JP3421912B2 - Rolling oil supply method in cold rolling mill - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling oil supply method for a cold rolling mill, and more particularly to a rolling oil supply method for a cold rolling mill that uses a circulating rolling oil supply system.

[0002]

BACKGROUND OF THE INVENTION Cold rolling requires a lubricating oil to reduce the friction between the steel sheet and the roll during rolling. Further, it is necessary to cool the roll and the steel plate in order to remove the frictional heat generation and the working heat generation. Generally, in cold rolling, emulsion rolling oil is used for lubrication. An emulsion is a mixed liquid in which rolling oil particles are stably suspended in water. Emulsions are characterized by concentration and particle size. The emulsion concentration is the ratio of the oil volume in the total volume of the emulsion. The particle size is the size of the rolling oil particles in the emulsion. Also, a surfactant is added to form an emulsion. The added amount is a concentration (relative to the oil concentration) with respect to the rolling oil amount, and a predetermined amount is added, and stirring and shearing by a pump are added to obtain an emulsion liquid. Further, the emulsion rolling oil supply method in cold rolling includes a direct method (direct method), a circulation method (recirculation method), and a hybrid method which is an eclectic method thereof.

Direct type rolling oil supply system (direct system)
Has excellent lubricity and coolability because high-concentration emulsion rolling oil is sprayed on the steel sheet for the purpose of lubrication and water is sprayed on the roll for the purpose of cooling. However, unlike the circulation method, the emulsion rolling oil is not circulated and used, and therefore the unit consumption of rolling oil is high.

On the other hand, the circulation type rolling oil supply system (recirculation system) is a low-concentration emulsion rolling oil prepared by mixing and stirring the rolling oil and cooling water in advance.
Since it sprays on steel plates and rolls for the purpose of lubrication and cooling while circulating, the unit consumption of rolling oil is low. However, it cannot be denied that lubricity and cooling are inferior to the direct rolling oil supply system. Therefore, in the conventional circulation system, lubrication becomes insufficient during high-speed rolling of a thin material having a finish plate thickness of 0.2 mm or less, and vibration of the rolling mill called chattering or surface flaws called heat scratches occur, so the rolling speed There was a problem that could not be raised.

On the other hand, as a conventional technique for improving the lubricity of the circulating rolling oil supply system, Japanese Patent Publication No. 59-24 is available.
Japanese Patent No. 888 discloses a method in which rolling oil having a concentration of 10% or more is directly supplied to the lower surface of the steel sheet immediately before biting. In addition to the circulating rolling oil supply system that supplies low-concentration and low-temperature emulsion, a hybrid system, which is an eclectic method of supplying high-concentration and high-temperature emulsion to a steel sheet to improve lubricity, has been proposed.

In JP-B-58-5731 and JP-A-9-122733, a high-concentration emulsion is heated to a high temperature (75 ° C.) and directly injected onto a steel plate immediately before biting, and the high-concentration emulsion is a circulating emulsion. The method of making by adding rolling oil to the extraction liquid from is proposed.

In JP-A-2-37911, the surfactant added to the high-concentration emulsion is the same as that of the emulsion of the circulation system, and the emulsion stability index (ESI) is lowered by changing only the addition amount. A method of directly injecting is proposed.

Further, in Japanese Patent Publication No. 63-5167,
Do not allow salt formation, or use an ionic surfactant with a low salt formation rate to directly inject into the steel sheet as an emulsion-unstable emulsion, and add excessive water-soluble counterionic substances in the tank of the circulation system. Then, a method of stabilizing the emulsion after mixing in the tank of the circulation system is proposed.

However, the above-mentioned conventional technique has the following problems.

In the prior art disclosed in Japanese Patent Publication No. 59-24888, a sufficient lubricity improving effect could not be obtained for the following reason.

A) Examining the relationship between the ratio of the amount of oil contained in the surface of the steel plate (the amount of oil adhered to the steel plate) to the amount of oil contained in the emulsion to be sprayed (hereinafter referred to as the adhesion efficiency) and the concentration However, if only the emulsion concentration was increased, the adhesion efficiency was lowered, and therefore sufficient increase in the plateout amount could not be obtained only by increasing the concentration.

B) During high speed rolling, heat scratches may occur not only on the lower surface side of the steel sheet but also on the upper surface side. In the high-speed rolling region, not only the lower surface but also the upper surface is reduced in plate-out amount, and improving the lubricity of only the lower surface of the steel sheet is not sufficient.

The prior arts disclosed in Japanese Patent Publication No. 58-5731 and Japanese Unexamined Patent Publication No. 9-122733 are as follows.
For the following reasons, sufficient lubricity improving effect could not be obtained.

A) Ascertaining the effect of raising the temperature of the emulsion with an actual machine, depending on the emulsifying dispersant constituting the emulsion, the adhesion efficiency does not necessarily increase even if the temperature of the emulsion is raised. Elevating the temperature of the emulsion has no effect. Further, if the concentration of the emulsion is increased, the adhesion efficiency is lowered, and therefore the plateout amount cannot be efficiently increased only by increasing the concentration. Therefore, there has been a problem in that a method such as excessively increasing the supply flow rate must be used in order to compensate for the decrease in the adhesion efficiency due to the increase in concentration. In addition, an extra device such as a heater is required to heat and pressurize the emulsion, while the temperature of the emulsion in the circulating rolling oil supply system rises when a high temperature emulsion enters the circulating rolling oil supply system. Therefore, the circulating rolling oil supply system requires extra equipment such as a large cooler.

B) When a hybrid emulsion is to be obtained by extraction from a circulation emulsion, the circulation emulsion does not have constant characteristics such as ESI, iron concentration, saponification value and acid value, and a stable extract is obtained. To obtain it, complicated equipment such as chemical treatment and iron removal filter is required. Further, once the characteristics of the extract change, the characteristics and physical properties of the hybrid emulsion also change correspondingly, and the originally desired improvement in lubricity cannot be achieved.

In the prior art disclosed in Japanese Patent Application Laid-Open No. 2-37911, a hybrid type rolling oil supply tank mixes an unstable emulsion having low ESI and unstable emulsification / dispersion property, and The ESI of the emulsion changes over time, making the emulsion dispersibility unstable,
When it was supplied, it became over-lubricated, and there was a problem that slip occurred on all stands and rolling became unstable.

Generally, the circulating type rolling oil supply tank has 10
Large capacity of about 000L
In the prior art presented in Japanese Patent Publication, it is necessary to add a large amount of counter ionic substance in the tank of the circulation system in advance, and the emulsion dispersion of the emulsion in the tank of the circulation system due to excess counter ionic substance. Stability may vary. Further, there is a problem that a salt forming reaction with an emulsion using an ionic surfactant having a low salt forming rate is unlikely to occur, resulting in destabilization of the emulsion in the tank of the circulation system.

[0018]

SUMMARY OF THE INVENTION The present invention provides a circulating rolling oil supply system in which a second rolling oil supply system is provided separately from the circulating rolling oil supply system (first rolling oil supply system). Improves lubricity by supplying an emulsion with an average particle size larger than that of the circulating rolling oil supply system and high adhesion efficiency to the upper and lower surfaces of the steel sheet, and emulsifies and disperses the emulsion even after mixing in the circulating rolling oil supply tank. It is intended to provide a rolling oil supply method capable of maintaining stability.

