A quenching process for austenitic stainless steel pipe

Abstract

The present invention provides a quenching process for an austenitic stainless steel pipe, and belongs to the technical field of stainless steel pipe processing. It solves the technical problem that the existing stainless steel pipe cannot be accurately air-cooled during quenching, and cannot be orderly flow-quenched. The present invention includes the following steps: workpiece processing; preheating treatment; heating treatment; cooling treatment; inspection treatment. In the present invention, by preheating the stainless steel pipe before entering the heating furnace, the precipitation of carbides from the grain boundaries is avoided, thereby effectively preventing the occurrence of grain boundary erosion, and the heated stainless steel pipe is air-cooled by the cooling equipment, which avoids the quenching cracking of the stainless steel pipe, and can effectively reduce distortion, improve the quenching quality and processing success rate of the stainless steel pipe, and through the setting of the cooling equipment, the pipe transport component can effectively transport the heated stainless steel pipe to the top of the tank body, and the turntable and the rotating plate are set by rotating on both sides of the tank body.

Description

Technical Field

[0001] The invention belongs to the technical field of stainless steel pipe processing, and relates to a stainless steel pipe quenching process, in particular to an austenitic stainless steel pipe quenching process. Background Art

[0002] Quenching is an important heat treatment process that changes the structure and properties of metal materials by rapid cooling. The significance of stainless steel quenching is to increase its hardness, strength, wear resistance and corrosion resistance, improve its service life and safety performance. Quenching can transform the ferrite in austenitic stainless steel into martensite, thereby improving the hardness and strength of the steel to a certain extent.

[0003] After searching, it is found that a stainless steel quenching device and a quenching process are disclosed in Chinese patent documents (application number: CN202210894227.X; publication number: CN115261573A). This stainless steel quenching device relates to the field of heat treatment technology. The document discloses that by adjusting the position of the stirring device in the quenching pool through a bracket, the angle between the stirring device and the quenching pool can also be adjusted, and the stirring angle can be adjusted, so that the quenching liquid in the quenching pool can be quickly stirred, and the flow rate of the quenching liquid can be quickly increased.

[0004] Although the stainless steel quenching device and quenching process disclosed in the patent stir the quenching liquid through a stirring device to facilitate the contact between the quenching liquid and the product, when the stainless steel pipe is quenched, due to the thin-walled structure of the stainless steel pipe, the movement of the stainless steel pipe between the heating furnace and the quenching tank is likely to cause deformation of the stainless steel pipe structure, resulting in a high scrap rate in the heat treatment of the stainless steel pipe. In addition, the existing stainless steel pipe is moved and transported by external lifting equipment, the work efficiency is low, and the air cooling time of the stainless steel pipe before quenching cannot be accurately controlled. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a quenching process for austenitic stainless steel pipes. The technical problem to be solved by the present invention is: how to achieve precise air cooling and fluidized water quenching of austenitic stainless steel pipes.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A quenching process for an austenitic stainless steel pipe comprises the following steps:

[0008] S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and block and seal the holes that do not need quenching;

[0009] S2. Preheating treatment: preheat the austenitic stainless steel pipe to 380-400°C and keep it isothermal for 5-10 minutes;

[0010] S3, heating treatment: the preheated austenitic stainless steel pipe is sent into a quenching furnace, the heating temperature is 1000-1350°C, the holding time is 15-40min, and then moved to the quenching tank through a cooling device;

[0011] S4, cooling treatment: the stainless steel tube is moved through the cooling equipment and pre-cooled in the air, and then immersed in the quenching tank for cooling treatment;

[0012] S5. Inspection and treatment: Cool the quenched stainless steel pipe to room temperature in air, perform structural correction at 20-25℃, and inspect for cracks and harmful scratches.

[0013] In the step S1, the plugging seal is a plug made of graphite or asbestos.

[0014] The heating temperature in step S3 is heated at a rate of 50-80°C / h to 680-780°C, and then heated to 1000-1350°C at a rate of 60-110°C / h after 12-15 minutes of equalization.

[0015] The precooling time in the air in step S4 is 25-75s, and the precooling temperature is 980-800°C;

[0016] The cooling rate of the cooling treatment in step S4 is 190-280° C. / s, and the residence time in the cooling medium is 8-15 s.

