JP2007203306A - Device and method for cooling rolling roll, and rolling line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent any adverse effect on a plate passing property and the thickness quality of a rolled material when a used roll has been used for a rolling operation is cooled by a simple device so as to start the grinding after the temperature thereof is brought close to the normal temperature as far as possible, and the roll is ground and again used for the rolling operation. <P>SOLUTION: A rolling roll cooling device 25 is installed on a rolling roll changing device 23. The used roll used for the rolling operation is cooled by a simple device so as to start the grinding after the temperature of the roll is brought close to the normal temperature as far as possible. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling roll cooling device, a cooling method, and a rolling line. Rolling is meant to include cold rolling as well as hot rolling including thick plate rolling. In many cases, a thick plate refers to a thick steel plate, but other types of metals may be targeted.

  The thick steel plate is partially described in, for example, Non-Patent Document 1, although there is a hot-rolled steel strip (manufactured by a hot strip mill) and a region that wraps in a manufacturable plate thickness range. Thus, it refers to a steel sheet having a thickness in the range of 4.5 mm to 300 mm. In JIS, for example, among various steel plates and steel strips typified by the 3100 series, the steel plate direction is indicated. A hot-rolled steel strip manufactured by a hot strip mill is wound in a coil shape after finish rolling, whereas a thick steel plate is not wound.

  Hereinafter, for simplicity, the case of thick plate rolling will be described as an example. In plate rolling, a metal material is heated to several hundred to several hundreds of degrees Celsius, and then extracted onto a plate rolling line, and the roll is rotated thinly while being clamped by a pair or a plurality of pairs of rolls, and is thinly stretched. That means. FIG. 7 shows an example of a conventional thick plate rolling line 100. A metal material (rolled material) M having a thickness of 150 to 300 mm heated to several hundred to several hundreds of degrees Celsius by the heating furnace 20 is extended to a thickness of 10 to 300 mm by a rough rolling mill 22, and a finish rolling mill 24. Is further thinned and rolled to a thickness of 4.5 to 300 mm.

  The thick plate rolling line 100 shown in FIG. 7 includes two rolling mills, a rough rolling mill 22 and a finish rolling mill 24, but there is also a thick rolling mill line that includes only one rolling mill.

  Although there are these differences, in general, rolling a total of several to thirty times inside and outside is performed by the rough rolling mill 22 and the finishing rolling mill 24 or by only one rolling mill, and the material M to be rolled is Roll to bring it closer to the desired width and length. For example, rolling a plurality of times such as 6 times or 7 times is also referred to as rolling with 6 passes or 7 passes.

  In the example of the thick plate rolling line 100 shown in FIG. 7, the material to be rolled M is rolled several passes by the rough rolling machine 22, and then the material to be rolled M is rotated 90 ° in a plane, and then the material is rolled by the rough rolling machine 22. First, rolling out of the rolled material M, which is adjusted to a substantially desired width by reciprocating several passes, is performed, and then the rolled material M is again rotated 90 ° planarly, and the finishing mill 24 is further rotated. Thus, the material M is adjusted to a substantially desired thickness by reciprocating several passes.

  Moreover, the scale material of the oxide has adhered to the surface layer of the to-be-rolled material M extracted by being heated to several hundred to several hundreds of degrees Celsius. In addition, since the rolled material M is exposed to the atmosphere at a high temperature even in the process of being rolled and thinned and lowered in temperature by heat radiation, a new scale is generated on the surface layer of the rolled material M. These scales are peeled off and removed by a high-pressure water jet in and out of 10 to 30 MPa as the supply pressure from the pump injected from the nozzle of the descaling device. Although not shown in FIG. 7, the descaling apparatus has a descaling header attached to the entrance side and the exit side of each rolling mill as viewed in the transport direction A of the material to be rolled M, and a plurality of nozzles attached thereto. It consists of a pipe that leads to them and a pump that supplies water for a high-pressure water jet.

  The rolled material M that has finished rolling is air-cooled or water-cooled in the cooling zone 26 and given desired mechanical properties (such as tensile strength).

  And the material M to be rolled may be flattened by correcting the shape by the hot leveler 28, and after being air-cooled by the cooling bed 30, cutting, correction, heat treatment, flaw detection, surface treatment, marking, etc. (not shown) Supplied to one or more of the various refining processes according to the required specifications from the customer and shipped.

