Device and method for reducing soft belt on whole induction heating edge of roller
By setting up insulation mechanisms at both ends of the roll induction heater and applying refractory mud on the end surface of the roll, the problem of soft tape on the edge during the overall induction heating of the roll is solved, and the uniformity of the hardness of the roll edge and the middle part is achieved, and the detection quality and use safety are improved.
Patent Information
- Application Number
- CN202411514692.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-03-04
AI Technical Summary
When the roll is subjected to overall induction heating, it is easy to have soft tape problems on the edge, resulting in the hardness being lower than the technical requirements, affecting the inspection pass rate and service life.
By setting up a cylindrical induction heater and insulation mechanism, including the front baffle, the back baffle and the insulation felt, seal the two ends of the induction heater to reduce heat loss, and apply refractory mud as an insulation layer on the end surface of the roll.
The temperature difference between the edge part and the middle part of the roll roller is effectively reduced, and controlled within 10°C, which improves the hardness difference between the edge part and the middle part of the roll after quenching, which reduces it to within 4HS, which improves product detection quality and use safety.
Smart Images
Figure CN119553061A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of roller manufacturing, in particular to the technical field of roller manufacturing heat treatment, and specifically to a device and method for reducing the overall induction heating edge soft band of a roller. Background Art
[0002] Overall induction heating is a relatively advanced process method used in the production process of roller heat treatment. It is more efficient than flame or resistance heating, and has advantages such as easier control of the hardened layer compared to mobile induction heating. It is currently the most economical, efficient and green roller heat treatment process. When the roller is quenched by overall induction heating, it relies on the induced current in the working layer for heating, and the outer surface and edge of the roller body dissipate heat to the environment. Therefore, the heating temperature of the roller side is relatively lower than that of the middle part, that is, the closer to the end face, the lower the quenching temperature, and it is easy to have soft bands, that is, areas with hardness lower than the technical requirements. In extreme cases, it may be as low as 6-10HS, which affects the inspection pass rate of the roller. At the same time, when the roller encounters abnormal working conditions such as steel plate deviation during use, the edge soft band may be more easily damaged, affecting the service life. Summary of the invention
[0003] In order to solve the problem of the soft band on the edge that is prone to occur when the roller is subjected to overall induction heating in the prior art, the present invention provides a device and method for reducing the soft band on the edge of the roller during overall induction heating. When the roller is quenched, the temperature difference between the edge and the middle of the roller is reduced, the soft band on the edge of the roller is improved, and the hardness level of the edge of the roller reaches the same level as that of the middle of the roller body, and the difference is controlled within 3HS, thereby improving the product inspection quality and use safety.
[0004] The technical solution adopted by the device and method for reducing the overall induction heating edge soft band of the roller of the present invention is:
[0005] A device for reducing the soft band of the edge of the whole induction heating roll, comprising a cylindrical induction heater and a roll inserted into the induction heater, characterized in that: both ends of the induction heater are provided with a heat preservation mechanism that fits the roll, and each end surface of the roll body is provided with a heat preservation layer; wherein,
[0006] The heat preservation mechanism comprises a front baffle located in front of the roller and in contact with the roller neck, and a rear baffle located behind the roller and in contact with the roller neck. Heat preservation felt is arranged on the side where the upper baffle and the lower baffle are in contact with the roller.
[0007] A further improvement of the technical solution of the present invention is that grooves matching with the rollers are provided on opposite sides of the front baffle and the rear baffle, and the thermal insulation felt is arranged on the inner wall of the groove.
[0008] A further improvement of the above technical solution of the present invention is that: the H of the front baffle and the rear baffle are both larger than the diameter of the induction heater shell, the L of the front baffle and the rear baffle are both larger than the radius of the induction heater shell, and the radius of the grooves of the front baffle and the rear baffle are the same as the radius of the roll neck of the rolling mill.
[0009] A further improvement of the technical solution of the present invention is that: the sides of the front baffle and the rear baffle that are in contact with the induction heater are both provided with arc-shaped plug-in plates that can be inserted into the interior of the induction heater; wherein, after the plug-in plates are inserted into the induction heater, they are in contact with the inner wall of the induction heater.
