layer on its surface; Second step: put the circular ring into the heat treatment device for heat treatment and uniform cooling at the same time to avoid stress concentration and improve overall strength; Third step: take out the workpiece, then correct the heat treatment deformation to ensure the roundness of the ring, specifically using special tooling to press and correct the ring at three or four points after tempering; Fourth step: take 3-5 points on the cross section of the ring to test hardness, and verify the yield strength and elongation after fracture through tensile test.

[0005] Preferably, the heat treatment device comprises a processing box, an upper end of the processing box is provided with a processing groove, the processing groove is filled with cooling oil; a rotating support mechanism, the rotating support mechanism comprises a motor fixedly connected to the rear side of the processing box, an output shaft of the motor extends to the inside of the processing groove and is fixedly connected with a rotating disc, four rotating columns are fixedly connected to the front side of the rotating disc at equal intervals, and an annular groove is formed in each rotating column; a rotating mechanism, the rotating mechanism comprises a fixed column fixedly connected to the inner wall of the front side of the processing groove, a second gear is fixedly connected to the rear side of the fixed column, a first gear is fixedly connected to each rotating column, and a plurality of first gears are meshed with the second gear; a heating mechanism, the heating mechanism is installed on the front side wall of the processing groove; and a liquid flow mechanism, the liquid flow mechanism is used for promoting quenching uniformity.

[0006] Preferably, the heating mechanism comprises a second piston cylinder installed on the front side wall of the processing groove, a piston plate slidably forward and backward is arranged in the second piston cylinder, the front side of the piston plate is elastically connected with the front side wall of the processing groove through a spring, a connecting rod is fixedly connected to the rear side of the piston plate, the rear side of the connecting rod penetrates through the rear side wall of the second piston cylinder, and an connecting plate is fixedly connected to the rear side of the connecting rod; and an electromagnetic induction coil is fixedly connected to the rear side of the connecting plate.

[0007] Preferably, the liquid flow mechanism comprises two first piston cylinders fixedly connected to the rear side of the processing box in a symmetrical manner, a piston block slidably left and right is arranged in each first piston cylinder, the piston blocks are fixedly connected through a fixed rod, a hollow strip is fixedly connected to the front side wall of the processing groove, a strip-shaped opening is formed in the rear side of the hollow strip, the left side space of the first piston cylinder on the left side is communicated with the rear side space of the processing groove through a liquid inlet pipe, and the left side space of the first piston cylinder on the right side is communicated with the inside space of the hollow strip through a liquid injection pipe.

[0008] Preferably, a transmission is installed on the rear side of the processing box, a synchronous wheel is installed on the output shaft of the motor and the input shaft of the transmission, and the two synchronous wheels are drivingly connected through a synchronous belt.

[0009] Preferably, the output shaft of the transmission is fixedly connected with a driving disc, a driving rod is rotatably connected to the rear side of the driving disc at an eccentric position, and the other end of the driving rod is rotatably connected to the right side of the left piston block.

[0010] Preferably, the right side space of the first piston cylinder on the right side is communicated with the outside through a one-way opening, a gas storage box is fixedly connected to the rear side of the processing box, the right side space of the first piston cylinder on the right side is communicated with the inside of the gas storage box through a one-way pipe, and the gas storage box is communicated with the front side space of the second piston cylinder through an air blowing pipe.

[0011] Preferably, the air blowing pipe is internally provided with a normally open electromagnetic valve, and the normally open electromagnetic valve is in the same circuit with the motor.

[0012] Preferably, the front side of the treatment tank is fixedly connected with a hollow box, a plurality of air holes are formed in the rear side of the hollow box, and the front side space of the second piston cylinder is communicated with the inside of the hollow box through a thin tube.

[0013] Preferably, the one-way port, the one-way pipe, the liquid inlet pipe and the liquid injection pipe are internally provided with one-way valves, the flow direction of the one-way valve in the one-way port is that the outside unidirectionally enters the right side space of the right side first piston cylinder, the flow direction of the one-way valve in the one-way pipe is that the right side space of the right side first piston cylinder unidirectionally enters the gas storage box, the flow direction of the one-way valve in the liquid inlet pipe is that the rear side space of the treatment tank unidirectionally enters the left side space of the left side first piston cylinder, and the flow direction of the one-way valve in the liquid injection pipe is that the left side space of the left side first piston cylinder unidirectionally enters the hollow strip.

[0014] Compared with the prior art, the application has the following beneficial effects: 1. The design of synchronous revolution and rotation of the rotating column makes the annular workpiece more evenly heated and cooled in the rotation process, effectively reduces the temperature gradient, avoids performance differences caused by local overheating or insufficient cooling, and improves the overall mechanical property stability of the workpiece.

