JP6995931B2 - Forged roll-based heat pipe roll and its manufacturing method - Google Patents

Description

The present invention relates to a forged roll-based heat pipe roll and a method for manufacturing the same, specifically, in order to improve the shape-correcting ability of high-strength steel and giga steel in a hot-rolled skin pass process, the temperature of the strip is not set to room temperature. The present invention relates to a forged roll-based heat pipe roll and a method for manufacturing the same, which enables continuous work without thermal crown growth of the roll in rolling work in a warm state (80 to 200 ° C.).

Steel sheets continue to increase in strength in order to respond to environmental regulations and improved collision characteristics in the automobile industry. As the strength of the steel sheet increases, the shape of the hot-rolled sheet deteriorates, and a load is applied to the hot-rolled SPM (Skin Pass Mill) process for correcting the shape. However, such high-strength steel has a problem that the yield strength of the material is high, and even after undergoing the SPM step of performing shape correction, the material is hardly stretched and the shape correction is not smoothly performed.

As a method for overcoming this, the temperature of the steel strip is raised and SPM work is performed. However, when warm work is performed without another roll cooling means, the work roll receives heat from the strip and a large thermal crown is formed, and conversely, an uncontrollable wave is formed in the center of the plate. ) Is violently generated, and the value as a product is reduced. On the other hand, in the process of hot-rolled SPM, many scales formed on the surface of the plate fall off and become present in the surroundings. At this time, if cooling water is used for roll cooling, the scale scatters and induces secondary surface defects, so it is not preferable to use cooling water.

In order to correct the shape of high-strength steel and giga steel in such an environment, conventionally, after rolling 4 to 5 coils of high-strength steel at about 80 ° C, general steel at room temperature is used to cool the roll. The process of rolling 8 to 10 coils is repeated. However, with such a method, not only the temperature of the strip is relatively low and there is a limit to shape correction, but also the temperature of the coil waiting in the yard is lowered, so that it is difficult to warm-roll many coils. There is.

As a solution to this, even if steel strips at 80 to 200 ° C. are continuously rolled regardless of the number of rolled sheets, the temperature distribution in the roll barrel direction can be made uniform, and as a result, the generation of thermal crowns on the roll can be suppressed. The manufacturing technology of the heat pipe roll that can be made is being developed. Currently, the roll used in the hot rolling correction SPM is a centrifugal casting roll, that is, the core part of the roll is gray cast iron or spheroidal graphite cast iron, and the shell layer is a roll composed of Hi-Cr. ing. However, due to the production of heat pipe rolls, the part where holes are machined in the roll is the core part with low yield strength, so polishing by using the roll progresses, and the roll surface and holes As the distance between the two becomes smaller, the stress acting on the holes in rolling becomes larger and cracks occur.

In order to improve this problem, CPC (Continuous Manufacturing Process for Cladding) is manufactured by using an SCM440 rod as a core part instead of a centrifugal casting roll and manufacturing a shell layer made of HSS (High Strength Steel) material as a casting. A technique for producing a heat pipe roll using a roll has been developed. However, although the SCM440 corresponding to the core part of the CPC roll is superior in mechanical properties to the gray cast iron corresponding to the core part of the centrifugal casting roll, the price of the roll is high and must be imported. The fact is that there is a limit to the expanded application due to the problem. Therefore, in order to expand and apply more heat pipe rolls to correct the shape of high-strength steel and giga steel, it is necessary to develop inexpensive forged roll-based heat pipe rolls with even better mechanical properties for CPC rolls. There is.

Korean Published Patent No. 10-2014-0080931 Korean Publication No. 10-2014-847671

An object of the present invention is to solve the above-mentioned problems of the prior art, and is applied not only to hot-rolling correction two-stage SPM but also to four-stage SPM rolling, and is applied to high-strength steel and giga steel. It is an object of the present invention to provide a heat pipe roll and a method for manufacturing the same, which can improve the actual yield by maximizing the shape correction ability of the steel.

Further, the technical problem to be solved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned above are usually described in the technical field to which the present invention belongs, as described later. Can be clearly understood by those who have the knowledge of.