[0017] The cooling device used in step S3 and step S4 is a material transfer cooling device, which includes a tank body and a bracket fixedly installed on one side of the tank body, a rotating rod is rotatably connected to the upper side of the tank body away from the bracket, and a rotating disk is fixedly connected to one end of the rotating rod, and the rotating disk is located inside the tank body, and a plurality of plug posts are equidistantly distributed in an annular manner on the surface of the rotating disk;

[0018] A rotating rod is rotatably connected to one side of the trough body away from the rotating disk, and one end of the rotating rod is fixedly connected to a rotating plate, a plurality of through holes are equidistantly opened in an annular shape inside the rotating plate, and both the rotating plate and the rotating disk are circularly arranged;

[0019] The rotating rod and the rotating rod are coaxially arranged on both sides of the groove body, and the rotating rod and the rotating rod rotate synchronously through the transmission assembly;

[0020] A tooth column is fixedly connected inside the bracket, and a transport assembly is movably arranged above the bracket;

[0021] The operation and management component includes an upright frame, and both sides of the upright frame are rotatably connected to lead screws through bearings. The lead screws are driven by a bidirectional motor, and the output end of the bidirectional motor is fixedly connected to the lead screws. The outer wall of the lead screw is connected to a lifting plate through a ball nut, and a limiting component is arranged inside the lifting plate in a lifting manner.

[0022] With the above structure, the heated stainless steel pipe can be moved above the bracket through the operation and management component. Moreover, with the rotating plate rotatably arranged on one side of the bracket, by penetrating and opening a through hole inside the rotating plate, the stainless steel pipe can move through the through hole to the outer wall of the plug post for plugging and limiting. By coaxially arranging the turntable and the rotating plate, the rotation of the rotating rod and the rotating bar can synchronously drive the turntable and the rotating plate to rotate, facilitating the turntable and the rotating plate to drive the stainless steel pipe to rotate downward to contact the cooling medium inside the tank for cooling.

[0023] Synchronous wheels are fixedly connected to the outer walls of the rotating rod and the rotating bar, and a synchronous belt is meshed with the outer walls of the synchronous wheels. The lower part of the synchronous belt is drivingly connected to a driving rod, and the driving rod is rotatably installed below the tank and is driven by a driving component;

[0024] The driving component is a biaxial motor, and the biaxial motor is fixedly installed at the inner bottom of the tank, and the output ends on both sides of the biaxial motor are respectively fixedly connected to the driving rods on both sides of the tank;

[0025] The plug post is arranged in a stepped cylindrical shape and is correspondingly arranged with the through hole.

[0026] With the above structure, through the setting of the driving component, the driving rods on both sides of the tank rotate synchronously. Through the transmission setting of the synchronous wheels and the synchronous belt, the rotating rod and the rotating bar rotate synchronously in the same direction, facilitating the rotating plate and the turntable to drive the stainless steel pipe to rotate synchronously on both sides. Through the setting of the turntable and the rotating plate, the plug post and the through hole can drive the stainless steel pipe to cool and swing inside the tank on both sides, and facilitate the turntable and the rotating plate to rotate to lift the stainless steel pipe, conveniently performing quenching treatment on the stainless steel pipe.

[0027] Bottom blocks are fixedly connected to both bottom ends of the upright frame, and a fixed block is fixedly connected to the middle bottom end of the upright frame. A cross bar is rotatably connected inside the fixed block, and a first bevel gear is fixedly connected to the outer wall of the cross bar. A second bevel gear is meshed with the bottom end of the first bevel gear, and a vertical rod is fixedly connected to the bottom end of the second bevel gear. The vertical rod is rotatably connected below the fixed block and is driven by a driving motor. Gear discs are fixedly connected to both ends of the cross bar, and the gear discs are meshed with the surface of the tooth column;

[0028] The two bottom blocks are symmetrically arranged about the central axis of the upright frame, and the bottom block has a "U" - shaped structure and is slidably connected to the outer wall of the bracket.

[0029] With the above structure, the bottom block is slidably connected to the outer wall of the bracket, so that the gear plate is guided when the outer wall of the gear column rotates and moves, ensuring the movement accuracy of the stand above the bracket, making it easy for the stand to drive the heated stainless steel pipe out of the furnace through the limit assembly, and the structure is simple and convenient.