[0015] 2. When the motor is paused, the transmission drives the piston cylinder to reciprocate, promotes the directional flow of the cooling oil, makes the oil temperature and composition distribution more uniform, further improves the quenching and cooling effect, and guarantees the consistency of the hardness and toughness of the workpiece.

[0016] 3. Through the linkage of pneumatic pressure storage and electromagnetic induction coil, the workpiece is automatically heated when the motor is paused, and the coil is automatically returned after heating, avoiding energy waste and overheating risk caused by continuous heating, and improving the heating efficiency and safety.

[0017] 4. After the workpiece is quenched, the centrifugal force generated by high-speed self-rotation cooperates with the continuous airflow blowing of the hollow box to quickly shake off and dry the surface residual oil, reduces the subsequent cleaning process, shortens the production cycle, and improves the overall processing efficiency.

[0018] 5. Each station is independently operated and cyclically connected, and the workpiece loading, heating, quenching, drying and taking can be simultaneously completed when the rotating disc rotates one fourth of a circle, realizing continuous production, improving the equipment utilization rate and production capacity. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The application provides a heat treatment process structure diagram for improving the mechanical property of a casting; Figure 2 The application provides a rear side schematic view of the heat treatment process structure diagram for improving the mechanical property of the casting; Figure 1 Figure 3 ​Fig. 1 is a schematic view of a left side direction cross-section of the device according to the present application; Figure 2 Fig. 2 is a schematic view of a front-rear direction cross-section of the device according to the present application at a first piston cylinder; Figure 4 Fig. 3 is a schematic view of a front-rear direction cross-section of the device according to the present application at a second piston cylinder; Figure 2 Fig. 4 is a schematic view of a front-rear direction cross-section of the device according to the present application at a synchronous wheel; Figure 5 Fig. 5 is a schematic view of a left-right side direction cross-section of the device according to the present application; Figure 2 Fig. 6 is a schematic view of a left-right side direction cross-section of the device according to the present application at a first piston cylinder; Figure 6 Fig. 7 is a schematic view of an enlarged view of A of the device according to the present application; Figure 5

[0020] Fig. 1 is a schematic view of a left side direction cross-section of the device according to the present application; DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described in connection with the drawings of the embodiments of the present application.

[0022] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and / or "include" as used in the specification indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Referring to Figures 1-6 A heat treatment process for improving the mechanical properties of castings, comprising the following steps: Step 1: Pretreat the ring-shaped workpiece to remove dust, impurities, oil stains and oxidation layer on its surface; Step 2: Put the ring into a heat treatment device for heat treatment, and at the same time, uniformly cool it to avoid stress concentration and improve overall strength; Step 3: Take out the workpiece, then correct the heat treatment deformation to ensure the roundness of the ring, specifically, use a special tool to press and correct the ring at three or four points after tempering; Step 4: Take 3-5 points on the cross-section of the ring to test hardness, and verify the yield strength and elongation after tensile test.

