Isothermal quenching equipment and process for nodular cast iron

Abstract

The invention discloses spheroidal graphite cast iron isothermal quenching equipment and process, and relates to the field of forging equipment, the spheroidal graphite cast iron isothermal quenching equipment comprises a heating furnace and a quenching tank body, the heating furnace is communicated with a smoke exhaust pipe, the smoke exhaust pipe is communicated with a heating and heat preservation assembly, an overflow frame body is arranged in the quenching tank body, a flow guide plate is arranged at the overflow frame body, and a stirring part is arranged at the overflow frame body; according to the spheroidal graphite cast iron isothermal quenching equipment, smoke generated in the workpiece heating process is exhausted through the smoke exhaust pipe, meanwhile, generated heat is used for carrying out heat preservation treatment on a workpiece conveyed out of the heating furnace, the workpiece is prevented from being rapidly cooled, the heat preservation effect is good, and the service life of the workpiece is prolonged. The discharged heat preheats a quenching medium in advance, the quenching medium can intensively flow in the middle of the quenching tank body through stirring treatment of the stirring part in the quenching tank body in cooperation with the flow guide plate, and therefore the quenching medium is kept in a flowing state and makes full contact with a workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of forging equipment, and particularly to a ductile iron austempering equipment and process. Background Technique

[0002] Ductile iron is a high-strength cast iron material, and its comprehensive performance is close to that of steel. Based on its excellent performance, it has been successfully used to cast some parts with complex stress, high requirements for strength, toughness, and wear resistance. In order to improve the performance of ductile iron, the ductile iron is treated by means of austempering. Austempering is a quenching method in which after the workpiece is quenched and heated, the austenite isothermally transformed to obtain a lower bainite structure.

[0003] When the existing method of austempering is used to treat ductile iron, first, the ductile iron is heated by a heating furnace to the austenitizing temperature (usually 850°C - 950°C). After the heat treatment, the ductile iron workpiece is put into a quenching tank for quenching treatment, and the heated workpiece is quickly cooled to the bainite transformation temperature range (usually 250°C - 400°C). Finally, the bainite transformation temperature range is maintained for a period of time through an isothermal tank to transform austenite into bainite. However, the existing oil or quenching agent for quenching is static in the quenching tank. After being heated by the heating furnace, it is directly put into the quenching tank. When the workpiece is clamped, the cooling conditions are different, resulting in different quenching effects when the medium in the quenching tank contacts the workpiece. At the same time, when the workpiece is placed in a relatively stable quenching tank, the quenching medium does not flow. After the workpiece with a higher temperature is put in, the workpiece is immersed in the quenching medium, causing the quenching medium to diffuse from the workpiece to the surroundings, which is not convenient for the quenching agent or oil to concentrate on quenching the workpiece. Moreover, after the high-temperature workpiece is thrown into the quenching tank, it is easy to cause the quenching medium to quickly overflow from the quenching tank, resulting in insufficient quenching medium, thus making the quenching effect poor. Therefore, we propose a ductile iron austempering equipment and process. Summary of the Invention

[0004] The purpose of the present invention is to provide a ductile iron austempering equipment and process to solve the problems raised in the above background technique.

[0005] To achieve the above object, the present invention provides the following technical solution: A ductile iron austempering quenching device includes a heating furnace and a quenching tank body. A lifting furnace door is provided at the furnace mouth position of the heating furnace. A track is provided below the heating furnace, and a trolley for transporting workpieces is provided on the track. The quenching tank body is arranged at one end of the track. Smoke exhaust pipes are communicated with both side walls of the heating furnace, and a heating and heat preservation component is communicated with the bottom of the smoke exhaust pipe. The heating and heat preservation components are distributed on both sides of the track. An overflow frame body is arranged in the quenching tank body. Flow guide plates are respectively arranged at the four corners of the overflow frame body. A stirring component is arranged at the center of the overflow frame body, and the four flow guide plates are circumferentially distributed outside the stirring component. An installation groove is provided at the bottom of the quenching tank body, and a preheating component for preheating the medium in the quenching tank body is arranged in the installation groove. One end of the preheating component is communicated with the heating and heat preservation component, and the other end of the preheating component is communicated with the bottom of the stirring component.

[0006] Preferably, the flow guide plate is provided with an arc section notch from top to bottom, and multiple groups of round holes are provided on the flow guide plate.