[0030] The limit assembly includes an adjustment frame, and the adjustment frame is arranged inside the lifting plate. Fixed columns are fixedly connected to both sides of the adjustment frame, and the outer wall of the fixed column is sleeved with a telescopic spring, and the bottom end of the telescopic spring is fixedly connected to the surface of the lifting plate.

[0031] By adopting the above structure, by setting a limit component on the surface of the lifting plate, the adjustment frame is set in a "U" shape, so that the adjustment frame can support the stainless steel pipe at the bottom. At the same time, the telescopic spring set on the surface of the lifting plate facilitates the lifting and lowering activities of the adjustment frame.

[0032] The top end of the telescopic spring is fixedly connected to a top plate, and the top plate is fixedly connected to the top of the adjusting frame, the bottom end of the top plate is fixedly connected to an electric push rod, and the bottom end of the electric push rod is fixedly connected to a clamping rod, the clamping rod is arranged through the inside of the lifting plate, and the clamping rod is located in the middle of the adjusting frame, a supporting spring is sleeved above the clamping rod, and the supporting spring is located on the surface of the lifting plate.

[0033] By adopting the above structure, an electric push rod is arranged between the top plate and the clamping rod. Under the action of the electric push rod, the distance between the top plate and the clamping rod can be adjusted, which is convenient for the adjustment frame and the clamping rod to move in opposite directions. The adjustment frame and the clamping rod limit the stainless steel pipe at the top and bottom, which is convenient for driving the stainless steel pipe to move stably.

[0034] Compared with the prior art, the austenitic stainless steel pipe quenching process of the present invention has the following advantages:

[0035] 1. In the present invention, the stainless steel pipe is preheated before entering the heating furnace, and the carbides are prevented from precipitating from the grain boundaries under the effect of preheating to 380-400°C, thereby effectively preventing the grain boundary erosion. The heated stainless steel pipe is air-cooled by a cooling device, thereby avoiding the quenching cracking of the stainless steel pipe, effectively reducing the distortion, and improving the quenching quality and processing success rate of the stainless steel pipe.

[0036] 2. In the present invention, by setting up the cooling equipment, the pipe transport assembly can effectively transport the heated stainless steel pipe to the top of the tank body, and by rotatably setting a turntable and a rotating plate on both sides of the tank body, the stainless steel pipe can flexibly contact the quenching medium above the tank body under the action of the turntable and the rotating plate, and the stainless steel pipe can be appropriately moved inside the tank body under the rotation of the rotating rod and the rotating rod, which can effectively improve the cooling rate of the medium and reduce the distortion of the stainless steel pipe.

[0037] 3. In the present invention, by arranging the turntable and the rotating plate coaxially, under the action of the plug column and the through hole, one end of the stainless steel tube is plugged into the outer wall of the plug column, and the other end is overlapped inside the through hole, so that the turntable and the rotating plate on both sides can synchronously drive multiple stainless steel tubes to rotate, so that the stainless steel tubes can contact the quenching medium in the inside of the trough body in turn to achieve quenching treatment, thereby improving the heat treatment efficiency of the stainless steel tubes, and the structure is simple, the practicability is strong, and it is conducive to the batch processing of stainless steel tubes.

[0038] 4. In the present invention, by setting the limiting component, the stainless steel pipe can be stably moved through the pipe transport component after being heated inside the heating furnace, so that the stainless steel pipes can be loaded sequentially through the through holes on one side of the turn plate, ensuring the loading stability of the stainless steel pipes and realizing stable docking with the heating furnace, with strong stability and low maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process flow chart of the present invention.

[0040] Figure 2 It is a schematic diagram of the structure of the cooling device in the present invention.

[0041] Figure 3 The present invention Figure 2 A is an enlarged structural diagram of FIG.

[0042] Figure 4 The present invention Figure 2 Schematic diagram of the enlarged structure at B.

[0043] Figure 5 It is a structural schematic diagram of a rotating disc and a rotating plate in the present invention.

[0044] Figure 6 It is a structural schematic diagram of the transfer plate of the present invention.

[0045] Figure 7 It is a structural schematic diagram of the transport management component in the present invention.

[0046] Figure 8 It is a schematic diagram of the front cross-sectional structure of the transport and management assembly in the present invention.

[0047] Fig. 9 It is a structural schematic diagram of the limit assembly and the lifting plate in the present invention.

[0048] Fig.10 It is a structural schematic diagram of the limiting component in the present invention.