[0024] ​As one of the embodiments of the present application, the heat treatment device comprises a treatment box 1, an upper end of the treatment box 1 is provided with a treatment groove 2, the treatment groove 2 is filled with cooling oil, a height of the cooling oil is located at one fourth of the rotating disc 4, further, a cooling structure not shown is provided, so as to ensure that the cooling liquid is always in a lower temperature state; As one of the embodiments of the present application, further comprising a rotating support mechanism, the rotating support mechanism comprises a motor 3 fixedly connected to the rear side of the treatment box 1, an output shaft of the motor 3 extends to the inside of the treatment groove 2 and is fixedly connected with the rotating disc 4, the front side of the rotating disc 4 is fixedly connected with four rotating columns 5 at equal intervals, an annular groove 9 is formed on each of the rotating columns 5, so as to facilitate the suspension of the annular workpiece, further, the uppermost rotating column 5 is placed into the workpiece to be heated, the rightmost rotating column 5 is heated, the lowermost is quenched, and the leftmost is dried and taken out; As one of the embodiments of the present application, further comprising a rotating mechanism, the rotating mechanism comprises a fixed column 8 fixedly connected to the inner wall of the front side of the treatment groove 2, the rear side of the fixed column 8 is fixedly connected with a second gear 7, each of the rotating columns 5 is fixedly connected with a first gear 6, a plurality of the first gears 6 are engaged with the second gear 7, with the rotation of the rotating disc 4, the plurality of the first gears 6 will rotate, so as to rotate the plurality of the rotating columns 5, by using the friction force, the workpiece can be rotated, the rotation can make the workpiece uniformly contact with the oil during the process that the workpiece enters into the oil after the heating is completed, and when the workpiece exits from the oil to the leftmost side, the rotation can make the workpiece quickly pass through the centrifugal force to be deoiled; As one of the embodiments of the present application, further comprising a heating mechanism, the heating mechanism is installed on the front side wall of the treatment groove 2, the heating mechanism comprises a second piston cylinder 29 installed on the front side wall of the treatment groove 2, a piston plate 31 slidably arranged in the second piston cylinder 29, the front side of the piston plate 31 is elastically connected with the front side wall of the treatment groove 2 through a spring 30, the rear side of the piston plate 31 is fixedly connected with a connecting rod 32, the rear side of the connecting rod 32 penetrates through the rear side wall of the second piston cylinder 29 and is fixedly connected with a connecting plate 33, the rear side of the connecting plate 33 is fixedly connected with an electromagnetic induction coil 34, the electromagnetic induction coil 34 is started when the motor 3 is turned off and is turned off when the motor 3 is started; As one of the embodiments of the present application, the liquid flow mechanism is further included for promoting the quenching uniformity, the liquid flow mechanism comprises two first piston cylinders 15 fixedly connected to the rear side of the processing box 1, a piston block 23 slidably arranged in each of the two first piston cylinders 15, and a fixed rod 20 fixedly connecting the two piston blocks 23, a hollow strip 27 fixedly connected to the front side wall of the processing tank 2, a strip-shaped opening 28 formed in the rear side of the hollow strip 27, a left space of the first piston cylinder 15 on the left side in communication with the rear space of the processing tank 2 through a liquid inlet pipe 16, a left space of the first piston cylinder 15 on the right side in communication with the inner space of the hollow strip 27 through a liquid outlet pipe 13, a transmission 21 mounted to the rear side of the processing box 1, the transmission 21 being an accelerator, a synchronous wheel 25 mounted to the input shaft of the transmission 21 and the output shaft of the motor 3, the two synchronous wheels 25 in transmission connection through a synchronous belt 26, a driving disc 22 fixedly connected to the output shaft of the transmission 21, a driving rod 24 rotatably connected to the rear side eccentric portion of the driving disc 22, and the other end of the driving rod 24 rotatably connected to the right side of the left piston block 23. As one of the embodiments of the present application, the right space of the first piston cylinder 15 on the right side is in communication with the outside through a one-way opening 18, a gas storage box 14 fixedly connected to the rear side of the processing box 1, the right space of the first piston cylinder 15 on the right side in communication with the inner space of the gas storage box 14 through a one-way pipe 19, the gas storage box 14 in communication with the front space of the second piston cylinder 29 through an air blowing pipe 12, a normally open electromagnetic valve 17 mounted to the inner portion of the air blowing pipe 12, the normally open electromagnetic valve 17 and the motor 3 being in the same series circuit, a hollow box 10 fixedly connected to the front side portion of the processing tank 2, a plurality of air holes formed in the rear side of the hollow box 10, the front space of the second piston cylinder 29 in communication with the inner portion of the hollow box 10 through a thin pipe 11, the motor 3 being stopped once in a quarter of a circle without starting, in this process, a large amount of high-pressure gas can be stored in the gas storage box 14 and then released, when the high-pressure gas enters the front space of the second piston cylinder 29, the high-pressure gas cannot be quickly released due to the slow release speed of the thin pipe 11, so that the gas pressure is accumulated, which pushes the piston plate 31 to move backward, and the connecting plate 33 and the electromagnetic induction coil 34 are driven by the connecting rod 32 to move backward for heating operation, the released gas at the thin pipe 11 is finally discharged from the plurality of air holes for air blowing to the castings to further remove the surface oil; As an embodiment of the present application, the one-way port 18, the one-way pipe 19, the liquid inlet pipe 16 and the liquid outlet pipe 13 are all equipped with one-way valves. The flow direction of the one-way valve in the one-way port 18 is from the outside to the right side of the first piston cylinder 15. The flow direction of the one-way valve in the one-way pipe 19 is from the right side of the first piston cylinder 15 to the gas storage box 14. The flow direction of the one-way valve in the liquid inlet pipe 16 is from the back side of the processing tank 2 to the left side of the first piston cylinder 15. The flow direction of the one-way valve in the liquid outlet pipe 13 is from the left side of the first piston cylinder 15 to the hollow strip 27.