In order to achieve the above object, the present invention rolls a neck portion connected to a bearing at both ends and a plate material passing between the neck portions, and a plurality of plate members are rolled to a predetermined depth along the circumferential direction. A heat pipe roll including a rolled portion in which an insertion hole is formed and a heat pipe inserted into the insertion hole inside the rolled portion and extended in the axial direction of the roll, wherein the heat pipe roll is by weight%. The present invention relates to a forged roll-based heat pipe roll, which is a forged roll containing 3.0 to 6.0% Cr, and the surface of the heat pipe is coated with a heat conductive material.

The journal portion formed as an inclined surface between the neck portion and the rolled portion is further included, the insertion hole is formed in the journal portion of the inclined surface, and the heat pipe can be incorporated.

The heat pipe includes a plurality of first heat pipes extending from one side in the roll axis direction to the central portion, and a plurality of second heat pipes extending from the opposite direction of the one side to the central portion. The 1 heat pipe and the second heat pipe can be arranged alternately along the circumferential direction of the roll.

The first heat pipe and the second heat pipe can intersect each other at the central portion in the length direction of the roll.

The conductive material can be Ni.

Further, the present invention is a rolled portion for rolling a plate material which is composed of 3.0 to 6.0% Cr in weight% and is connected to a bearing at an end portion and passes between the neck portions. , And a step of providing a forged roll including a journal portion formed as an inclined surface between the neck portion and the rolled portion, and forming a plurality of insertion holes at a predetermined depth in the circumferential direction from the journal portion. The present invention relates to a method for manufacturing a forged roll-based heat pipe roll, including a step of inserting a heat pipe having a surface coated with a conductive material into the insertion hole using a vacuum pump.

The heat pipe includes a plurality of first heat pipes extending from one side in the roll axis direction to the central portion, and a plurality of second heat pipes extending from the opposite direction of the one side to the central portion. The 1 heat pipe and the second heat pipe can be arranged alternately along the circumferential direction of the roll.

The first heat pipe and the second heat pipe can intersect each other at the central portion in the length direction of the roll.

The conductive material can be Ni.

After inserting the heat pipe, it is not necessary to perform heat treatment for expansion of the heat pipe.

The present invention having the above configuration is a high value-added steel, that is, high carbon, by using a forged roll-based heat pipe roll having further improved performance in a hot-rolling correction two-stage SPM or four-stage SPM process. The actual yield of high value-added steel can be improved by maximizing the shape straightening ability of steel, directional electric steel plate, high-strength steel, and giga steel to minimize the factors of shape defects.

In addition, the life of the heat pipe roll can be doubled or more as compared with the conventional centrifugal cast roll heat pipe roll, and the manufacturing cost of the expensive heat pipe roll can be reduced to half or less.

Furthermore, by enabling SPM processing at high temperature instead of normal temperature, the time to wait in the yard for cooling the hot-rolled coil for about 3 to 5 days is greatly reduced, which is insufficient in addition to the effect of shortening the delivery time. Correction There is an effect that the yard space can be used efficiently.

It is a schematic diagram of the high-strength steel shape straightening apparatus including the heat pipe roll of this invention. It is a front view of the heat pipe roll of this invention. It is a side view of a heat pipe roll. It is the arrangement conceptual diagram of the heat pipe inserted and arranged in the circumferential direction of the roll of this invention. (A) is a vertical sectional view of a heat pipe, and (b) is a sectional view of the heat pipe. It is a photograph showing the crack generated on the surface of the heat pipe roll of the conventional centrifugal casting roll base. It is a front view which shows the state which the insertion hole was machined in the inside of the roll in order to manufacture the heat pipe roll of this invention. It is a photograph which shows the process of inserting a heat pipe using a vacuum pump into a roll. It is a partial perspective view which shows the end part of the heat pipe of this invention. It is a graph which shows the temperature distribution in the roll barrel direction according to the manufacturing conditions of the heat pipe roll of the forged roll base of this invention. It is a graph which shows the heat crown amount of the roll according to the manufacturing conditions of the heat pipe roll of the forged roll base of this invention. It is a figure which shows the modeling for the stress analysis for the safety examination for the conventional centrifugal casting roll heat pipe roll and the forging roll-based heat pipe roll. It is a graph which shows the stress analysis result of FIG. It is a figure which shows the stability evaluation result based on the stress analysis result of FIG. It is a figure which shows the modeling for comparative analysis for the fatigue life of the heat pipe roll of this invention based on the conventional centrifugal casting roll heat pipe roll and the forging roll base. It is a graph which shows the calculated stress when the work roll of FIG. 15 makes one rotation.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view of a high-strength steel shape straightening device including a heat pipe roll 100.

