Rolling process and device for inhibiting rolling edge cracks of magnesium alloy plate

Abstract

The invention discloses a rolling process and device for inhibiting rolling edge cracks of a magnesium alloy plate, and relates to the technical field of rolling forming of magnesium alloy plate strips, and the rolling process for inhibiting rolling edge cracks of the magnesium alloy plate comprises the following steps that a magnesium alloy plate blank to be treated is pretreated; the pretreatment comprises the steps of sequentially carrying out polishing treatment, wiping and cleaning treatment and oil coating treatment on the magnesium alloy plate blank to be treated; the rolling device for inhibiting the rolling edge cracks of the magnesium alloy plate is applied to the rolling process for inhibiting the rolling edge cracks of the magnesium alloy plate. According to the device, the magnesium alloy plate blank to be treated can be subjected to the pretreatment processes of polishing treatment, wiping cleaning treatment and oil coating treatment, the stress uniformity and stability of the magnesium alloy plate blank to be treated in the subsequent rolling process are guaranteed, the width-limited rolling effect is achieved in the subsequent rolling process, and therefore cracks are effectively prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of magnesium alloy plate and strip rolling forming, and in particular to a rolling process and device for suppressing edge cracks of magnesium alloy plates during rolling. Background Art

[0002] As a lightweight, high-strength material, magnesium alloy is increasingly used in modern industrial manufacturing, particularly in the aerospace, automotive, and telecommunications industries. Its superior strength-to-weight ratio, good vibration damping properties, and ease of processing make it a promising alternative to traditional steel and aluminum alloys. However, edge cracks are a common problem during the production and processing of magnesium alloy sheets, particularly during rolling.

[0003] During the rolling process, magnesium alloy sheets are susceptible to excessive stress concentration at the edges of the sheet due to the material's anisotropy, uneven thermal stress distribution, and complex tribological behavior between the rollers and the sheet. This can lead to the formation of edge cracks. These cracks not only affect the product's appearance but, more importantly, reduce the sheet's mechanical properties and corrosion resistance. In severe cases, they can even render the product scrapped, increasing production costs and limiting the widespread application of magnesium alloy sheets. Traditional solutions have focused on optimizing rolling parameters, improving roller design and material, and strengthening post-rolling heat treatment. While these methods can alleviate the cracking problem to a certain extent, their effectiveness is limited.

[0004] Therefore, the industry urgently needs a more effective rolling process and equipment that can properly pre-treat the magnesium alloy slab before rolling to improve its surface condition, reduce stress concentration during rolling, and implement more precise control during the rolling process to ensure that the plate is evenly stressed, thereby fundamentally suppressing the occurrence of edge cracks.

[0005] Based on the above background, a rolling process and device for suppressing edge cracks in magnesium alloy sheets are designed. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a rolling process and device for suppressing edge cracks in magnesium alloy plates.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A rolling process for suppressing edge cracks in magnesium alloy sheets comprises the following steps: Step 1: pre-treating the magnesium alloy slab to be treated, wherein the pre-treating comprises sequentially performing a grinding treatment, a wiping cleaning treatment, and an oiling treatment on the magnesium alloy slab to be treated to obtain a pre-treated magnesium alloy slab; Step 2: heating the pretreated magnesium alloy slab to 350-400° C. and keeping the temperature for 1-2 hours to obtain a preheated magnesium alloy slab; Step 3: Roll the preheated magnesium alloy slab using multi-pass rolling, controlling the reduction of each pass to 10%-20%, and the total reduction not exceeding 60%. The rolling rate is divided into three stages: During the initial rolling stage (deformation 0-30%), the rolling rate is 0.5-1.0 m / s; In the middle rolling stage (deformation 30-50%), the rolling rate is 1.0-1.5 m / s; In the final rolling stage (deformation 50-60%), the rolling rate is 0.8-1.2 m / s. Dynamically adjust the rolling force to control the rolling force peak value to 500-1000 kN, and the rolling force fluctuation between adjacent passes does not exceed 10%. The rolling force calculation formula is: P = K · σ · √(R · Δh) P is the rolling force (unit: kN), K is the process correction coefficient (range: 0.8-1.2), σ is the high-temperature flow stress of magnesium alloy (unit: MPa, range: 50-150 MPa), R is the work roll radius (unit: mm), Δh is the single-pass reduction (unit: mm); Step 4: Immediately after final rolling, the plate is subjected to slow cooling treatment on the edge at a slow cooling rate of 5-10°C / min until the overall temperature of the plate drops below 250°C.

