JP2012096245A - Rolling lubricating method in cold rolling and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling lubricating method in cold rolling including: performing rolling while circularly supplying an emulsion rolling lubricating oil and/or neat rolling lubricating oil, in which the emulsion rolling lubricating oil and/or neat rolling lubricating oil subjected to lubrication and oxidized, and supplied to an inlet portion of a roll bite is prevented from degradation, and to provide a device therefor.SOLUTION: In the cold rolling in which rolling is performed while circularly supplying the emulsion rolling lubricating oil or neat rolling lubricating oil to the inlet portion of the roll bite, an electromagnetic wave generator 45 for generating reduction potential is disposed in a rolling lubricating oil tank 31, through which the rolling lubricating oil subjected to lubrication and oxidized, and supplied to an inlet portion of a roll bite is passed, to apply negative load to the oxidized emulsion rolling lubricating oil or neat rolling lubricating oil in the rolling lubricating oil tank 31, so that the rolling lubricating oil is reduced and prevented from degrading.

Description

  The present invention is capable of preventing reduction in lubricity and deterioration in oil intensity due to deterioration of oil in cold rolling in which rolling is performed while circulatingly supplying emulsion rolling lubricating oil or neat rolling lubricating oil, and mill contamination and The present invention relates to a rolling lubrication method and apparatus in cold rolling capable of preventing surface defects due to dropping off.

  In cold tandem rolling, generally called a thick mill, emulsion rolling lubricating oil having a rolling lubricating oil concentration of 1 to 5% is circulated and used, which is called recirculation lubrication. In this recirculation lubrication, the emulsion rolling lubricating oil supplied to the rolling mill is once recovered in a lubricating oil tank called a dirty tank, and after the deteriorated floating oil is removed, a purification process such as a filter or an iron powder removing device is performed. The emulsion rolling lubricant in the clean tank is supplied to a cold tandem rolling mill.

  In the recirculation lubrication described above, emulsion rolling lubricant or neat rolling lubricating oil is oxidized by thermal load due to heat generated in the roll bite during rolling of a cold tandem rolling mill or contact with air or water during spraying. It becomes positively charged and gradually deteriorates. For this reason, the lubricating performance of emulsion rolling lubricating oil or neat rolling lubricating oil is degraded. Moreover, the deteriorated emulsion rolling lubricant or neat rolling lubricating oil tends to aggregate. As a result, the agglomerated oil easily adheres to the rolling mill, and surface defects called “bottom dropping” caused by mill dirt or mill dirt occur. Furthermore, the amount of floating oil increases, and the emulsion rolling lubricating oil or neat rolling lubricating oil discharged from the recirculation system increases.

  Therefore, in operation, in order to prevent the deterioration of the lubricating oil, the emulsion rolling lubricating oil or neat rolling lubricating oil that is difficult to deteriorate, such as partial replacement or total replacement of the emulsion rolling lubricating oil in the tank regularly (for example, Patent Document 1, paragraphs [0005] and [0006]). In addition, the surface potential of the emulsion rolling lubricating oil is measured and managed, and an electrolyte is replenished to increase the electrical conductivity of the new lubricant, emulsifier, emulsified stock solution or emulsifier concentration on the aqueous phase side of the lubricant (for example, Patent Document 2, (See paragraphs [0025] and [0031]).

  However, replenishment of emulsion rolling lubricating oil due to concentration reduction, partial replacement of emulsion rolling lubricating oil in the tank several times a month and full replacement several times a year will cause deterioration in oil intensity, and are difficult to deteriorate. Although emulsion rolling lubricant is effective, it will lead to an increase in cost due to an increase in the unit price of oil. Corresponding to the control of the surface potential exhibits a remarkable effect although it is effective for the timing and amount of replenishment of the emulsion rolling lubricant. Not a translation.

  As described above, the conventional technology also aims to maintain the performance by exchanging the quality of the deteriorated emulsion rolling lubricating oil with a new oil. In addition, the concentration reduction here refers to a decrease in oil content that adheres to the surface of the sheet rolled by cold rolling, and a rolling lubricant containing a lot of iron powder adheres to the tank or rolling mill. It means that the oil content is reduced by depositing as scum around, the oil content is removed when iron powder is removed, or the oil content is removed by adhering to the filter.