As shown in FIG. 1, the coil wound by the coiler 3 in the hot rolling process is placed in the temperature control step 20, that is, the yard by the first transfer step. The coil wound in the temperature control step 20 is continuously measured in temperature and transferred to the shape correction line in a state having a predetermined temperature, for example, a temperature of 150 ° C. or higher, by the second transfer step.

In the shape correction line, a plurality of coils are applied to a plurality of payoff reels 30a and 30b, and the coils are sequentially unwound. The strip unwound from the coil via the payoff reels 30a, 30b is shape-corrected by the skin pass mill 40 and then rewound by the coiler 35.

At this time, the skin pass mill 40 uses the heat pipe roll 100 to correct the shape of the strip. Here, by using the heat pipe roll 100, for example, even if a strip of 150 ° C. or higher enters the heat pipe roll 100, the heat crown can be maintained constant, and high strength is achieved at a temperature of 150 ° C. or higher. Since the steel strip is provided, the shape correction can be smoothly performed.

The heat pipe roll of the present invention is a forged roll-based heat pipe roll 100 that can be generally applied to the above-mentioned hot rolling correction SPM line. Then, as shown in FIGS. 2 and 3, the forged roll-based heat pipe roll 100 of the present invention rolls a plate material passing between the neck portion 103 connected to the bearing at both ends and the neck portion. A rolling portion 102 in which a plurality of insertion holes are formed along the circumferential direction at a predetermined depth, and a heat pipe 110 inserted into the insertion holes inside the rolling portion and extended in the axial direction of the roll. Consists of including.

Specifically, the heat pipe roll 100 of the present invention is similar to a general shape-correcting rolling roll, but differs from each other in that the heat pipe 110 is built in the journal portion 104 between the rolling portion 102 and the neck portion 103. ..

Preferably, as shown in FIG. 4, the heat pipe 110 includes a plurality of first heat pipes 113 extending from one side in the roll axis direction to the central portion, and a plurality of first heat pipes 113 extending from the opposite direction of the one side to the central portion. The first heat pipe and the second heat pipe are arranged alternately along the circumferential direction of the roll, including the second heat pipe 115 of the above.

More preferably, the first heat pipe 113 and the second heat pipe 115 intersect each other at the central portion in the length direction of the roll.

5 (a) is a vertical sectional view of the heat pipe, and FIG. 5 (b) is a sectional view of the heat pipe.

In the present invention, the heat pipe roll 100 means a roll in which the heat pipe 110 is built in the work roll. As shown in FIGS. 5A and 5B, in the heat pipe 110, a groove 112 is formed in a pipe 111 having a vacuum inside, and the groove is filled with pure water. When the heat pipe 110 receives heat in the heating portion, pure water evaporates due to the heat, and the central portion 113a is filled with steam. Due to the water vapor formed in the central portion 113a in this way, the pressure in the central portion 113a becomes high, the water vapor moves to both sides where the pressure is low, is cooled by the side surface portion 113b, and returns to pure water again. On the other hand, when the pure water in the groove 112 in the central portion 113a evaporates due to heat, the pure water in the side surface portion 113b moves to the central portion 113a again due to the capillary phenomenon of the groove 112.

In this way, evaporation occurs at the central portion 113a, and condensation occurs at the side surface 113b. Further, water vapor moves from the central portion 113a to the side surface portion 113b, and pure water moves from the side surface 113b to the central portion 113a. As a result, the heat pipe 110 plays a role of uniformly dispersing the heat in the heating portion by the internal circulation.

Further, the heat pipe roll 100 of the present invention is a forged heat pipe roll, and is distinguished from the centrifugal casting roll and the CPC heat pipe roll of the conventional heat pipe roll.

As the heat pipe roll 100 of the present invention, a forged roll containing 3 to 6% Cr is used instead of the conventional centrifugal casting roll or CPC roll. Preferably, the forged roll is C: 0.8 to 1.0%, Si: 0.8 to 1.2%, Mn: 0.8 to 1.2%, P: 0.030 in% by weight. % Or less, S: 0.020% or less, Ni: 0.6 to 1.0%, Cr: 3.0 to 6.0%, Mo: 0.3 to 0.7%, balance Fe and unavoidable impurities It can be composed by including.

