JPH10314805A - Aluminum cold rolling method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a cold rolling method for aluminum capable of performing high-speed and high-pressure rolling continuously and stably. SOLUTION: In a cold rolling method of aluminum using an aqueous emulsion lubricating oil, a water-based emulsion lubricating oil supplied to a cold-rolled portion where aluminum as a material to be rolled comes into contact with a rolling roll is separated from oil-water separated water. And for the separated oil, at least after the separated oil is filtered,
Aqueous emulsion-based lubricating oil to be used in addition to the cold-rolled portion, which is obtained by filtering the aqueous emulsion before the oil-water separation, whereby high-speed and high-pressure rolling of aluminum is performed. It can be performed continuously and stably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cold rolling aluminum (including an aluminum alloy), and more particularly to a method which is excellent in rolling lubricity and is stable, and can reduce stains on the plate surface.
Furthermore, oil-water separation equipment, filtration equipment and oil-water mixing equipment of the emulsion after rolling are inexpensive and easy to manage,
The present invention relates to a method for cold rolling aluminum using an aqueous emulsion lubricating oil that can be used in a stable and circulating manner.

[0002]

2. Description of the Related Art Generally, in cold rolling of aluminum,
In order to obtain a good plate surface and to prevent the generation of annealing residue (oil stain) in the annealing step after rolling, 2 to 5 m
A low viscosity mineral oil of m ² / s is used as a lubricant.
When a low-viscosity mineral oil is used in cold rolling, not only an aluminum plate having good gloss can be obtained, but also the cost is advantageous. However, in high-speed and high-pressure rolling, the cooling ability of the rolled plate and rolls is inferior, and the temperature of the rolled plate and rolls rises remarkably, making shape control difficult and causing the risk of fire. There was a problem.

In order to solve such a problem, a water-soluble cold-rolling oil for aluminum has been proposed. By using the water-soluble cold-rolling oil for aluminum as a lubricant, a rolled sheet material or a rolling roll is used in a rolling process. Can be suppressed to a sufficient degree, and the above-described problem can be solved.

However, conventional water-soluble cold rolling oils are:
It is an oil-in-water emulsion formed using an emulsifier, and there is a problem that this emulsifier causes the aforementioned oil stain. In order to solve this problem, the present inventors have proposed a water-soluble cold-rolling oil that does not use an emulsifier and a cold-rolling method thereof (JP-A-5-65492, JP-A-6-108083, JP-A-6-170409
JP-A-6-179888).

[0005] The water-soluble cold-rolling oil described above uses a specific α-olefin, polybutene or polypropylene as a base oil and an alkoxyalkyl ester or the like as an oily additive. This rolling oil is pumped into high-pressure water by a mixer that mixes oil (self-emulsifying oil) and water, where it forms an emulsion and is subjected to rolling. In addition, the emulsion after rolling is subjected to oil-water separation, and the rolling oil and water are respectively filtered for the purpose of constantly maintaining the properties of the emulsion to be subjected to rolling and for precision filtering aluminum abrasion powder in the oil,
The emulsion is formed again, and is recycled.

Here, centrifugal separation using a centrifugal separator or stationary separation using a fixed type fiber membrane separator is used as a method for separating the emulsion after rolling from oil and water. In order to respond to demands for productivity improvement and cost reduction by high-speed and high-pressure rolling caused by elongation, development of an oil-water separation method that is excellent in oil-water separation efficiency, inexpensive, and easy to manage is strongly desired.

Although centrifugal separation has the advantage that oil and water can be separated with high accuracy and the installation area can be small, it cannot be said that the centrifugal separation sufficiently satisfies the above demand because of the expensive equipment. On the other hand, for stationary oil-water separation,
Although the equipment cost is low, there is a problem that the separation efficiency is low and the installation area needs to be large. in this way,
Both centrifugation and stationary oil-water separation have advantages and disadvantages,
It cannot be said that the above requirements are satisfied.