[0019]

The first aspect of the present invention is, in a circulation type supply method of an emulsion rolling oil in cold rolling, a second aspect of the invention in addition to the circulation type rolling oil supply system (first rolling oil supply system). A rolling oil supply system is provided, a surfactant of the same type as the emulsion of the circulating rolling oil supply system and with an oil concentration lower than that of the circulating rolling oil supply system is added, and a larger average than the circulating rolling oil supply system. Particle size (eg 20 μm
The emulsion with high adhesion efficiency adjusted to the above) is supplied to the upper surface and the lower surface of the steel plate on the rolling stand entry side, and then the emulsion that has not adhered to the steel plate is recovered, and the interface of the circulating rolling oil supply system is recovered. Rolling oil in a cold rolling mill, characterized in that a surfactant is added so as to have the same concentration as that of the active agent, mechanical stirring is performed, and then the emulsion is merged with the emulsion of the circulating rolling oil supply system. It is a supply method.

According to the second aspect of the present invention, when the amount of oil mixed into the tank of the circulating rolling oil supply system from the second rolling oil supply system is larger than the amount of oil loss of the circulating rolling oil supply system, the circulating rolling is performed. Diluting water is replenished so that the concentration in the tank of the oil supply system is constant, and the amount of oil mixed into the tank of the circulating rolling oil supply system from the second rolling oil supply system is equal to that of the circulating rolling oil supply system. When the amount of oil loss is smaller than the amount of oil loss, in the step of joining the emulsion of the second rolling oil supply system to the circulating rolling oil supply system, the oil concentration of the surfactant becomes the same as the emulsion of the circulating rolling oil supply system. The rolling oil supply method in the cold rolling mill according to the first aspect of the invention is characterized in that the emulsion thus additionally added and adjusted is replenished to the tank of the circulation type rolling oil supply system and the dilution water is replenished.

The principle of the first invention will be described below.

The inventors of the present invention have earnestly studied the means for improving the adhesion efficiency when the emulsion is supplied to the steel sheet. As a result, when the average particle size of the emulsion is increased by adjusting the concentration of the surfactant added, the adhesion efficiency is improved. Have been found to be significantly improved.

FIG. 3 shows the relationship between the amount of the surfactant added and the average particle size of the emulsion. At this time, mechanical stirring and shearing were sufficiently given to prepare an emulsion. For example, FIG. 3 (a) shows the case of a cationic dispersion type surfactant, which is a stable emulsion having an average particle size of 8 to 15 μm at a surfactant concentration of 0.4% or more with respect to oil. The amount added to the circulating rolling oil supply system is in this range. On the other hand, when the oil concentration is 0.005 to 0.2%, the emulsion has an average particle size of 20 μm or more. FIG. 3B shows the case of a nonionic emulsification type surfactant, which is a stable emulsion having an average particle size of 10 μm or less at an oil concentration of 0.3% or more. Further, it becomes an emulsion of 20 μm or more at an oil concentration of 0.003 to 0.2%. If the oil concentration is lower than 0.003%, the self-emulsifying action may result in an emulsion having a small particle size of 20 μm or less.

In FIG. 4, using a plate-out tester,
The results of investigating the relationship between the average particle size of the emulsion and the adhesion efficiency are shown, but the adhesion efficiency increases as the average particle size increases. In particular, when the average particle size is 20 μm or more, the adhesion efficiency sharply increases.

Further, FIG. 5 shows the relationship between the emulsion concentration and the adhesion efficiency, but the adhesion efficiency decreases as the concentration increases. However, when the average particle size of the emulsion is as large as 20 μm or more, the decrease in the adhesion efficiency with respect to the emulsion concentration is small.

Particularly in the high-speed rolling zone, the spraying time becomes shorter as the speed increases, and the amount of rolling oil supplied per unit area of the steel sheet decreases, so that the adhesion efficiency can be improved even if the emulsion is concentrated to a high temperature as in the prior art. The effect of improving the lubricity is not sufficiently obtained under the condition of low, and it is effective to use an emulsion having a large average particle size and high adhesion efficiency as in the present invention. Further, during high speed rolling, heat scratches may occur not only on the lower surface side of the steel sheet but also on the upper surface side, so it is necessary to improve the lubricity of the upper surface side of the steel sheet, and the average grain size on the upper surface side should be It is necessary to supply a large emulsion with high adhesion efficiency.

The emulsion of the second rolling oil supply system is
In order to obtain stable lubricity, a rolling oil stock solution, a surfactant, and dilution water are newly prepared and prepared. The surfactant added for emulsifying and dispersing is an interface of the same type as the circulating rolling oil supply system in order to eliminate the influence when the emulsion of the second rolling oil supply system is mixed in the circulating rolling oil supply tank. An emulsion having a large average particle diameter is obtained by adjusting the addition concentration of the surfactant as the surfactant.

According to the first aspect of the present invention, an emulsion of the same type as the circulating rolling oil supply system and having a lower oil concentration is added to the emulsion and having an average particle size larger than that of the circulating rolling oil supply system. The reason why the steel sheets are supplied to the upper and lower surfaces of the steel sheet on the rolling stand entrance side is based on the above-described examination results.

Among the emulsions supplied from the second rolling oil supply system to the upper surface and the lower surface of the steel sheet, the emulsions not adhered to the steel sheet are recovered and combined with the circulating rolling oil supply tank in the step of adding a surfactant. After additional addition, mechanical stirring is performed to make a stable emulsion that is subdivided to the same particle size as the circulating emulsion, whereby the emulsion stability of the circulating rolling oil supply system can be maintained. The additional amount of the surfactant added at this time is determined based on the equation (6).

[0030]

[Equation 1]

However, qe (L / min) is the addition amount of the surfactant, q1 (L / min) is the emulsion supply amount of the second rolling oil supply system, and f (%) is the second rolling amount. It is the adhesion efficiency of the emulsion in the oil supply system, q1 in the formula
-(1-f / 100) represents the amount of emulsion that did not adhere to the upper and lower surfaces of the steel sheet. c (%) is the emulsion concentration of the second rolling oil supply system, c0 (%) is the emulsion concentration of the circulating rolling oil supply system, and ce (%) is the surfactant of the second rolling oil supply system. Oil concentration, ce0
(%) Represents the oil concentration of the surfactant in the circulating rolling oil supply system.

As a method for obtaining a stable emulsion which has been subdivided to the same particle size as the circulating emulsion by additional addition of a surfactant and additional stirring and shearing, there are the following methods.

(1) A method in which a surfactant is additionally added to the tank of the circulation system, and the rotation speed of the agitator in the tank of the circulation system is increased to add strong stirring to the emulsion.

(2) A surfactant is added in the middle of the return pipe from the oil pan for collecting the emulsion to the emulsion storage tank of the circulation type rolling oil supply system, and an orifice or a stirring pump is installed in the middle of the pipe. how to.

(3) A surfactant is additionally added in the oil pan for collecting the emulsion, and an orifice or a stirring pump is installed in the return pipe from the oil pan to the emulsion storage tank of the circulating rolling oil supply system. how to.

(4) A buffer tank for collection is provided separately from the emulsion storage tank of the circulating rolling oil supply system, a surfactant is additionally added to the emulsion collected therein, and an agitator is provided to stir the mixture. How to apply shear.