[0007] Preferably, motors are installed on both side walls of the quenching tank body, and the output ends of the motors are connected with stirring blades. The stirring blades are distributed between two groups of flow guide plates. The height of the overflow frame body is lower than the height of the quenching tank body.

[0008] Preferably, the heating and heat preservation component includes a hot gas discharge pipe connected to the bottom of the smoke exhaust pipe. One end of the hot gas discharge pipe is connected with a temperature control valve, and the outside of the temperature control valve is communicated with the preheating component. An inclined air guide rod is connected to the hot gas discharge pipe, and a collision body is connected to the inclined air guide rod. Heat conducting plates are respectively installed on both sides of the trolley. The inside of the heat conducting plate is a cavity, and multiple pressing blocks in contact with the collision body are respectively arranged on the outer sides of the heat conducting plates. Air ports are provided at the tops of the heat conducting plates.

[0009] Preferably, a dust-proof plate for protecting the air ports is arranged at the top of the heat conducting plate. The top of the smoke exhaust pipe is an ellipsoidal absorber, and a smoke exhaust dust-proof cover is installed on the absorber.

[0010] Preferably, the preheating component includes a communicating pipe connected to the outside of the temperature control valve. A centralized box is installed in the installation groove. The back of the centralized box is connected with two communicating pipes. An air cut-off switch is installed on the centralized box. A heat conducting air pipe is installed on the centralized box and is connected with the stirring component. Multiple preheating pipes are installed on the centralized box, and the preheating pipes are distributed in the installation groove.

[0011] Preferably, the stirring member includes a mounting body installed on the heat-conducting gas pipe. A gasket is installed on the heat-conducting gas pipe, and the gasket is installed on the quenching tank body. A driving blade is installed at the bottom of the mounting body, and a rotating rod is installed at the top of the mounting body. A telescopic rod is installed at the top of the rotating rod, and stirring blades are installed outside the rotating rod.

[0012] Preferably, the top of the gasket is rotatably connected to a first cover body and a second cover body. The first cover body and the second cover body are cross-arranged. A cover plate is installed at the top of the second cover body, and the top of the telescopic rod is connected to the cover plate.

[0013] Preferably, elastic folding areas are provided on the first cover body and the second cover body.

[0014] A process of an isothermal quenching device for ductile iron: a: Heating the workpiece. The workpiece is placed on the trolley and pushed into the heating furnace, and the lifting furnace door is closed for heating. b: Heat conduction. The soot in the heating furnace is discharged from the exhaust pipe, and the heat is used by the heating and heat preservation component to keep the workpiece pushed out of the heating furnace warm. c: Preheating. The heating and heat preservation component conducts the heat to the preheating component to preheat the quenching medium in the quenching tank body. d: Loading the workpiece. The workpiece is put into the quenching tank body by a lifting tool. e: Isothermal quenching. The conducted heat drives the stirring member to cooperate with the flow guide plate to centrally distribute the quenching medium at the center position of the quenching tank body, and the concentrated flow cools the workpiece. f: Isothermal cooling. The workpiece is lifted out of the quenching tank body for isothermal cooling.

[0015] Compared with the prior art, the beneficial effects of the present invention are: In the present invention, the smoke generated during the workpiece heating process is discharged through the provided exhaust pipe. At the same time, the generated heat is used to keep the workpiece transported out of the heating furnace warm, avoiding the rapid cooling of the workpiece. Meanwhile, the discharged heat preheats the quenching medium in advance. When the workpiece is put in, the stirring member stirs in the quenching tank body, making the quenching medium in the quenching tank body in a flowing state. Cooperating with the flow guide plate, the quenching medium can be centrally flowed at the middle position of the quenching tank body, so that the quenching medium remains in a flowing state and fully contacts the workpiece, improving the quenching effect.