On the other hand, the fixed fiber membrane (polyester type) separation has the advantages of both centrifugal separation and stationary oil-water separation at the same time. Are better. However, the fixed fiber membrane (polyester-based) separation has a problem that the aluminum abrasion powder in the emulsion easily causes clogging and the separation efficiency is reduced immediately. As a countermeasure, it is conceivable to remove aluminum abrasion powder through a cartridge filter before the separation process, but there are other problems such as increase in running cost and management man-hour, and fluctuation of separation efficiency due to it. At present, it is not possible to sufficiently respond to the demands for productivity improvement and cost reduction by high-speed, high-pressure rolling or the like using the conventionally known oil-water separation method. In order to solve this, the present inventor has proposed that the oil-water separation efficiency can be improved by a continuously moving fiber membrane (Japanese Patent Application No. 8-2981748).

[0009]

However, in the conventional rolling method, as described above, the whole amount of the emulsion subjected to the rolling is separated into oil and water, the separated oil and water are entirely filtered, and the whole amount is mixed with oil and water again. Because it is a method used for rolling, it must be a large-scale system, equipment cost,
Although it is an excellent method if the problem of the equipment space is neglected, a great deal of cost is required for initial cost, running cost or maintenance. For this reason, in particular, in recent years, there has been an increasing demand for reduction of equipment cost and space saving for installation of equipment. Further, a method of separating a part of the emulsion after rolling into oil and water and circulating and using the remaining emulsion as it is can be considered. However, the remaining emulsion is not subjected to microfiltration, and metal sludge such as aluminum abrasion powder generated by rolling is used. Accumulates in the emulsion, and this sludge degrades the quality of the plate surface.

Accordingly, it is an object of the present invention to provide a water-soluble emulsion-based lubricating oil supplied to a cold-rolled portion that is always stable in property and that the metal sludge concentration in the emulsion contacting the plate surface is low and stable. Furthermore, it is possible to drastically reduce oil and water mixing equipment, oil and water separation equipment and related equipment costs and running costs, reduce the installation space for these equipment, and perform continuous and stable rolling at high speed and high pressure. It is an object of the present invention to provide a method of cold rolling aluminum.

[0011]

Under such circumstances, the present inventors have conducted intensive studies, and as a result, completed the present invention. That is, the present invention relates to a cold rolling method for aluminum using an aqueous emulsion lubricating oil, wherein an aqueous emulsion lubricating oil to be supplied to a cold-rolled portion where a material to be rolled is in contact with aluminum and a rolling roll is oil-water separated. The separated water and the separated oil are obtained by filtering at least the separated oil and then mixing the separated water with the separated water, and the aqueous emulsion lubricating oil used for other than the cold-rolled portion filters the aqueous emulsion before the oil-water separation. It is intended to provide a method for cold rolling aluminum, which is characterized in that:

Further, in the cold rolling method for aluminum according to the present invention, the aqueous emulsion lubricating oil used for other than the cold rolling portion is mixed into the cold rolling portion above the cold rolling portion. It is characterized by installing a partition part for preventing