  By the way, the thick plate rolling line 100 is provided with a large number (more than one hundred) of table rollers 40 except for a certain position of each rolling mill, and conveys the material M to be rolled. Some table roller groups on the exit side of the roughing mill 22 are divided into two in the extending direction and reverse to each other, or rolls that are not divided but whose diameter is changed in the longitudinal direction are alternately arranged. Therefore, the material M to be rolled can be rotated 90 ° in a plane by alternately reversing.

  Reference numeral 50 denotes a control device, 70 denotes a process computer, and 90 denotes a business computer.

  The gap between the upper and lower rolls of each of the roughing mill 22 and the finishing rolling mill 24 is stored as data in the process computer 70, and the planned (desired) thickness of the material M to be rolled on the delivery side of each rolling mill. On the other hand, the result of calculating the elongation of the rolling mill housing due to the rolling reaction force (rolling load) is calculated in the process computer 70 so as to be added, and set before the tip of each material to be rolled M is bitten. Adjusted. The rotational speed of each roll is also calculated in the process computer 70, and is set and adjusted before the tip of each material to be rolled M is bitten.

  Now, in the field of thick plate rolling, during rolling, a rolling roll (hereinafter simply referred to as “roll”) 10 is in rolling contact with the material to be rolled M as it rolls the material to be rolled, and generates heat. receive. For this reason, there is a cooling water injection device (not shown) inside the rolling mill (both the rough rolling mill 22 and the finishing rolling mill 24), and the roll is rolled while being cooled.

  Even under such conditions of cooling, by rolling a number of materials to be rolled, the surface layer of the roll 10 rolls and fatigues, and if used as it is, the surface layer of the roll 10 peels off, resulting in a product thickness. Since it becomes a defect in the surface quality of the steel sheet, it is periodically replaced with a polished or new roll at a frequency empirically known as a condition that does not lead to peeling. The used roll 10 is subjected to rolling again after the surface layer is ground by a roll grinder (62 in FIG. 8 described later) not shown.

  FIG. 8 schematically shows how the roll 10 is replaced. Now, the state shown to Fig.8 (a) is the last rolling material which should be rolled with the roll 10 currently used with the rolling mill 22 (or it may be 24) during the operation of the thick plate rolling line 100. The state where rolling of M has been completed and the state where the replacement of the roll 10 is just started is viewed from above in a plan view. On the roll exchanging device 23, a polished or new roll 11 is in standby.

  As the next step, as shown in FIG. 8 (b), the used roll 10 used in the rolling mill 22 or 24 is extracted onto the roll changer 23.

  As a next step, as shown by an arrow B in FIG. 8B, the roll exchanging device 23 slides sideways to a state shown in FIG. 8C.

  Then, as the last step, as shown in FIG. 8 (d), the roll 11 that has been on standby, polished or new is incorporated into the rolling mill 22 or 24.

  Then, the operation of the thick plate rolling line 100 is resumed.

  Next, FIG. 9 is moved to explain the treatment of the used roll 10 that has been extracted. FIG. 9A is the same state as FIG. 8D described above.

  As the next step, as indicated by an arrow C in FIG. 9A, the roll exchanging device 23 slides sideways in the opposite direction to the previous state and enters the state shown in FIG. 9B.

  As a next step, as shown in FIG. 9C, the used roll 10 is moved from the roll changer 23 and carried into the roll shop 60.

  Then, as the last step, as shown in FIG. 9D, the used roll 10 is placed on the roll grinder 62 by a transfer machine (not shown). The roll grinder 62 polishes and removes the fatigue layer formed on the used roll 10. The polished rolls 12 are arranged in the temporary storage place 64 and are kept waiting until the next chance to use them in the rolling mill 22 or 24.

  In the above description, when the used roll 10 extracted from the rolling mill 22 or 24 is carried into the roll shop 60, the roll grinder 62 starts polishing immediately. Thus, immediately starting polishing of the used roll 10 extracted from the rolling mill 22 or 24 by the roll grinder 62 is referred to as warm polishing (or sometimes referred to as warm grinding).

  The used roll 10 extracted from the rolling mill 22 or 24 is still warm inside and outside at 40 to 60 ° C. and is more thermally expanded than the room temperature state.