  Moreover, there exists a technique which prevents deterioration of such edible oil in edible oil. In this technology, rare earth elements that strengthen magnetic force such as neodymium are mixed with porcelain and applied to the entire inside or the bottom of the pan and sintered at a high temperature, or the bottom is sintered in a ceramic form as an electrode. Prevent deterioration of cooking oil by electromagnetic induction high frequency. High-frequency waves from the electromagnetic induction equipment cause a current to flow through the electrode (coated ceramic layer) inside the pan, and a large amount of electrons are released to the edible oil extraction temperature, forming an electromagnetic field, creating a plasma state and oxidizing or overoxidizing the edible oil There is a method in which lipidation is decomposed and reduced (see, for example, Patent Document 3: [Claim 1] and paragraph [0005]).

  Cited Document 3 discloses that the oxidized oil is certainly reduced by electromagnetic waves. However, since the transformer (No. 4), the CPU (No. 5) and the inverter (No. 8) are connected in series in FIG. 1 following the rectifier (No. 3), the inverter (No. 8) is connected. ) Is unknown. Also, with regard to the number of turns and current of the magnetic coil (No. 20) that emits intense radio waves from the electrodes in the oil tank by high frequency, oxidizes the edible oil and decomposes lipid peroxide, and reduces the oil. It is not explained to the extent that can be implemented by a contractor (see column 4: “20. Magnetic coil”). Therefore, those skilled in the art cannot implement the invention described in the cited document 3.

JP 2000-017284 A JP 2002-102914 A JP 2002-209518 A

  The present invention relates to a lubricated oxidized emulsion rolling lubricant and / or neat rolling lubrication supplied to a roll bite inlet in cold rolling in which rolling is performed while circulatingly supplying emulsion rolling lubricating oil and / or neat rolling lubricating oil. It is an object of the present invention to provide a rolling lubrication method and apparatus for preventing deterioration of oil.

The gist of the present invention for solving the above problems is as follows.
(1) In cold rolling in which rolling is performed while circulatingly supplying emulsion rolling lubricating oil or neat rolling lubricating oil to the roll bite inlet, lubricated oxidized emulsion rolling lubricating oil or neat rolling supplied to the roll bite inlet An electromagnetic wave generator that oscillates a reduction potential is provided in a rolling lubricating oil tank through which the lubricating oil passes, and a negative charge is imparted to the oxidized emulsion rolling lubricating oil or neat rolling lubricating oil in the rolling lubricating oil tank. A rolling lubrication method in cold rolling, which comprises reducing rolling lubrication oil or neat rolling lubrication oil and preventing deterioration of the rolling lubrication oil.
(2) In cold rolling, in which rolling is performed while emulsion rolling lubricating oil or neat rolling lubricating oil is circulated and supplied to the roll bite inlet, the rolling lubricating oil circulation pipe through which the emulsion rolling lubricating oil or neat rolling lubricating oil circulates, and An electromagnetic wave generator that oscillates a reduction potential outside the rolling lubricating oil circulation pipe is provided, and a negative charge is imparted to the emulsion rolling lubricating oil or neat rolling lubricating oil in the rolling lubricating oil circulating pipe. A rolling lubrication method in cold rolling, characterized by reducing neat rolling lubricating oil and preventing deterioration of the rolling lubricating oil.
(3) A rolling lubricating oil tank through which lubricated oxidized emulsion rolling lubricating oil or neat rolling lubricating oil supplied to the roll bite inlet is passed, and the rolling lubricating oil circulation is provided on the outlet side of the rolling lubricating oil tank. The rolling lubrication method in cold rolling according to (2), wherein a negative charge is imparted to the rolling lubricant in the pipe.
(4) Further supplying neat rolling lubricating oil to the roll bite inlet, imparting a negative charge to the emulsion rolling lubricating oil and / or neat rolling lubricating oil, reducing the emulsion rolling lubricating oil / or neat rolling lubricating oil, The rolling lubrication method in cold rolling according to (1), (2) or (3), which prevents deterioration of emulsion rolling lubricating oil / neat rolling lubricating oil.
(5) The rolling lubrication method in cold rolling according to any one of (1) to (4), wherein the temperature of the emulsion lubricant and / or neat rolling lubricant is 40 ° C. or lower.
(6) the emulsion rolling lubrication oil or neat rolling lubrication oil in cold rolling mill is rolling while circulating fed to the roll bite inlet, emulsion rolling lubrication oil or neat the oxidation of lubricating supplied to the said roll bite inlet An electromagnetic wave generator that oscillates a reduction potential in a rolling lubricating oil tank through which the rolling lubricating oil passes, and imparts a negative charge to the oxidized emulsion rolling lubricating oil or neat rolling lubricating oil in the rolling lubricating oil tank, A rolling lubrication apparatus in cold rolling, wherein emulsion rolling lubricating oil or neat rolling lubricating oil is reduced to prevent deterioration of rolling lubricating oil.
(7) In a cold rolling mill that performs rolling while circulatingly supplying emulsion rolling lubricating oil or neat rolling lubricating oil to the roll bite inlet, the rolling lubricating oil circulation pipe through which the emulsion rolling lubricating oil or neat rolling lubricating oil circulates; An electromagnetic wave generator that oscillates a reduction potential outside the rolling lubricating oil circulation pipe, and imparts a negative charge to the emulsion rolling lubricating oil or neat rolling lubricating oil in the rolling lubricating oil circulating pipe, and the emulsion rolling lubrication A rolling lubrication apparatus in cold rolling characterized by reducing oil or neat rolling lubricating oil to prevent deterioration of rolling lubricating oil.
(8) A rolling lubricating oil tank through which the lubricated oxidized emulsion rolling lubricating oil or neat rolling lubricating oil supplied to the roll bite inlet is passed, and the rolling lubricating oil circulation is provided on the outlet side of the rolling lubricating oil tank. The rolling lubrication apparatus in cold rolling according to (7), wherein a negative charge is imparted to the rolling lubricating oil in the pipe.
(9) A neat rolling lubricating oil supply nozzle for further supplying a neat rolling lubricating oil to the roll bite inlet, and a neat rolling lubricating oil supply device for supplying the neat rolling oil to the nozzle, and an emulsion rolling lubricating oil and / or Alternatively, a negative charge is imparted to the neat rolling lubricating oil, the emulsion rolling lubricating oil / or neat rolling lubricating oil is reduced, and deterioration of the emulsion rolling lubricating oil / or neat rolling lubricating oil is prevented (6) to (8) The rolling lubrication apparatus in the cold rolling of any one of Claims 1.