[0013]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a water-based emulsion lubricating oil (hereinafter also referred to as "lubricating coolant") supplied to a cold-rolled portion where a material to be rolled comes into contact with a rolling roll is an oil-water separator. The separated water and separated oil are obtained by filtering at least the separated oil and then mixing with the separated water. The aqueous emulsion-based lubricating oil may be any oil that does not contain an emulsifier and is capable of forming an emulsion by mixing a rolling oil having self-emulsifying properties with water, and in particular, a weak self-emulsifying agent for stabilizing the properties of the emulsion. Those having emulsifying properties are preferred. The rolling oil having self-emulsifying properties includes a base oil and an oily additive, and the base oil includes α-olefin, polypropylene,
Examples include polyisobutylene or polybutene,
Alkoxyalkyl esters suitable as oily additives include, for example, methoxyethyl caprate, methoxyethoxyethyl caprate, ethoxyethyl caprate, ethoxyethoxyethyl caprate, propoxyethyl caprate, propoxyethoxyethyl caprate, butoxy caprate. Ethyl, butoxyethoxyethyl caprate, pentyloxyethyl caprate, pentyloxyethoxyethyl caprate, hexyloxyethyl caprate, hexyloxyethoxyethyl caprate, methoxyethyl laurate, methoxyethoxy laurate , Ethoxyethyl laurate, ethoxyethoxyethyl laurate, propoxyethyl laurate, propoxyethoxyethyl laurate, butoxyethyl laurate, la Butoxyethoxyethyl phosphate, pentyloxyethyl laurate, pentyloxyethoxyethyl laurate, hexyloxyethyl laurate, hexyloxyethoxyethyl laurate, methoxyethyl myristate, methoxyethoxyethyl myristate, myristine Ethoxyethyl acid, ethoxyethoxyethyl myristate, propoxyethyl myristate, propoxyethoxy myristate, butoxyethyl myristate, butoxyethoxyethyl myristate, pentyloxyethyl myristate, pentyloxyethoxyethyl myristate, myristic acid Hexyloxyethyl, hexyloxyethoxyethyl myristate, methoxyethyl palmitate, methoxyethoxyethyl palmitate, ethoxypalmitate Xylethyl, ethoxyethoxyethyl palmitate, propoxyethyl palmitate, propoxyethoxyethyl palmitate, butoxyethyl palmitate, butoxyethoxyethyl palmitate, pentyloxyethyl palmitate, pentyloxyethoxyethyl palmitate, hexyloxy palmitate Ethyl, hexyloxyethoxyethyl palmitate, methoxyethyl stearate, methoxyethoxyethyl stearate, ethoxyethyl stearate, ethoxyethoxyethyl stearate, propoxyethyl stearate, propoxyethoxyethyl stearate, butoxyethyl stearate,
Examples include butoxyethoxyethyl stearate, pentyloxyethyl stearate, pentyloxyethoxyethyl stearate, hexyloxyethyl stearate, and hexyloxyethoxyethyl stearate. The hydrocarbon group of the acid and alcohol of the alkoxyalkyl ester may be a straight-chain hydrocarbon or a hydrocarbon having a side chain. In addition, the above-mentioned alkoxyalkyl esters contained in the rolling oil may be used alone or in combination, and the mixing ratio thereof is 3 to 50% by weight in the rolling oil. Is preferred. Preferred examples of the rolling oil include 40 to 95% by mass of α-olefin, alkoxyalkyl ester 5
-20% by mass, the balance being refined mineral oil; one or more selected from polypropylene, polyisobutylene and polybutene 80
1 to 95% by mass, alkoxyalkyl ester 5 to 50% by mass; at least one selected from polypropylene, polyisobutylene and polybutene 80 to 95% by mass, alkoxyalkyl ester 5 to 20% by mass, fatty acid ester 0 to
10% by mass; at least one selected from polypropylene, polyisobutylene and polybutene, 5 to 90% by mass, α-olefin, 5 to 90% by mass, alcoholic alkyl ester,
One or more selected from neopentyl glycol esters and glycerin derivatives in an amount of 2 to 20% by mass.

In the present invention, the average emulsion particle size of the lubricating coolant is in the range of 20 to 90 μm. Generally, in cold rolling of aluminum, the particle size of the emulsion greatly affects the rolling lubricity and the oil-water separation property. As the particle size of the emulsion is uniform and larger, the plate-out property (water separation spreadability) on the roll surface or the material to be rolled is improved, and the rolling oil is introduced into the roll bite (in the contact portion between the roll and the material to be rolled). The amount increases, and the rolling lubricity improves. Further, the oil-water separation property is improved by Stokes law. For this reason, in order to obtain good rolling lubricity and oil-water separation properties, the particle diameter needs to be in the above range. When the average particle size of the emulsion is less than 20 μm, the oil-water separation property and the rolling lubricity are poor, and the plate-out property is reduced. On the other hand, if it exceeds 90 μm, the plate-out property of the emulsion supplied to the interface between the roll surface and the surface of the aluminum material to be rolled becomes non-uniform, and the amount of oil introduced into the roll bite partially increases. Oil pits and seizure failure occur, resulting in uneven plate surface quality.

Further, when the oil concentration is 2% in the lubricating coolant,
-30%, preferably 5-15%. If the oil concentration is less than 2%, the amount of oil plate-out at the roll bite portion is not sufficient, the oil film is likely to be cut, and the plate surface quality is deteriorated due to poor lubrication. On the other hand, if the oil concentration exceeds 30%, it becomes difficult to form a uniform emulsion, and an uneven oil film is formed in the roll bite, thereby deteriorating the plate surface quality.