[0008] A rolling device for suppressing edge cracks in magnesium alloy plates during rolling, the device is applied to the rolling process for suppressing edge cracks in magnesium alloy plates during rolling, the device comprises a bottom plate, a machine table is provided at the upper end of the bottom plate, a movable groove is provided at the upper end of the machine table, a second electric drive roller is arranged and installed inside the movable groove, a first accommodating groove and a second accommodating groove are provided on the inner wall of the movable groove, a loading positioning mechanism is provided inside the first accommodating groove, a grinding mechanism is provided at the upper end of the machine table located above the first accommodating groove, and a There are two clamping mechanisms connected to the grinding mechanism, and the two clamping mechanisms are respectively arranged on both sides of the first accommodating groove. The interior of the second accommodating groove is provided with a wiping and cleaning mechanism and an oiling mechanism. The inner wall of the second accommodating groove is provided with a hair dryer located between the wiping and cleaning mechanism and the oiling mechanism. The upper end of the machine is provided with two electric-driven pressure rollers, and the two electric-driven pressure rollers are symmetrically arranged on the left and right sides of the second accommodating groove. The upper end of the machine is provided with a heating furnace located on the right side of the second accommodating groove, and the upper end of the bottom plate is provided with a rolling mechanism located on the right side of the heating furnace.

[0009] As a further improvement of the present invention, the loading positioning mechanism is located on the support frame inside the first accommodating groove, two positioning blocks are fixed on the left side of the upper end of the support frame, first electric drive rollers are arranged and installed on the inner side of the support frame, and two second electric telescopic rods are installed on the upper end of the base plate, and the telescopic ends of the two second electric telescopic rods are both facing upward and fixed to the bottom of the support frame.

[0010] As a further improvement of the present invention, the grinding mechanism includes a mounting bracket fixedly connected to the upper end of the machine platform, a first electric telescopic rod is installed on the upper end of the mounting bracket, the telescopic end of the first electric telescopic rod passes downward through the mounting bracket and is fixedly connected to the movable bracket, two guide rods are fixed to the upper end of the movable bracket, the two guide rods are symmetrically arranged on both sides of the first electric telescopic rod, the guide rods pass through the mounting bracket and are slidably connected to the mounting bracket, a belt grinder is installed on the inner side of the movable bracket, and a dust hood is installed on the left side wall of the movable bracket.

[0011] As a further improvement of the present invention, the clamping mechanism includes a fixed block fixed to the upper end of the machine table, a rotating shaft passing through the fixed block, a clamping block fixed to the end of the rotating shaft close to the first accommodating groove, and a first gear sleeved on the end of the rotating shaft away from the first accommodating groove. Racks are fixed on the opposite side walls of the movable frame, and a strip groove matching the rack is passed through the side wall of the mounting frame. The rack meshes with the first gear, and the lower end of the rack passes through the upper end of the machine table and is slidably connected to the machine table. Two third electric telescopic rods are fixedly installed on the side walls of the fixed block, and the telescopic ends of the two third electric telescopic rods pass through the fixed block and are fixed with the same movable block, and the movable block is rotatably sleeved on the rotating shaft.

[0012] As a further improvement of the present invention, the wiping cleaning mechanism includes two L-shaped plates, which are respectively fixedly connected to the inner walls on both sides of the opposite sides of the second accommodating groove, and two wiping rollers are arranged upper and lower between the two L-shaped plates. The two cylindrical shaft ends of the two wiping rollers respectively pass through the two L-shaped plates and are rotatably connected to the L-shaped plates. A fixed plate is fixed on the side wall of one of the L-shaped plates, and a second motor is installed on the side wall of the fixed plate. The output shaft of the second motor passes through the fixed plate and is fixed to the cylindrical shaft end of the upper wiping roller. The cylindrical shaft ends of the two wiping rollers are fixedly sleeved with a second gear, and the two second gears are meshed. The cylindrical shaft end of the upper wiping roller is fixedly sleeved with a first synchronous wheel.

