WO2023000522A1 - Cooling roller and fitting method therefor - Google Patents

Abstract

A cooling roller, comprising a roller sleeve (1) and a roller core (2). The roller sleeve (1) is provided on the periphery of the roller core (2); the roller sleeve (1) and the roller core (2) are interference-fitted; and an interference ratio between the inner diameter of the roller sleeve and the outer diameter of the roller core is 2-3.5‰. Also provided is a fitting method for a cooling roller, comprising: designing an interference ratio between a roller sleeve and a roller core; performing aging on the roller sleeve, wherein the aging is performed simultaneously with preheating; and interference-fitting the aged hot-sleeved roller sleeve and the roller core and cooling same to room temperature to obtain a cooling roller. The design of an interference ensures the implementation of pre-stress of the roller sleeve; and the aging of the roller sleeve and the preheating process before roller sleeve fitting are combined into one process, thereby avoiding the problem that overaging is prone to occur during preheating in the case that aging is completed before machining and preheating before fitting.

Description

A kind of cooling roller and its assembly method technical field

The invention belongs to the technical field of cooling roll preparation, in particular to a cooling roll and an assembly method thereof.

Background technique

Amorphous nanocrystalline alloy is a kind of soft magnetic material that has been developed rapidly in recent years. Compared with traditional soft magnetic materials such as electrical steel and ferrite, it has higher magnetic permeability and lower AC loss, and has been widely used Iron cores in magnetic components such as transformers, inductors, transformers, and motor stators.

Amorphous and nanocrystalline alloy strips are generally manufactured by planar flow technology. The technical principle is to rapidly solidify a certain composition of alloy liquid on the outer peripheral surface of a cooling roll rotating at high speed to form a continuous thin strip with an amorphous structure. The method is: melt a certain ratio of raw materials into alloy liquid in a smelting furnace; then, pour the alloy liquid into a nozzle bag with a slit nozzle at the bottom; the alloy liquid in the nozzle bag flows out from the nozzle and spreads on the nozzle The outer peripheral surface of the high-speed rotating copper alloy cooling roller below forms a molten pool of a certain size between the surface of the cooling roller and the bottom surface of the nozzle. The alloy liquid is quickly drawn out and cooled rapidly, and the alloy liquid in the nozzle gap is continuously replenished In the molten pool, a continuous thin ribbon with an amorphous structure is formed. The thin strip clings to the outer surface of the cooling roll and rotates at high speed with the cooling roll, and is peeled off by high-pressure gas or mechanical device at an appropriate position on the outer peripheral surface of the cooling roll, and finally the thin strip is wound into a roll by the coiling device.

The cooling roll is the core component to realize the rapid solidification of the alloy liquid. As shown in Figure 1, it is generally made of an annular roll sleeve and a cylindrical roll core. A thin annular passage is formed between the outer peripheral surfaces of the roller core, and high-speed flowing cooling water is introduced into the passage, and the heat conducted from the outer surface of the roller sleeve to the inner surface of the roller sleeve is taken away by forced convection. Among them, the roll sleeve is usually made of copper alloy with high thermal conductivity and high strength, such as CuBe, CuNiSi, CuCrZr, etc. The diameter of the roll sleeve is generally between 400mm and 2000mm, and the thickness of the roll sleeve is generally between 5 and 30mm. The manufacturing and assembly process of the roller sleeve generally includes: copper alloy smelting, casting, multiple forging or rolling and annealing, solution treatment, aging treatment, machining, interference assembly, installation and use. When the roll sleeve is heated and deformed, the outer surface of the roll sleeve forms a drum-shaped roll surface, as shown in Figure 4, the drum-shaped roll surface makes the distance between the roll surface and the bottom surface of the nozzle (roller mouth spacing) become uneven, and the width of the strip The distance between the middle area is obviously smaller than that on both sides, so that the flow rate of the alloy liquid in the middle area of the strip width is smaller than that on both sides, resulting in uneven transverse thickness of the produced strip, forming a "concave core" plate shape with a thin center and thick sides, seriously Reduce the lamination factor. During the belt making process, when a certain point on the roll surface enters the molten pool and contacts the alloy liquid in a high-temperature state, the local temperature will instantly rise above about 300°C due to thermal shock, and when the point leaves the molten After the pool, due to the rapid conduction of heat to the inside of the roller sleeve, its temperature drops sharply, so under the action of periodic thermal shock, the temperature of the roller surface also changes periodically, as shown in Figure 5 (the dotted line in the figure is the roll surface equilibrium temperature). When the roll surface is just in contact with the alloy liquid, the material of the roll surface is heated and expands rapidly. At this time, the internal stress is compressive stress. Then, the heat is transferred to the inside of the roll sleeve, and the roll sleeve 1 is cooled rapidly and shrinks. At this time, it is tensile stress. The roll sleeve The schematic diagram of the internal stress change at a certain point on the surface within one rotation cycle is shown in Figure 6. The cooling roll assembly method in the prior art is shown in Figure 7. First, the aging treatment is performed on the roll sleeve, and then the aging treated roll sleeve is machined; the machined roll sleeve is preheated, and the preheated roll sleeve is processed. The roller sleeve and the roller core are shrink-fitted for final installation and use. During this process, the preheating and aging treatment of the sleeve are carried out separately.