FIG. 6 shows the results of investigating the relationship between the emulsion temperature and the sticking efficiency of emulsions prepared by using a plate-out tester and using different surfactants a, b and c as emulsifying dispersants. According to this, increasing the emulsion temperature means that the surfactant c
Depending on the emulsifying dispersant, the plate-out amount may be reduced. Like surfactants a and b, the plate-out amount may increase, but the increase in adhesion efficiency is small, and considering that equipment such as a heater is required to keep the emulsion at a high temperature, Doing so is not a good idea. Further, when mixed in the circulating rolling oil supply system, the emulsion temperature of the circulating rolling oil supply system rises steadily, so that the circulating rolling oil supply system requires a cooler. Therefore, in the present invention, the emulsions in the second rolling oil supply system and the circulation type rolling oil supply system have the same temperature.

The concentration and flow rate of the emulsion in the second rolling oil supply system are determined in consideration of the conditions and plate-out characteristics described below. First, it is a necessary condition to secure a predetermined plate-out amount. The necessary plate-out amount is Pφmin (unit is mg / m ² ). Pφmin is a minimum amount that does not cause heat scratches or chattering. Hereinafter, the plate-out amount is represented by the symbol PΦ (unit is mg / m ² ). The first condition is expressed by equation (1).

Pφmin ≦ PΦ Equation (1) Second, as shown in FIG. 7, the plate-out amount saturates at a certain emulsion supply amount or more, and the adhesion efficiency decreases. For this reason, it is desirable to set the emulsion supply amount within a range in which the plate-out amount is not saturated. The supply amount at the saturation limit is ωτmax (unit: L /
m ² ). However, ωτ represents the emulsion supply amount (unit is L / m ² ), and ω is the flow rate density (unit is L / m ² ).
m ² ) and τ represent spray residence time (unit: min). According to FIG. 7, ωτmax is about 0.1 L / m ² . The flow rate per header of the rolling mill is Q (L / mi
n), the width of the spray portion is w (m), and the rolling speed is V (m /
min) and the emulsion supply amount is ωτ (L / m ² ), Q = (ωτ) · w · V can be calculated. w = 1.2
When m, V = 1800 m / min and ωτ = 0.1 L / m ² , Q = 215 L / min. From this, 1
The maximum flow rate per header is 215 L / min. The second condition is expressed by equation (2).

Ωτ ≦ ωτmax Equation (2) Further, in the region where the plateout amount is not saturated with respect to the emulsion supply amount, the plateout amount can be calculated by the equation (3). However, PΦ is the plate-out amount (unit is m
g / m ² ), c is the emulsion concentration (%), f is the adhesion efficiency (%), and K is the unit conversion coefficient (mg / L). K
Varies depending on the oil type, but 0.89 × 10 ^{6 to} 0.9 ×
It is about 10 ⁶ .

PΦ = Kc / 100ωτf / 100 (3) Thirdly, as shown in FIG. 5, the adhesion efficiency f decreases as the emulsion concentration increases. To do. Further, as shown in FIG. 4, the adhesion efficiency f is affected by the emulsion particle size. The relationship among the adhesion efficiency f (%), the concentration c (%), and the oil content average particle diameter d (μm) is represented by Expression (4). However, f represents a function.

F = f (c, d) Equation (4) When Equation (1), Equation (3) and Equation (4) are arranged, the condition of Equation (5) is obtained.

C · f (c, d) ≧ Pφmin / ωτ · K (Equation (5)) From the above, the concentration and average particle size of the emulsion in the second rolling oil feed system satisfy Equation (5). There is a need.

For example, in the case of the emulsion having the adhesion efficiency shown in FIG. 4, an example of calculating the minimum concentration when the average particle diameter is 20 μm is shown below.

PΦmin in the equation (5) is obtained according to the following procedure. First, the relationship between the occurrence of heat scratches and chattering and the amount of oil adhered to the steel plate of the rolled material was investigated, and the lower limit value of the amount of oil adhered to the steel plate was 0 min when neither occurred.
(Unit is mg / m ² ). At this time, the plate-out amount Pφmin (the unit is mg /
m ² ) is P, assuming that the same amount of rolling oil as that of the steel sheet adhered to the rolled material adheres to the roll surface on the rolling mill exit side.
φmin = 2.0 min / (1-r, where r represents the rolling reduction during rolling. For example, 0 min is 3
When 00 mg / m ² and the rolling reduction r is 0.3, Pφmin
Is 860 mg / m ² . Assuming that the emulsion supply amount ωτ is 50% of ωτmax, the average particle size 20 shown in FIG.
The minimum concentration of the emulsion satisfying the formula (5) is calculated to be 6.2% by using the relation between the emulsion concentration and the adhesion efficiency in the case of μm.

On the other hand, when the emulsion of the above example is used as the emulsion of the conventional circulating rolling oil supply system,
Shearing is sufficient to reduce the average particle size to less than 20 μm to obtain an emulsion-stable emulsion, with a concentration of 1.0 to 5.
Used as 0%.

As can be seen from this example, the emulsion concentration of the second rolling oil supply system becomes higher than that of the circulation type rolling oil supply system, considering the conditions of the above equations (1) to (5). .

The injection pressure of rolling oil is 0.5 kg
/ Cm ^{2 to} 7 kg / cm ² is preferable. 0.5 kg / c
m ² is the minimum pressure at which the emulsion sprayed from the header for the bottom surface of the steel sheet can reach the steel sheet surface. On the other hand, if it is 7 kg / cm ² or more, the amount of emulsion that collides with the surface of the steel sheet and is scattered increases, and the adhesion efficiency decreases. Therefore, it is preferably set to about 0.5 to ⁷ kg / cm ² .

By using the rolling oil supply system according to the first aspect of the present invention described above, the lubricity can be greatly improved as compared with the conventional circulating rolling oil supply system. FIG. 8 is a comparison result of the amount of oil adhering to the steel plate of the rolled material in the circulating rolling oil supply system and the second rolling oil supply system. In addition, the measurement of the amount of oil adhered to the steel plate is
The oil on the surface of the steel sheet was extracted with an organic solvent such as hexane, and the amount of extracted oil was measured (solvent extraction method). At this time, the concentration of the circulation type rolling oil supply system emulsion was 3.5%, the average particle size was 10 μm, and the emulsion supply rate from the upper and lower headers was 4000 L / min. On the other hand, the concentration of the second rolling oil supply type emulsion was 10%, the average particle size was 20 μm, and the emulsion supply rate from the upper and lower headers was 130 L / min. The steel plate adhesion amount when the present first invention is used is increased by about 40% as compared with the conventional circulating rolling oil supply system, and in terms of the adhesion efficiency indicated by the ratio of the adhesion oil amount to the supply oil amount, The effect was about 12 times that of the conventional one.

Further, in the first aspect of the present invention, it is preferable that the position of the spray nozzle for supplying the emulsion of the second rolling oil supply system is as close as possible to the upstream stand apart from the roll bite. This is for the following reason.

In order to form a stable plate-out layer, the time required for phase inversion from the state of an O / W emulsion in which oil is dispersed in water to a W / O emulsion in which water is dispersed in oil or an oil content single phase. (Hereinafter referred to as the phase inversion time) is preferably ensured. In the rolling mill, the time from when the emulsion is supplied to the surface of the steel sheet at the rolling mill entrance side until the emulsion reaches the roll bite according to the plate feeding speed corresponds to the phase inversion time. Therefore, it is assumed that the higher the rolling speed, the shorter the phase inversion time, which makes it difficult to form the plate-out layer. On the other hand, the phase inversion time can be secured by setting the position of the spray nozzle as close to the upstream stand as possible apart from the roll bite.

The second invention is based on the following examination results.

In the circulation type rolling oil supply system, the oil content adhering to the strip is replenished with rolling oil content taken out of the system, evaporation and leakage in the rolling mill, and rolling oil and water lost due to scum out, and the oil in the tank is replenished. Emulsion volume and emulsion concentration are maintained at constant levels.