As shown in Table 1 above, in the case of a forged roll of 5% Cr, the yield strength and fatigue strength are remarkably superior to those of the centrifugal casting roll or the CPC roll, and crack resistance is generated, so that the CPC roll has a crack resistance. It is cheaper than that and has the advantage that it does not need to be imported.

FIG. 6 is a photograph showing a case where crack C is generated on the surface of a heat pipe roll based on a centrifugal casting roll. Crack C occurs at the time of use, which is half the life of a general roll, and the actual situation is that expensive heat pipe rolls are discarded.

On the other hand, in the case of the forged roll of the present invention, BUR (Backup Roll) or WR (Work Roll), which is supplied by the manufacturer or used for hot-rolled rough rolling and has reached the disposal diameter and is in a state of disposal. ) Can be recycled and used. In order to recycle BUR or WR, first, annealing heat treatment is performed to make the BUR or WR easy to process, and the roll used in hot-rolling rough rolling is changed to the size of a hot-rolling correction SPM roll through roughing. After that, it is completed again through quenching-tempering heat treatment, medium cutting, low frequency heat treatment, and fine cutting to complete the WR for the final hot-rolled SPM.

On the other hand, even in the case of a conventional centrifugal casting roll or the like, when the heat pipe is inserted into the insertion hole machined into the roll, a gap is formed between the general heat pipe and the insertion hole machined into the roll. When such a gap exists, the heat transfer performance of the heat pipe deteriorates, and it is necessary to remove this gap. Conventionally, a method of increasing the temperature of the roll to expand the heat pipe has been used. Specifically, conventionally, the heat pipe roll into which the heat pipe is inserted is maintained at a maximum temperature rise temperature of 285 ° C. and a temperature rise rate of 8.5 ° C./hour, and the built-in heat pipe is expanded. The gap between the hole machined in the roll and the heat pipe is removed.

On the other hand, in the case of the forged roll of the present invention, it is not preferable to perform the tube expansion heat treatment on the heat pipe roll as described above. This is because the conventional centrifugal casting roll and CPC roll have a tempering heat treatment temperature of 300 ° C. or higher in the final manufacturing process of the roll, whereas in the case of the forged roll of the present invention, the surface hardness is ensured. This is because the tempering heat treatment is performed at 200 ° C. or lower. That is, even in the case of the forged roll of the present invention, when the heat pipe roll is heated to 285 ° C. in order to eliminate the space between the hole machined in the roll and the heat pipe in the process of manufacturing the heat pipe roll, the final tempering is performed. This is because since the heat treatment temperature is 200 ° C. or lower, the surface hardness becomes weak and the mechanical properties of the roll itself deteriorate.

Therefore, in the case of the forged roll of the present invention, in order to insert the heat pipe, it is necessary to reduce the size of the insertion hole to be machined in the roll as compared with the conventional centrifugal casting roll or the like.

Preferably, the difference between the diameter of the insertion hole and the diameter of the heat pipe is controlled to 100 μm or less. More preferably, the difference between the diameters is controlled to 50 μm or less, more preferably to the range of 5 to 50 μm.

At the same time, it is preferable to coat (plat) a conductive material on the surface of the heat pipe to be inserted into the heat pipe roll of the present invention. At this time, the formed plating layer plays a role of adjusting the gap between the above-mentioned insertion hole and the inserted heat pipe. Specifically, when the gap is large, the conductive substance is coated thickly, and when the gap is small, the conductive substance is coated thinly. In addition, since it has excellent thermal conductivity, it plays a role of effectively discharging the heat accumulated in the roll to the outside through the heat pipe.

In the present invention, the specific method for coating the conductive material is not particularly limited, and various methods such as electroplating can be used.

Further, a thermally conductive metal material can be used as the conductive material, and for example, Ni can be used as the conductive material.

Next, a method for manufacturing a forged roll-based heat pipe roll having a built-in heat pipe of the present invention will be described.

The method for manufacturing a forged roll-based heat pipe roll according to the present invention is composed of 3.0 to 6.0% Cr in weight%, and is between a neck portion connected to a bearing at an end portion and the neck portion. A step of providing a forged roll including a rolled portion for rolling a plate material passing through a plate material and a journal portion formed as an inclined surface between the neck portion and the rolled portion, and a predetermined depth in the circumferential direction from the journal portion. It includes a step of forming a plurality of insertion holes at the position of the above and a step of inserting a heat pipe having a surface coated with a conductive material into the insertion holes using a vacuum pump.