[0013] As a further improvement of the present invention, the oiling mechanism includes a storage box fixed on the inner wall of the second accommodating groove, a connecting pipe is fixed on the side wall of the storage box, two nozzles arranged upper and lower are connected to the side wall of the connecting pipe, and a nozzle is provided on the nozzle, and a pump is installed on the side wall of the storage box, the input end of the pump is connected to the storage box, and the output end of the pump is connected to the nozzle, and an agitator rotatably connected to the storage box is penetrated by the upper end of the storage box, a worm gear is fixed on the upper end of the agitator, and a fixed frame is fixed to the upper end of the storage box, a worm meshing with the worm gear is provided on the inner side of the fixed frame, both ends of the worm gear penetrate the fixed frame and are rotatably connected to the fixed frame, a second synchronous wheel is fixed to one end of the worm gear, and the second synchronous wheel is connected to the first synchronous wheel through a synchronous belt.

[0014] As a further improvement of the present invention, the rolling mechanism includes two vertical plates fixed on the upper end of the bottom plate, and upper and lower rolling rollers are rotatably installed between the two vertical plates. A first motor is installed on the side wall of one of the vertical plates, and the output shaft of the first motor passes through the vertical plate and is fixed to the end of the upper rolling roller.

[0015] As a further improvement of the present invention, fixing rods are fixed at the four corners of the lower end of the machine, and the lower ends of the fixing rods are fixed to the upper end of the bottom plate.

[0016] As a further improvement of the present invention, an annular groove is provided in the middle of the side wall of the upper roller.

[0017] Beneficial effects of the present invention: By grinding and wiping the magnesium alloy slab to be treated, oxides, burrs, dirt and wire cutting marks on the surface of the magnesium alloy slab to be treated can be removed to ensure that the surface is flat and smooth, thereby ensuring the uniformity and stability of the force on the magnesium alloy slab to be treated during the subsequent rolling process, thereby effectively preventing the occurrence of cracks; by oiling the magnesium alloy slab to be treated, the graphite oil solution has good lubricity, which can reduce the friction between the magnesium alloy plate and the roller during the rolling process, and help prevent the plate from cracking during the rolling process. At the same time, the graphite oil solution can also prevent the plate from sticking to the roller during the rolling process to a certain extent, improve the rolling efficiency and product quality, and reduce the stress concentration on the material surface, thereby effectively preventing the occurrence of cracks.

[0018] By setting up a loading positioning mechanism and a grinding mechanism, the loading positioning mechanism can be used to position the magnesium alloy slab to be processed, thereby ensuring the accuracy of the loading position of the magnesium alloy slab to be processed and improving the convenience of loading the magnesium alloy slab to be processed; the grinding mechanism can be used to achieve efficient grinding of the magnesium alloy slab to be processed, and can conveniently complete double-sided grinding of the magnesium alloy slab to be processed, thereby improving grinding efficiency.

[0019] By setting up a rolling mechanism, the annular groove of the upper rolling roller can play the role of width-limiting rolling during the rolling of the magnesium alloy slab to be processed, and can successfully apply the compressive stress field to the edge of the plate, reducing the tensile stress in the rolling direction, thereby effectively suppressing the occurrence of rolling edge cracks.

[0020] The present invention can perform a pretreatment process of grinding, wiping and cleaning, and oiling the magnesium alloy slab to be processed, thereby ensuring the uniformity and stability of the force applied to the magnesium alloy slab to be processed during the subsequent rolling process, and in the subsequent rolling process, achieving the effect of width-limited rolling, thereby effectively preventing the generation of cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a rolling device for suppressing edge cracks in magnesium alloy plates proposed by the present invention; Figure 2 This is a schematic structural diagram of a loading and positioning mechanism of a rolling device for suppressing edge cracks in magnesium alloy plates proposed by the present invention; Figure 3 This is a schematic structural diagram of a grinding mechanism and a clamping mechanism of a rolling device for suppressing edge cracks in a magnesium alloy plate, as proposed by the present invention; Figure 4 This is a schematic structural diagram of a wiping and cleaning mechanism and an oiling mechanism of a rolling device for suppressing edge cracks in magnesium alloy plates proposed by the present invention; Figure 5 This is a schematic structural diagram of an agitator and a worm gear of a rolling device for suppressing edge cracks in magnesium alloy plates proposed by the present invention; Figure 6 This is a structural schematic diagram of the machine platform, movable groove, first accommodating groove, second accommodating groove and second electric drive roller of a rolling device for suppressing edge cracks of magnesium alloy plates proposed by the present invention.