  Originally, when the used roll 10 extracted from the rolling mill 22 or 24 is cooled to room temperature and started to be polished by the roll grinder 62, it is finished closer to the desired polishing profile. Although it is desirable, there is a demand from another aspect that the number of stocks of roll 10 must be kept as small as possible due to problems such as asset taxation costs. The fact is that it must be warm-polished because it must be rotated by being incorporated into or extracted from the rolling mill 22 or 24.

  There is no doubt that it is preferable to start polishing after the temperature is brought close to room temperature even if it is inevitably subjected to warm polishing.

  In patent document 1, as shown in FIG. 10, the method and apparatus which immerse the roll 10 in the water tank 90 called a pallet are described, and also conveying by the trolley | bogie 92 in that state is also described.

  Moreover, although it does not directly refer to the warm polishing, in Patent Document 2, a cooling header 94 is provided along the roll axis directly above the circumferential direction of the roll 10, and the partial length directly above the circumferential direction of the roll. A method for cooling a roll that supplies cooling water uniformly in a rectified state is described.

“Refining and Quality of Hot Rolled Steel Sheet (Revised 2nd Edition: March 1994) p31” (Steel Institute, Industrial Technology College, Human Resources Development Center) JP 09-155416 A Japanese Patent Laid-Open No. 11-057822

  As described above, although it is necessary to perform warm polishing, it is preferable to start polishing after bringing the temperature close to room temperature. However, the method of immersing the roll 10 in the water tank 80 described in Patent Document 1 has a problem that the apparatus is too large and expensive. The present invention has been made to solve such problems of the prior art.

  That is, the present invention is as follows.

  (1) A rolling roll cooling device which is installed on a rolling roll changer.

  (2) The rolling roll cooling device according to (1), wherein the rolling roll cooling device transmits water on the surface of the rolling roll.

  (3) A rolling roll cooling method characterized by incorporating a polished or new rolling roll into a rolling mill while cooling a used rolling roll.

  (4) The method of cooling a rolling roll according to (3), wherein the cooling of the rolling roll is performed by transferring water onto the surface of the rolling roll.

  (5) A rolling line comprising the rolling roll cooling device according to any one of (1) and (2).

  According to the present invention, it is possible to start polishing after cooling a used roll subjected to a rolling operation with a simple apparatus and bringing it to room temperature as much as possible.

  Thereby, when the roll is ground and then subjected to a rolling operation again, it is possible to prevent adverse effects on the sheet passing property and the plate thickness quality of the material to be rolled.

(First embodiment)
FIG. 1 is a diagram for explaining a first embodiment of the present invention. A roll cooling device 25 is installed on a conventional roll exchanging device 23 that has appeared in FIGS.

  FIG. 2 is a diagram illustrating an example of the roll cooling device 25. A header 252 in which nozzles 251 are arranged is further attached to the collective pipe 253, and cooling water w sent from a cooling water supply system (not shown) is injected from the nozzle 251 and sprinkled toward the roll 10. It has become a mechanism. The roll 10 is pulled up and down from the rolling mill 22 or 24 because the chocks (bearing boxes) (not shown) are stacked and pulled out from the rolling mill 22 or 24. In FIG. For simplicity, the neck portion and the chock (bearing box) attached thereto are not shown. Of the chocks (bearing housings) not shown, those attached to the lower roll 10B are also not shown, but wheels are attached, and the rolls 10 are stacked one above the other with a hydraulic cylinder or an electric motor. It can be transported as it is.

  In FIG. 2, the cooling water w is sprinkled toward the upper roll 10 </ b> A, but the cooling water w applied to the upper roll 10 </ b> A falls naturally and is applied to the lower roll 10 </ b> B. It is sufficient to spray the cooling water w, but even if it is directed to the lower roll 10B, there is no problem with spraying the cooling water w.

(Second Embodiment)
FIG. 3 is a diagram for explaining a second embodiment of the present invention. A header 252 may be provided immediately above the circumferential direction of the roll 10 along the roll axis (in the normal direction of the paper surface), and cooling water may be supplied over the entire length of the portion directly above the roll 10. A water film having a substantially uniform thickness is formed on the roll surface, and the occurrence of uneven cooling in the circumferential direction and the axial direction of the roll 10 can be more reliably suppressed.

(Other embodiments)
In addition to the two embodiments described above, for example, not the full length of the roll but the concentrated water sprayed on the plate path (the area in contact with the material to be rolled M during rolling), the rolls stacked one above the other However, the present invention can be applied to various types of variations, such as those that cool separately, those that spray mist instead of cooling water, and those that inject air. As long as 25 is installed, any embodiment may be adopted.