In the manufacturing process of amorphous alloy strip, with the high-speed rotation of the cooling roll, the outer circumferential surface of the roll sleeve is subjected to periodic thermal shocks from the alloy liquid, resulting in uneven thermal crown of the roll sleeve and thermal stress that generate heat on the roll surface. Fatigue is a big problem. However, most of the existing technologies do not fully consider these problems. For example, due to the uneven thermal crown of the roller surface, the gap between the roller nozzles is uneven, and the manufactured strip is likely to have a concave core shape. Offset; but this method cannot compensate the changing thermal crown of the roll surface. As another example, in order to reduce the thermal fatigue of the roller surface, the prior art always tries to improve the mechanical strength of the roller sleeve material, but the improvement range is very limited. Although there are also people who have considered the above problems and provided some solutions, they have brought other problems, and the scope of application is limited.

Chinese utility model patent CN2452652Y discloses an arc-shaped nozzle for amorphous tape spraying equipment. The bottom surface of the nozzle is processed into an arc shape, which basically offsets the thermal convexity of the roll surface, so that the distance between the roll nozzles in the width direction of the strip is basically the same, thereby improving Strip plate type. However, on the one hand, this method increases the amount of nozzle processing and is likely to cause defects in nozzle processing. On the other hand, the thermal crown of the roll surface is constantly changing with the tape-making time and process conditions. Therefore, the radian of the bottom surface of the nozzle processed in advance It cannot well compensate the changing thermal crown of the roller surface.

US Patent No. 4,537,239 discloses a method for manufacturing CuBe ₂ alloy roll sleeves for manufacturing amorphous alloy strips, using prestressing technology to avoid the thermal crown of the roll surface. The diameter of the sleeve is 15 inches (about 380 mm), and the initial thickness of the sleeve is about 1/4 inch (6.35 mm). The radius interference between the roller sleeve and the roller core is 0.076cm (interference ratio is about 3.94‰). Then, the roller sleeve is heated to 316° C. for a certain period of time, and then the roller core is placed inside the roller sleeve. After the roller sleeve is cooled, the shrinkage of the roller sleeve will cause it to be tightly hooped on the roller core to achieve interference fit, and a tensile prestress of 75,000 psi (about 517 MPa) will be generated inside the roller sleeve. Since the roll sleeve is pre-stretched by the internal stress, when the cooling roll is used, the heat of the roll sleeve only reduces its internal stress, and no longer generates thermal expansion, eliminating the problem of thermal crown. At the same time, because the inside of the roller sleeve is always in a state of tensile stress, there is no alternating internal stress, so the thermal fatigue of the roller surface is avoided and the deterioration of the roller surface is delayed. However, this method has many deficiencies: First, it can be known from simple calculation that in this technical solution, after the roller sleeve is heated to the target temperature, its relative expansion is about 5‰, while the design interference is as high as nearly 4‰ , which results in a margin of only about 0.4mm between the outer diameter of the roll core at room temperature and the inner diameter of the roll sleeve at high temperature. Due to factors such as differences in thermal expansion, it is very difficult to insert the roller core into the roller sleeve, and the requirements for the machining accuracy of the roller core and roller sleeve and the positioning accuracy of the shrink-fitting equipment are extremely strict. Second, the solution treatment and aging treatment of the roller sleeve have been completed before assembly, and the aging strengthening effect makes the mechanical properties (strength or hardness) of the roller sleeve already in the best state. Therefore, the preheating of the roller sleeve before the assembly of the roller sleeve must strictly control the temperature and the temperature equalization time, otherwise, the roll sleeve will continue to age during preheating, which will deteriorate the mechanical properties of the roll sleeve (called overaging). In order to ensure that the roll sleeve does not produce the side effect of overaging, this technical solution can only be applied to occasions where the roll sleeve is very thin and the required temperature equalization time is short. At present, a large number of thicker and larger roller sleeves have been used. The upper limit of the thickness of the roller sleeve has reached 25mm, and the diameter of the roller sleeve is close to 2000mm. This kind of large-size roller sleeve needs to be heated to temperature before assembly. The temperature equalization time is as long as 5 hours, if the technical solution of this patent is still adopted, the long-time heat preservation of the roller sleeve above 300°C will inevitably lead to overaging of the roller sleeve, resulting in the loss of the original excellent mechanical properties. Third, in the technical solution of this patent, the prestress applied to the roller sleeve through interference fit reaches 517MPa, which is close to 50% of the yield strength of the roller sleeve material. In order to manufacture thick amorphous alloy strips or amorphous nanocrystalline strips with higher requirements on cooling rate, it is necessary to use roller sleeve materials with higher thermal conductivity. However, the mechanical properties of metal materials tend to change inversely with the thermal conductivity, and roller sleeve materials with higher thermal conductivity have lower strength or hardness. For example, the tensile strength of the low Be copper alloy roll sleeve material with relatively high thermal conductivity is only about 600-800 MPa. If the technical solution of this patent is still used to assemble the roller sleeve with higher thermal conductivity, then the prestress inside the roller sleeve will be too close to the tensile strength of the material of the roll sleeve, and there will be macroscopic or microscopic defects such as inclusions and porosity inside the roll sleeve , there is a risk of the roller sleeve being pulled off (burst). In other words, the technical solution of this patent is only applicable to the roller sleeve made of CuBe2 material, but not to the roller sleeve made of material with higher thermal conductivity.