[0049] In the figure, 1, trough body; 2, bracket; 3, rotating rod; 4, turntable; 5, plug column; 6, synchronous wheel; 7, synchronous belt; 8, driving rod; 9, rotating rod; 10, rotating plate; 11, through hole; 12, gear column; 13, transportation management assembly; 1301, vertical frame; 1302, screw rod; 1303, lifting plate; 1304, bottom block; 1305, fixed block; 1306, cross bar; 1307, first bevel gear; 1308, second bevel gear; 1309, vertical pole; 1310, driving motor; 1311, gear plate; 1312, top plate; 1313, adjusting frame; 1314, fixed column; 1315, telescopic spring; 1316, electric push rod; 1317, clamping rod; 1318, supporting spring; 1319, bidirectional motor. DETAILED DESCRIPTION

[0050] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0051] Embodiment 1

[0052] The present invention provides a quenching process for an austenitic stainless steel pipe, comprising the following steps:

[0053] S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and use plugs to block and seal the holes that do not need quenching. At the same time, both ends of the stainless steel pipe can be sealed with plugs. Specifically, the plugs are made of asbestos;

[0054] S2. Preheating treatment: preheat the austenitic stainless steel pipe to 380°C and keep it isothermal for 10 minutes;

[0055] S3, heating treatment: the preheated austenitic stainless steel pipe is sent to a quenching furnace. Specifically, the heating rate is 80°C / h to 780°C, and the temperature is kept uniform for 12 minutes, then the temperature is increased to 1050°C at 110°C / h, and then the temperature is kept for 30 minutes;

[0056] S4, cooling treatment: the stainless steel pipe is manually lifted out of the material and pre-cooled in the air for 28 seconds. After the pre-cooling temperature reaches 980°C, it is lifted and immersed in the quenching tank for cooling treatment. Specifically, the cooling medium is salt water, and the stainless steel pipe is lifted and kept in the cooling medium for 9 seconds;

[0057] S5. Inspection and treatment: The quenched stainless steel pipe is air-cooled to room temperature. The structure can be corrected at 20-25℃, and the edge cracks and harmful scars are inspected at the same time.

[0058] The equipment used in this embodiment are all lifting equipment and quenching equipment that can be purchased on the market.

[0059] Embodiment 2

[0060] The present invention provides a quenching process for an austenitic stainless steel pipe, comprising the following steps:

[0061] S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and use plugs to block and seal the holes that do not need quenching. At the same time, both ends of the stainless steel pipe can be sealed with plugs. Specifically, the plugs are made of graphite.

[0062] S2. Preheating treatment: preheat the austenitic stainless steel pipe to 380°C and keep it isothermal for 10 minutes;

[0063] S3, heating treatment: the preheated austenitic stainless steel pipe is sent to the quenching furnace, specifically, the heating rate is 80 ° C / h to 780 ° C, and the temperature is kept uniform for 12 minutes, and then the temperature is increased to 1050 ° C at 110 ° C / h, and then the temperature is kept for 30 minutes, and then the pipe is moved to the quenching tank through the cooling equipment;

[0064] S4, cooling treatment: the stainless steel pipe is moved through the cooling equipment and pre-cooled in the air. Specifically, by setting the bracket 2 on one side of the heating furnace, the pipe transport component 13 limits and fixes the heated stainless steel pipe through the limit component. By setting the gear plate 1311 and the bottom block 1304 under the stand 1301, when the drive motor 1310 drives the gear plate 1311 to rotate, the stand 1301 drives the bottom block 1304 to slide on the surface of the bracket 2, so that the pipe transport component 13 drives the stainless steel pipe to move on one side. By setting a rotating plate 10 on the side of the trough body 1 close to the bracket 2, and through the through hole 11 opened inside the rotating plate 10, the stainless steel pipe can pass through the through hole 11 to move to the outer wall of the plug column 5 for plugging and limiting, so that the stainless steel pipe Air cooling is performed above the tank body 1. After precooling for 28 seconds, when the precooling temperature reaches 980°C, the turntable 4 and the turn plate 10 are coaxially arranged. Under the action of the driving rod 8 driving the rotating rod 3 and the rotating rod 9 for transmission, the rotation of the rotating rod 3 and the rotating rod 9 can simultaneously drive the turntable 4 and the turn plate 10 on both sides to rotate, so that the turntable 4 and the turn plate 10 drive the stainless steel pipe to rotate downward to the bottom and immerse it in the quenching tank inside the tank body 1, so that the stainless steel pipe is contacted with the cooling medium for cooling. At the same time, the cooling medium is water, and the residence time in the cooling medium is 9 seconds. After the cooling is completed, the driving rod 8 is rotated again. Under the circular action of the turntable 4 and the turn plate 10, the cooled stainless steel pipe is rotated out of the cooling medium, and the next stainless steel pipe is sequentially entered into the tank body 1 for cooling;