  In the rolling lubrication method and apparatus for cold rolling according to the present invention, it is possible to prevent deterioration in lubricity and deterioration in oil intensity due to oxidation of rolling lubricating oil, and it is possible to prevent surface defects due to mill stains and dropping off of a button, It is possible to improve productivity and reduce manufacturing costs.

  In the invention which concerns on (5), the viscosity of emulsion lubricating oil or neat rolling lubricating oil becomes high because the temperature of rolling lubricating oil shall be 40 degrees C or less. As a result, since the lubrication effect becomes high, a low-viscosity rolling lubricating oil can be used, and the basic unit and the cooling effect can be improved.

It is one of the embodiments of this invention, and is a schematic diagram of a rolling mill equipped with a deteriorated emulsion rolling lubricating oil reducing device. It is a block diagram of the cold tandem rolling equipment which consists of a rolling mill shown in FIG. It is other embodiment of this invention, and is the schematic of the rolling mill provided with the deteriorated emulsion rolling lubricating oil reduction apparatus. FIG. 5 is a schematic view of a rolling mill that is still another embodiment of the present invention and includes a deteriorated rolling lubricating oil reducing device. It is a block diagram of the cold tandem rolling equipment which consists of a rolling mill shown in FIG. FIG. 5 is a schematic view of a rolling mill that is still another embodiment of the present invention and includes a deteriorated rolling lubricating oil reducing device.

  A first embodiment of the present invention will be described with reference to FIG.

  The rolling mill 1 is a quadruple rolling mill, and the roll configuration includes an upper work roll 2 and a lower work roll 3, and an upper backup roll 4 and a lower backup roll 5. Each of the rolls 2 to 5 is supported by a roll chock (not shown). In the present invention, the roll configuration is not limited to four stages, and may be five stages, six stages, clusters, or the like.

  The rolling mill 1 is formed with an emulsion rolling lubricating oil circulation system 6 including an emulsion rolling lubricating oil circulation pipe 7. The emulsion rolling lubricating oil circulation pipe 7 includes a reduced emulsion rolling lubricating oil supply pipe 8, an emulsion rolling lubricating oil supply pipe 12, an emulsion rolling lubricating oil recovery pipe 22, a deteriorated emulsion rolling lubricating oil supply pipe 34, and a clean emulsion. It consists of a rolling lubricating oil feed pipe 40 and the like. In addition to the emulsion rolling lubricating oil circulation pipe 7, the emulsion rolling lubricating oil circulation system 6 further includes an emulsion rolling lubricating oil recovery unit 21, an emulsion rolling lubricating oil tank 31, pumps 35 and 41, a filter 37, and a flow control valve 13. , 34, and the like.