On the other hand, the emulsion recovered after spraying the steel sheet from the second rolling oil supply system has a higher concentration than the emulsion in the circulation system, and the concentration of the surfactant against oil and the average particle size are in the circulation system emulsion. Since a surfactant is additionally added so that it becomes the same as the above, it can be used as a replenishing oil for a circulating rolling oil supply system.

The second aspect of the present invention is based on this point of view. That is, in the second aspect of the present invention, when the amount of oil mixed into the tank of the circulating rolling oil supply system from the second rolling oil supply system exceeds the amount of oil loss of the circulating rolling oil supply system, Only the dilution water is replenished so that the concentration in the rolling oil supply system tank is constant. At this time, the amount of emulsion liquid in the tank increases while maintaining a constant concentration, which is equivalent to replenishing the oil loss amount in advance.

The amount of oil mixed into the tank of the circulating rolling oil supply system from the second rolling oil supply system exceeds the amount of oil loss of the circulating rolling oil supply system and the amount of emulsion liquid in the tank. Is above a certain level,
No new oil replenishment is necessary, only dilution water is replenished so as to keep the concentration constant.

The amount of oil mixed into the tank of the circulation system from the second rolling oil supply system is less than the amount of oil loss of the circulation type rolling oil supply system, and the amount of emulsion liquid in the tank is constant. If it is maintained at or less than, the emulsion of the second rolling oil supply system is adjusted so that the surfactant oil concentration in the emulsion is adjusted to be the same as the emulsion of the circulating rolling oil supply system. Refill the oil supply tank and replenish the dilution water.

The replenishment amount of the dilution water and the emulsion of the second rolling oil supply system is, as shown in the equation (7), the oil amount of the emulsion of the second rolling oil supply system mixed into the circulation type rolling oil supply system. (8) to (11) according to the oil amount ΔQo obtained by subtracting the oil loss amount of the circulation type rolling oil supply system from
Based on. Further, the additional amount of the surfactant added to the emulsion of the second rolling oil supply system is determined based on the equation (12).

[0059]

[Equation 2]

[0060]

[Equation 3]

[0061]

[Equation 4]

[0062]

[Equation 5]

[0063]

[Equation 6]

[0064]

[Equation 7]

However, ΔQo (L / min) is the amount of increase in the oil content of the circulating rolling oil supply system, ΔQw (L / min)
Is the amount of water increase in the circulating rolling oil supply system, QLo (L /
min) is the oil loss amount of the circulating rolling oil supply system, QL
w (L / min) is the amount of water loss in the circulating rolling oil supply system, ΔQE (L) is the amount of deviation of the emulsion liquid amount in the tank from a certain level, and W (L / min) is the dilution water. The supply amount, q2 (L / min), is the supply amount from the tank of the second rolling oil supply system to the tank of the circulating rolling oil supply system,
q1 (L / min) is the emulsion supply amount from the second rolling oil supply system to the steel sheet, qe (L / min) is the surfactant addition amount, and c (%) is the second rolling oil supply. The system concentration, c0 (%), is the concentration of the circulating rolling oil supply system, c0
e (%) is the oil concentration of the surfactant of the second rolling oil supply system, ce 0 (%) is the oil concentration of the surfactant of the circulating rolling oil supply system, and f (%) is the 2 is the adhesion efficiency of the emulsion of the rolling oil supply system of No. 2.

A surfactant is additionally added to the emulsion to be replenished from the tank of the second rolling oil supply system to the tank of the circulation type rolling oil supply system, and the same average as that of the emulsion of the circulation system is obtained by additional stirring and shearing. There are the following methods for obtaining an emulsion having a stable particle size.

(1) After the emulsion of the second rolling oil supply system is replenished in the tank of the circulation type rolling oil supply system, a surfactant is additionally added to increase the rotation speed of the agitator in the tank. Strong stirring and shearing method.

(2) A surfactant is additionally added in the middle of the feed pipe from the tank of the second rolling oil supply system to the tank of the circulation type rolling oil supply system, and then the solution is passed through a supply pump to give an emulsion. How to apply shear.

(3) In addition to the tank of the second rolling oil supply system, a buffer tank for adjusting the amount of the surfactant is provided, in which the surfactant is additionally added, and an agitator is provided to form an emulsion. Method of adding stirring and shearing.

(4) A method of providing a storage tank for a replenishing emulsion to which a surfactant having the same oil concentration as that of the emulsion of the circulating rolling oil supply system is added, separately from the tank of the second rolling oil supply system.

By using the above-mentioned replenishing method, the emulsion of the second rolling oil supply system can be effectively used also for replenishing the oil shortage in the circulation type supply system.
As in the case of the conventional circulating rolling oil supply system, the unit consumption of rolling oil can be lowered.

Further, according to the second aspect of the present invention, the second rolling oil supply system supplements the oil loss amount of the circulating rolling oil supply system even when rolling is performed using only the circulating rolling oil supply system. It can be applied as a method. The emulsion replenishment amount and the dilution water of the second rolling oil supply system are ΔQo = −QLo, ΔQ
Let w = -QLw, and determine based on equation (11).

[0073]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1 of the Invention] FIG.
It is an example of the embodiment of the 1st present invention, and is the case where it is applied to the 4th and 5th stands of the tandem mill of all 5 stands.
The reason why the fourth and fifth stands are applied is that the rolling speed is higher and the strip thickness is smaller as the latter-stage stand is, so that the rolling load becomes higher and the lubrication condition becomes more severe. In FIG. No. 1 to No. 3 stands were lubricated and cooled by the conventional circulating rolling oil supply system.
In the 4th and 5th stands, the rolling oil supply system in which lubrication is performed by the second rolling oil supply system according to the present invention and cooling is performed by the circulation type rolling oil supply system is shown. The circulation type rolling oil supply system is No. For 1 to 3 stands, and N
o. Divided into 2 systems for 4 to 5 stands.

Reference numeral 1 in FIG. 1 denotes an emulsion storage tank of the second rolling oil supply system. Hot water, crude oil, and surfactant are supplied from respective tanks 2, 3, 4 by pumps 5a, 5b, 5
Via c, the replenishment amount is adjusted by the flow rate adjusting valves 6a, 6b, 6c so that a predetermined oil concentration and a surfactant-to-oil concentration are obtained, and then the emulsion storage tank 1 is supplied. The emulsion concentration in the tank is in the range of 4 to 15%, the type of surfactant is the same as in the circulating rolling oil supply system, and the oil concentration is lower than that in the circulating rolling oil supply system. For example, in the case of a cationic dispersion type surfactant, the circulating type rolling oil supply system has an oil concentration of 0.5%, whereas
Oil concentration of rolling oil supply system of 0.005-0.2%
The range is. Then, mechanical agitation is sufficiently applied by the agitator 7 to adjust the average particle diameter in the tank to 20 to 40 μm. The emulsion temperature is the same as that of the circulating rolling oil supply system.

The emulsion liquid of the second rolling oil supply system is supplied to the upper and lower surfaces of the strip from the headers 10a and 10b by the pump 8a via the rolling oil supply line 9a. The maximum flow rate per header is 215 L / min, and it is adjusted according to the size of the rolled material and the steel type.