The method of forming the emulsion is not particularly limited, but a rolling oil having self-emulsifying properties does not form an emulsion simply by being mixed with water. Therefore, it is necessary to carry out strong stirring after mixing. . The strong stirring can be performed with a homomixer or the like.
Using a mixer as shown in FIG. 2 described in Japanese Patent No. 0409, mixing in a form such that oil is injected into water immediately before a nozzle forms a uniform emulsion, and
This is preferable because it can be supplied.

FIG. 1 shows a basic conceptual diagram of the rolling oil supply system of the present invention. According to the system shown in FIG. 1, the lubricating coolant used for rolling flows into the collection tank 10 below the roll stand 4, and is sent to the aqueous emulsion tank 8 from here. Next, a part of the emulsion in the aqueous emulsion tank is sent to the oil / water separator 1 by the feed conduit 11, where the oil / water is separated. The separated oil is finely filtered by a filter 2b by a filter 2a, if necessary, and then mixed by a mixer 3 if necessary. Is 20 to 90 μm
Is reproduced. The regenerated lubricating coolant is again subjected to rolling and is used in circulation.
On the other hand, an aqueous emulsion-based lubricating oil (hereinafter, also referred to as “cooling coolant”) used for portions other than the cold-rolled portion is taken out as another part of the emulsion in the aqueous emulsion layer, and is sent to the emulsion filter 9 through the feed conduit 12. Then, after mainly filtering metal sludge and the like, it is supplied to rolls other than the roll bite portion.

In the present invention, as described above, the rolls other than the roll bite portion are cooled by the cooling coolant. This is done in order to cope with the increase in the rolling speed and the rolling reduction. That is, the higher the rolling speed, the greater the amount of heat generated per unit time. Further, since the heat generated is mainly due to the processing heat, the higher the rolling reduction, the larger the amount of heat generated. This is to prevent the roll temperature from rising and the shape of the plate from becoming difficult to control.

The cooling coolant may be any water system of the same kind as the lubricating coolant, but an emulsion having the same properties as the lubricating coolant is preferred. Further, the oil concentration of the cooling coolant is preferably equal to or less than the oil concentration of the lubricating coolant. Further, the supply amount of the cooling coolant is not particularly limited, and may be appropriately selected according to the degree of heat generation of the roll, but is usually used in a range of 2 to 15 times the supply amount of the lubricating coolant.

In the present invention, it is necessary to prevent the cooling coolant from entering the cold rolling section. Although there is no particular limitation on such a method for preventing mixing, for example, as shown in FIG. 3, it is preferable to install the partition plate 24 above the cold rolling section 25, preferably near the lower part of the upper backup roll 22. . If the cooling coolant is not prevented from being mixed, as shown in FIG. 4, after the cooling coolant is supplied to the backup roll 22, the cooling coolant falls and hinders the supply of the lubricating coolant. It enters the roll bite and makes the properties of the lubricating coolant non-uniform. As a result, the introduction of oil into the roll bite is hindered, adversely affecting the rolling lubricity and making the sheet surface quality non-uniform.

As the structure of the partition plate 24, if it is a structure for preventing the cooling coolant from entering the cold rolling section,
There is no particular limitation. For example, the cooling coolant collected by the partition plate is caused to flow in the width direction of the partition plate,
So that it flows below the roll stand outside of 4a,
The upper surface on the entry side of the partition plate may not be in contact with the cooling coolant. Further, it is preferable that the partition plate 24 is brought into contact with the backup roll 22 or the work roll 21, but if the roll is damaged, a very small gap may be formed. The partition may be installed at any position as long as it is above the lubricating coolant supply unit.

In the present invention, as described above, after the lubricating coolant is supplied to the cold rolling section, the lubricating coolant is
Oil-water separation treatment. The oil-water separation method is not particularly limited, and examples thereof include a centrifugal separation method, a stationary separation method, and a fiber membrane separation method, and these may be used alone or in combination.

Next, the separated oil from which the oil-water separation has been performed is microfiltered by a filtration device. As a filtration method, a filtration method using diatomaceous earth is preferred. As a result, the 1 μm-diameter aluminum powder that can be immediately clogged by the cartridge filter can be adsorbed and removed by the activity of the clay. The amount of water in the separated oil after filtration is preferably as small as possible,
For practical use, the water content in oil is preferably 1000 ppm or less.