First, in the present invention, a forged roll containing 3.0 to 6.0% Cr by weight is produced. Such a forging roll can be manufactured by using a known forging method, and has a neck portion connected to a bearing at an end portion, a rolled portion for rolling a plate material passing between the neck portions, and a rolled portion. It includes a journal portion formed as an inclined surface between the neck portion and the rolled portion.

In the present invention, such a forged roll can be directly manufactured, but a BUR (Backup Roll) or a WR (Work Roll) that has reached the disposal diameter and is in a state of disposal, which is used in hot-rolling rough rolling, can be produced. It can be recycled and used.

Next, in the present invention, as shown in FIG. 7, a plurality of insertion holes 105 and 106 are formed at positions at predetermined depths in the circumferential direction from the journal portion. In the present invention, the specific method for forming such an insertion hole is not particularly limited.

As a method of processing such an insertion hole, first, a method of processing from one side of the roll so as to penetrate to the other side of the roll using a gun drill, and secondly, the roll is bisected in the barrel direction and each of the rolls is processed. A method of processing 1/2 of each roll barrel from the side surface, thirdly, the roll is bisected in the barrel direction, 1/2 is processed from each side surface, and as shown in FIG. An example is a method in which the tips of the holes machined from both sides are not machined so as to be in contact with each other at the central portion, but are machined so as to overlap each other by a certain amount. When the roll is repeatedly loaded, cracks are generated at that part and the roll may break, so the third method is to shift the tips of the insertion holes machined from both sides slightly without touching exactly at the center of the roll. Has the advantage of being able to prevent accidents.

Next, the heat pipes 110a and 110b having the surfaces of the formed insertion holes 105 and 106 coated with a conductive material are inserted into the insertion holes using a vacuum pump.

As described above, the conventional centrifugal casting roll and CPC roll are heated to 285 ° C., and the heat pipe built in the roll is expanded to remove the gap between the insertion hole and the heat pipe. In some cases, it is not preferable to perform the above-mentioned high-temperature heat treatment on the forged roll. That is, unlike the prior art, it is preferable that the present invention does not perform the tube expansion heat treatment for the expansion of the heat pipe after the heat pipes 110a and 110b are inserted.

In the present invention, since the forged roll is used as the heat pipe roll, the diameter of the insertion hole is reduced and the heat pipe is coated with a conductive material (Ni) in order to reduce the gap between the insertion hole and the heat pipe described above. Suggest a method. However, this method has a problem that the gap between the hole and the heat pipe is reduced, and it becomes difficult to insert the heat pipe into the insertion hole due to the air resistance inside the insertion hole.

Therefore, in order to solve this problem, the present invention provides a method of inserting a heat pipe by discharging the air inside the hole machined by using the vacuum pump 16 to the outside as shown in FIG. That is, via the heat pipe 210 plated with the conductive material, the guide outlet 230 configured to guide the heat pipe 210 in contact with the insertion hole of the heat pipe roll, and the guide outlet 230. By using an insertion device that includes a vacuum pump 250 that discharges air inside the insertion hole so that the heat pipe 210 can be inserted into the insertion hole, the heat pipe can be inserted into the insertion hole even if the above-mentioned gap is small. Can be effectively inserted inside. Reference numeral 270 in FIG. 8 is an accommodating member having a structure having an insertion hole inside thereof, and the insertion hole is shown by replicating a heat pipe roll.

The thickness of the conductive material on the surface of the heat pipe is finally determined by repeating the above-mentioned work to determine the thickness that can be inserted.

As shown in FIG. 9, the heat pipe 110 includes a stopper 108 inserted into the insertion holes 105 and 106 so as to close the end portion of the heat pipe 110, and air in the gap between the insertion holes 105 and 106 and the heat pipe 110. A hole 109 is formed in the stopper 108 so that the stopper 108 can be discharged.

On the other hand, as described above, after reducing the gap between the insertion hole and the heat pipe, increasing the overlap length of the heat pipe at the center of the roll, and coating the surface of the heat pipe with a conductive material to a certain thickness. By inserting a heat pipe using a vacuum pump, a forged roll-based heat pipe roll can be manufactured. Then, in order to confirm the performance of the heat pipe roll, the central portion of the roll can be heated to 100 ° C. with respect to the surface in an offline state, and then the temperature distribution in the roll barrel direction and the amount of heat crown can be measured.