[0065] S5. Inspection and treatment: Cool the quenched stainless steel pipe to room temperature in air, perform structural correction at 20-25℃, and inspect for cracks and harmful scratches.

[0066] The cooling equipment used in step S3 and step S4 is a material transfer cooling device, which includes a trough body 1 and a bracket 2 fixedly installed on one side of the trough body 1, a rotating rod 3 is rotatably connected to the upper side of the trough body 1 away from the bracket 2, and one end of the rotating rod 3 is fixedly connected to a turntable 4, and the turntable 4 is located inside the trough body 1, and a plurality of plug posts 5 are distributed in an annular manner at equal intervals on the surface of the turntable 4. At the same time, under the action of a rotating plate 10 rotatably arranged on one side of the bracket 2, a through hole 11 is opened through the inside of the rotating plate 10, so that the stainless steel pipe can pass through the through hole 11 and move to the outer wall of the plug post 5 for insertion and limiting. A rotating rod 9 is rotatably connected to the side of the trough body 1 away from the turntable 4, and one end of the rotating rod 9 is fixedly connected to the rotating plate 10. By setting the turntable 4 and the turntable 10 coaxially, the rotation of the rotating rod 3 and the rotating rod 9 can simultaneously drive the turntable 4 and the turntable 10 to rotate, so that the turntable 4 and the turntable 10 can drive the stainless steel pipe to rotate to the bottom and contact and cool with the cooling medium inside the tank body 1. The inner ring of the turntable 10 is equidistantly provided with a plurality of through holes 11. The plug column 5 is arranged in a stepped cylindrical shape, and the plug column 5 and the through hole 11 are arranged correspondingly. The plug column 5 and the through hole 11 can drive the stainless steel pipe on both sides to cool and swing inside the tank body 1, and the turntable 4 and the turntable 10 can rotate to contact or raise the stainless steel pipe inside the tank body 1 with the medium, so as to conveniently quench the stainless steel pipe and realize the orderly flow quenching of the stainless steel pipe.

[0067] The rotating rod 3 and the rotating rod 9 are coaxially arranged on both sides of the trough body 1, and the rotating rod 3 and the rotating rod 9 rotate synchronously through the transmission assembly. The outer walls of the rotating rod 3 and the rotating rod 9 are fixedly connected with synchronous wheels 6, and the outer walls of the synchronous wheels 6 are meshed with synchronous belts 7. The lower part of the synchronous belt 7 is transmission-connected with a driving rod 8, and the driving rod 8 is rotatably installed under the trough body 1, and the driving rod 8 is driven by the driving assembly. The driving assembly is a double-axis motor, and the double-axis motor is fixedly installed on the inner bottom of the trough body 1, and the output ends of the double-axis motor on both sides are fixedly connected to the driving rods 8 on both sides of the trough body 1. Through the transmission setting of the synchronous wheel 6 and the synchronous belt 7, the rotating rod 3 and the rotating rod 9 are synchronously rotated in the same direction, so that the rotating plate 10 and the turntable 4 can drive the stainless steel pipe to rotate at the same time on both sides. The structure is simple and the driving resources are saved.

[0068] A gear column 12 is fixedly connected inside the bracket 2, and a transport management component 13 is movably arranged above the bracket 2. The transport management component 13 includes a stand 1301, and screw rods 1302 are rotatably connected to both sides of the stand 1301 through bearings. The screw rod 1302 is driven by a bidirectional motor 1319, and the output end of the bidirectional motor 1319 is fixedly connected to the screw rod 1302. The outer wall of the screw rod 1302 is connected to a lifting plate 1303 through a ball nut, and a limit position component is arranged inside the lifting plate 1303.