[0016] The design of the flow guide plate in the present invention not only guides the quenching medium to the workpiece multiple times, but also facilitates the slow dispersion of the quenching medium from the surrounding areas when the workpiece is put into the quenching tank, avoiding the direct overflow of the quenching medium from the quenching tank. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic structural diagram after the lifting furnace door of the present invention is opened; Figure 3 This is a schematic structural diagram after the heating furnace of the present invention is removed; Figure 4 For Figure 3 This is a schematic structural diagram after the quenching tank body in Figure 5 This is a schematic structural diagram of the trolley and track of the present invention; Figure 6 This is a schematic partial cross-sectional structure diagram of the trolley of the present invention; Figure 7 This is a schematic structural diagram of the quenching tank body and overflow frame body of the present invention; Figure 8 This is a schematic structural diagram of the heating and heat preservation assembly and preheating component of the present invention; Figure 9 This is a schematic structural diagram of the preheating component and agitation component of the present invention; Figure 10 This is a schematic diagram of the separation of the first cover body and the second cover body; Figure 11 This is a schematic diagram of the stirring blade; Figure 12 For Figure 6 This is an enlarged schematic structural diagram of the area at A in

[0018] In the figure: 1 - heating furnace; 2 - quenching tank body; 3 - trolley; 4 - heating and heat preservation assembly; 5 - overflow frame body; 6 - guide plate; 7 - agitation component; 8 - preheating component; 11 - lifting furnace door; 12 - exhaust pipe; 13 - absorber; 14 - exhaust and dust-proof cover; 15 - track; 21 - installation groove; 22 - motor; 23 - stirring blade; 41 - hot gas discharge pipe; 42 - temperature control valve; 43 - inclined gas guide rod; 44 - collision body; 45 - heat conduction plate; 46 - pressing block; 47 - air port; 48 - dust-proof plate; 71 - installation body; 72 - sealing gasket; 73 - driving blade; 74 - rotating rod; 75 - telescopic rod; 76 - stirring blade; 77 - first cover body; 78 - second cover body; 79 - cover plate; 81 - connecting pipe; 82 - air cut-off switch; 83 - centralized box; 84 - heat conduction gas pipe; 85 - preheating pipe. Specific embodiments

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] Please refer to Figures 1-12 , the present invention provides a technical solution: a ductile iron austempering device, which is used to solve the process of existing ductile iron quenching treatment. The design includes a heating furnace 1 and a quenching tank 2. A lifting furnace door 11 is arranged at the furnace mouth position of the heating furnace 1. A track 15 is arranged below the heating furnace 1. A trolley 3 for transporting workpieces is arranged on the track 15. The quenching tank 2 is arranged at one end of the track 15. The quenching tank 2 is a rectangular tank, and its interior is filled with a quenching medium. Generally, waste engine oil or the like is selected as the quenching medium. Before quenching treatment, the quenching medium such as waste engine oil is poured into the interior of the quenching tank 2. A discharge port is opened at the lower side wall of the quenching tank 2 for discharging the quenching medium such as waste engine oil; Smoke exhaust pipes 12 are communicated with both side walls of the heating furnace 1. The design of the smoke exhaust pipes 12 is as shown in the attached Figure 1 -attached Figure 4 . The top of the smoke exhaust pipe 12 is an ellipsoidal absorber 13, and a smoke exhaust dust-proof cover 14 is installed on the absorber 13. The position where the smoke exhaust pipe 12 contacts the heating furnace 1 is a semi-circular opening, which reduces the rapid diffusion of heat.

[0021] When heat-treating ductile iron, first, a ductile iron workpiece is clamped by a lifting tool or a fixture, etc. For both the lifting tool and the fixture, existing equipment is used. Different fixtures are required for different ductile iron workpieces. Therefore, according to the fixtures or lifting tools commonly used in the specific production process, the workpiece is lifted and placed on the trolley 3. The design of the trolley 3 is the same as that of the existing trolley. The bottom is driven by a driving device such as a motor to drive the rollers, and the trolley 3 moves on the track 15, so that the trolley 3 enters or exits the heating furnace 1. The cooperation between the trolley 3 and the heating furnace 1 refers to the existing heating furnace 1 and trolley (that is, a groove is designed below the heating furnace 1, and a protrusion matching the groove is designed on the top of the trolley 3. After the trolley 3 completely enters the heating furnace 1 and the lifting furnace door 11 is closed, the heating furnace 1 forms a complete heating space).

[0022] When the heating furnace 1 heats and treats the ductile iron workpiece, the generated soot and the like are discharged through the smoke exhaust pipe 12. During the soot discharge process, the ellipsoidal absorber 13 preliminarily absorbs the soot, and a secondary absorption treatment is carried out when passing through the smoke exhaust dust-proof cover 14, reducing the discharge pollution.