Chinese invention patent applications CN111804733A and CN112247478A respectively disclose a method for assembling copper alloy roll sleeves for thin metal strip casting and rolling. The design interference ratio between the roll sleeve and the roll core is 1.8‰ or less. Because the interference amount adopted by this technology is too small, it is impossible to generate a large enough prestress inside the roll sleeve, and it cannot be used for the assembly of the roll sleeve for manufacturing amorphous nanocrystalline alloy strip.

Chinese invention patent application CN102582015A discloses an assembly process of a roll sleeve for amorphous strips: the roll sleeve is preheated to 160° C. for 24 hours, and then hot-fitted with the roll core. Because the preheating temperature of the roll sleeve used in this technology is too low, the thermal expansion of the roll sleeve is too small, and the interference between the roll sleeve and the roll core must also be small, so it is impossible to generate sufficient prestress inside the roll sleeve. Moreover, this assembly method only realizes the interference assembly between the two ends of the width of the roll sleeve and the end covers (flanges) at both ends of the roll core, while the middle area of the entire roll sleeve is still in a suspended state, so the middle area of the roll sleeve after shrink fitting It will shrink due to lack of support, and the phenomenon of "slumping waist" will appear, and the predetermined prestress cannot be produced.

Contents of the invention

In view of the above problems, the present invention discloses a cooling roll, which includes a roll sleeve and a roll core, the roll sleeve is arranged on the outer periphery of the roll core, and the roll sleeve and the roll core are interference fit; the inner diameter of the roll sleeve and the outer diameter of the roll core The interference ratio between them is 2~3.5‰.

The roll sleeve material includes copper alloy, and after the roll sleeve is interference-fitted with the roll core, the internal prestress is 20-50% of the tensile strength of the roll sleeve material.

The cooling roll also includes support strips; the support strips are distributed on the inner surface of the roll sleeve or the outer peripheral surface of the roll core, the support strips are arranged along the axial direction of the roll core, and the height and width of the support strips and the adjacent support strips The spacing between them is not fixed.

Further, the height of the support bars is less than or equal to 10 mm, the circumferential width of the support bars is 5-30 mm, and the circumferential distance between adjacent support bars is 5-50 mm.

The invention also discloses an assembly method of the cooling roll,

The assembly method includes the following steps:

Aging treatment is carried out on the roller cover, aging treatment and preheating are carried out simultaneously;

The heat-sleeved roll sleeve and the roll core that have completed the aging treatment are interference-fitted and cooled to room temperature to obtain a cooling roll; wherein, the interference ratio between the inner diameter of the roll sleeve and the outer diameter of the roll core is 2-3.5‰.

The aging treatment process is also a preheating process before the roll sleeve and roll core are assembled.

Further, the temperature of the aging treatment is 300-550° C., and the holding time is 1-20 hours.

The assembly method also includes performing the following operations before aging treatment:

Design the interference ratio between the roller sleeve and the roller core;

The sleeves are machined to pre-designed interference ratios.

While the aging treatment is carried out on the roller sleeve, the cold treatment is carried out on the roller core.

Further, the cold treatment includes placing the roller core in a cold treatment furnace, passing in low-temperature gas, and reducing the temperature of the roller core to below -30°C.