[0069] Both bottom ends of the vertical frame 1301 are fixedly connected with bottom blocks 1304. The two bottom blocks 1304 are symmetrically arranged about the central axis of the vertical frame 1301. The bottom block 1304 has a "U" - shaped structure and is slidably connected to the outer wall of the bracket 2. Under the action of the bottom block 1304 slidingly connected to the outer wall of the bracket 2, when the gear disk 1311 rotates and moves on the outer wall of the tooth column 12, it is guided, ensuring the accurate movement of the vertical frame 1301 above the bracket 2, facilitating the vertical frame 1301 to drive the heated stainless - steel pipe out of the furnace through the limiting component. Moreover, the structure is simple and convenient. The bottom end of the middle part of the vertical frame 1301 is fixedly connected with a fixed block 1305. A cross - bar 1306 is rotatably connected inside the fixed block 1305. A first bevel gear 1307 is fixedly connected to the outer wall of the cross - bar 1306. A second bevel gear 1308 is meshed and connected to the bottom end of the first bevel gear 1307. A vertical rod 1309 is fixedly connected to the bottom end of the second bevel gear 1308. The vertical rod 1309 is rotatably connected below the fixed block 1305 and is driven by a driving motor 1310. Gear disks 1311 are fixedly connected to both ends of the cross - bar 1306, and the gear disks 1311 are meshed and connected to the surface of the tooth column 12. Under the action of fixedly connecting the gear disks 1311 on both sides of the cross - bar 1306, the heated stainless - steel pipe can be moved above the bracket 2 through the pipe - transporting component 13, and it is convenient for the vertical frame 1301 to drive the heated stainless - steel pipe out of the furnace through the limiting component.

[0070] The limiting component includes an adjusting frame 1313, and the adjusting frame 1313 is arranged throughout the interior of the lifting plate 1303. Fixed columns 1314 are fixedly connected to both sides of the adjusting frame 1313, and the outer wall of the fixed column 1314 is provided with a telescopic spring 1315, and the bottom end of the telescopic spring 1315 is fixedly connected to the surface of the lifting plate 1303, and the top of the telescopic spring 1315 is fixedly connected to the top plate 1312, and the top plate 1312 is fixedly connected to the top of the adjusting frame 1313. The adjusting frame 1313 is arranged in a "U"-shaped structure, so that the adjusting frame 1313 can support the stainless steel pipe at the bottom. At the same time, the telescopic spring 1315 is arranged on the surface of the lifting plate 1303, which facilitates the lifting and lowering activities of the adjusting frame 1313. The bottom end of the top plate 1312 is fixedly connected to an electric push rod 1316, and the bottom end of the electric push rod 1316 is fixedly connected with a clamping rod 1317, and the top end of the clamping rod 1317 is fixedly connected to the fixed end of the electric push rod 1316, and the output end of the electric push rod 1316 is fixedly connected to the bottom end of the top plate 1312. At the same time, the clamping rod 1317 is arranged through the inside of the lifting plate 1303, and the clamping rod 1317 is located in the middle of the adjusting frame 1313, and a support spring 1318 is sleeved on the top of the clamping rod 1317, and the support spring 1318 is located on the surface of the lifting plate 1303. By arranging the electric push rod 1316 between the top plate 1312 and the clamping rod 1317, under the action of the electric push rod 1316, the distance between the top plate 1312 and the clamping rod 1317 can be adjusted, so that the adjusting frame 1313 and the clamping rod 1317 can move in the opposite direction.

[0071] Embodiment 3

[0072] The present invention provides a quenching process for an austenitic stainless steel pipe, comprising the following steps:

[0073] S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and use plugs to block and seal the holes that do not need quenching. At the same time, both ends of the stainless steel pipe can be sealed with plugs. Specifically, the plugs are made of asbestos;

[0074] S2. Preheating treatment: preheat the austenitic stainless steel pipe to 400°C and keep it isothermal for 10 minutes;

[0075] S3, heating treatment: the preheated austenitic stainless steel pipe is sent to a quenching furnace. Specifically, the heating rate is 50°C / h to 680°C, and the temperature is kept uniform for 12 minutes, then the temperature is increased to 1350°C at 60°C / h, and then the temperature is kept for 40 minutes;

[0076] S4, cooling treatment: precool the stainless steel pipe in the air through a cooling device for 75 seconds, and then immerse it in a quenching tank through a cooling device for cooling after the precooling temperature reaches 800°C. Specifically, the cooling medium is salt water, and the stainless steel pipe is kept in the cooling medium for 12 seconds through the cooling device;

[0077] S5. Inspection and treatment: The quenched stainless steel pipe is air-cooled to room temperature. The structure can be corrected at 20-25℃, and the edge cracks and harmful scars are inspected at the same time.