[0022] In the figure: 1 bottom plate, 2 fixed rod, 3 machine table, 4 mounting frame, 5 movable frame, 6 dust cover, 7 belt grinder, 8 guide rod, 9 first electric telescopic rod, 10 first receiving groove, 11 electric drive pressure roller, 12 blower, 13 second receiving groove, 14 heating furnace, 15 vertical plate, 16 lower roller, 17 first motor, 18 upper roller, 19 second electric telescopic rod, 20 support frame, 21 positioning block, 22 first electric drive roller, 23 rack, 24 first gear wheel, 25 rotating shaft, 26 fixed block, 27 third electric telescopic rod, 28 moving block, 29 clamping block, 30 L-shaped plate, 31 wiping roller, 32 fixed plate, 33 second motor, 34 nozzle, 35 second gear, 36 first synchronous wheel, 37 synchronous belt, 38 second synchronous wheel, 39 fixed frame, 40 worm, 41 worm wheel, 42 storage box, 43 pump, 44 connecting pipe, 45 nozzle, 46 agitator, 47 movable trough, 48 second electric drive roller. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] A rolling process for suppressing edge cracks in magnesium alloy sheets comprises the following steps: Step 1: pre-treating the magnesium alloy slab to be treated, wherein the pre-treating comprises sequentially performing a grinding treatment, a wiping cleaning treatment, and an oiling treatment on the magnesium alloy slab to be treated to obtain a pre-treated magnesium alloy slab; Step 2: heating the pretreated magnesium alloy slab to 350-400° C. and keeping the temperature for 1-2 hours to obtain a preheated magnesium alloy slab; Step 3: Roll the preheated magnesium alloy slab using multi-pass rolling, controlling the reduction of each pass to 10%-20%, and the total reduction not exceeding 60%. The rolling rate is divided into three stages: During the initial rolling stage (deformation 0-30%), the rolling rate is 0.5-1.0 m / s; In the middle rolling stage (deformation 30-50%), the rolling rate is 1.0-1.5 m / s; In the final rolling stage (deformation 50-60%), the rolling rate is 0.8-1.2 m / s. Dynamically adjust the rolling force to control the rolling force peak value to 500-1000 kN, and the rolling force fluctuation between adjacent passes does not exceed 10%. The rolling force calculation formula is: P = K · σ · √(R · Δh) P is the rolling force (unit: kN), K is the process correction coefficient (range: 0.8-1.2), σ is the high-temperature flow stress of magnesium alloy (unit: MPa, range: 50-150 MPa), R is the work roll radius (unit: mm), Δh is the single-pass reduction (unit: mm); Step 4: Immediately after final rolling, the plate is subjected to slow cooling treatment on the edge at a slow cooling rate of 5-10°C / min until the overall temperature of the plate drops below 250°C.

[0025] Reference Figures 1-6 , a rolling device for suppressing edge cracks in magnesium alloy plates during rolling, the device is applied to the rolling process for suppressing edge cracks in magnesium alloy plates during rolling, the device includes a bottom plate 1, a machine table 3 is provided on the upper end of the bottom plate 1, and fixed rods 2 are fixed at the four corners of the lower end of the machine table 3, the lower end of the fixed rod 2 is fixed to the upper end of the bottom plate 1, and a movable groove 47 is provided on the upper end of the machine table 3, and a second electric drive roller 48 is arranged and installed inside the movable groove 47. A first accommodating groove 10 and a second accommodating groove 13 are penetrated on the inner wall of the movable groove 47, and a loading positioning mechanism is provided inside the first accommodating groove 10. The upper end of the machine table 3 is provided with a positioning mechanism located in the first accommodating groove 10 The upper end of the machine table 3 is provided with two clamping mechanisms connected to the grinding mechanism, and the two clamping mechanisms are respectively arranged on both sides of the first accommodating groove 10. The interior of the second accommodating groove 13 is provided with a wiping and cleaning mechanism and an oiling mechanism. The inner wall of the second accommodating groove 13 is provided with a hair dryer 12 located between the wiping and cleaning mechanism and the oiling mechanism. The upper end of the machine table 3 is provided with two electric-driven pressure rollers 11, and the two electric-driven pressure rollers 11 are symmetrically arranged on the left and right sides of the second accommodating groove 13. The upper end of the machine table 3 is provided with a heating furnace 14 located on the right side of the second accommodating groove 13, and the upper end of the base plate 1 is provided with a rolling mechanism located on the right side of the heating furnace 14.