[0010] A further improvement of the above technical solution of the present invention is that the plug plate and the thermal insulation felt are both made of a material that is resistant to high temperatures and has low thermal conductivity.
[0011] A further improvement of the technical solution of the present invention is that the thermal insulation layer includes a viscous non-flowing refractory cement applied to the end surface of the roller. When the roller is heated in the preliminary heat treatment, the refractory cement will dry, sinter and adhere to the end surface of the roller body.
[0012] A further improvement of the technical solution of the present invention is that arc tracks corresponding to the insulation mechanism are arranged on the front and rear sides of the ground at both ends of the induction heater, and each arc track is slidably provided with a slider connected to the corresponding front baffle or rear baffle through a connecting rod.
[0013] A method for reducing the overall induction heating of the edge soft belt of a roller, using the above-mentioned device for reducing the overall induction heating of the edge soft belt of a roller, comprises the following steps:
[0014] S1. Rough turning the end surface of the roller body, and apply refractory cement on the end surface after rough turning;
[0015] S2, inserting the roller with the refractory cement adhered to it into the induction heater;
[0016] S3, making the heat preservation mechanism fit with the roll neck of the roll and the end of the induction heater;
[0017] S4, quenching the roller in the induction heater;
[0018] S5. After quenching, remove the heat preservation mechanism, move the roll out of the induction heater, and allow the roll to enter the next cooling process.
[0019] A further improvement of the above technical solution of the present invention is that: in the step S1, the end surface of the roller body is rough-turned, specifically, the roughness of the end surface of the roller body is processed to Ra12.5-25.
[0020] A further improvement of the above technical solution of the present invention is that: in the step S1, the end surface after rough turning is smeared with refractory cement, and the thickness of the refractory cement is 5 to 8 mm.
[0021] Due to the adoption of the above technical solution, the technical advances achieved by the present invention include:
[0022] The present invention provides a heat preservation mechanism, which can seal both ends of the induction heater when the roller is quenched and heated in the induction heater, preventing the heat of the roller from being lost from the gap between the induction heater and the roller during quenching, thereby achieving the purpose of achieving a better quenching effect on the roller.
[0023] At the same time, the present invention provides a thermal insulation layer on the end surface of the roller body, which can minimize the heat loss of the roller from the end surface of the roller body. Compared with the case without the thermal insulation layer, the present invention can reduce the temperature difference between the inner temperature and the middle temperature of the roller body. Specifically, the temperature difference between the inner temperature and the middle temperature of the roller body can be controlled within 10°C, so that the hardness difference between the edge and the middle of the roller after quenching can be reduced to within 4HS. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic structural diagram of a device for induction heating the edge soft belt of a reduction roller as a whole according to the present invention;
[0025] Figure 2 The present invention Figure 1 Schematic diagram of the explosion structure;
[0026] Figure 3 It is a schematic diagram of the structure of the front baffle or the rear baffle of the present invention;
[0027] Figure 4 It is a schematic diagram of the main structure of the front baffle and the rear baffle of the present invention.
[0028] In the accompanying drawings: 1. Induction heater;
[0029] 2. Roller; 21. Roller body; 22. Roller neck;
[0030] 31. front baffle; 32. rear baffle; 33. groove; 34. thermal insulation felt; 35. plug board;
[0031] 4. Insulation layer; 5. Track; 51. Slider; 52. Connecting rod. DETAILED DESCRIPTION
[0032] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. In the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.
[0033] First reference Figure 1 and Figure 2 ,according to Figure 1 and Figure 2 It can be seen that the device for reducing the overall induction heating edge soft belt of the roll in the present invention includes an induction heater 1, and the induction heater 1 is a cylindrical induction heater 1 commonly used in the prior art. At the same time, the roll 2 can be inserted into the induction heater 1, so as to facilitate heating and quenching the roll 2. The roll 2 can be referred to in the specific setting. Figure 2 ,according to Figure 2 It can be seen that the roller 2 includes a roller body 21 and roller necks 22 located at both ends of the roller body 21 . When the roller 2 is inserted into the induction heater 1 , the roller body 21 is completely located in the induction heater 1 , and the roller neck 22 is exposed outside the induction heater 1 .