After spraying the steel sheet, the emulsion that does not plate out on the steel sheet is recovered together with the emulsion in the cooling circulation system in the recovery oil pan 17b and is fed into the stirring section 27 via the return line 30b. . In the stirring section, the amount of the surfactant determined by the formula (6) is additionally added by adjusting the opening of the valve 29, and after the additional stirring by the agitator 18, the pump 28 is added.
It is put into the circulating type rolling oil supply tank 13b via. For example, an emulsion of a circulating rolling oil supply system,
Concentration 2.5%, surfactant to oil concentration 0.5%, the second rolling oil supply system emulsion 10% concentration, surfactant to oil concentration 0.1%, emulsion to steel plate Supply amount is 20 L / min for # 4 STD, 30 for # 5 STD
When the flow rate is L / min, the additional amount of the surfactant added to the stirring section 27 is 8.4 cc / min.

FIG. 9 shows the results of investigation of the particle size distribution of the emulsion in the circulation system tank 13b when the second rolling oil supply system according to the first aspect of the present invention is used. As a comparison, the particle size distribution of the emulsion in the tank 1 of the second rolling oil supply system and the particle size distribution of the emulsion in the circulation system tank 13b when the second rolling oil supply system is not used are also shown. The emulsion in the circulation system tank 13b when the second rolling oil supply system is used matches the particle size distribution of the emulsion when the second rolling oil supply system is not used. According to this, it is understood that the emulsification dispersibility of the circulating rolling oil supply system can be maintained.

The following method may be used as a method of adding a surfactant to the recovered second rolling oil supply system emulsion and additionally stirring and shearing.

(1) A method in which, after merging with the circulation system tank, a surfactant is additionally added into the circulation system tank and the agitator is rotated at a high speed to add strong stirring to the emulsion.

(2) As shown in FIG. 10, in the middle of the return pipe 30b from the recovery oil pan 17b, a surfactant is additionally added from the tank 4 via the pipe 32 and the valve 33 and installed in the middle of the pipe. The emulsion is sheared by the stirring pump 34 described above, and then combined with the tank 13b of the circulating rolling oil supply system.

(3) As shown in FIG. 11, the surfactant is supplied from the tank 4 to the pipe 3 in the recovery oil pan 17b.
5, additional addition via valve 36, oil pan 17b
From the tank to the tank, the emulsion is sheared by a stirring pump 34 installed in the middle of the return pipe 30b, and then the emulsion is joined to the tank 13b of the circulating rolling oil supply system.

On the other hand, the emulsion liquid of the circulating rolling oil supply system was No. 1-3 stand tank 13a, No.
Stirrer 18 stored in tanks 13b for 4, 5 stands
Stirs to form a stable emulsion with a small radius. The emulsion particle size is 8 to 8 when the cationic dispersion type surfactant is used and the oil concentration is 0.5%.
Although it was 15 μm, the average particle size may be 10 μm or less when other emulsion type surfactants are used. The emulsion concentration is usually within the range of 1 to 4%. When beef tallow is used as the base oil, the temperature of the emulsion is 5
5 to 70 ° C. In the case of other synthetic ester rolling oils, it may be lower than this. The emulsion of this circulation system is fed from the stirring tanks 13a and 13b to the rolling oil supply line 15 by the pumps 14a and 14b.
a, 15b. Lubrication by circulation system N
o. For the 1 to 3 stands, the headers 19a, 19
From b, the emulsion is supplied to the roll bite. The flow rate is 1000 to 2000 for each header.
It is in the range of L / min. In addition, No. On the outlet side of the 1st to 5th stands, the strip 21 and the work roll 22 and the backup roll 23 are sprayed from the cooling emulsion supply system 20 to cool the strip and the roll. The flow rate is 1000 to 2 for each header.
It is in the range of 000 L / min. Thereafter, the emulsion in the circulation system is recovered by the recovery oil pans 17a and 17b and returned to the tanks 13a and 13b in the circulation system via the return lines 30a and 30b.

FIG. 22 shows an embodiment in which the position of the header for supplying the emulsion of the second rolling oil supply system is set as close as possible to the upstream stand apart from the roll bite in the embodiment as shown in FIG. is there. This secures the time for phase conversion from the O / W emulsion to the W / O emulsion or the oil single phase.
The header position was set immediately after being affected by the coolant header 20 for cooling the roll and the strip on the front stand outlet side (1.0 m from the front stand outlet side). The distance between the stands is 4.5 m.

[Embodiment 2 of the present invention] FIG. 2 relates to an embodiment of the present invention 2 and shows an apparatus configuration when it is applied to a tandem mill having all five stands. The device configuration of the second rolling oil supply system is the same as that of FIG. 1 shown in the first embodiment.

The emulsion replenished from the tank 1 of the second rolling oil supply system to the tanks 13a and 13b of the circulation system is supplied from the pump 8b through the supply pipe 9b to the oil pan 31 for adjusting the amount of the surfactant. It is thrown in. Here, after adjusting the opening degree of the valve 6d and additionally adding a predetermined amount of the surfactant determined by the formula (12), the supply pump 1
After shearing at 6, circulation system tanks 13a, 13
b is replenished. The amount of replenishment is determined by the valves 26a, 26b.
It is adjusted by the opening degree of.

The oil concentration of the surfactant of the emulsion to be replenished from the second rolling oil supply system tank to the circulation system tanks 13a and 13b is adjusted to be the same as that of the circulation system emulsion, and additional stirring is performed. The method for applying shearing may be the method described below.

(1) After supplementing the emulsion of the second rolling oil supply system into the tanks 13a and 13b of the circulation system, the surfactant is additionally added to increase the rotation speed of the agitator in the tank of the circulation system. By adding strong stirring to the emulsion.

(2) As shown in FIG. 12, a surfactant is used as a valve 39 and a pipe 40 in the middle of the feed pipe 38 from the tank 1 of the second rolling oil supply system to the tank 13b of the circulation system.
A method in which the emulsion is sheared by passing it through the supply pump 41 after additional addition via the.

(3) As shown in FIG. 13, a tank 42 for replenishing the circulation system is provided, and the emulsion concentration thereof is the second.
Of the hot oil tank 2, the crude oil tank 3, and the surfactant tank 4 so that the oil concentration of the surfactant is the same as that of the circulation system.
3c, the amount of replenishment is adjusted by valves 44a, 44b, 44c, and strong agitation by agitator 45 is added in replenishment tank 42 to subdivide the particle size, and a stable emulsion similar to the emulsion in the circulation system. And a replenishment pump 46 is used to replenish the circulation system tank via the pipe 47.

The calculation device 24b calculates the replenishment amount of the emulsion and dilution water of the second rolling oil supply system to be replenished to the tank 13b and the surfactant amount additionally added to the oil pan 48. The calculation flow is shown in FIG. The supply amount q1 sprayed on the surface of the steel sheet on the entry side of the 4,5th stand is measured, and based on this, the replenishment amount q2 of the emulsion of the second rolling oil supply system and the amount qe of the surfactant additionally added to the oil pan 48. Also, the dilution water amount W is calculated from the equations (7) to (12). Based on this, the flow control valves 6d, 31, 1
2b and 26b are controlled.

For example, No. The emulsion concentration of the circulation system for 4, 5 stands is 3.5%, the concentration of surfactant to oil is 0.5%, and the amount of oil loss and the amount of water loss are 1.
4 L / min, 18.4 L / min, when the emulsion concentration in the tank 1 of the second rolling oil supply system was 10% and the surfactant oil concentration was 0.1%, the supply amount to the steel sheet was N.
o. 20 L / min and 30 L / m for 4 and 5 stands respectively
When in is set, the oil amount increase amount of the circulation type rolling oil supply system is ΔQo = 2.1 L / min and ΔQo> from the equation (7).
It becomes 0. Only dilution water is replenished to keep the emulsion concentration in the circulating rolling oil supply system constant. The replenishment amount W is 55.3 L / min from the equation (9).