[0078] The cooling device used in this embodiment is the same as the cooling device in the second embodiment.

[0079] Embodiment 4

[0080] The present invention provides a quenching process for an austenitic stainless steel pipe, comprising the following steps:

[0081] S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and use plugs to block and seal the holes that do not need quenching. At the same time, both ends of the stainless steel pipe can be sealed with plugs. Specifically, the plugs are made of asbestos;

[0082] S2. Preheating treatment: preheat the austenitic stainless steel pipe to 380°C and keep it isothermal for 8 minutes;

[0083] S3, heating treatment: the preheated austenitic stainless steel pipe is sent to a quenching furnace. Specifically, the heating rate is 65°C / h to 730°C, and the temperature is kept uniform for 13 minutes, then the temperature is increased to 1280°C at 80°C / h, and then the temperature is kept for 15 minutes;

[0084] S4, cooling treatment: precool the stainless steel pipe in the air through a cooling device, the precooling time is 75 seconds, the precooling temperature reaches 800°C, and then the stainless steel pipe is immersed in a quenching tank through a cooling device for cooling treatment. Specifically, the cooling medium is mineral oil, and the stainless steel pipe is kept in the cooling medium by the cooling device for 15 seconds;

[0085] S5. Inspection and treatment: The quenched stainless steel pipe is air-cooled to room temperature. The structure can be corrected at 20-25℃, and the edge cracks and harmful scars are inspected at the same time.

[0086] The cooling device used in this embodiment is the same as the cooling device in the second embodiment.

[0087] In summary, the heated stainless steel pipe can be moved above the bracket 2 through the pipe transport assembly 13, and under the action of the rotating plate 10 that is rotatably set on one side of the bracket 2, by opening a through hole 11 through the inside of the rotating plate 10, the stainless steel pipe can be moved to the outer wall of the plug column 5 through the through hole 11 for plug-in limiting, and the turntable 4 and the turntable 10 are coaxially arranged, so that the rotation of the rotating rod 3 and the rotating rod 9 can simultaneously drive the turntable 4 and the turntable 10 to rotate, so that the turntable 4 and the turntable 10 drive the stainless steel pipe to rotate in turn to the bottom and contact and cool with the cooling medium inside the tank body 1, thereby solving the problem that the existing stainless steel pipe cannot be accurately air-cooled during quenching and cannot be orderly flow-cooled.

[0088] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A quenching process for austenitic stainless steel pipes, It is characterized in that The following steps are involved: S1. Workpiece processing: Check the surface of the austenitic stainless steel pipe to be quenched to avoid oil stains, bumps and cracks, and block and seal the holes that do not need quenching; S2. Preheating treatment: preheat the austenitic stainless steel pipe to 380-400°C and keep it isothermal for 5-10 minutes; S3, heating treatment: the preheated austenitic stainless steel pipe is sent into a quenching furnace, the heating temperature is 1000-1350°C, the holding time is 15-40min, and then moved to the quenching tank through a cooling device; S4, cooling treatment: the stainless steel tube is moved through the cooling equipment and pre-cooled in the air, and then immersed in the quenching tank for cooling treatment; S5. Inspection and treatment: Cool the quenched stainless steel pipe to room temperature in air, perform structural correction at 20-25℃, and inspect for cracks and harmful scratches; The cooling device used in step S3 and step S4 is a material transfer cooling device, comprising a tank body (1) and a bracket (2) fixedly mounted on one side of the tank body (1), a rotating rod (3) being rotatably connected to the upper side of the tank body (1) away from the bracket (2), and a rotating disk (4) being fixedly connected to one end of the rotating rod (3), and the rotating disk (4) being located inside the tank body (1), and a plurality of plug posts (5) being equidistantly distributed in an annular manner on the surface of the rotating disk (4); A rotating rod (9) is rotatably connected to a side of the trough body (1) away from the rotating disk (4), and one end of the rotating rod (9) is fixedly connected to a rotating plate (10), a plurality of through holes (11) are equidistantly provided in an annular shape inside the rotating plate (10), and the rotating plate (10) and the rotating disk (4) are both circularly arranged; The rotating rod (3) and the rotating rod (9) are coaxially arranged on both sides of the trough body (1), and the rotating rod (3) and the rotating rod (9) rotate synchronously via a transmission assembly; A tooth column (12) is fixedly connected to the interior of the bracket (2), and a transport pipe assembly (13) is movably arranged above the bracket (2); The transport pipe assembly (13) comprises a stand (1301), and screw rods (1302) are rotatably connected to both sides of the stand (1301) via bearings, the screw rods (1302) are driven by a bidirectional motor (1319), and the output end of the bidirectional motor (1319) is fixedly connected to the screw rod (1302), the outer wall of the screw rod (1302) is connected to a lifting plate (1303) via a ball nut, and a limit position assembly is provided inside the lifting plate (1303); The limit assembly comprises an adjustment frame (1313), and the adjustment frame (1313) is arranged to penetrate the interior of the lifting plate (1303), and fixed columns (1314) are fixedly connected to both sides of the adjustment frame (1313), and the outer wall of the fixed column (1314) is provided with a telescopic spring (1315), and the bottom end of the telescopic spring (1315) is fixedly connected to the surface of the lifting plate (1303).