  Upper and lower emulsion rolling lubricant supply nozzles 10 and 11 are arranged on the rolling mill inlet side, and upper and lower coolant supply nozzles 15 and 16 are arranged on the outlet side. The top and bottom emulsion rolling lubricating oil supply nozzles 10 and 11 are connected to the tip of an emulsion rolling lubricating oil supply pipe 12 to which an emulsion rolling lubricating oil flow rate adjustment valve 13 is attached. Connected to the upper and lower coolant supply nozzles 15, 16 is a tip of a coolant supply pipe 17 to which a coolant flow rate adjusting valve 18 is attached. Further, the emulsion rolling lubricating oil supply pipe 12 and the coolant supply pipe 17 are connected to the terminals of the emulsion feeding pipe 8 on the discharge side of the reduced emulsion rolling lubricating oil pump 9. The emulsion supply pipe 8 supplies clean and reduced emulsion rolling lubricating oil to the upper and lower emulsion supply nozzles 10 and 11 and the upper and lower coolant supply nozzles 15 and 16.

  An emulsion rolling lubricating oil recovery device 20 and a deteriorated emulsion rolling lubricating oil reducing device 30 are disposed immediately below the lower backup roll of the rolling mill 1.

  The emulsion rolling lubricating oil recovery device 20 includes a funnel-shaped emulsion rolling lubricating oil recovery part 21 and an emulsion rolling lubricating oil recovery pipe 22 extending downward from the bottom thereof. The lubricated oxidized and deteriorated emulsion rolling lubricating oil supplied to the roll bite inlet is recovered.

  The deteriorated emulsion rolling lubricating oil reduction device 30 includes an emulsion rolling lubricating oil tank 31 including a dirty tank 32 and a clean tank 33. An emulsion rolling lubricating oil recovery pipe 22 extending from the bottom of the lubricating oil recovery device 20 is connected to the upper surface of the dirty tank 32. Further, a dirty emulsion rolling lubricating oil supply pipe 34 extending from the bottom surface of the dirty tank 32 extends, and a dirty emulsion rolling lubricating oil pump 35 is attached to the dirty emulsion rolling lubricating oil supply pipe 34. Further, a filter 37 is attached to the tip of the dirty emulsion rolling lubricating oil supply pipe 34. Connected to the filter 37 is a clean emulsion rolling lubricating oil feed pipe 40 having a tip extending to the clean tank 33 and having a clean emulsion rolling lubricating oil pump 41 attached thereto. Further, the suction-side emulsion supply pipe 8 of the reduced emulsion rolling lubricating oil pump 9 extends into the clean tank 33.

  Here, the effect | action of the rolling mill 1 provided with the deteriorated emulsion rolling lubricating oil reducing apparatus 30 comprised as mentioned above is demonstrated with reference to FIG.

  The emulsion rolling lubricating oil supplied to the upper and lower emulsion rolling lubricating oil supply nozzles 10 and 11 on the rolling mill 1 is brought into contact with the thermal load due to heat generated in the roll bite during rolling and contact with air and water during spraying. Oxidizes to become positively charged and gradually deteriorates. The deteriorated emulsion rolling lubricant contains dust, scales generated by rolling, and the like. Along with the coolant, it is recovered by the emulsion rolling lubricant recovery unit 21 of the emulsion rolling lubricant recovery device 20. The recovered deteriorated emulsion rolling lubricating oil is sent from the emulsion rolling lubricating oil recovery pipe 22 to the dirty tank 32 of the emulsion rolling lubricating oil tank 31. Further, the deteriorated emulsion rolling lubricating oil in the dirty tank 32 is sent to the filter 37 via the deteriorated emulsion rolling lubricating oil supply pipe 34 by the deteriorated emulsion rolling lubricating oil supply pump 35.

  The filter 37 removes the dust contained in the deteriorated emulsion rolling lubricating oil, the scale generated by the rolling, etc., and cleans the deteriorated emulsion rolling lubricating oil. The clean emulsion rolling lubricant is sent to the clean tank 33 via the clean emulsion rolling lubricant feed pipe 40 by the clean emulsion rolling lubricant feed pump 41. In the clean tank 33, a negative charge is imparted to the clean emulsion rolling lubricant by the electromagnetic wave generator 45 that oscillates the reduction potential, and the clean emulsion rolling lubricant is reduced.