[0025] In the present application, the processing tank 2 of the processing box 1 is filled with cooling oil to the height of one fourth of the rotating disc 4. A cooling structure (not shown) maintains the low temperature state of the cooling oil. The circular ring-shaped workpiece is hung on the rotating column 5 through the annular groove 9 and initially placed on the uppermost rotating column 5 to be heated. The starting motor 3 drives the rotating disc 4 to rotate, which drives the four rotating columns 5 to revolve around the center of the processing tank 2. When the rotating column 5 revolves, the first gear 6 on the rotating column 5 meshes with the second gear 7 on the back side of the fixed column 8, which drives the rotating column 5 to rotate, so that the suspended workpiece rotates synchronously with the revolving and rotating of the rotating column 5. The motor 3 is paused when it is closed for one fourth of a circle. In the rotating process, the transmission 21 (accelerator) transmits the rotation of the output shaft of the motor 3 to the driving disc 22 through the synchronous wheel 25 and the synchronous belt 26. The driving disc 22 drives the piston block 23 in the left side of the first piston cylinder 15 to slide back and forth through the eccentrically connected driving rod 24. When the left side piston block 23 moves to the right, the cooling oil on the back side of the processing tank 2 is sucked into the left side space of the left side first piston cylinder 15 through the liquid inlet pipe 16. When the left side piston block 23 moves to the left, the cooling oil is pressed into the hollow strip 27 through the liquid outlet pipe 13 and sprayed out from the strip-shaped port 28, which impacts the cooling oil on the back side of the processing tank 2 and promotes the uniformity of the oil flow. The piston block 23 in the right side of the first piston cylinder 15 slides synchronously with the fixed rod 20. When the right side piston block 23 moves to the left, the outside air enters the right side space of the right side first piston cylinder 15 through the one-way port 18. When the right side piston block 23 moves to the right, the high pressure air in the right side space is pressed into the gas storage box 14 through the one-way pipe 19. The high pressure gas in the gas storage box 14 enters the front side space of the second piston cylinder 29 through the air pipe 12 (the normally open electromagnetic valve 17 is connected in series with the motor 3, and the valve is opened when the motor 3 is paused). The high pressure gas is slowly released to the hollow box 10 through the thin pipe 11 and discharged from the air hole to form a continuous air flow. The gas accumulation pressure drives the piston plate 31 in the second piston cylinder 29 to move backward, which drives the connecting plate 33 and the activated electromagnetic induction coil 34 to move to the outside of the workpiece through the connecting rod 32. The activated electromagnetic induction coil 34 inductively heats the workpiece. With the complete release of the gas, the electromagnetic induction coil 34 moves back to the initial position under the elastic action of the spring 30, and the heating is completed. After heating is completed, the motor 3 is restarted, the rotating disc 4 drives the workpiece to rotate to the rightmost rotating column 5 to heat and maintain; when continuing to rotate to the lowermost rotating column 5, the workpiece is immersed in the cooling oil to quench, and the rotation makes the workpiece surface uniformly contact the oil, reducing the temperature gradient; With the completion of quenching, the motor 3 is started again, and rotated to the leftmost rotating column 5; in this process, the workpiece leaves the oil to the leftmost rotating column 5, and the centrifugal force generated by the high-speed rotation of the workpiece cooperates with the airflow discharged by the hollow box 10 to quickly shake off the surface oil and dry, facilitating subsequent processing; at this time, it is taken down, and then subsequent operation is performed. In the above process, the workpiece can be placed from the uppermost rotating column 5 and taken out from the leftmost rotating column 5 after rotating one fourth of a circle each time, and the whole has good continuity.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A heat treatment process for improving the mechanical properties of castings, characterized in that: The following steps are involved: Step 1: Pre-treat the ring workpiece to remove dust, oil, impurities and oxide layer on its surface; Step 2: Place the ring into a heat treatment device for heat treatment and cool it evenly at the same time to avoid stress concentration and improve overall strength; Step 3: Remove the workpiece and correct the heat treatment deformation to ensure the roundness of the ring. Specifically, use a special tool to perform three-point or four-point press calibration on the ring after tempering; Step 4: Test the hardness at 3-5 points evenly on the annular section, and verify the yield strength and elongation through a tensile test.