[0023] After the workpiece is heated into austenite, by opening the lifting furnace door 11, the trolley 3 transports the workpiece out of the heating furnace 1 along the track 15. In order to avoid the rapid cooling of the workpiece during transportation, the workpiece is heat-insulated. A heating and heat-insulating component 4 is communicated with the bottom of the smoke exhaust pipe 12, and the heating and heat-insulating component 4 is distributed on both sides of the track 15; The heating and heat preservation assembly 4 includes a hot gas discharge pipe 41 connected to the bottom of the smoke exhaust pipe 12. One end of the hot gas discharge pipe 41 is connected with a temperature control valve 42, and the outside of the temperature control valve 42 is communicated with the preheating component 8. An inclined air guide rod 43 is connected to the hot gas discharge pipe 41, and a collision body 44 is connected to the inclined air guide rod 43. Heat conduction plates 45 are respectively installed on both sides of the trolley 3. The inside of the heat conduction plate 45 is a cavity, and a plurality of pressing blocks 46 in contact with the collision body 44 are respectively arranged on the outer sides of the heat conduction plates 45. An air port 47 is opened at the top of the heat conduction plate 45. A dust-proof plate 48 for protecting the air port 47 is arranged at the top of the heat conduction plate 45.

[0024] The temperature in the heating furnace 1 is discharged through the hot gas discharge pipe 41 and then conducted through the collision body 44 on the inclined air guide rod 43. During the heat flow process, the inclined air guide rod 43 expands due to heat, causing the collision body 44 to tilt in the inclined direction of the inclined air guide rod 43, so that the collision body 44 contacts the pressing block 46, enabling the heat to be conducted to the heat conduction plate 45. The temperature in the cavity of the heat conduction plate 45 changes, facilitating the generated heat to be ejected along the air port 47, thereby having a heat preservation effect on the workpiece on the trolley 3 during the movement process.

[0025] In order to make the quenching medium such as waste engine oil achieve a better quenching effect, an installation groove 21 is provided at the bottom of the quenching tank body 2, and a preheating component 8 for preheating the medium in the quenching tank body 2 is arranged in the installation groove 21. At the same time, in order to keep the quenching medium in full contact with the workpiece, an overflow frame body 5 is arranged in the quenching tank body 2. Flow guide plates 6 are respectively arranged at the four corners of the overflow frame body 5, and a stirring component 7 is arranged at the center of the overflow frame body 5. The four flow guide plates 6 are distributed in a circular pattern outside the stirring component 7. One end of the preheating component 8 is communicated with the heating and heat preservation assembly 4, and the other end of the preheating component 8 is communicated with the bottom of the stirring component 7.

[0026] The preheating component 8 includes a connecting pipe 81 connected to the outside of the temperature control valve 42. A centralized box 83 is installed in the installation groove 21. The back of the centralized box 83 is connected with the two connecting pipes 81. An air cut-off switch 82 is installed on the centralized box 83. A heat conduction air pipe 84 is installed on the centralized box 83 and is connected with the stirring component 7. A plurality of preheating pipes 85 are installed on the centralized box 83 and are distributed in the installation groove 21.

[0027] During the process of the workpiece being heat-preserved, the heat initially conveyed by the heating furnace 1 and the heat remaining in the heating furnace 1 after heating continuously enter the hot gas discharge pipe 41. When the temperature drops below 100 °C (the preheating of oil is generally at 60 °C - 80 °C, and the preheating of oil is conducive to better quenching treatment of the workpiece), at this time, by opening the temperature control valve 42, the heat enters the centralized box 83 along the connecting pipe 81, and then preheats the oil at the bottom of the quenching tank body 2 along the preheating pipes 85 with a loop design.