Advantages of the present invention:

According to different copper alloy roll sleeve materials, the present invention sets the interference ratio between the inner diameter of the roll sleeve and the outer diameter of the roll core at 2 to 3.5‰, and sets the prestress inside the roll sleeve after assembly to 20% to 50% of the tensile strength of the material, to minimize the thermal convexity of the roller sleeve during the belt making process, reduce the cracks and pits on the roller surface caused by thermal fatigue, and also avoid the damage caused by excessive prestress Risk of the roll sleeve being pulled off (burst).

According to the requirements of the interference, the present invention designs a reasonable shape of the inner surface of the roller sleeve and the outer peripheral surface of the roller core to ensure the realization of the prestress of the roller sleeve; Different positions in the width direction of the roller sleeve can have different prestress.

The present invention combines the aging treatment of the roller sleeve with the preheating process before the assembly of the roller sleeve, completely avoiding the prior art to complete the aging treatment first, then perform machining and preheat before assembly, which is prone to overheating during preheating. aging problem; if necessary, the present invention can also cold-treat the roll core while preheating the roll sleeve, which increases the size margin between the cold roll core and the hot roll sleeve, and reduces the The precision requirements for the assembly mechanism make the assembly proceed more smoothly.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows a schematic cross-sectional view of the center of a cooling roll in the prior art;

Fig. 2 shows a schematic diagram of the interference assembly state of the annular roller sleeve and the roller core with support strips on the outer surface in the embodiment of the present invention;

Fig. 3 shows a schematic diagram of an interference assembly state of a roller sleeve with a support strip on the inner surface and a cylindrical roller core in an embodiment of the present invention;

Fig. 4 shows a schematic diagram of thermal deformation of a cooling roll sleeve in an embodiment of the prior art;

Fig. 5 shows the schematic diagram of the surface temperature change of the cooling roller sleeve after the start of strip making in the prior art;

Fig. 6 shows a schematic diagram of the internal stress variation of a certain point on the surface of the roller sleeve in one rotation cycle in the prior art;

Fig. 7 shows the flow chart of cooling roll assembly method in the prior art;

Fig. 8 shows a flow chart of the cooling roll assembly method in the embodiment of the present invention.

In the figure: 1. Roller cover; 2. Roller core.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a cooling roll, which includes a roll sleeve 1 and a roll core 2. In order to realize the smooth assembly of the roll sleeve 1 and the roll core 2, avoid the over-aging of the roll sleeve 1, and generate prestress inside the roll sleeve 1, it is necessary to adjust the roll The interference ratio and prestress of sleeve 1 and roller core 2 are designed.

The interference ratio between the roll sleeve 1 and the roll core 2 of the present invention ranges from 2.0 to 3.5‰. After the roll sleeve 1 is assembled with the roll core 2, the internal prestress (tensile stress along the circumferential direction of the roll sleeve) ) is 20-50% of the tensile strength of the roller cover material.

Among them, the calculation formula of the interference ratio (interference amount) is:

In the formula, d ₀ is the inner diameter of the roller sleeve 1 at room temperature; d ₁ is the outer diameter of the roller core 2 at room temperature.

Exemplarily, the cooling roll may be a combination of an annular roll sleeve 1 and a cylindrical roll core 2 . The roller sleeve 1 is arranged on the outer periphery of the roller core 2, and the roller sleeve 1 and the cylindrical roller core 2 are interference-fitted. A thin annular channel is formed between the inner surface of the roller sleeve 1 and the outer peripheral surface of the roller core 2. It can be a flat and smooth cylindrical surface. The outer circumferential surface of the roller core 2 is distributed with a plurality of axially extending support bars (machined by the roller core 2), as shown in Figure 2; the support bars can also be arranged on the inner surface of the roller sleeve 1 (machined by the roller sleeve 1 processing), as shown in Figure 3.

The support bars can be a plurality of strips extending in the axial direction, or a plurality of cylinders distributed on the entire surface; the width and spacing of the support bars are not fixed, and the height of the support bars is also not fixed. Exemplarily, the middle part of the width of the roll sleeve 1 is often the tape-making position. In order to focus on eliminating the thermal crown at this position during tape production, the inner surface of the roll sleeve 1 or the outer peripheral surface of the roll core 2 at this position can be The height of the support bars is higher than that of the two sides, so that the height difference between the belt-making position area and the support bars of the two sides areas is between 0.1 mm and 2.0 mm. In this way, the internal prestress of the roll sleeve will be greater in the zone of the strip making position than in the zone on its sides.