On the other hand, the cooling coolant is used for cooling a roll after filtering an aqueous emulsion before oil-water separation. Since the filtration is performed in an emulsion state, it is preferable to use diatomaceous earth filtration. As a result, aluminum powder of several μm can be removed. If a filtration method using diatomaceous clay is used, the clay absorbs moisture and immediately becomes clogged and cannot be used.

In the present invention, by adopting the above-described system, the amount of aluminum powder in the lubricating coolant is reduced as much as possible, and even if a relatively large amount of aluminum powder or the like is present in the cooling coolant, the amount of the aluminum powder is reduced by the partition plate. The metal sludge does not contact the aluminum plate surface. Therefore, the quality of the plate surface after rolling can be improved. In addition, since the properties of the lubricating coolant are always stable and the metal sludge concentration is stable at a low concentration, it is not necessary to separate the entire amount of the coolant after the rolling process into oil and water, and it is not necessary to filter and mix the oil and water. Dramatic reduction of equipment costs and running costs associated with it, enabling smaller installation space for those equipment,
Rolling can be performed continuously and stably under high speed and high pressure

In the present invention, it is preferable that the separated water obtained by separating the lubricating coolant by an oil / water separator is also microfiltered. Further, the filtration devices 2a and 2b shown in FIG.
The installation position of is not limited to this, and may be installed on the downstream side of the separation oil tank 7 and the separation water tank 6, respectively. Further, in the separation oil tank 7 and the separation water tank 6, circulation filtration may be performed.

Further, the separation oil tank 7 and the separation water tank 6 shown in FIG. 1 are provided with an introduction pipe for replenishing fresh oil and fresh water, replenishing these appropriately, then mixing with a mixing device, and then supplying. Is also good. Further, a part of the lubricating coolant supplied to the cold rolling section may be mixed in the cooling coolant supplied to the backup roll.

Further, when rolling is repeated in the above-mentioned circulation system, metal sludge in the cooling coolant increases and does not adversely affect the sheet surface, but the rolls may be contaminated. In this case, it is preferable to perform the partial dumpout periodically or continuously.

[0029]

Next, the present invention will be described in more detail with reference to examples, but this is merely an example and does not limit the present invention.

The following test rolling oils were prepared, and the effects of the oil concentration of the lubricating coolant and the cooling coolant, the average particle size of the emulsion, and the presence or absence of the partition between the lubricating coolant and the cooling coolant on the rolling lubricity and the plate surface quality were evaluated. did. Experimental conditions and evaluation conditions are shown below.

(1) Sample Rolling Oil A rolling oil having 90% by mass of an α-olefin having 14 carbon atoms as a self-emulsifying rolling oil and 10% by mass of butoxyethyl myristate as an oily additive was used. (2) Formation of emulsion A 15% emulsion was formed using the mixer shown in FIG. The average particle size of the emulsion to be rolled is 15 to 15 depending on the pressure of the oil to be pressed and the nozzle.
It was changed to 100 μm. The average particle size of the emulsion is measured using a laser diffraction particle size distribution analyzer (LA7 manufactured by Horiba, Ltd.).
00). (3) Oil Concentration Conditions The oil concentration was varied from 1 to 35% by changing the flow rate of the rolling oil press-fitted by the mixer shown in FIG.