2. A heat treatment process for improving the mechanical properties of castings according to claim 1, characterized in that: The heat treatment device comprises: A processing box (1), wherein a processing tank (2) is provided at the upper end of the processing box (1), and the processing tank (2) is filled with cooling oil; A rotation support mechanism, the rotation support mechanism comprising a motor (3) fixedly connected to the rear side of the processing box (1), the output shaft of the motor (3) extending into the interior of the processing tank (2) and fixedly connected to a rotating disk (4), the front side of the rotating disk (4) being fixedly connected to four rotating columns (5) at equal intervals, each of the rotating columns (5) being provided with an annular groove (9); A rotating mechanism, comprising a fixed column (8) fixedly connected to the inner wall of the front side of the processing tank (2), a second gear (7) fixedly connected to the rear side of the fixed column (8), a first gear (6) fixedly connected to each of the rotating columns (5), and a plurality of the first gears (6) meshing with the second gear (7); A heating mechanism, the heating mechanism being mounted on the front side wall of the processing tank (2); A liquid flow mechanism is provided for promoting quenching uniformity.

3. A heat treatment process for improving the mechanical properties of castings according to claim 2, characterized in that: The heating mechanism comprises a second piston cylinder (29) mounted on the front side wall of the processing tank (2), a piston plate (31) that can slide back and forth is provided in the second piston cylinder (29), the front side of the piston plate (31) is elastically connected to the front side wall of the processing tank (2) via a spring (30), the rear side of the piston plate (31) is fixedly connected to a connecting rod (32), the rear side of the connecting rod (32) passes through the rear side wall of the second piston cylinder (29) and is fixedly connected to a connecting plate (33), and the rear side of the connecting plate (33) is fixedly connected to an electromagnetic induction coil (34).

4. A heat treatment process for improving the mechanical properties of castings according to claim 3, characterized in that: The liquid flow mechanism comprises two first piston cylinders (15) symmetrically fixedly connected to the rear side of the processing box (1), and a piston block (23) that can slide left and right is provided in each of the two first piston cylinders (15). The two piston blocks (23) are fixedly connected via a fixing rod (20). A hollow bar (27) is fixedly connected to the front side wall of the processing tank (2), and a strip-shaped opening (28) is provided on the rear side of the hollow bar (27). The left side space of the first piston cylinder (15) on the left side is connected to the rear side space of the processing tank (2) through the liquid inlet pipe (16), and the left side space of the first piston cylinder (15) on the right side is connected to the internal space of the hollow bar (27) through the liquid injection pipe (13).

5. A heat treatment process for improving the mechanical properties of castings according to claim 4, characterized in that: A transmission (21) is installed on the rear side of the processing box (1), and the input shaft of the transmission (21) and the output shaft of the motor (3) are both installed with synchronous wheels (25), and the two synchronous wheels (25) are connected by a synchronous belt (26).

6. A heat treatment process for improving the mechanical properties of castings according to claim 5, characterized in that: The output shaft of the transmission (21) is fixedly connected to a drive disc (22), a rear eccentric portion of the drive disc (22) is rotatably connected to a drive rod (24), and the other end of the drive rod (24) is rotatably connected to the right side of the left piston block (23).

7. A heat treatment process for improving the mechanical properties of castings according to claim 4, characterized in that: The right side space of the first piston cylinder (15) located on the right side is connected to the outside through a one-way port (18), and the rear side of the processing box (1) is fixedly connected to the gas storage box (14). The right side space of the first piston cylinder (15) located on the right side is connected to the inside of the gas storage box (14) through a one-way tube (19), and the gas storage box (14) is connected to the front side space of the second piston cylinder (29) through an air pipe (12).

8. A heat treatment process for improving the mechanical properties of castings according to claim 7, characterized in that: A normally open electromagnetic valve (17) is installed inside the air blast pipe (12). The normally open electromagnetic valve (17) and the motor (3) are in the same series circuit.

9. The heat treatment process for improving the mechanical properties of castings according to claim 4, characterized in that: The front portion of the treatment tank (2) is fixedly connected to a hollow box (10), a plurality of air holes are provided on the rear side of the hollow box (10), and the front space of the second piston cylinder (29) is connected to the interior of the hollow box (10) via a thin tube (11).

10. The heat treatment process for improving the mechanical properties of castings according to claim 4, characterized in that: One-way valves are installed inside the one-way port (18), the one-way tube (19), the liquid inlet tube (16) and the liquid spraying tube (13). The one-way valve inside the one-way port (18) flows from the outside to the right side space of the first piston cylinder (15) on the right side. The one-way valve inside the one-way tube (19) flows from the right side space of the first piston cylinder (15) on the right side to the gas storage box (14) on the right side. The one-way valve inside the liquid inlet tube (16) flows from the rear side space of the treatment tank (2) to the left side space of the first piston cylinder (15) on the left side. The one-way valve inside the liquid spraying tube (13) flows from the left side space of the first piston cylinder (15) on the left side to the hollow bar (27) on the left side.

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