[0034] Continue to refer Figure 1 and Figure 2 It can be seen that the above device also includes a heat preservation mechanism located at both ends of the induction heater 1, and the heat preservation mechanism includes a front baffle 31 and a rear baffle 32. The front baffle 31 and the rear baffle 32 can be referred to in the specific setting. Figure 3 ,according to Figure 3 It can be seen that grooves 33 are provided on the opposite sides of the front baffle 31 and the rear baffle 32, and the inner wall of the groove 33 is provided with a thermal insulation felt 34. At the same time, the sides of the front baffle 31 and the rear baffle 32 that are in contact with the end of the induction heater 1 are fixedly connected with an arc-shaped plug-in plate 35 that can be inserted into the induction heater 1. The above-mentioned plug-in plate 35 and the thermal insulation felt 34 are both made of materials (such as ceramic fibers) that are resistant to high temperatures and have low thermal conductivity in the prior art.
[0035] refer to Figure 4 It can be seen that the H of all the front baffles 31 and the rear baffles 32 in the above device is larger than the diameter of the shell of the induction heater 1, the L of the front baffles 31 and the rear baffles 32 is larger than the radius of the shell of the induction heater 1, and the radius of the groove 33 of the front baffles 31 and the rear baffles 32 is the same as the radius of the roll neck 22 of the roller 2.
[0036] Continue to refer Figure 1 and Figure 2 The above-mentioned device is provided with an L-shaped track 5 under each front baffle 31 or rear baffle 32, and the corners of each track 5 are arranged in an arc shape. At the same time, each track 5 is slidably connected with a slider 51, and each slider 51 is connected to the corresponding front baffle 31 or rear baffle 32 through a vertical connecting rod 52.
[0037] Continue to refer Figure 2It can be known that both ends of the roller body 21 of the roller 2 in the above-mentioned device are provided with an insulation layer 4. Specifically, the insulation layer 4 is a refractory clay smeared on the end surface of the roller body 21 of the roller 2. The refractory clay is in a viscous and non-flowing state. When the roller 2 is heated in the preliminary heat treatment, the refractory clay will dry and sinter and adhere to the end surface of the roller body 21.
[0038] like Figure 1 As shown, in the above device, when the roller 2 is inserted into the induction heater 1, the movable slider 51 drives the corresponding front baffle 31 or rear baffle 32 to move until the plug plate 35 on the front baffle 31 and the rear baffle 32 is inserted into the induction heater 1. At this time, the plug plate 35 is in contact with the inner wall of the induction heater 1, and the front baffle 31 and the rear baffle 32 are in contact with the end of the induction heater 1. At this time, the thermal insulation felt 34 in the groove 33 of the front baffle 31 and the rear baffle 32 is tightly fitted with the roller neck 22 of the roller 2.
[0039] In order to ensure the sealing and heat-insulating effect of the heat-insulating felt 34 in the above device, the thickness of the heat-insulating felt 34 is 15 to 20 mm.
[0040] The above device comprises the following steps when used:
[0041] S1. Rough turning the end surface of the roller body 21 of the roller 2 until the roughness of the end surface of the roller body 21 is processed to Ra12.5-25, and then apply refractory clay on the end surface after rough turning, and the thickness of the refractory clay is 5-8 mm.
[0042] S2. Insert the roller 2 with refractory mortar adhered to it into the induction heater 1.
[0043] S3. Make the heat preservation mechanism fit with the roll neck 22 of the roll 2 and the end of the induction heater 1.
[0044] S4, quenching the roller 2 in the induction heater 1.
[0045] S5. After quenching is completed, the heat preservation mechanism is removed, the roll 2 is moved out of the induction heater 1, and the roll 2 enters the next cooling process.