(4) Rolling Lubricity Evaluation Conditions As the material to be rolled, a JIS 5052 aluminum alloy material (sheet thickness 2.0 mm, sheet width 40 mm, sheet length 450 mm) was used. Surface roughness R
a Rolling mill having a roll of 0.4 μm and a rolling speed of 70
It rolled at m / min and a reduction of 50%. The lubricating coolant flow rate is 4 L / min (including upper and lower), and the cooling coolant flow rate is 4 L / min.
２０20 L / min (including upper and lower). Rolling lubricity during rolling is determined by the Bland & Ford equation based on the rolling load measured by the load cell, the advanced ratio measured from the engraved marks on the roll surface transferred to the plate surface at 100 mm intervals, the plate thickness before and after rolling, and the roll diameter from the roll diameter It evaluated by the coefficient. The pass / fail was judged to be acceptable when the friction coefficient was 0.2 or less, and there was a problem when the friction coefficient exceeded 0.2. The advance rate was calculated from the following equation (1). Advanced ratio (%) = (L ₂ −L ₁ ) × 100 / L ₁ (1) L ₁ : Length between stamp marks on the roll surface (mm) L ₂ : Length between stamp marks on the sheet surface after rolling Thickness (mm) The plate surface quality was sampled from three places in the width direction of the plate, and the surface was observed with an electron microscope (SEM) at a magnification of 200 times. The case where the plate surface quality (oil pit) is the same at all three places is A, the case where the product is slightly non-uniform but B is a level where there is no problem in the product, and the case where the product is non-uniform and there is a problem with the product C.

(5) Glossiness variation: The glossiness of the plate surface was measured at each of 30 locations in the width direction and the rolling direction, and the variation in glossiness was calculated as (standard deviation / average value) × 100 (%). . The measuring method was based on JIS Z 8741 (Method for measuring specular gloss).

Examples 1 to 6 and Comparative Examples 1 to 7 (when the flow rates of the lubricating coolant and the cooling coolant are the same)
When the flow rate of the lubricating coolant and that of the cooling coolant were the same, the effects of the emulsion average particle size and the oil concentration were evaluated. The results are shown in Table 1. According to Table 1, when the oil concentration of the cooling coolant is 0, that is, water, the coefficient of friction tends to be slightly higher (Example 2). This is probably because the cooling coolant obstructed or thinned the lubricating coolant. However, there is no problem. This shows that there is no problem even if the oil concentration of the cooling coolant is lower than the oil concentration of the lubricating coolant.
Also, the coefficient of friction tends to decrease with an increase in the oil concentration, and when the oil concentration is in the range of 2 to 30%, the friction coefficient,
The plate surface quality is at a level that does not cause any problem (Examples 2 to 4). Further, as the emulsion average particle size increases, the friction coefficient tends to decrease (Examples 3 to 6). This is because the larger the emulsion particle size, the better the plate-out property and the greater the amount of rolling oil introduced into the roll bite. Thereby, the emulsion average particle size is 20 to
In the range of 90 μm, the coefficient of friction is 0.2 or less, the plate surface quality is A or B, and the variation in the surface glossiness is 15% or less, which is a level that is no problem.

On the other hand, it can be seen that even when the cooling coolant is the same as the lubricating coolant, the friction coefficient sharply increases when the average particle size of the emulsion is less than 20 μm (Comparative Example 1). When the cooling coolant is water, if the average particle size of the emulsion is less than 20 μm, the coefficient of friction is further increased, some burn-in is observed, the surface quality of the sheet is deteriorated, and the fluctuation of the surface gloss exceeds 15%. (Comparative Example 2). When the oil concentration is 35%, the friction coefficient slightly decreases, but the surface quality deteriorates (Comparative Examples 3 and 5). This is presumably because the variation in surface glossiness was 15% or more, and the formation of oil pits on the plate surface became uneven due to the uneven emulsion. When the oil concentration is less than 2%, the coefficient of friction is extremely high, and the surface quality is also deteriorated (Comparative Examples 4 and 6). This is because the amount of oil introduced into the roll bite is insufficient and lubrication is insufficient. In this case, it can be seen that there is a difference in surface gloss between the portion having a little lubrication and the portion having no lubrication. When the average particle size of the emulsion exceeds 90 μm, the coefficient of friction is slightly lowered, but the surface quality of the sheet is deteriorated (Comparative Example 7).

[0036]

[Table 1]

From the above results, when the flow rates of the lubricating coolant and the cooling coolant are the same, the lubricating coolant has an oil concentration of 2 to 30% and an average emulsion particle size of 20 to 90 μm.
It can be understood that, when the oil concentration of the cooling coolant is lower than the oil concentration of the lubricating coolant, the rolling lubricity and the sheet surface quality are not adversely affected.