As described above, in the present invention, the gap between the insertion hole and the heat pipe is minimized, but the heat pipe roll is inserted by heating the heat pipe roll to 285 ° C. in a heating furnace and then expanding the pipe heat treatment as compared with the conventional technique. Some gaps will continue to remain between the holes and the heat pipes.

Therefore, in the present invention, the temperature difference in the roll barrel direction and the amount of heat crown are slightly higher than in the prior art, and in preparation for this, the initial crown amount of the roll can be finally made slightly smaller than in the prior art. preferable. For example, in the prior art, the initial crown amount of the heat pipe roll is 5/100 mm, whereas in the case of the forged roll-based heat pipe roll of the present invention, it is considered that a larger amount of heat crown is formed. It is preferable to control the initial crown amount to less than 5/100 mm, and more preferably to control it to 3/100 mm or less. This value can be finally determined by the amount of thermal crown obtained from the results of an offline test on the forged roll-based heat pipe roll of the present invention.

Hereinafter, the present invention will be described with reference to examples.

(Example 1)
10 and 11 show the heat when the heat pipe is not inserted after heating the central portion of the heat pipe roll manufactured based on the forged roll made of 5% Cr material to the roll surface reference of 100 ° C. (No HP). When the pipe is inserted without Ni plating (bare HP), when the heat pipe is Ni-plated and then inserted (Ni HP), and the roll barrel with the conventional heat pipe roll (EX HP) that has undergone tube expansion heat treatment. It is a graph which shows by measuring the temperature distribution in a direction and the amount of a heat crown respectively.

As shown in FIGS. 10 and 11, in the case of the conventional heat pipe roll that has undergone tube expansion heat treatment, the temperature difference between the central portion and the edge portion in the roll barrel direction is 1.6 ° C., whereas the heat pipe has Ni. When plated, the temperature difference between the central portion and the edge portion in the roll barrel direction was 4.7 ° C. It is determined that this difference can be further reduced through a decrease in hole diameter, an increase in overlap length, and a decrease in the initial crown amount of the roll. In addition, in the case of the amount of heat crown, it is about 2 μm in the case of the conventional heat pipe roll that has been subjected to tube expansion heat treatment, whereas it is about 5 μm in the case of Ni plating on the heat pipe, which is also an additional measure. It is judged that the difference can be reduced when the proposed technology is applied.

(Example 2)
Safety studies were conducted on conventional centrifugal cast roll heat pipe rolls and forged roll-based heat pipe rolls. FIG. 12 shows modeling for stress analysis, FIG. 13 shows the stress analysis results, and FIG. 14 shows the stability evaluation results.

When the roll diameter is 630 mm, the hole diameter is 16.5 mm, the number of holes is 42, and the distance from the roll surface to the hole center line is 91 mm, the stress around the holes when a rolling load of 1000 tons is applied is applied. It was calculated and the stability was evaluated by the value (stress ratio) obtained by dividing the stress by the yield strength of the material. When the stress ratio is 0.3 or less, it means safety, when it is 0.3 to 0.6, it means conditional safety, and when it is 0.6 or more, it means danger. It can be confirmed that the forged roll of the present invention is evaluated as safe while the conventional centrifugal cast roll shows a danger level.

Then, an analysis was performed to compare the fatigue life of the heat pipe roll of the present invention based on the conventional centrifugal cast roll heat pipe roll and the forged roll base.

FIG. 15 shows the modeling for analysis, and FIG. 16 shows the calculated stress when the work roll makes one rotation. The fatigue life was calculated in consideration of the stress calculated in this way and the surface processing state in the hole processing, and the results are shown in Table 2 below.

As shown in Table 2 above, in the case of the conventional centrifugal casting roll heat pipe roll, the life was sharply reduced when considering the conditions of the machined surface in the actual machining, whereas the forged roll-based book In the case of the heat pipe roll of the present invention, it can be confirmed that the heat pipe roll exhibits an infinite life even when the surface conditions at the time of processing are taken into consideration. On the other hand, in Table 2 above, surf. Factor 1 and surf. Factor 2 indicates the degree of appearance in the processing mark in the processing of the hole and the condition of the surface roughness when the processed surface is very rough, respectively.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to this, and various modifications and modifications are made within the scope of the technical idea of the present invention described in the claims. It is clear to those with ordinary knowledge in the art that this is possible.