[0026] In the present invention, the loading positioning mechanism is located on the support frame 20 inside the first accommodating groove 10, two positioning blocks 21 are fixed on the left side of the upper end of the support frame 20, and the first electric drive rollers 22 are arranged and installed on the inner side of the support frame 20. Two second electric telescopic rods 19 are installed on the upper end of the base plate 1, and the telescopic ends of the two second electric telescopic rods 19 are both facing upward and fixed to the bottom of the support frame 20.

[0027] The grinding mechanism includes a mounting frame 4 fixedly connected to the upper end of the machine table 3, and a first electric telescopic rod 9 is installed on the upper end of the mounting frame 4. The telescopic end of the first electric telescopic rod 9 passes through the mounting frame 4 downward and is fixedly connected to the moving frame 5. Two guide rods 8 are fixed to the upper end of the moving frame 5. The two guide rods 8 are symmetrically arranged on both sides of the first electric telescopic rod 9. The guide rods 8 pass through the mounting frame 4 and are slidably connected to the mounting frame 4. A belt grinder 7 is installed on the inner side of the moving frame 5, and a dust hood 6 is installed on the left side wall of the moving frame 5. The dust hood 6 is externally connected to an existing vacuum cleaner, which can promptly suck out the dust generated during the grinding process.

[0028] The clamping mechanism includes a fixed block 26 fixed to the upper end of the machine table 3, and a rotating shaft 25 is provided through the fixed block 26. The rotating shaft 25 can both slide and rotate on the fixed block 26. A clamping block 29 is fixed to the end of the rotating shaft 25 close to the first accommodating groove 10, and the end of the rotating shaft 25 away from the first accommodating groove 10 is connected to the first gear 24 through a one-way bearing. Racks 23 are fixed to the opposite side walls of the movable frame 5. Since the one-way bearing has a one-way transmission function, when the rack 23 moves downward, the rack 23 drives the first gear 24 to rotate, but at this time the one-way bearing is in an idling state, and thus will not drive the rotating shaft 2 5 rotates. When the rack 23 moves upward, the one-way transmission effect of the one-way bearing can drive the rotating shaft 25 to rotate. A strip groove that cooperates with the rack 23 is penetrated on the side wall of the mounting frame 4. The rack 23 meshes with the first gear 24. The lower end of the rack 23 penetrates the upper end of the machine table 3 and is slidably connected to the machine table 3. Two third electric telescopic rods 27 are fixedly installed on the side wall of the fixed block 26. The telescopic ends of the two third electric telescopic rods 27 both penetrate the fixed block 26 and are fixed with the same moving block 28. The moving block 28 is rotatably sleeved on the rotating shaft 25. The moving block 28 is rotatably connected to the rotating shaft 25 through a bearing.

[0029] The wiping and cleaning mechanism includes two L-shaped plates 30, which are respectively fixedly connected to the inner walls on both sides of the opposite sides of the second accommodating groove 13. Two wiping rollers 31 are arranged upper and lower between the two L-shaped plates 30. The two cylindrical shaft ends of the two wiping rollers 31 respectively pass through the two L-shaped plates 30 and are rotatably connected to the L-shaped plates 30. A fixed plate 32 is fixed on the side wall of one of the L-shaped plates 30, and a second motor 33 is installed on the side wall of the fixed plate 32. The output shaft of the second motor 33 passes through the fixed plate 32 and is fixed to the cylindrical shaft end of the upper wiping roller 31. The cylindrical shaft ends of the two wiping rollers 31 are fixedly sleeved with second gears 35, and the two second gears 35 are meshed. The cylindrical shaft end of the upper wiping roller 31 is fixedly sleeved with a first synchronous wheel 36.