Examples 7 to 11 and Comparative Examples 8 to 14 (When the cooling coolant flow rate is larger than the lubricating coolant) When the cooling coolant flow rate is larger than the lubricating coolant, the partition plate between the cooling coolant and the lubricating coolant is formed. The presence or absence was evaluated. Table 2 shows the results. Even if the cooling coolant flow rate is higher than the lubrication coolant flow rate,
If there is a partition plate, the coefficient of friction is low in the range of 0.11 to 0.13, the plate surface quality is good, and the variation in glossiness is good at 15% or less (Examples 7 to 11). In Example 8, since the oil concentration was low, the amount of oil introduced into the roll bite was small, and the plate surface quality was slightly deteriorated.

In Comparative Examples 8 to 14, the flow rate of the cooling coolant was larger than the flow rate of the lubricating coolant and the emulsion oil concentration of the cooling coolant was lower than the oil concentration of the lubricating coolant irrespective of the emulsion average particle size. Even if there is no partition plate, the friction coefficient is 0.2
As described above, it can be seen that the plate surface quality is in the C class, and the fluctuation of the surface gloss exceeds 15%, which is a problem level. This is probably because the absence of the partition plate caused the cooling coolant to hinder the lubricating coolant at the roll bite portion, thereby making the amount of oil introduced into the roll bite non-uniform. From the above results, it is clear that the partition plate must be provided when the oil concentration of the cooling coolant is lower than that of the lubricating coolant and the flow rate of the cooling coolant is higher than that of the lubricating coolant.

[0040]

[Table 2]

Example 12 and Comparative Example 15 (Confirmation of Partition Plate Effect by Continuous Circulation Test) Using the system shown in FIG. 1, the presence or absence of a partition plate was continuously used by using a coolant, and the average of emulsion of lubricating coolant and cooling coolant was used. Particle size, oil concentration, amount of aluminum powder in each coolant and friction coefficient during rolling, sheet surface quality after rolling,
The amount of aluminum powder adhering to the plate surface was determined. The experimental conditions are shown below, and the results are shown in Table 3 in Example 12 and Comparative Example 1
5 is shown in Table 4. The amount of aluminum powder in the coolant was measured by adding 20 ml of aqua regia to 100 ml of the coolant, heating the mixture to 80 ° C., and quantifying the aluminum in the water layer by atomic absorption spectrometry. The amount of aluminum powder on the plate surface was determined by wiping the rolled plate surface (0.05 m ² ) with absorbent cotton soaked with ethanol, dissolving the aluminum powder attached to the absorbent cotton with aqua regia, and performing atomic absorption spectroscopy. Quantified by

<Continuous circulation test conditions> Rolling conditions Rolled material: JIS 5082 aluminum alloy, 2.5 mm (t), 100 m
m (W) coil (15 pieces) Roll diameter 155mm, Roll surface roughness 0.4μm Rolling reduction 50%, Rolling speed 35m / min Rolling oil: Base oil α-olefin 95%, Oil additive Methoxyethoxyethyl myristate 5% Emulsion: oil concentration 10%, temperature 30 ° C, lubricating coolant; oil pressure 8 kg /
cm ² , oil flow 0.4 L / min, water pressure 3 kg / cm ² and water flow 3.
6L / min, spray nozzle (KSS0450 manufactured by Kyoritsu Gokin)
To prepare an emulsion. Cooling coolant: 20 pumps from emulsion tank
Supply at a flow rate of L / min Oil / water separation conditions Centrifuge: α Laval WSPS303-71 type Conditions: Centrifugal force 1000 G, inlet flow rate: 4 L / min Filtering equipment: Schneider filter manufactured by Mitsubishi Kakoki Co., Ltd. / cm ² white clay; Galleon earth V2R, diatomaceous earth; central silica #
600S assistant; diatomaceous earth: clay mixed at a ratio of 6: 4 Filtration flow rate: 2 L / min