[0046] Embodiment 1
[0047] The diameter of the rough turning roller body 21 is 600mm, the diameter of the rough turning roller neck 22 is 400mm, and the diameter of the induction heater 1 is 800mm. The insulation baffles at both ends use 5mm thick steel plate + 20mm thick ceramic fiber felt, H = 820mm, L = 410mm, R = 210mm.
[0048] In the rough turning state before quenching of the rolling roller 2, the roughness of the end surface of the roller body 21 is Ra15~18. When loading the furnace for preparatory heat treatment, 5~7mm of refractory clay is applied to the end surface. After the preparatory heat treatment is heated, the refractory clay is dried and sintered and attached to the end surface of the roller body 21, and is retained until the overall induction quenching heating is completed.
[0049] Before the roll 2 is loaded into the induction heater 1 for power supply and heating, a pair of heat preservation mechanisms are inserted at both ends of the induction heater 1, and the heat preservation felt 34 in the groove 33 of the heat preservation mechanism fits with the outer wall of the roll neck 22, and the maximum gap between the heat preservation felt 34 and the outer wall of the roll neck 22 is ≤10mm. After the quenching and heating is completed, the heat preservation baffles at both ends are removed and the roll 2 is moved out of the induction heater 1 to enter the cooling process.
[0050] During the induction heating process, the quenching and holding section process was set at 980°C, and the temperature of the outer circle at 20mm on the edge of the roller body 21 was measured at 970-974°C with an average of 972°C, and the temperature of the outer circle in the middle of the roller body 21 was measured at 978-982°C with an average of 980°C. After heat treatment, the hardness of the middle part of the roller body 21 was 80-81HS, and the hardness of the edges 20mm, 50mm, and 100mm was 78HS, 79HS, and 80HS respectively.
[0051] Comparative Example 1
[0052] The diameter of the rough-turned roll body 21 is 600 mm, the diameter of the rough-turned roll neck 22 is 400 mm, and the diameter of the induction heater 1 is 800 mm. The end faces of the rough-turned roll 2 are in a rough-turned state without protection during the rough-turning, preparatory heat treatment, and overall induction quenching process before quenching. There is no insulation mechanism at both ends of the induction heater 1 during the induction heating process.
[0053] During the induction heating process, the quenching and holding section was set at 980°C. The outer circle of the roller body 21 at 20mm on the edge was measured at 908-942°C with an average of 933°C. The outer circle of the middle part of the roller body 21 was measured at 978-982°C with an average of 980°C. After heat treatment, the hardness of the middle part of the roller body 21 was 80-81HS, and the hardness of the edges of 20mm, 50mm, and 100mm was 72HS, 74HS, and 77HS respectively.
[0054] With reference to the above-mentioned Example 1 and Comparative Example 1, it can be known that the present invention can reduce the temperature difference between the edge temperature and the middle temperature of the roller, and specifically can control the temperature difference between the edge temperature and the middle temperature of the roller to be within 10°C, so that the hardness difference between the edge and the middle of the roller after quenching can be reduced to within 4HS.
[0055] In the above embodiment, the present invention provides a device and method for reducing the soft band of the edge of the whole induction heating of the roller. By setting up a heat preservation mechanism, when the roller is quenched and heated in the induction heater, the two ends of the induction heater can be sealed to prevent the heat of the roller from being lost from the gap between the induction heater and the roller during quenching, thereby achieving the purpose of achieving a better quenching effect on the roller; at the same time, in the present invention, by setting a heat preservation layer on the end face of the roller body, the heat loss of the roller from the end face of the roller body can be reduced to the greatest extent, so that compared with no heat preservation layer, the present invention can reduce the temperature difference between the edge temperature and the middle temperature of the roller, and specifically can control the temperature difference between the edge temperature and the middle temperature of the roller within 10°C, so that the hardness difference between the edge and the middle of the roller after quenching can be reduced to within 4HS.
[0056] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents for which protection is sought in the present invention have been fully recorded in the claims.