[0028] After the workpiece is conveyed to the front end position of the quenching tank body 2, the workpiece is lifted by a sling at this time; at this time, part of the heat and smoke remain inside the centralized box body 83, and then stirring treatment is carried out through the stirring component 7. The design of the stirring component 7 includes an installation body 71 installed on the heat-conducting air pipe 84. A gasket 72 is installed on the heat-conducting air pipe 84, and the gasket 72 is installed on the quenching tank body 2. A driving blade 73 is installed at the bottom of the installation body 71, and a rotating rod 74 is installed at the top of the installation body 71. A telescopic rod 75 is installed at the top of the rotating rod 74, and stirring blades 76 are installed outside the rotating rod 74. The top of the gasket 72 is rotatably connected with a first cover body 77 and a second cover body 78. The first cover body 77 and the second cover body 78 are arranged in a crosswise staggered manner. A cover plate 79 is installed at the top of the second cover body 78, and the top of the telescopic rod 75 is connected to the cover plate 79. Elastic folding areas are provided on the first cover body 77 and the second cover body 78. When the preheating temperature of the oil reaches the set temperature, at this time, by opening the air cut-off switch 82, the heat and smoke in the centralized box 83 are discharged through the heat-conducting air pipe 84. When the discharged smoke and heat converge on the driving blade 73, the driving blade 73 is driven to drive the rotating rod 74 to rotate, so that the stirring blades 76 rotate. At the position where the first cover body 77 and the second cover body 78 are staggered, the quenching medium oil is in a flowing state. After the workpiece is placed inside the quenching tank body 2, the oil is driven into a flowing state. When the flowing oil contacts the flow guide plate 6, the flow of the oil is blocked and it flows back to the central position, so that the quenching oil fully contacts the workpiece, improving the quenching effect.

[0029] At the same time, in order to improve the flow of the quenching medium in the upper part of the quenching tank body 2, motors 22 are installed on the two side walls of the quenching tank body 2, and the output ends of the motors 22 are connected with stirring blades 23. The stirring blades 23 are distributed between the two groups of flow guide plates 6. The height of the overflow frame body 5 is lower than that of the quenching tank body 2.

[0030] The flow guide plate 6 is provided with arc-shaped section notches from top to bottom, and a plurality of round holes are provided on the flow guide plate 6. After the workpiece enters the quenching tank body 2, because the flow guide plate 6 is designed with arc-shaped section notches, so after the workpiece enters, the excess oil will overflow. The overflowed oil is more likely to flow into the corner of the overflow frame body 5 along the arc-shaped slope and will not directly overflow. The excess oil will re-converge to the central position of the quenching tank body 2 along the arc-shaped slope, thereby avoiding insufficient quenching medium caused by excessive oil overflow and also keeping the quenching medium scouring the surface of the workpiece, improving the quenching efficiency.

[0031] After quenching, isothermal cooling is carried out by lifting the workpiece.

[0032] The process of an isothermal quenching equipment for ductile iron a: Workpiece heating. The workpiece is placed on the trolley 3 and pushed into the heating furnace 1. The lifting furnace door 11 is closed for heating. b: Heat conduction. The soot in the heating furnace 1 is discharged from the exhaust pipe 12, and the heat is used to keep the workpiece that has been pushed out of the heating furnace 1 warm through the heating and heat preservation component 4. c: Preheating. The heating and heat preservation component 4 conducts heat to the preheating component 8 to preheat the quenching medium in the quenching tank 2. d: Placing the workpiece. The workpiece is put into the quenching tank 2 by a sling. e: Isothermal quenching. The conducted heat drives the stirring component 7 to cooperate with the flow guide plate 6 to centrally distribute the quenching medium at the center of the quenching tank 2, and the concentrated flow cools the workpiece. f: Isothermal cooling. The workpiece is lifted out of the quenching tank 2 for isothermal cooling.

[0033] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0034] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ductile iron isothermal quenching device, comprising a heating furnace (1) and a quenching tank (2), characterized in that: A lifting furnace door (11) is provided at the furnace opening of the heating furnace (1), a track (15) is provided below the heating furnace (1), a trolley (3) for conveying workpieces is provided on the track (15), and the quenching tank (2) is provided at one end of the track (15); The two side walls of the heating furnace (1) are connected to a smoke exhaust pipe (12), and the bottom of the smoke exhaust pipe (12) is connected to a heating and heat preservation component (4), and the heating and heat preservation component (4) is distributed on both sides of the track (15); An overflow frame (5) is arranged in the quenching tank (2), guide plates (6) are respectively arranged at the four corners of the overflow frame (5), a stirring component (7) is arranged at the center of the overflow frame (5), and the four guide plates (6) are distributed in a circular shape outside the stirring component (7); The bottom of the quenching tank body (2) is provided with a mounting groove (21), and a preheating component (8) for preheating the medium in the quenching tank body (2) is arranged in the mounting groove (21), one end of the preheating component (8) is connected to the heating and heat preservation component (4), and the other end of the preheating component (8) is connected to the bottom of the stirring component (7).