  Clean reduced emulsion rolling lubricating oil is sent to the emulsion rolling lubricating oil circulation pipe 7 via the reduced emulsion rolling lubricating oil feed pipe 8 by the reduced emulsion rolling lubricating oil pump 9. Next, clean reduced emulsion rolling lubricating oil is supplied from the emulsion rolling lubricating oil circulation pipe 7 to the upper and lower emulsion rolling lubricating oil supply nozzles 10 and 11. Further, clean reduced emulsion rolling lubricating oil is supplied to the upper and lower coolant supply nozzles 15 and 16 from the coolant supply pipe 17. In addition, the amount of emulsion rolling lubricating oil supplied to the upper and lower emulsion rolling lubricating oil supply nozzles 10 and 11 is adjusted by an emulsion rolling lubricating oil flow rate adjustment valve 13 according to rolling conditions. Similarly, the coolant supply amount to the upper and lower coolant supply nozzles 15 and 16 is adjusted by the coolant flow rate adjusting valve 18 in accordance with rolling conditions.

  FIG. 2 is an example of cold tandem rolling equipment, and includes four rolling mills 1a to 1d shown in FIG. The four rolling mills 1a to 1d of the cold tandem rolling mill share the emulsion rolling lubricating oil circulation pipe 7 and the deteriorated emulsion rolling lubricating oil reducing device 30 shown in FIG. The functions of the emulsion rolling lubricating oil circulation pipe 7 and the deteriorated emulsion rolling lubricating oil reducing device 30 are the same as those shown in FIG.

  FIG. 3 shows a second embodiment of the present invention. In the following, components having the same structure and function as the apparatus and members of the embodiment shown in FIG.

  The second embodiment is different from the first embodiment in that the electromagnetic wave generating device 52 of the emulsion rolling lubricating oil deterioration reducing device 50 is arranged outside the reduced emulsion rolling lubricating oil supply pipe 8. Yes. The first embodiment and the second embodiment are different in the deployment position of the electromagnetic wave generator, but the performance is not greatly different.

  FIG. 4 shows a third embodiment of the present invention. The third embodiment is different from the first embodiment in that the upper and lower neat rolling lubricant supply nozzles 60 and 61 and the neat rolling lubricant supply device 65 are added to the first embodiment. . In the neat rolling lubricating oil supply device 65, a neat rolling lubricating oil supply pipe 67 is connected to a neat rolling lubricating oil tank 66. A neat rolling lubricating oil pump 67 and a neat rolling lubricating oil flow control valve 69 are attached to the neat rolling lubricating oil supply pipe 67. Further, the upper and lower neat rolling lubricating oil supply nozzles 60 and 61 are connected to the tip of the neat rolling lubricating oil supply pipe 67.

  In the third embodiment, neat rolling lubricating oil is supplied to the roll bite inlet in addition to the emulsion rolling lubricating oil. Then, a negative charge is imparted to the emulsion rolling lubricating oil and / or the neat rolling lubricating oil, the emulsion rolling lubricating oil / or the neat rolling lubricating oil is reduced, and the deterioration of the emulsion rolling lubricating oil / or the neat rolling lubricating oil is prevented. .

  When only neat rolling lubricating oil is supplied, it is oxidized and deteriorated by a roll bite. The deteriorated neat rolling lubricating oil is recovered as shown in FIG. 4, reduced by the electromagnetic wave generator 45, and circulated through the emulsion rolling lubricating oil circulation system 6.

  When only neat rolling lubricating oil or emulsion rolling lubricating oil and neat rolling lubricating oil are supplied, emulsion rolling lubricating oil having a higher concentration than that of only emulsion rolling lubricating oil is supplied. Performance is high. Therefore, the third embodiment is suitable for, for example, high-tensile rolling that requires high lubrication conditions.

  FIG. 5 is another example of the cold tandem rolling equipment, and includes four rolling mills 1a to 1d shown in FIG. The four rolling mills 1a to 1d of the cold tandem rolling mill share the emulsion rolling lubricating oil circulation pipe 7, the deteriorated emulsion rolling lubricating oil reducing device 30, and the neat rolling lubricating oil supplying device 65 shown in FIG. . The functions of the emulsion rolling lubricating oil circulation pipe 7 deteriorated emulsion rolling lubricating oil reducing device 30 and the neat rolling lubricating oil supplying device 65 are the same as those shown in FIG.