Claims
1. A device for reducing the soft band of the edge of a roller by induction heating, comprising a cylindrical induction heater (1) and a roller (2) inserted into the induction heater (1), characterized in that: Both ends of the induction heater (1) are provided with heat-insulating mechanisms that fit the roller (2), and each end surface of the roller body (21) of the roller (2) is provided with a heat-insulating layer (4); wherein: The heat-insulating mechanism comprises a front baffle (31) located in front of the roller (2) and in contact with the roller neck (22) of the roller (2), and a rear baffle (32) located behind the roller (2) and in contact with the roller neck (22) of the roller (2), and heat-insulating felt (34) is provided on the side where the upper baffle and the lower baffle are in contact with the roller (2).
2. The device for reducing the overall induction heating of the edge soft strip of a rolling roller according to claim 1 is characterized in that: A groove (33) matching with the roller (2) is provided on the opposite side of the front baffle (31) and the rear baffle (32), and a heat-insulating felt (34) is arranged on the inner wall of the groove (33).
3. According to claim 2, a device for reducing the overall induction heating of the edge soft strip of the roller, characterized in that: The H of the front baffle (31) and the rear baffle (32) are both larger than the diameter of the induction heater (1) shell, the L of the front baffle (31) and the rear baffle (32) are both larger than the radius of the induction heater (1) shell, and the radius of the groove (33) of the front baffle (31) and the rear baffle (32) is the same as the radius of the roller neck (22) of the roller (2).
4. The device for reducing the overall induction heating of the edge soft strip of a rolling roller according to claim 1, characterized in that: The front baffle plate (31) and the rear baffle plate (32) are both provided with an arc-shaped insert plate (35) that can be inserted into the induction heater (1) on one side thereof that is in contact with the induction heater (1); wherein the insert plate (35) is inserted into the induction heater (1) and is in contact with the inner wall of the induction heater (1).
5. The device for reducing the overall induction heating of the edge soft strip of the roller according to claim 4 is characterized in that: The plug plate (35) and the thermal insulation felt (34) are both made of materials that are resistant to high temperatures and have low thermal conductivity.
6. A device for reducing the overall induction heating of the edge soft strip of a rolling roller according to any one of claims 1 to 5, characterized in that: The thermal insulation layer (4) comprises a refractory mortar in a viscous, non-flowing state applied to the end surface of the roller (2). When the roller (2) is heated during the preliminary heat treatment, the refractory mortar will dry, sinter and adhere to the end surface of the roller body (21).
7. A device for reducing the overall induction heating of the edge soft strip of a roller according to any one of claims 1 to 5, characterized in that: Arc tracks (5) corresponding to the heat preservation mechanism are arranged on the ground at both the front and rear sides of the two ends of the induction heater (1), and each arc track (5) is slidably provided with a slider (51) connected to the corresponding front baffle (31) or rear baffle (32) through a connecting rod (52).
8. A method for reducing the soft band of the edge of the whole induction heating roller, characterized in that: The device for induction heating the edge soft strip of a reduction roller as a whole according to any one of claims 1 to 7 comprises the following steps: S1, rough turning the end surface of the roller body (21) of the roller (2), and applying refractory cement to the end surface after rough turning; S2, inserting the roller (2) adhered with refractory cement into the induction heater (1); S3, making the heat preservation mechanism fit with the roll neck (22) of the roll (2) and the end of the induction heater (1); S4, quenching the roller (2) in the induction heater (1); S5. After quenching is completed, the heat preservation mechanism is removed, the rolling roller (2) is moved out of the induction heater (1), and the rolling roller (2) enters the next cooling process.
9. A method for reducing the overall induction heating edge soft strip of a roller according to claim 8, characterized in that: In the step S1, the end surface of the roller body (21) of the rolling roller (2) is rough-turned, specifically, the roughness of the end surface of the roller body (21) of the rolling roller (2) is processed to Ra12.5-25.
10. The method for reducing the overall induction heating edge soft strip of a roller according to claim 8, characterized in that: In the step S1, the end surface after rough turning is smeared with refractory mortar, and the thickness of the refractory mortar is 5-8 mm.