2. A ductile iron austempering equipment according to claim 1, characterized in that: The guide plate (6) is provided with an arc-shaped notch from top to bottom, and a plurality of groups of circular holes are provided on the guide plate (6).

3. A ductile iron austempering equipment according to claim 2, characterized in that: A motor (22) is installed on both side walls of the quenching tank body (2), and an output end of the motor (22) is connected to a stirring blade (23). The stirring blade (23) is distributed between the two groups of guide plates (6). The height of the overflow frame (5) is lower than the height of the quenching tank body (2).

4. The ductile iron austempering equipment according to claim 1, characterized in that: The heating and heat-insulating component (4) comprises a hot gas discharge pipe (41) connected to the bottom of the smoke exhaust pipe (12); one end of the hot gas discharge pipe (41) is connected to a temperature control valve (42), and the outside of the temperature control valve (42) is in communication with the preheating component (8); an inclined air guide rod (43) is connected to the hot gas discharge pipe (41), and a collision body (44) is connected to the inclined air guide rod (43); heat conduction plates (45) are respectively installed on both sides of the trolley (3); the interior of the heat conduction plate (45) is a cavity, and the outer side of the heat conduction plate (45) is respectively provided with a plurality of pressing blocks (46) in contact with the collision body (44); and a gas outlet (47) is opened at the top of the heat conduction plate (45).

5. A ductile iron austempering equipment according to claim 4, characterized in that: A dustproof plate (48) for protecting the gas port (47) is arranged on the top of the heat conduction plate (45); the top of the smoke exhaust pipe (12) is an ellipsoidal absorber (13), and a smoke exhaust dustproof cover (14) is installed on the absorber (13).

6. A ductile iron austempering equipment according to claim 4, characterized in that: The preheating component (8) comprises a connecting pipe (81) connected to the outside of the temperature control valve (42); a centralizing box (83) is installed in the installation groove (21); the back of the centralizing box (83) is connected to the two connecting pipes (81); a gas cut-off switch (82) is installed on the centralizing box (83); a heat-conducting air pipe (84) is installed on the centralizing box (83), and the heat-conducting air pipe (84) is connected to the stirring component (7); a plurality of preheating pipes (85) are installed on the centralizing box (83), and the preheating pipes (85) are distributed in the installation groove (21).

7. A ductile iron austempering equipment according to claim 6, characterized in that: The stirring component (7) comprises a mounting body (71) mounted on a heat-conducting air pipe (84), a sealing gasket (72) being mounted on the heat-conducting air pipe (84), and the sealing gasket (72) being mounted on a quenching tank body (2), an actuating blade (73) being mounted on the bottom of the mounting body (71), a rotating rod (74) being mounted on the top of the mounting body (71), a telescopic rod (75) being mounted on the top of the rotating rod (74), and a stirring blade (76) being mounted on the outside of the rotating rod (74).

8. A ductile iron austempering equipment according to claim 7, characterized in that: The top of the sealing pad (72) is rotatably connected to a first cover body (77) and a second cover body (78); the first cover body (77) and the second cover body (78) are arranged in a cross-staggered manner; a cover plate (79) is installed on the top of the second cover body (78); and the top of the telescopic rod (75) is connected to the cover plate (79).

9. A ductile iron austempering equipment according to claim 8, characterized in that: The first cover body (77) and the second cover body (78) are provided with elastic folding areas.

10. A process used in the ductile iron austempering equipment according to claim 1, characterized in that: a: Heating the workpiece: the workpiece is placed on a trolley (3) and pushed into a heating furnace (1), and the lifting furnace door (11) is closed for heating; b: heat conduction, smoke and dust in the heating furnace (1) are discharged from the smoke exhaust pipe (12), and the heat is used to keep the workpieces exiting the heating furnace (1) warm through the heating and heat preservation component (4); c: preheating, the heating and heat preservation component (4) conducts heat to the preheating component (8) to preheat the quenching medium in the quenching tank (2); d. Place the workpiece into the quenching tank (2) using a lifting device; e: Isothermal quenching, the conducted heat drives the stirring component (7) to cooperate with the guide plate (6) to distribute the quenching medium in the center of the quenching tank (2), thereby concentrating the flow and cooling the workpiece; f: Isothermal cooling: lift the workpiece out of the quenching tank (2) for isothermal cooling.

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