  FIG. 6 shows a fourth embodiment of the present invention. In the fourth embodiment, the electromagnetic wave generating device 52 is disposed outside the reduced emulsion rolling lubricating oil supply pipe 8. In the third embodiment shown in FIG. 4, the electromagnetic wave generating device 45 is an emulsion rolling lubricating oil tank. 31 is different in that it is deployed in the area. Although the deployment position of the electromagnetic wave generator is different between the fourth embodiment and the third embodiment, the performance is not greatly different.

  Experiments on the present invention were conducted using the rolling lubrication apparatus shown in FIG. As the emulsion rolling lubricating oil, a rolling lubricating oil (viscosity 50 cSt, 40 ° C.) of a polymer synthetic ester base oil was used at a concentration of 1.5% and a temperature of 50 ° C. As the metal strip S, a coil having a plate thickness of 2.0 to 0.8 mm and a plate width of 800 to 1200 mm was used, and as a steel type, ordinary steel (SPCC) was used. The inlet side tension was 50 MP, the outlet side tension was 100 MPa, the rolling reduction was 20 to 30%, and the rolling speed was 300 to 1000 m / min. In the experiment, the dirty tank 32 was cleaned and a new oil was created before the experiment was started. Weighing plates were placed on the upper and side parts of the rolling mill housing, and the amount of oil deposited on the weighing plate was measured to measure mill dirt, and the amount of accumulated scum in the dirty tank 32 was measured.

  The above steel type was continuously rolled for one month while supplying emulsion rolling lubricant at 150 L / min from the rolling mill inlet side and 50 L / min from the rolling mill outlet side. The frequency and strength of the electromagnetic wave generator 45 were adjusted so that the potential of the emulsion rolling lubricant was negative. Further, once a day, the concentration of the emulsion rolling lubricating oil in the clean tank 33 was measured, the oil was added so as to be a predetermined concentration, and the added amount was integrated. As a result, it was found that the use of the electromagnetic wave generator 45 reduces the amount of additional oil and the amount of scum by about 50% compared to the case where the amount of oil is not used.

  FIG. 2 is a block diagram of a cold tandem rolling mill for carrying out the present invention. Although not shown, a pickling facility is disposed upstream of the cold tandem rolling mill, and a metal strip that has been hot-rolled to remove the scale of the surface layer is continuously supplied. Although not shown, downstream of the cold tandem rolling mill are a cutting machine for cutting the cold rolled metal strip and a take-up reel for winding the cold rolled metal strip into a coil shape. Has been placed.

  The cold tandem rolling mill is composed of four rolling stands 1a to 1d, all of which are quadruple rolling mills. The work roll is composed of upper work rolls 1a to 1d and lower work rolls 2a to 2d having a roll diameter of 500 mm and a cylinder length of 2000 mm, and the backup roll is an upper backup roll 3a to 3d having a roll diameter of 1400 mm and a cylinder length of 2000 mm. And lower backup rolls 4a to 4d, and each roll is supported by a roll chock (not shown).

  In addition to supplying emulsion rolling lubricating oil to the entrance sides of the respective rolling mills 1a to 1d, lower lubricating supply nozzles 10a to 10d and 11a to 11d are arranged. During rolling, the emulsion rolling lubricating oil in the clean tank 33 is a roll bite. Supplied to the inlet. The same emulsion rolling lubricating oil is supplied from the upper and lower coolant supply nozzles 15a to 15d and 16a to 16d for cooling the upper work roll and the lower work roll from the exit side of the rolling mill. Emulsion lubricating oil used for rolling is collected in a dirty tank 32, filtered by a filter 37, and recycled to a clean tank 33. An electromagnetic wave generator 45 is provided in the clean tank 33.

  As the emulsion rolling lubricating oil, a rolling lubricating oil (viscosity 50 cSt, 40 ° C.) of a polymer synthetic ester base oil was used at a concentration of 1.5% and a temperature of 50 ° C.