[0030] The oiling mechanism includes a storage box 42 fixed on the inner wall of the second accommodating tank 13, and the storage box 42 stores graphite oil solution. A connecting pipe 44 is fixed to the side wall of the storage box 42, and two nozzles 45 arranged upper and lower are connected to the side wall of the connecting pipe 44. The nozzle 45 is provided with a nozzle 34. A pump 43 is installed on the side wall of the storage box 42, and the input end of the pump 43 is connected to the storage box 42, and the output end of the pump 43 is connected to the nozzle 45. The upper end of the storage box 42 is penetrated by a stirrer 46 that is rotatably connected to the storage box 42, and the upper end of the stirrer 46 is fixed with a worm gear 41. The upper end of the storage box 42 is fixed with a fixing frame 39, and the inner side of the fixing frame 39 is provided with a screw thread that is connected to the worm gear 41. The worm 40 is meshed with the worm 40. Both ends of the worm 40 pass through the fixed frame 39 and are rotatably connected to the fixed frame 39. A second synchronous wheel 38 is fixed to one end of the worm 40. The second synchronous wheel 38 is connected to the first synchronous wheel 36 via a synchronous belt 37. The transmission effect of the first synchronous wheel 36, the synchronous belt 37, and the second synchronous wheel 38 can drive the worm 40 to rotate while the upper wiping roller 31 rotates. Since the worm 40 is meshed with the worm wheel 41, the agitator 46 can be driven to rotate. The agitator 46 stirs the graphite oil solution. Since the graphite oil solution is a suspension, stirring the graphite oil solution can ensure the uniformity of the graphite oil solution.

[0031] The rolling mechanism includes two vertical plates 15 fixed to the upper end of the base plate 1, and an upper roller 18 and a lower roller 16 are rotatably installed between the two vertical plates 15. An annular groove is provided in the middle of the side wall of the upper roller 18. A first motor 17 is installed on the side wall of one of the vertical plates 15. The output shaft of the first motor 17 passes through the vertical plate 15 and is fixed to the end of the upper roller 18.

[0032] When the rolling device for suppressing edge cracks of magnesium alloy sheets during rolling of the present invention is used, the magnesium alloy slab to be processed is placed on the support frame 20, and the left end of the magnesium alloy slab to be processed is abutted against the positioning block 21 to locate the position of the magnesium alloy slab to be processed. Then, the third electric telescopic rod 27 is started to extend, driving the moving block 28 to move, and the magnesium alloy slab to be processed is clamped and fixed by the clamping block 29. Then, the belt grinder 7 is started, and then the first electric telescopic rod 9 is started to extend, driving the moving frame 5 to move downward. The belt grinder 7 is used to move downward to grind the surface of the magnesium alloy slab to be processed. At the same time, the dust generated by the grinding is sucked away by the dust hood 6. After the upper surface of the magnesium alloy slab to be processed is polished, the belt grinder 7 is stopped. Then the second electric telescopic rod 19 is started to retract, driving the support frame 20 to descend, and then the first electric telescopic rod 9 is started to retract, driving the mobile frame 5 to move up. Since the one-way bearing has a one-way transmission function, when the rack 23 moves down, the rack 23 drives the first gear 24 to rotate, but at this time the one-way bearing is in an idling state, and thus will not drive the rotating shaft 25 to rotate. When the rack 23 moves up, the one-way transmission function of the one-way bearing can drive the rotating shaft 25 to rotate, and the rack 23, the first gear 24, and the one-way bearing can drive the rotating shaft 25 to rotate, thereby driving the clamping block 29 to rotate, and the clamping block 29 drives the magnesium alloy blank to be processed to rotate, so that the magnesium alloy blank to be processed is turned over, so that the lower surface of the magnesium alloy blank to be processed faces upward, and then the second electric telescopic rod 19 is started to extend, driving the support frame 20 to move up, supporting and limiting the magnesium alloy blank to be processed, and similarly, according to the above process, the grinding process of the lower surface of the magnesium alloy blank to be processed is completed; Then, the first electrically driven roller 22 and the electrically driven pressure roller 11 are started to move the polished magnesium alloy slab to be processed to the top of the second receiving groove 13, and the second motor 33 is started. The two second gears 35 are meshed to make the two wiping rollers 31 rotate synchronously. When the polished magnesium alloy slab to be processed passes between the two wiping rollers 31, the two wiping rollers 31 can wipe and clean the surface of the polished magnesium alloy slab to be processed, and then the blower 12 is used to dry the wiped and cleaned magnesium alloy slab to be processed. When the cleaned magnesium alloy slab passes between the two nozzles 45, the pump 43 is started to suck out the graphite oil solution in the storage box 42 and spray it onto the surface of the magnesium alloy slab through the nozzle 34. Then, the oiled magnesium alloy slab to be processed is introduced into the heating furnace 14 through the second electrically driven roller 48 for preheating; Then the first motor 17 is started to drive the upper roller 18 to rotate, and the preheated magnesium alloy slab to be processed is introduced into the space between the upper roller 18 and the lower roller 16 through the second electric drive roller 48 for rolling.