Further, the supply amount to the steel plate is set to No. When 5 L / min is used for each of the 4th and 5th stands, the oil amount increase amount of the circulating rolling oil supply system is ΔQo = -0.14 from the equation (7).
Since L / min and ΔQo <0, it becomes necessary to supply rolling oil to the circulating rolling oil supply system. At this time, when the amount of emulsion liquid in the tank of the circulation system is maintained at a constant level (ΔQ _E = 0), the emulsion and dilution water of the second rolling oil supply system are replenished. From the formula (11), the emulsion feeding amount q2 is 1.4 L / min, and the replenishing amount W of the diluting water is 6.4 L / min. From the formula (12), the additional addition amount of the surfactant is 0. It becomes 6 cc / min.

When the amount of emulsion liquid in the tank is larger than a certain level (ΔQ _E > 0), only the dilution water is replenished. The replenishment amount W is 33.0L from the formula (10).
/ Min.

The calculator 24a calculates the replenishment amounts of emulsion and dilution water from the tank 1 of the second rolling oil supply system to the tank 13a. The emulsion supply amount q2 from the tank 1 and the replenishment amount W of the dilution water are calculated by the formula (1
1), the additional amount qe of the surfactant is calculated from the equation (12), and based on this, the flow control valves 6d, 31, 12a,
26a is controlled to replenish oil in the circulating rolling oil tank 13a.

For example, in No. The emulsion concentration of the circulation system for 1 to 3 stands is 2.5%, the surfactant concentration against oil is 0.5%, and the oil loss amount and the water loss amount are each 0.
6 L / min, 7.9 L / min, and when the emulsion concentration in the tank 1 of the second rolling oil supply system is 10% and the concentration of surfactant to oil is 0.1%, the replenishment amount W of dilution water
Is 25.9 L / min, and the emulsion feed rate q2 from the second rolling oil supply system is 6 L / min. Further, the additional amount of the surfactant added is 13 cc / min.

[0096]

EXAMPLES Example 1 The present invention (first embodiment) is applied to the fourth and fifth stands of a tandem rolling mill with all five stands, and the fourth and fifth stands are lubricated with a second rolling oil. The supply system was used. The base oil of rolling oil was beef tallow (viscosity at 40 ° C 45
cSt) and a cationic surfactant as an emulsifying dispersant. The coolant temperature of the emulsion of the second rolling oil supply system was 60 ° C., which is the same as that of the circulation type rolling oil supply system. The emulsion concentration of the second rolling oil supply system is 10%, and the emulsion particle size is 0.1%, which is lower than the emulsion concentration of the circulating rolling oil supply system, and the average particle size is the average particle size. It was adjusted to 20 μm. Also,
The emulsion supply amount of the second rolling oil supply system is 100 L / min at the fourth stand and 130 L / min at the fifth stand.
It was set to min. Further, as for lubrication of other stands and cooling of all stands, a circulation type rolling oil supply system was used as usual.
The emulsion concentration of the circulating rolling oil supply system is 3.5%,
Oil concentration of surfactant is 0.6%, average particle size is 10 μm
And

Further, as a comparison of the present invention, when the lubrication of the fourth and fifth stands is carried out in the conventional rolling type rolling oil supply system, the emulsion supply amount at the fourth stand is 2500 L /
min and 4000 L / min on the fifth stand.

The rolling oil was supplied as described above, rolling was carried out while changing the speed, and the occurrence of chattering and heat scratches was investigated. The target materials are hard tin and soft tin with a finished thickness of 0.2t or less.
It was a kind. The results of each survey are shown in Tables 1 and 2 below.

(1) The steel type of the target material 1 is a hard tin plate, and its dimensions are a base material of 1.8 mm and a finished thickness of 0.
The width is 18 mm and the plate width is 900 mm.

As shown in Table 1, by using the first invention, it was possible to accelerate to 2100 mpm without causing chattering or heat scratches. On the other hand, in the conventional method, 1
Chattering occurred at 500 mpm and further acceleration was impossible.

FIGS. 15 and 16 show the relationship between the rolling speed and the amount of oil adhered to the steel plate of the rolled material, and the relationship between the rolling speed and the friction coefficient of the fifth stand, comparing the method according to the present invention with the conventional method. The amount of oil adhered to the steel plate is an average value of the upper and lower surfaces obtained by the solvent extraction method.

In the conventional method, the amount of oil adhered to the steel sheet was greatly reduced in the high speed range of 800 mpm or more, whereas in the present invention, the amount of oil adhered to the steel plate was stable even in the high speed range. In addition, in response to this, it is understood that the increase in the friction coefficient of the fifth stand is suppressed, a stable friction coefficient is obtained even in the high speed range, and insufficient lubrication is eliminated.

As shown by the results of the test, when the target material 1 is rolled, if the fifth stand is lubricated by the conventional circulating rolling oil supply method, the rolling speed is reduced due to the occurrence of chattering due to insufficient lubrication. The limit is 1500 mpm,
High speed rolling was hindered. On the other hand, by using the first aspect of the present invention, the lack of lubrication in the high speed range can be eliminated, and therefore chattering can be prevented in advance.
High speed rolling of 0 mpm is possible. FIG. 17 shows a distribution of average speeds when rolling the target material 1 when the conventional circulating rolling oil supply system and the first invention are used. Speed is 1350m
It was improved from pm to 1700 mpm.

[0104]

[Table 1]

(2) The steel type of the target material 2 is a soft tin plate, and its dimensions are a base material thickness of 2.3 mm and a finished thickness of 0.
It is 20 mm and the plate width is 1000 mm.

The target material 2 is softer than the target material 1 but has a high cold pressing rate, so that the heat scratch defect was frequently generated in the fifth stand particularly in the conventional method.

As shown in Table 2, by using the first aspect of the present invention, it was possible to accelerate to 2100 mpm with no heat scratches. On the other hand, in the case of the conventional method, 1700 mpm
At that time, slight heat scratches occurred, and at higher speeds, remarkable heat scratches occurred.

18 and 19 show the relationship between the rolling speed and the amount of oil adhered to the steel plate of the rolled material, and the relationship between the rolling speed and the friction coefficient of the fifth stand, comparing the method according to the present invention and the conventional method. In the conventional method, the amount of adhered steel plate was greatly reduced in the high speed range, whereas in the present invention, a stable amount of oil adhered to the steel plate was obtained even in the high speed range. In addition, in response to this, it is understood that the increase in the friction coefficient of the fifth stand is suppressed, a stable friction coefficient is obtained even in the high speed range, and the lack of lubrication is resolved.

FIG. 20 shows the relationship between the rolling speed and the temperature of the steel sheet on the delivery side of the fifth stand. In the conventional method, the temperature increased greatly with the speed, and exceeded 170 ° C. at 1700 mpm or more, and heat scratches occurred. On the other hand, according to the first aspect of the present invention, the temperature rise is suppressed and the occurrence of heat scratch flaws is eliminated. The reason for this is that according to the first aspect of the present invention, an increase in the friction coefficient in the high-speed rolling region can be suppressed, friction heat generation is reduced, and as a result, the steel plate temperature on the delivery side of the fifth stand is reduced.