As is apparent from Table 3, even when the number of coils is increased, the average particle size and the oil concentration of the emulsion of the lubricating coolant are 29 to 3 even when the number of coils is increased.
0 μm, 9.8 to 10.3%, which is extremely stable. Also, the amount of aluminum powder in the lubricating coolant is 1 ppm or less, which is extremely good. This is because oil-water separation is used for lubricating coolant, and the separated oil is used to remove aluminum powder with diatomaceous earth, and the separated water is used to remove aluminum powder with a cartridge filter (1 μm diameter). Again to form an emulsion in the oil-water mixing device. For cooling coolant,
As the number of circulations increases, oil starts to float in the emulsion tank, and the oil concentration decreases with the number of coils, that is, with time. In addition, since the oil component floats from a particle having a large particle size, the average particle size of the emulsion tends to decrease with time. Also, the amount of aluminum powder in the cooling coolant tends to increase with the number of coils. This is because the cooling coolant is only diatomaceous earth filtration, so that aluminum powder of 1 μm or less cannot be removed and accumulates. Thus, it can be understood that the presence of the partition plate has no adverse effect on the coefficient of friction during rolling and the surface quality of the plate with respect to the change in the properties of the emulsion during continuous rolling. In addition, the amount of aluminum powder on the plate is also 10mg.
/ m ² or less, indicating that the plate is very clean.

On the other hand, as is apparent from Table 4, the change in the properties of the emulsion and the accumulation state of the aluminum powder are almost the same as those of the embodiment, but without the partition plate, the friction coefficient starts to increase after the two-coil rolling. This has a negative effect on the sheet surface quality. Further, the amount of aluminum powder on the plate surface increases with the number of coils, and particularly exceeds 15 mg / m ² after rolling 10 coils, and the plate surface becomes very dirty. From the above results, if a partition plate is provided,
A part of the emulsion after rolling is separated into oil and water, and the separated water and the separated oil are respectively filtered.Then, the emulsion is used again as a lubricating coolant, and the remaining emulsion without oil and water separation is used as a cooling coolant, and is again subjected to cold rolling. By providing, continuous rolling is possible.

[0045]

[Table 3]

[0046]

[Table 4]

[0047]

As described above, according to the method for cold rolling aluminum of the present invention, the oil-water mixing device, the oil-water separation device and the equipment costs and running costs associated therewith are drastically reduced, and the installation space for these equipment is reduced. The scale can be increased, the cold rolling of aluminum can be performed continuously and stably under high speed and high pressure, and the surface gloss of the plate surface is uniform and there is little contamination such as aluminum abrasion powder adhered to the plate surface. Obtainable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration of an apparatus for implementing a cold rolling method for aluminum according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of an oil-water mixer suitable for use in the method for cold rolling aluminum according to the present invention.

FIG. 3 is a conceptual diagram for supplying lubricating coolant and cooling coolant to an upper roll.

FIG. 4 shows a case where a partition plate is installed in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Separation tank 2a, 2b Filtration apparatus 3 Mixer 4 Roll stand 5 Nozzle 6 Water tank 7 Oil tank 11 Lubricating coolant feed pipe 12 Cooling coolant feed pipe 21 Work roll 22 Backup roll 23 Non-rolled material 24 Partition plate

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI // C10N 40:24

Claims (4)

[Claims] 1. A method for cold rolling aluminum using a water-based emulsion lubricating oil, wherein the water-based emulsion lubricating oil supplied to the cold-rolled portion where the aluminum to be rolled contacts the rolling rolls is separated by oil-water separation. For water and separated oil, at least the separated oil is filtered,
An aqueous emulsion-based lubricating oil which is mixed with the separated water, and which is used for other than the cold-rolled portion, wherein the aqueous emulsion before the oil-water separation is filtered. . 2. A water-based emulsion-based lubricating oil to be supplied to a cold-rolled portion where the rolled material comes into contact with aluminum as the material to be rolled contains a self-emulsifying rolling oil and water without an emulsifier. The oil concentration is 2 to 30% and the average emulsion particle size is 20 to 90.
2. The method according to claim 1, wherein the emulsion is a μm emulsion. 3. The aqueous emulsion-based lubricating oil to be supplied to the cold-rolled portion where the aluminum as the material to be rolled comes into contact with a rolling roll, wherein the oil concentration of the aqueous emulsion-based lubricating oil used in portions other than the cold-rolled portion is 3. The method for cold rolling aluminum according to claim 1, wherein the concentration is not more than an oil concentration. 4. A partition for preventing the aqueous emulsion lubricating oil used in other than the cold rolled portion from being mixed into the cold rolled portion is provided above the cold rolled portion. The aluminum cold rolling method according to claim 1.