As the metal strip S, a coil having a plate thickness of 1 to 5 mm and a plate width of 700 to 1240 mm was used, and ordinary steel was used as the steel type. Table 1 shows typical rolling conditions. As for the roughness of the work roll, the first rolling mill 1a to the third rolling mill 1c are scratch rolls (surface roughness 0.3 to 0.5 μmRa), and the final rolling mill 1d is a dull roll (surface roughness 3.8 μmRa). In addition, the mill stain was measured by measuring the oil adhering to the measuring freight by placing measuring plates on the upper and side portions of the housing of the rolling mill. The maximum rolling speed of this cold tandem rolling mill is 1200 m / min.

  The case where the electromagnetic wave generator was not used as the prior art and the case where the electromagnetic wave generator 45 was used as the present invention were compared. In the embodiment of the present invention, the output of the electromagnetic wave was 50 kW, and the frequency was 8 kHz. In addition, the oil concentration in the clean tank 33 was measured every day, and new oil was replenished so that it might become a predetermined concentration. In addition, when the acid value of the oil in the clean tank 33 is measured and exceeds the control standard, even if the partial replacement of the emulsion lubricant is further replaced, if the effect cannot be maintained for one week, the entire replacement is performed. did. At the time of complete replacement, the scum accumulated in the dirty tank 32 was removed and its weight was measured. The prior art and the present invention were each continuously implemented for one year, and the effects were compared.

  In the prior art, the oil deteriorates with time and the acid value increases, requiring three partial replacements on average month and full replacement twice a year. In the present invention, partial replacement once per average month and full replacement once a year are required. Further, the amount of new oil to be replenished was about 1/3 of the prior art in the present invention. In addition, the scum and the dirt of the mill accumulated in the dirty tank 32 were about ¼ that of the prior art in the present invention as compared with the year. Furthermore, the surface defect called “bottom drop” is about 1/10 of the prior art in the case of the present invention. As a result, in the past, surface defects due to the deterioration of the oil intensity and the drop of the button occurred, but this invention improves the oil intensity and reduces the manufacturing cost and causes the surface defect due to the loss of the button. No cold rolling became possible.

  The present invention is not limited to the above embodiment. For example, the emulsion rolling lubricating oil circulation system 6 includes an emulsion rolling lubricating oil recovery unit 21, an emulsion rolling lubricating oil tank 31, pumps 35 and 41, a filter 37 and a flow control valve 13 in addition to the emulsion rolling lubricating oil circulation pipe 7. 34, etc., but at least one of them may be omitted. Moreover, although the cold tandem rolling mill is composed of four rolling stands, it may be composed of five or more rolling stands.

  Moreover, although the said embodiment is described in emulsion rolling lubrication, rolling lubricating oil is not limited to emulsion lubricating oil and may be neat. Even if the emulsion is replaced with neat, rolling lubrication oil may be used neat if there is no need for additional equipment for this purpose.

DESCRIPTION OF SYMBOLS 1 Cold rolling mill 2, 3 Work rolls 4, 5 Backup roll 6 Emulsion rolling lubricating oil circulation system 7 Emulsion rolling lubricating oil circulation piping 8 Reduced emulsion rolling lubricating oil supply pipe 9 Reducing emulsion rolling lubricating oil pump 10, 11 Emulsion supply nozzle 12 Emulsion Rolling Lubricating Oil Supply Pipe 13 Emulsion Rolling Lubricating Oil Pump 15, 16 Coolant Supply Nozzle 17 Coolant Supply Pipe 18 Coolant Flow Rate Control Valve 20 Emulsion Recovery Device 21 Emulsion Recovery Unit 22 Emulsion Recovery Tube 30, 50 Degraded Emulsion Rolling Lubricating Oil Reduction Device 31 Emulsion Rolling Lubricating Oil Tank 32 Dirty Tank 33 Clean Tank 34 Degraded Emulsion Rolling Lubricating Oil Supply Pipe 35 Degraded Emulsion Rolling Lubricating Oil Pump 37 Filter 40 Clear Emulsion rolling lubricating oil feed pipe 41 Clean emulsion rolling lubricating oil pumps 45, 52 Electromagnetic wave generators 60, 61 Neat rolling lubricating oil supply nozzle 65 Neat rolling lubricating oil supply apparatus 66 Neat rolling lubricating oil tank 67 Neat rolling lubricating oil supply pipe 68 Neat Rolling Lubricating Oil Pump 69 Neat Rolling Lubricating Oil Flow Control Valve S Metal Strip

Claims (9)