The supporting strips can be the same in the axial direction of the roller sleeve 1 or the roller core 2, so that the same interference is generated between different parts of the roller sleeve 1 in the axial direction and the roller core 2, and the same interference is generated in different axial parts of the roller sleeve 1. of prestress. Exemplarily, the height of the support bars is no more than 10 mm, the width in the circumferential direction is 5-30 mm, and the distance between adjacent support bars in the circumferential direction is 5-50 mm. The supporting bar shown in Figure 2 is used for illustration. When the roll sleeve 1 and the roll core 2 are interference-fitted, the support bar on the outer peripheral surface of the roll core 2 supports the inner surface of the roll sleeve 1, so that the inner surface of the roll sleeve 1 generates 200-500 MPa. The prestress (that is, the tensile stress along the circumferential direction of the roller sleeve 1). The gap between the support strips on the outer peripheral surface of the roller core 2 and the inner surface of the roller sleeve 1 form a cooling water channel, and high-speed flowing cooling water is introduced into the channel, and the cooling water is taken away from the outer surface of the roller sleeve 1 to the inner surface of the roller sleeve 1 by forced convection. The heat conducted by the surface.

In addition to the structure of the cooling roll, the material of the roll sleeve 1 and the internal structure of the roll core 2 also have an influence on the performance of the cooling roll and the effect of subsequent strip making. Roller sleeve 1 can be made of copper alloy, but not limited to copper alloy, with a thickness of 5-30mm, an inner diameter of 400-2000mm, and an axial width of 50-600mm. The thermal conductivity range after solution and aging treatment is 80-350W/ mK, tensile strength ≥ 600MPa. The internal structure of the roller core 2 must have sufficient rigidity to ensure that no obvious shrinkage deformation will occur when it is subjected to the shrinkage pressure of the roller sleeve 1 after assembly. The stress will be significantly less than the design value.

Preferably, the material of the roller sleeve 1 can be a copper alloy with a Be content of 1.7-2.1wt%, and other elements with a total content of no more than 10wt% can be added, including but not limited to Ni, Co, Fe, Si, Al, Ti, Cr, P, Sn, Zn, Pb, etc. After finishing the solid solution and aging treatment, the interference ratio between the roll sleeve 1 and the roll core 2 is 2.5-3.5‰, the internal prestress of the roll sleeve 1 is 300-500MPa, and the thermal conductivity of the roll sleeve 1 material ranges from 80-150W/ mK, tensile strength ≥ 1000MPa.

Preferably, the material of the roller sleeve 1 can be a copper alloy with a Be content of 0.2-0.7 wt%, a total content of Ni and/or Co of 0.5-2.5 wt%, and other elements with a total content of no more than 10 wt% can be added, including but not Limited to Ni, Co, Fe, Si, Al, Ti, Cr, P, Sn, Zn, Pb, etc. After the solid solution and aging treatment, the interference ratio between the roll sleeve 1 and the roll core 2 is 2.0-3.0‰, and the internal prestress of the roll sleeve 1 is 180-400MPa. The thermal conductivity of the roll sleeve 1 material ranges from 150-300W/mK , Tensile strength ≥ 600MPa.

Preferably, the material of the roller sleeve 1 can be a copper alloy with a Ni content of 2-10wt%, and other elements with a total content of no more than 10wt% can be added, including but not limited to Ni, Co, Fe, Si, Al, Ti, Cr , P, Sn, Zn, Pb, etc. After the solid solution and aging treatment, the interference ratio between the roll sleeve 1 and the roll core 2 is 2.0-3.0‰, the internal prestress of the roll sleeve 1 is 180-400MPa, and the thermal conductivity of the roll sleeve 1 material ranges from 100-300W/ mK, tensile strength ≥ 600MPa.

The present invention also provides an assembly method of the cooling roll. The interference assembly of the roll sleeve 1 and the roll core 2 of the present invention adopts a shrink-fitting process. By setting a reasonable amount of interference in advance and combining the aging treatment of the roller sleeve 1 with the shrink-fitting process, the prestress will be generated inside the roller sleeve 1 after the assembly of the roller sleeve 1 and the roller core 2, reducing the tension in the belt making process. Roller sleeve 1 thermal deformation and fatigue cracks.

The assembly method of the cooling roll proposed by the present invention is shown in Figure 8, specifically comprising the following steps:

Roller sleeve 1 (completed solution treatment) and roll core 2 are machined according to pre-designed interference; Exemplary, machining can process the outer surface of roll core 2 into a shape similar to a gear, then each The racks are equivalent to support bars, they contact the inner surface of the roller sleeve 1, support the roller sleeve 1 and generate prestress inside the roller sleeve 1.

Carry out aging treatment and preheating of the machined roller sleeve 1, that is: combine the aging treatment of the roller sleeve with the preheating before assembly, the aging treatment process of the roller sleeve is also the preheating before the assembly of the roller sleeve and the roller core process; the heating temperature is 300-550°C, and the holding time is 1-20 hours; the aging treatment is to reheat the roller sleeve 1 that has completed the solution treatment to above 300°C and keep it warm, so that the dispersed strengthening phase is precipitated in the supersaturated alloy solid solution, to obtain excellent mechanical properties.