2. A quenching process for an austenitic stainless steel pipe according to claim 1, It is characterized in that In the step S1, a plug is used for plugging and sealing, and the material of the plug is graphite or asbestos.

3. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that in the step S3, the heating rate of the heating temperature is increased from 50 - 80 °C / h to 680 - 780 °C, and after soaking for 12 - 15 minutes, it is increased to 1000 - 1350 °C at a rate of 60 - 110 °C / h.

4. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that in the step S4, the pre-cooling time in the air is 25 - 75 s, and the pre-cooling temperature is 980 - 800 °C.

5. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that in the step S4, the cooling rate of the cooling treatment is 190 - 280 °C / s, and the residence time in the cooling medium is 8 - 15 s.

6. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that synchronous wheels (6) are fixedly connected to the outer walls of the rotating rod (3) and the rotating bar (9), and a synchronous belt (7) is meshed with the outer walls of the synchronous wheels (6). A driving rod (8) is drivingly connected below the synchronous belt (7), and the driving rod (8) is rotatably installed below the tank body (1) and is driven by a driving component; the driving component is a biaxial motor, and the biaxial motor is fixedly installed at the inner bottom of the tank body (1), and the output ends on both sides of the biaxial motor are respectively fixedly connected to the driving rods (8) on both sides of the tank body (1); the plug post (5) is arranged in a stepped cylindrical shape and is correspondingly arranged with the through hole (11).

7. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that bottom blocks (1304) are fixedly connected to both bottom ends of the vertical frame (1301), and a fixing block (1305) is fixedly connected to the middle bottom end of the vertical frame (1301). A cross bar (1306) is rotatably connected inside the fixing block (1305), and a first bevel gear (1307) is fixedly connected to the outer wall of the cross bar (1306). A second bevel gear (1308) is meshed with the bottom end of the first bevel gear (1307), and a vertical rod (1309) is fixedly connected to the bottom end of the second bevel gear (1308). The vertical rod (1309) is rotatably connected below the fixing block (1305) and is driven by a driving motor (1310). Gear disks (1311) are fixedly connected to both ends of the cross bar (1306), and the gear disks (1311) are meshed with the surface of the tooth column (12); the two bottom blocks (1304) are symmetrically arranged about the central axis of the vertical frame (1301), and the bottom block (1304) has a "U" - shaped structure and is slidably connected to the outer wall of the support (2).

8. A quenching processing technology for austenitic stainless steel pipes according to claim 1, characterized in that The top end of the telescopic spring (1315) is fixedly connected to a top plate (1312), and the top plate (1312) is fixedly connected to the top end of the adjustment frame (1313); the bottom end of the top plate (1312) is fixedly connected to an electric push rod (1316), and the bottom end of the electric push rod (1316) is fixedly connected to a clamping rod (1317); the clamping rod (1317) is arranged to penetrate the interior of the lifting plate (1303), and the clamping rod (1317) is located in the middle of the adjustment frame (1313); a support spring (1318) is sleeved above the clamping rod (1317), and the support spring (1318) is located on the surface of the lifting plate (1303).

Images