[0033] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A rolling process for suppressing edge cracks in magnesium alloy sheets, characterized in that: The steps include: Step 1: pre-treating the magnesium alloy slab to be treated, wherein the pre-treating comprises sequentially performing a grinding treatment, a wiping cleaning treatment, and an oiling treatment on the magnesium alloy slab to be treated to obtain a pre-treated magnesium alloy slab; Step 2: heating the pretreated magnesium alloy slab to 350-400° C. and keeping the temperature for 1-2 hours to obtain a preheated magnesium alloy slab; Step 3: Roll the preheated magnesium alloy slab using multi-pass rolling, controlling the reduction of each pass to 10%-20%, and the total reduction not exceeding 60%. The rolling rate is divided into three stages: In the initial rolling stage, when the deformation is 0-30%, the rolling rate is 0.5-1.0 m / s; In the middle rolling stage, when the deformation is 30-50%, the rolling rate is 1.0-1.5 m / s; When the deformation in the final rolling stage is 50-60%, the rolling rate is 0.8-1.2 m / s. Dynamically adjust the rolling force to control the rolling force peak value to 500-1000 kN, and the rolling force fluctuation between adjacent passes does not exceed 10%. The rolling force calculation formula is: P = K · σ · √(R · Δh) P is the rolling force, K is the process correction coefficient, ranging from 0.8 to 1.2, σ is the high-temperature flow stress of magnesium alloy, ranging from 50 to 150 MPa, R is the radius of the work roll, and Δh is the reduction per single pass; Step 4: Immediately after final rolling, the plate is subjected to slow cooling treatment on the edge at a slow cooling rate of 5-10°C / min until the overall temperature of the plate drops below 250°C.

2. A rolling device for suppressing edge cracks in magnesium alloy sheets, characterized in that: The device is applied to the rolling process for suppressing edge cracks of magnesium alloy plates as claimed in claim 1, the device comprises a bottom plate (1), a machine table (3) is provided at the upper end of the bottom plate (1), a movable groove (47) is provided at the upper end of the machine table (3), a second electric drive roller (48) is arranged and installed inside the movable groove (47), a first receiving groove (10) and a second receiving groove (13) are provided through the inner wall of the movable groove (47), a loading positioning mechanism is provided inside the first receiving groove (10), a grinding mechanism is provided at the upper end of the machine table (3) and a grinding mechanism is provided above the first receiving groove (10), and a second electric drive roller (48) is provided at the upper end of the machine table (3) and a second electric drive roller (48) is provided. Two clamping mechanisms, the two clamping mechanisms are respectively arranged on both sides of the first receiving groove (10), the interior of the second receiving groove (13) is provided with a wiping cleaning mechanism and an oiling mechanism, the inner wall of the second receiving groove (13) is provided with a hair dryer (12) located between the wiping cleaning mechanism and the oiling mechanism, the upper end of the machine (3) is provided with two electric drive pressure rollers (11), the two electric drive pressure rollers (11) are symmetrically arranged on the left and right sides of the second receiving groove (13), the upper end of the machine (3) is provided with a heating furnace (14) located on the right side of the second receiving groove (13), and the upper end of the bottom plate (1) is provided with a plurality of rolling mechanisms located on the right side of the heating furnace (14).

3. A rolling device for suppressing edge cracks in magnesium alloy sheets according to claim 2, characterized in that: The loading positioning mechanism is located on a support frame (20) inside the first accommodating groove (10), two positioning blocks (21) are fixed on the left side of the upper end of the support frame (20), first electric drive rollers (22) are arranged and installed on the inner side of the support frame (20), and two second electric telescopic rods (19) are installed on the upper end of the base plate (1), and the telescopic ends of the two second electric telescopic rods (19) are both facing upward and fixed to the bottom of the support frame (20).

4. A rolling device for suppressing edge cracks in magnesium alloy sheets according to claim 2, characterized in that: The grinding mechanism comprises a mounting frame (4) fixedly connected to the upper end of the machine platform (3); a first electric telescopic rod (9) is mounted on the upper end of the mounting frame (4); the telescopic end of the first electric telescopic rod (9) passes through the mounting frame (4) downward and is fixedly connected to the movable frame (5); two guide rods (8) are fixed to the upper end of the movable frame (5); the two guide rods (8) are symmetrically arranged on both sides of the first electric telescopic rod (9); the guide rods (8) pass through the mounting frame (4) and are slidably connected to the mounting frame (4); a belt grinder (7) is mounted on the inner side of the movable frame (5); and a dust cover (6) is mounted on the left side wall of the movable frame (5).