30a, 30b Payoff reel 40 Skin pass mill 100 Heat pipe roll 102 Rolled part 103 Neck part 104 Journal part 105, 106 Insert hole 108 Stopper 109 hole 110 Heat pipe

Claims (15)

Neck parts connected to bearings at both ends and
A rolled portion in which a plate material passing between the neck portions is rolled to form a plurality of insertion holes along the circumferential direction at a predetermined depth, and a rolled portion.
A heat pipe roll including a heat pipe inserted into the insertion hole inside the rolled portion and extended in the axial direction of the roll.
The heat pipe roll has C: 0.8 to 1.0%, Si: 0.8 to 1.2%, Mn: 0.8 to 1.2%, P: 0.030% or less in terms of weight%. , S: 0.020% or less, Ni: 0.6 to 1.0%, Cr3.0 to 6.0%, Mo: 0.3 to 0.7%, the balance Fe and unavoidable impurities. A forged roll-based heat pipe roll in which the surface of the heat pipe is coated with a thermally conductive material. The first aspect of the present invention, wherein the journal portion formed as an inclined surface between the neck portion and the rolled portion is further included, the insertion hole is formed in the journal portion of the inclined surface, and the heat pipe is incorporated. Forged roll-based heat pipe roll. The heat pipe includes a plurality of first heat pipes extending from one side in the roll axis direction to the central portion, and a plurality of second heat pipes extending from the opposite direction of the one side to the central portion. The forged roll-based heat pipe roll according to claim 1 or 2, wherein the 1 heat pipe and the second heat pipe are alternately arranged along the circumferential direction of the roll. The forged roll-based heat pipe roll according to claim 3, wherein the first heat pipe and the second heat pipe intersect each other at the central portion in the length direction of the roll. The forged roll-based heat pipe roll according to any one of claims 1 to 4, wherein the conductive material is Ni. The forged roll-based heat pipe roll according to any one of claims 1 to 5, wherein the forged roll is a recycled hot-rolled BUR (Backup Roll) or WR (Work Roll) that has reached the waste diameter. .. The forged roll-based heat pipe roll according to any one of claims 1 to 6, wherein the difference between the diameter of the insertion hole and the diameter of the heat pipe is controlled to 100 μm or less. The forged roll-based heat pipe roll according to any one of claims 1 to 7, wherein the initial crown amount of the forged roll-based heat pipe roll is controlled within a range of less than ± 0.05 mm. By weight%, C: 0.8 to 1.0%, Si: 0.8 to 1.2%, Mn: 0.8 to 1.2%, P: 0.030% or less, S: 0.020 % Or less, Ni: 0.6 to 1.0%, Cr3.0 to 6.0%, Mo: 0.3 to 0.7%, the balance is composed of Fe and unavoidable impurities , and the bearing at the end. A step of providing a forged roll including a neck portion connected to, a rolling portion for rolling a plate material passing between the neck portions, and a journal portion formed as an inclined surface between the neck portion and the rolled portion.
The stage of forming a plurality of insertion holes at a predetermined depth in the circumferential direction from the journal portion, and
A method for manufacturing a forged roll-based heat pipe roll, comprising a step of inserting a heat pipe having a surface coated with a conductive material into the insertion hole using a vacuum pump. The heat pipe includes a plurality of first heat pipes extending from one side in the roll axis direction to the central portion, and a plurality of second heat pipes extending from the opposite direction of the one side to the central portion. The method for manufacturing a forged roll-based heat pipe roll according to claim 9 , wherein the 1 heat pipe and the second heat pipe are alternately arranged along the circumferential direction of the roll. The method for manufacturing a forged roll-based heat pipe roll according to claim 10 , wherein the first heat pipe and the second heat pipe intersect each other at the central portion in the length direction of the roll. The method for manufacturing a forged roll-based heat pipe roll according to any one of claims 9 to 11 , wherein the conductive material is Ni. The production of a forged roll-based heat pipe roll according to any one of claims 9 to 12 , wherein no tube expansion heat treatment is performed for the expansion of the heat pipe after the heat pipe is inserted into the inside of the forged roll. Method. The method for manufacturing a forged roll-based heat pipe roll according to any one of claims 9 to 13 , wherein the difference between the diameter of the insertion hole and the diameter of the heat pipe is controlled to 100 μm or less. The method for manufacturing a forged roll-based heat pipe roll according to any one of claims 9 to 14 , wherein the initial crown amount of the forged roll is controlled within a range of less than ± 0.05 mm.

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