Assemble the hot roll sleeve 1 and the roll core 2 after aging treatment; after the temperature of the two is consistent, the roll sleeve 1 is hooped on the roll core 2, and a predetermined tensile stress along the circumferential direction is generated inside the roll sleeve 1, A cooling roll assembly is obtained.

Install the assembled chill roll assembly on the tape machine.

For example, when the design of the interference is large, so that the size difference between the hot roll sleeve 1 and the room temperature roll core 2 is small, and the assembly is not easy to operate, the roll core 2 can be adjusted while the roll sleeve 1 is being aged. Carry out cold treatment, that is: place the roller core 2 in a cold treatment furnace, pass in low-temperature gas and keep it warm for a period of time, and reduce the temperature of the roller core 2 to below -30°C; wherein, the low-temperature gas can be produced by dry ice, liquid nitrogen, etc.; The cold treatment of the roller core 2 causes the roller core 2 to shrink to a certain extent, so as to increase the dimensional margin between the cold roller core 2 and the hot roller sleeve 1, reduce the requirements for the accuracy of the assembly mechanism, and make the shrinking process smooth conduct.

Preferably, for the roll sleeve 1 made of copper alloy with a Be content of 1.7-2.1 wt%, the preheating temperature is 300-400° C., and the holding time is 1-20 hours.

Preferably, for the roll sleeve 1 made of a copper alloy with a Be content of 0.2-0.7wt% and a total Ni and/or Co content of 0.5-2.5wt%, the preheating temperature is 400-550°C and the holding time is 1-20 hours.

Preferably, for the roller sleeve 1 made of a copper alloy with a Ni content of 2-10 wt%, the preheating temperature is 400-500° C., and the holding time is 1-20 hours.

The present invention proves that the cooling roll and the assembly method proposed by the present invention are practicable and have better effects through multiple embodiments and comparative examples. Iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percent) strips of the same size are produced respectively by using the cooling rollers assembled under the conditions of Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and the strips start The surface temperature change of post-cooling roll sleeve 1 is shown in Figure 7. The dotted line in Figure 7 is the equilibrium temperature of the roll surface, and the internal stress change at a certain point on the roll sleeve 1 surface within one rotation cycle is shown in Figure 8.

Example 1

The material of the roller sleeve is CuBe ₂ alloy, which has a tensile strength of 1250MPa, an elastic modulus of 132GPa, a thermal conductivity of 105W/mK, and a thermal expansion coefficient of 17ppm. The shape of the outer surface of the core is a gear-shaped support strip, the outer diameter of the roller core is 1195mm, the design interference ratio is 3.36‰, and the design prestress is 443MPa;

A cooling roll assembly method comprises the following steps:

The roller sleeve is machined according to the pre-designed interference;

Carry out aging treatment and preheating of the machined roller sleeve; the preheating temperature is 330°C, and the holding time is 8 hours. After the heat preservation is completed, the inner diameter of the hot roller sleeve is 1197mm; Cold treatment, cold treatment at -70°C for 6 hours, the outer diameter of the roller core after cold treatment is 1193.7mm;

The preheated roll sleeve and the cold-treated roll core were assembled and cooled to room temperature; the cooled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 1194.9 mm, and the actual prestress inside the roll sleeve was 432 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Example 2

The material of the roller sleeve is CuBe _0.5 Co _2.5 alloy, the tensile strength of this material is 750MPa, the elastic modulus is 140GPa, the thermal conductivity is 220W/mK, the thermal expansion coefficient is 18ppm, the inner surface of the roller sleeve is cylindrical, and the inner diameter of the roller sleeve is 1915mm , the shape of the outer surface of the roller core is a gear-shaped support strip, the outer diameter of the roller core is 1920mm, the design interference ratio is 2.61‰, and the design prestress is 366MPa;

A cooling roll assembly method comprises the following steps:

The roller sleeve is machined according to the pre-designed interference;

Carry out aging treatment and preheating of the machined roller sleeve; the preheating temperature is 460°C, and the holding time is 19 hours. After the heat preservation is completed, the inner diameter of the hot roller sleeve is 1930mm; the roller core is not treated, and the outer diameter of the roller core is 1920mm ;

The preheated roll sleeve and the untreated roll core were assembled and cooled to room temperature; the cooled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 1919.7 mm, and the actual prestress inside the roll sleeve was 344 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Example 3

The material of the roller sleeve is CuNiSi alloy, which has a tensile strength of 720MPa, an elastic modulus of 140GPa, a thermal conductivity of 230W/mK, and a thermal expansion coefficient of 16ppm. The outer surface of the roller core is cylindrical, the outer diameter of the roller core is 606.3mm, the design interference ratio is 2.15‰, and the design prestress is 301MPa;