5. The rolling device for suppressing edge cracks of magnesium alloy sheets according to claim 4, characterized in that: The clamping mechanism comprises a fixed block (26) fixed to the upper end of the machine table (3), a rotating shaft (25) passing through the fixed block (26), a clamping block (29) fixed to the end of the rotating shaft (25) close to the first accommodating groove (10), and a first gear (24) sleeved on the end of the rotating shaft (25) away from the first accommodating groove (10) via a one-way bearing, racks (23) are fixed on the opposite side walls of the movable frame (5), and a gear (23) passing through the side wall of the mounting frame (4) is provided. The rack (23) is matched with a strip groove, the rack (23) is meshed with the first gear (24), the lower end of the rack (23) passes through the upper end of the machine (3) and is slidably connected to the machine (3), two third electric telescopic rods (27) are fixedly installed on the side wall of the fixed block (26), the telescopic ends of the two third electric telescopic rods (27) both pass through the fixed block (26) and are fixed with the same moving block (28), and the moving block (28) is rotatably sleeved on the rotating shaft (25).

6. A rolling device for suppressing edge cracks in magnesium alloy sheet according to claim 2, characterized in that: The wiping and cleaning mechanism comprises two L-shaped plates (30), the two L-shaped plates (30) being fixedly connected to the inner walls on opposite sides of the second accommodating groove (13), two wiping rollers (31) being arranged upper and lower between the two L-shaped plates (30), the two cylindrical shaft ends of the two wiping rollers (31) respectively passing through the two L-shaped plates (30) and being rotatably connected to the L-shaped plates (30), a fixed plate (32) being fixed on the side wall of one of the L-shaped plates (30), a second motor (33) being installed on the side wall of the fixed plate (32), an output shaft of the second motor (33) passing through the fixed plate (32) and being fixed to the cylindrical shaft end of the upper wiping roller (31), the cylindrical shaft ends of the two wiping rollers (31) being fixedly sleeved with a second gear (35), the two second gears (35) being meshed, and the cylindrical shaft end of the upper wiping roller (31) being fixedly sleeved with a first synchronous wheel (36).

7. A rolling device for suppressing edge cracks in magnesium alloy sheet according to claim 6, characterized in that: The oiling mechanism includes a storage box (42) fixed on the inner wall of the second accommodating groove (13), a connecting pipe (44) is fixed on the side wall of the storage box (42), two nozzles (45) arranged upper and lower are connected to the side wall of the connecting pipe (44), and the nozzles (45) are provided with nozzles (34), a pump (43) is installed on the side wall of the storage box (42), the input end of the pump (43) is connected to the storage box (42), the output end of the pump (43) is connected to the nozzle (45), and the upper end of the storage box (42) is penetrated by a A stirrer (46) is rotatably connected to a storage box (42), wherein a worm gear (41) is fixed to the upper end of the stirrer (46), and a fixing frame (39) is fixed to the upper end of the storage box (42). A worm (40) is provided on the inner side of the fixing frame (39) and is engaged with the worm gear (41). Both ends of the worm (40) pass through the fixing frame (39) and are rotatably connected to the fixing frame (39). A second synchronous wheel (38) is fixed to one end of the worm (40), and the second synchronous wheel (38) is connected to the first synchronous wheel (36) via a synchronous belt (37).

8. The rolling device for suppressing edge cracks of magnesium alloy sheets according to claim 2, characterized in that: The rolling mechanism comprises two vertical plates (15) fixed at the upper end of the bottom plate (1), and an upper roller (18) and a lower roller (16) arranged vertically are rotatably mounted between the two vertical plates (15). A first motor (17) is mounted on the side wall of one of the vertical plates (15), and an output shaft of the first motor (17) passes through the vertical plate (15) and is fixed to the end of the upper roller (18).

9. The rolling device for suppressing edge cracks in magnesium alloy sheet according to claim 2, characterized in that: Fixed rods (2) are fixed at the four corners of the lower end of the machine platform (3), and the lower ends of the fixed rods (2) are fixed to the upper end of the bottom plate (1).

10. The rolling device for suppressing edge cracks in magnesium alloy sheet according to claim 8, characterized in that: An annular groove is provided in the middle of the side wall of the upper roller (18).

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