As shown by the results of this test, when the target material 2 is rolled and the lubrication of the fourth and fifth stands is performed by the conventional lubrication type rolling oil supply method, the rolling speed is 1700 mpm due to the occurrence of heat scratch flaws. Was the limit, and high-speed rolling was hindered. However, by using the first aspect of the present invention, the lack of lubrication in the high speed range is resolved, and the occurrence of heat scratches can be prevented, and high speed rolling of 2100 mpm becomes possible. FIG. 21 shows the distribution of the average speed when rolling the target material 2 when using the conventional circulating rolling oil supply system and the first invention, but using the first invention. Has improved the average speed from 1550 mpm to 1900 mpm.

[0111]

[Table 2]

[Embodiment 2] The present invention is applied to the fourth and fifth stands of a tandem rolling mill with all five stands, and the fourth and fifth stands are applied.
When lubrication of the stand is performed by the second rolling oil supply system,
The amount of oil loss and replenishment of water in the circulating rolling oil supply system were performed according to the second invention (Embodiment 2). The base oil of the rolling oil was beef tallow (viscosity at 40 ° C., 45 cSt), and a cationic surfactant was used as an emulsifying dispersant. The concentration of the emulsion of the second rolling oil supply system according to the present invention is 10%, the oil concentration of the surfactant is 0.1% lower than that of the emulsion of the circulation type rolling oil supply system, and the average particle size is 20 μm. It was adjusted. Further, the concentration of the emulsion in the circulating rolling oil supply system was 3%, the concentration of the surfactant against oil was 0.6%, and the average particle size was 9 μm. The temperature of the emulsions was the same, and was 60 ° C.

Table 3 shows the target rolled materials with a base metal thickness of 1.8 to
2.0 mm, finish thickness 0.16 to 0.20 mm, plate width 8
The rolling oil consumption rate when a thin tin plate having a thickness of 00 to 1200 mm is shown by comparing the method according to the present invention with the conventional method. The amount of emulsion supplied from the second rolling oil supply system at this time is adjusted according to the finishing thickness. When the finishing thickness is 0.16 to 0.20 mm, the feeding amount of the fourth stand and the fifth stand is adjusted. , 100 L / min, 130 each
L / min, and when the finished thickness was 0.20 to 0.25 mm, 5 L / min and 15 L / min, respectively. on the other hand,
The supply amount of the emulsion sprayed for lubrication in the conventional method was 3000 L / min in the fourth stand and 4000 L / min in the fifth stand.

According to the second aspect of the present invention, the rolling oil consumption rate can be made lower than that of the conventional system (circulation system). This is because the effect of effectively using the emulsion of the second rolling oil supply system as a supplementary oil for the oil loss of the circulating rolling oil supply system according to the present invention and the amount of emulsion supply can be made smaller than the conventional system. This is due to the effect that the amount of oil loss due to fumes, etc. can be reduced compared to the conventional method.

[0115]

[Table 3]

[0116]

As described above, according to the first aspect of the present invention, an emulsion having a high adhesion efficiency and an average particle size of 20 μm or more is supplied to the upper surface and the lower surface of the steel plate on the rolling stand entrance side, so that in the high speed rolling zone. Can significantly improve the amount of oil adhered to the upper and lower steel plates. As a result, the finish plate thickness is 0.2
In the case of rolling a thin material of mm or less, the lack of lubrication that occurs in the conventional method during high-speed rolling can be solved, and the occurrence of chattering and heat scratch defects can be prevented in advance.
Along with this, the rolling speed can be improved, and the productivity can be greatly improved. Further, according to the first aspect of the present invention, the emulsion dispersion stability of the emulsion in the circulating rolling oil supply system is ensured, so that stable operation is possible.

Further, according to the second aspect of the present invention, the emulsion of the second rolling oil supply system can also be used as a replenishing oil for the circulating rolling oil supply system, and the basic unit of rolling oil can be a conventional circulating rolling oil. It can be lower than the supply method.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of application to a tandem rolling mill according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of application to a tandem rolling mill according to a second embodiment of the present invention.

FIG. 3 is a diagram showing the relationship between the oil concentration of the surfactant and the average particle size of the emulsion. (A) shows the case where the surfactant is a cationic dispersant and the rolling oil is beef tallow, and (b) shows The case where the surfactant is a nonionic emulsifier and the rolling oil is a synthetic ester rolling oil is shown.

FIG. 4 is a graph showing the relationship between the average particle size of emulsion and the adhesion efficiency.

FIG. 5 is a graph showing the relationship between emulsion concentration and adhesion efficiency.

FIG. 6 is a diagram showing the relationship between the temperature of the emulsion and the adhesion efficiency.

FIG. 7 is a diagram showing a relationship between an emulsion supply amount ωτ and a plateout amount.

FIG. 8 is a comparison diagram of the amount of adhered steel sheet on rolled material in the circulating rolling oil supply system and the second rolling oil supply system.

FIG. 9 is a diagram showing a comparison of emulsion particle size distributions of the circulating rolling oil supply system when the second rolling oil supply system is used and when it is not used.

FIG. 10 is a diagram showing an example of a method for supplementing the amount of a surfactant in a circulation system tank and an additional stirring method.

FIG. 11 is a diagram showing another example of a method for supplementing the amount of surfactant in the circulation system tank and an additional stirring method.

FIG. 12 is a diagram showing an example of a method of replenishing a circulation system tank from a second rolling oil supply system.

FIG. 13 is a diagram showing another example of a method for replenishing the circulation system tank from the second rolling oil supply system.

FIG. 14 is a diagram showing a calculation flow in a calculation device.

FIG. 15 is a view showing a comparison (steel material 1) of the amount of oil adhered to the steel sheet of the rolled material of the present invention and the conventional method.

FIG. 16 is a view showing a comparison (friction material 1) of the friction coefficient between the fifth stand of the present invention and the conventional method.

FIG. 17 is a diagram showing a comparison (rolling target material 1) of rolling speed distributions of the present invention and the conventional method.

FIG. 18 is a view showing a comparison (steel material 2) of the amount of oil adhered to the steel sheet of the rolled material of the present invention and the conventional method.

FIG. 19 is a diagram showing a comparison (friction material 2) of the friction coefficient between the fifth stand of the present invention and the conventional method.

FIG. 20 is a view showing a comparison (steel material 2) of the steel plate temperatures on the delivery side of the fifth stand of the present invention and the conventional method.

FIG. 21 is a diagram showing a comparison (rolling material 2) of rolling speed distributions of the present invention and the conventional method.

FIG. 22 is a diagram showing an example of application to the tandem rolling mill according to the embodiment of the present invention, in which the supply position of the second supply system emulsion is on the upstream side of the roll bite.