A cooling roll assembly method comprises the following steps:

The roller sleeve is machined according to the pre-designed interference;

Aging treatment and preheating are carried out on the machined roller sleeve; the preheating temperature is 480°C, and the holding time is 4 hours. After the heat preservation is completed, the inner diameter of the hot roller sleeve is 609mm; the outer diameter of the roller core is 606.3mm without treatment. mm;

The preheated roll sleeve and the untreated roll core were assembled and cooled to room temperature; the cooled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 606.26 mm, and the actual prestress inside the roll sleeve was 292 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Comparative example 1

The material of the roller sleeve is CuBe ₂ , the tensile strength of this material is 1250MPa, the elastic modulus is 132GPa, the thermal conductivity is 105W/mK, and the thermal expansion coefficient is 17ppm. The shape of the outer surface is a gear-shaped support strip, the outer diameter of the roller core is 1195mm, the design interference ratio is 1.26‰, and the design prestress is 166MPa;

A cooling roll assembly method comprises the following steps:

Carry out aging treatment to the roller cover after solution treatment, and the aging treatment time is 8 hours;

The roller sleeve is machined according to the pre-designed interference;

Preheat the machined roller sleeve; the preheating temperature is 330°C, and the inner diameter of the hot roller sleeve after heat preservation is 1197mm; the outer diameter of the roller core is 1195mm without treatment;

The preheated roll sleeve and the untreated roll core were assembled and cooled to room temperature; a chilled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 1194.9 mm, and the actual prestress inside the roll sleeve was 155 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Comparative example 2

The material of the roller sleeve is CuBe _0.5 Co _2.5 , which has a tensile strength of 750MPa, an elastic modulus of 140GPa, a thermal conductivity of 220W/mK, and a thermal expansion coefficient of 18ppm. The inner surface of the roller sleeve is cylindrical, and the inner diameter of the roller sleeve is 1918mm. The shape of the outer surface of the roller core is a gear-shaped support strip, the outer diameter of the roller core is 1920mm, the design interference ratio is 1.04‰, and the design prestress is 146MPa;

A cooling roll assembly method comprises the following steps:

Carry out aging treatment to the roller cover after solution treatment, and the aging treatment time is 19 hours;

The roller sleeve is machined according to the pre-designed interference;

Preheat the machined roller sleeve; the preheating temperature is 300°C, and the inner diameter of the hot roller sleeve after heat preservation is 1928mm; the outer diameter of the roller core is 1920mm without treatment;

The preheated roll sleeve and the untreated roll core were assembled and cooled to room temperature; a chilled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 1919.4 mm, and the actual prestress inside the roll sleeve was 102 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Comparative example 3

The material of the roller sleeve is CuNiSi, which has a tensile strength of 720MPa, an elastic modulus of 140GPa, a thermal conductivity of 230W/mK, and a thermal expansion coefficient of 16ppm. 605.8mm, the shape of the outer surface of the roller core is cylindrical, the outer diameter of the roller core is 606.3mm, the design interference ratio is 0.83‰, and the design prestress is 116MPa;

A cooling roll assembly method comprises the following steps:

Carry out aging treatment to the roller cover after solid solution treatment, and the aging treatment time is 4 hours;

The roller sleeve is machined according to the pre-designed interference;

Preheat the machined roller sleeve; the preheating temperature is 300°C, and the inner diameter of the hot roller sleeve after the heat preservation is completed is 609mm; the outer diameter of the roller core is 606.3mm without treatment;

The preheated roll sleeve and the untreated roll core were assembled and cooled to room temperature; the cooled roll was obtained. At this time, the actual inner diameter of the roll sleeve was 606.2 mm, and the actual prestress inside the roll sleeve was 92 MPa.

After the assembled cooling roll is installed, an iron-based amorphous alloy Fe ₇₉ Si ₉ B ₁₂ (atomic percentage) strip is manufactured.

Table 1 shows the material of the roll sleeve and its aging performance, the shape and size of the roll sleeve and the roll core in the above-mentioned examples and comparative examples. The assembly process of the roll sleeve and the roll core and the actual prestress inside the roll sleeve are shown in Table 2.