In cold rolling in which rolling is performed while circulatingly supplying emulsion rolling lubricating oil or neat rolling lubricating oil to the roll bite inlet, the lubricated oxidized emulsion rolling lubricating oil or neat rolling lubricating oil supplied to the roll bite inlet is An electromagnetic wave generator that oscillates a reduction potential is provided in a rolling lubricant tank that passes, and a negative charge is imparted to the oxidized emulsion rolling lubricant or neat rolling lubricant in the rolling lubricant tank, and the emulsion rolling lubricant Or the rolling lubrication method in cold rolling characterized by reducing neat rolling lubricating oil and preventing deterioration of rolling lubricating oil. In cold rolling in which rolling is performed while emulsion rolling lubricating oil or neat rolling lubricating oil is circulated and fed to the roll bite inlet, the rolling lubricating oil circulation pipe through which the emulsion rolling lubricating oil or neat rolling lubricating oil circulates and the rolling lubricating oil An electromagnetic wave generator that oscillates the reduction potential is provided outside the circulation pipe, and a negative charge is imparted to the emulsion rolling lubricant or neat rolling lubricating oil in the rolling lubricating oil circulation pipe, and the emulsion rolling lubricating oil or neat rolling lubrication. A rolling lubrication method in cold rolling characterized by reducing oil and preventing deterioration of rolling lubricating oil. A rolling lubricating oil tank through which the lubricated oxidized emulsion rolling lubricating oil or neat rolling lubricating oil supplied to the roll bite inlet is passed, and in the rolling lubricating oil circulation pipe on the outlet side of the rolling lubricating oil tank The rolling lubrication method in cold rolling according to claim 2, wherein a negative charge is imparted to the rolling lubricating oil. Further, neat rolling lubricating oil is supplied to the roll bite inlet, a negative charge is applied to the emulsion rolling lubricating oil and / or neat rolling lubricating oil, the emulsion rolling lubricating oil / or neat rolling lubricating oil is reduced, and emulsion rolling lubricating is performed. The rolling lubrication method in cold rolling according to claim 1, 2 or 3, wherein deterioration of the oil / neat rolling lubricating oil is prevented. The rolling lubrication method in cold rolling according to any one of claims 1 to 4, wherein a temperature of the emulsion lubricant and / or neat rolling lubricant is set to 40 ° C or lower. The emulsion rolling lubrication oil or neat rolling lubrication oil in cold rolling mill is rolling while circulating fed to the roll bite inlet, emulsion rolling lubrication oil to oxidize the lubricating supplied to the said roll bite inlet or neat rolling lubrication oil An electromagnetic wave generator that oscillates the reduction potential is provided in the rolling lubricant tank through which the oil passes, and a negative charge is imparted to the oxidized emulsion rolling lubricant or neat rolling lubricant in the rolling lubricating oil tank. A rolling lubrication apparatus in cold rolling characterized by reducing oil or neat rolling lubricating oil to prevent deterioration of rolling lubricating oil. In a cold rolling mill that performs rolling while circulatingly supplying emulsion rolling lubricating oil or neat rolling lubricating oil to a roll bite inlet, the rolling lubricating oil circulation pipe through which the emulsion rolling lubricating oil or neat rolling lubricating oil circulates and the rolling lubrication An electromagnetic wave generator that oscillates a reduction potential outside the oil circulation pipe, and imparts a negative charge to the emulsion rolling lubricant or neat rolling lubricating oil in the rolling lubricating oil circulation pipe, and the emulsion rolling lubricating oil or neat A rolling lubrication apparatus in cold rolling characterized by reducing rolling lubricant and preventing deterioration of rolling lubricant. It has a rolling lubricating oil tank through which the lubricated oxidized emulsion rolling lubricating oil or neat rolling lubricating oil supplied to the roll bite inlet passes, and in the rolling lubricating oil circulation pipe on the outlet side of the rolling lubricating oil tank The rolling lubrication apparatus in cold rolling according to claim 7, wherein a negative charge is imparted to the rolling lubricating oil. A neat rolling lubricating oil supply nozzle for further supplying a neat rolling lubricating oil to the roll bite inlet, and a neat rolling lubricating oil supply device for supplying the neat rolling oil to the nozzle, and emulsion rolling lubricating oil and / or neat rolling. The negative charge is given to lubricating oil, this emulsion rolling lubricating oil / or neat rolling lubricating oil is reduce | restored, and deterioration of emulsion rolling lubricating oil / or neat rolling lubricating oil is prevented in any one of Claims 6-8 The rolling lubrication apparatus in cold rolling as described.

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