[Explanation of symbols]

1 ... Storage tank, 2 ... Tank, 3 ... Tank, 4 ... Tank, 5a, 5b, 5c ... Supply pump, 6a, 6b, 6
c, 6d ... Flow rate adjusting valve, 7 ... Stirrer, 8a, 8b ... Pump, 9a, 9b ... Rolling oil supply line, 10a, 10b ...
Header, 11 ... Rolling oil feeding line, 12a, 12b ...
Flow control valves, 13a, 13b ... Circulation system tank, 14
a, 14b ... Pump, 15a, 15b ... Rolling oil supply line, 16 ... Stirring pump, 17a, 17b ... Recovery oil pan, 18 ... Stirrer, 19a, 19b ... Header, 2
0 ... Emulsion supply system for cooling, 21 ... Strip,
22 ... Work roll, 23 ... Backup roll, 24
a, 24b ... Calculation device, 25 ... Flowmeter, 26a, 26b
... flow control valve, 27 ... stirring section, 28 ... pump,
29 ... Flow control valve, 30a, 30b ... Return line, 31
... Flow control valve, 32 ... Piping, 33 ... Flow control valve, 34 ...
Stirring pump, 35 ... Piping, 36 ... Flow rate adjusting valve, 37 ...
Flow rate adjusting valve, 38 ... Piping, 39 ... Flow rate adjusting valve, 40 ... Piping, 41 ... Pump, 42 ... Replenishment tank, 43a, 43
b, 43c ... Piping, 44a, 44b, 44c ... Flow control valve, 45 ... Agitator, 46 ... Replenishing pump, 47 ... Piping, 48 ... Oil pan.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshimi Sakurai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Steel Tube Stock Company (72) Hiroyoshi Sakai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Shigehiro Tomotsune 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (56) Reference JP-A-2-37911 (JP, A) JP-A-9-239430 ( JP, A) JP 56-41010 (JP, A) JP 9-122733 (JP, A) JP 2000-94013 (JP, A) JP 2000-94025 (JP, A) (58) Survey Areas (Int.Cl. ⁷ , DB name) B21B 27/10 B21B 45/02 310

Claims (5)

(57) [Claims] 1. An emulsion rolling oil for cold rolling
Circulating type first rolling oil supply system and emulsion
Second rolling oil that supplies the rolling oil to the upper and lower surfaces of the steel sheet
A supply system is provided so that the second rolling oil supply system can
The same type as the emulsion of the first rolling oil supply system
And interface with lower oil concentration than the first rolling oil supply system
Activator is added, and further, the emulsion of the first rolling oil supply system
Emuls adjusted to have a larger average particle size
Supply process and whether it adheres to the steel plate in this process
Collected emulsion and used in the first rolling oil supply system
Adjust the surfactant so that it is the same as the oil concentration of the surfactant.
After charging and adding mechanical agitation, the first rolling oil supply system
Cold rolling mill having a step of merging with another emulsion
In the rolling oil supply method according to the second aspect , when the amount of rolling oil mixed from the second rolling oil supply system to the tank of the first rolling oil supply system is larger than the amount of oil loss of the first rolling oil supply system, A step of replenishing the tank of the first rolling oil supply system with dilution water so that the concentration of the first rolling oil supply system becomes constant, and a first rolling oil supply from the second rolling oil supply system When the amount of rolling oil mixed into the tank of the system is smaller than the amount of oil loss of the first rolling oil supply system, in the step of joining the emulsion of the second rolling oil supply system to the first rolling oil supply system, The emulsion prepared by additionally adding the surfactant to the oil concentration to be the same as the emulsion of the first rolling oil supply system is replenished to the tank of the first rolling oil supply system, and the dilution water is replenished. a step, comprising the cold Rolling oil supply method in the rolling mill. 2. An emulsion rolling oil for cold rolling
Circulating type first rolling oil supply system and emulsion
Second rolling oil that supplies the rolling oil to the upper and lower surfaces of the steel sheet
A supply system is provided so that the second rolling oil supply system can
The same type as the emulsion of the first rolling oil supply system
And interface with lower oil concentration than the first rolling oil supply system
Activator is added, and further, the emulsion of the first rolling oil supply system
Emuls adjusted to have a larger average particle size
Supply process and whether it adheres to the steel plate in this process
Collected emulsion and used in the first rolling oil supply system
Adjust the surfactant so that it is the same as the oil concentration of the surfactant.
The charged, after a mechanical stirrer was pressurized example, the first rolling oil supply system
Cold rolling mill having a step of merging with another emulsion
In the method for supplying rolling oil according to the first aspect of the present invention, the step of merging the emulsion of the second rolling oil supply system with the emulsion of the first rolling oil supply system includes the step of mixing the emulsion of the second rolling oil supply system with the circulation type rolling oil supply system. Cold rolling mill, which is equipped with a step of adding a surfactant after replenishing into the tank, and then strongly stirring and shearing the emulsion by increasing the rotation speed of the agitator in the tank. Oil supply method in. 3. An emulsion rolling oil in cold rolling
Circulating type first rolling oil supply system and emulsion
Second rolling oil that supplies the rolling oil to the upper and lower surfaces of the steel sheet
A supply system is provided so that the second rolling oil supply system can
The same type as the emulsion of the first rolling oil supply system
And interface with lower oil concentration than the first rolling oil supply system
Activator is added, and further, the emulsion of the first rolling oil supply system
Emuls adjusted to have a larger average particle size
Supply process and whether it adheres to the steel plate in this process
Collected emulsion and used in the first rolling oil supply system
Adjust the surfactant so that it is the same as the oil concentration of the surfactant.
After charging and adding mechanical agitation, the first rolling oil supply system
Cold rolling mill having a step of merging with another emulsion
In the rolling oil supply method according to claim 1, the step of merging the emulsion of the second rolling oil supply system with the emulsion of the first rolling oil supply system is performed from the tank of the second rolling oil supply system to the circulating rolling oil supply system. A method for supplying rolling oil in a cold rolling mill, which comprises a step of adding a surfactant in the middle of the feeding pipe to the tank and then shearing the emulsion by passing it through a supply pump. . 4. An emulsion rolling oil for cold rolling
Circulating type first rolling oil supply system and emulsion
Second rolling oil that supplies the rolling oil to the upper and lower surfaces of the steel sheet
A supply system is provided so that the second rolling oil supply system can
The same type as the emulsion of the first rolling oil supply system
And interface with lower oil concentration than the first rolling oil supply system
Activator is added, and further, the emulsion of the first rolling oil supply system
Emuls adjusted to have a larger average particle size
Supply process and whether it adheres to the steel plate in this process
Collected emulsion and used in the first rolling oil supply system
Adjust the surfactant so that it is the same as the oil concentration of the surfactant.
After charging and adding mechanical agitation, the first rolling oil supply system
Cold rolling mill having a step of merging with another emulsion
The method of supplying a rolling oil according to claim 1, wherein the step of merging the emulsion of the second rolling oil supply system with the emulsion of the first rolling oil supply system is carried out separately from the tank of the second rolling oil supply system. the buffer tank for adjusting the amount provided, the surfactant was additionally added therein, the cold rolling mill according to, characterized in that it comprises the step of adding an agitation to the emulsion and shear provided agitator Rolling oil supply method. 5. An emulsion rolling oil for cold rolling
Circulating type first rolling oil supply system and emulsion
Second rolling oil that supplies the rolling oil to the upper and lower surfaces of the steel sheet
A supply system is provided so that the second rolling oil supply system can
The same type as the emulsion of the first rolling oil supply system
And interface with lower oil concentration than the first rolling oil supply system
Activator is added, and further, the emulsion of the first rolling oil supply system
Emuls adjusted to have a larger average particle size
Supply process and whether it adheres to the steel plate in this process
Collected emulsion and used in the first rolling oil supply system
Adjust the surfactant so that it is the same as the oil concentration of the surfactant.
After charging and adding mechanical agitation, the first rolling oil supply system
Cold rolling mill having a step of merging with another emulsion
In the method for supplying rolling oil according to claim 1, the step of merging the emulsion of the second rolling oil supply system with the emulsion of the first rolling oil supply system is performed by circulating rolling separately from the tank of the second rolling oil supply system. A rolling oil supply method in a cold rolling mill according to claim 1, further comprising the step of providing a storage tank for a replenishment emulsion to which a surfactant having the same oil concentration as the emulsion of the oil supply system is added.