In order to facilitate the comparison of strip-making effects, all the examples and comparative examples used the same process parameters during strip manufacture: alloy liquid temperature 1380±5°C, alloy liquid static pressure at the nozzle 35±2kPa, no arc on the bottom of the nozzle, Nozzle gap width 0.40±0.02mm, roller nozzle spacing 0.25±0.01mm, cooling roller surface linear speed 22±1m/s, cooling water flow rate 150t/h, cooling water inlet temperature 31±2℃. The nominal dimensions of the manufactured strips are: width 142 mm, average thickness 25 microns. Use a high-precision capacitive ranging sensor to measure the thermal crown of the roll surface, and use the method of the national standard GB/T 19345.1-2017 to measure the width and transverse thickness distribution of the strip. The measured data are shown in Table 3:

As can be seen from Table 3, after adopting the technical scheme of the present invention, the thermal crown of the roll surface and the difference thereof when the roll sleeve is made into a strip are all significantly reduced, the strip shape is greatly improved, and the transverse thickness of the strip is greatly improved. Uniformity, especially the concave core phenomenon is basically avoided; at the same time, the pits on the roll surface due to thermal fatigue are eliminated or greatly reduced, which significantly improves the surface quality of the strip.

Principle of the present invention:

In the manufacturing process of amorphous and nanocrystalline strips, the thermal crown of the roll surface is caused by the thermal expansion of the roll sleeve, and the cracks on the roll surface are caused by the thermal fatigue caused by the periodic thermal shock of the roll surface. The pre-existing tensile stress inside the roller sleeve can simultaneously reduce or avoid the thermal expansion and thermal fatigue of the roller sleeve during strip making. Interference fit means that the outer diameter of the shaft core is slightly larger than the inner diameter of the shaft sleeve, and the shaft core is squeezed into the sleeve by means of external force. When the interference is large, it is necessary to heat and expand the shaft sleeve first, and then insert the shaft core; after the two cool down and reach the same temperature, the shaft sleeve will shrink and be tightly hooped on the shaft core. The roll sleeve and the roll core are assembled together to achieve a predetermined prestress inside the roll sleeve.

The present invention considers three aspects: roller sleeve prestress design, roll sleeve and roll core structure design, roll sleeve and roll core assembly process; It has different mechanical properties, so the prestress range must be reasonably determined according to the mechanical properties of different materials. After the prestress is determined, the interference of the roller sleeve is determined according to the prestress; the structure of the roller sleeve and the core: the roller sleeve is full The support strips on the surface or the outer circumferential surface of the roller core ensure the realization of the internal prestress of the entire roller sleeve; the assembly process of the roller sleeve and the roller core: prevent the roll sleeve from over-aging due to preheating, and ensure the relationship between the hot roll sleeve and the cold roll core. There is a sufficient size margin between them.

Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (9)

1. A cooling roll, comprising a roll sleeve and a roll core, the roll sleeve is arranged on the outer periphery of the roll core, and the roll sleeve and the roll core are interference fitted;

   It is characterized in that the interference ratio between the inner diameter of the roller sleeve and the outer diameter of the roller core is 2-3.5‰.
2. A kind of cooling roll according to claim 1, is characterized in that:

   The roll sleeve material includes copper alloy, and after the roll sleeve is interference-fitted with the roll core, the internal prestress is 20-50% of the tensile strength of the roll sleeve material.
3. A cooling roll according to claim 1, characterized in that:

   The cooling roll also includes support strips; the support strips are distributed on the inner surface of the roll sleeve or the outer peripheral surface of the roll core, the support strips are arranged along the axial direction of the roll core, and the height and width of the support strips and the adjacent support strips The spacing between them is not fixed.
4. A cooling roll according to claim 3, characterized in that:

   The height of the support bar is less than or equal to 10 mm, the circumferential width of the support bar is 5-30 mm, and the circumferential distance between adjacent support bars is 5-50 mm.
5. A cooling roll assembly method, characterized in that:

   The assembly method includes the following steps:

   Aging treatment is carried out on the roller cover, aging treatment and preheating are carried out simultaneously;

   The heat-sleeved roll sleeve and the roll core that have completed the aging treatment are interference-fitted and cooled to room temperature to obtain a cooling roll; wherein, the interference ratio between the inner diameter of the roll sleeve and the outer diameter of the roll core is 2-3.5‰.
6. A cooling roll assembly method according to claim 5, characterized in that:

   The aging treatment process is also a preheating process before the roll sleeve and roll core are assembled.
7. A cooling roll assembly method according to claim 5 or 6, characterized in that:

   The temperature of the aging treatment is 300-550° C., and the holding time is 1-20 hours.
8. A cooling roll assembly method according to claim 5, characterized in that:

   The assembly method also includes performing the following operations before aging treatment:

   Design the interference ratio between the roller sleeve and the roller core;

   The sleeves are machined to pre-designed interference ratios.
9. A cooling roll assembly method according to claim 5, characterized in that:

   While performing aging treatment on the roller sleeve, cold treatment is carried out on the roller core; the cold treatment includes placing the roller core in a cold treatment furnace, passing in low-temperature gas, and reducing the temperature of the roller core to below -30°C.

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