  FIG. 4 shows the effect of the present invention. The elapsed time after extraction from the rolling mill on the horizontal axis, and the roll surface temperature on the vertical axis. The time when the roll 10 is extracted from the rolling mill 22 at a roll surface temperature of 57 ° C. is defined as the elapsed time 0, and the surface temperature of the upper roll thereafter is shown. The effect is shown about the case where said 2nd Embodiment is taken.

The diameter of the roll is 1200 mm, the length of the body (meaning the part excluding the neck) is 5500 mm, the nozzle pitch is 50 mm, the cooling water temperature is 25 ° C., and the cooling water flow rate is 0 per nozzle. 0.002 m ³ / min.

  When the cooling is not performed, that is, when the present invention is not carried out, the temperature of the roll surface is slightly lower than that immediately after the extraction even when the elapsed time after the extraction from the rolling mill reaches 12 hours. It has only dropped by 10 ° C.

  In this regard, according to the present invention, even when the elapsed time from extraction from the rolling mill is at most 4 hours, the surface temperature of the upper roll when water is sprayed from the roll cooling device 25 on the roll changer 23 and both the upper and lower rolls 10 are cooled. Is as low as 25 ° C up to 32 ° C. The same applies to the lower roll.

  In the case of a thick plate rolling line, although the frequency of roll exchange varies somewhat, it is roughly a ratio of about once every 24 hr, and the time required for polishing the roll is about 1 hr per roll or more than that. Since it is short, cooling on a rolling roll changer for about 4 hr has no problem in operation.

  In the above description, the case where the present invention is applied to the thick plate rolling line has been described as an example. However, the present invention is not limited to the thick plate rolling line as shown in FIG. The present invention can be similarly applied to a hot rolling line 200 of a metal strip such as a metal strip, a cold rolling line 300 of a metal strip such as a steel strip shown in FIG. In the case of a hot rolling line or a cold rolling line, the frequency of roll exchange is roughly a ratio of about once every 3 to 8 hours, although it varies depending on which stand if it is a finishing rolling mill. If the time required for polishing is subtracted, the time for cooling on the roll changer is shorter than that for the thick plate rolling line, but it is effective. In FIG. 5, 14 is a backup roll, 16 is an edger roll, 21 is a width press, 23 is a crop shear, 25 is a descaling device, 27 is a run-out table, 29 is a coiler, and 42 in FIG. An unwinding reel, 43 is a take-up reel, 44 is a cutting machine, 46 is a joining machine, and 48 is a loop facility.

The top view for demonstrating the 1st Embodiment of this invention The perspective view which similarly shows the principal part Side view for explaining a second embodiment of the present invention Diagram for explaining the effect of the present invention The figure for demonstrating another rolling line which should apply this invention The figure for demonstrating another rolling line which should apply this invention The figure for demonstrating the example of the plate rolling line which should apply this invention The top view for demonstrating the state of the roll exchange in the thick plate rolling line which should apply this invention A plan view for explaining the process up to roll polishing. Longitudinal sectional view for explaining the prior art described in Patent Document 1 Cross-sectional view for explaining the prior art described in Patent Document 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Thick plate rolling line 10, 11, 12 ... Roll (roll)
DESCRIPTION OF SYMBOLS 20 ... Heating furnace 22 ... Rough rolling mill 23 ... Roll changer 24 ... Finishing mill 25 ... Roll cooling device 251 ... Nozzle 252 ... Header 253 ... Collecting piping 26 ... Cooling zone 30 ... Cooling bed 40 ... Table roller 50 ... Control device 60 ... Roll shop 62 ... Roll grinder 70 ... Process computer 80 ... Water tank 90 ... Business computer A ... Conveying direction M ... Rolled material w ... Cooling water

Claims (5)

  A rolling roll cooling device, which is installed on a rolling roll changer.   The rolling roll cooling device according to claim 1, wherein the rolling roll cooling device is configured to transmit water onto the surface of the rolling roll.   A rolling roll cooling method, wherein a polished or new rolling roll is incorporated into a rolling mill while cooling a used rolling roll.   The method of cooling a rolling roll according to claim 3, wherein the cooling of the rolling roll is performed by transferring water onto the surface of the rolling roll.   A rolling line comprising the rolling roll cooling device according to claim 1.

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