JPH038510A - Method of lubrication in hot rolling for aluminum - Google Patents

Abstract

PURPOSE:To improve the surface quality of a product by forming draining areas respectively on both upper and lower surfaces of an aluminum stock to be rolled, spraying lubricant on these areas to form oily films and rolling the above stock to be rolled before these oily films disappear. CONSTITUTION:Rolling oil emulsion sprayed to a rolling stand 10 is prevented from flowing and expanding to the upstream side of the aluminum stock 12 to be rolled and compressed gas is sprayed to the surface to form the respective draining area 26, 28. Lubricant is atomized and sprayed to the above areas 26, 28 to form oily films provided with lubricating function on both upper and lower surfaces of the stock 12 to be rolled and the stock 12 to be rolled is rolled at the rolling stand 10 before those oily films disappear. Consequently, the cooling performance of the rolling oil emulsion is not lowered, the oily component of the lubricant is not mixed excessively with the rolling oil emulsion and lubricating performance can be improved in time of rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a lubrication method when hot rolling an aluminum material in a rolling mill, and particularly to a technique for improving lubrication performance.

(Background Art) In aluminum hot rolling, a water-soluble emulsion in which a lubricant is mixed with water together with an emulsifier is used as rolling oil in order to obtain a lubricating effect and a cooling effect. The lubricant, which is the oily component of the rolling oil emulsion, is generally prepared by adding additives such as fatty acids and esters that act as lubricity improvers to the base oil. .

By the way, in aluminum hot rolling, generally,
By spraying the rolling oil emulsion as described above onto the rolling stand, or at the same time as the operation, rolling oil is applied to the aluminum material to be rolled on the upstream side of the rolling stand. By directly spraying the emulsion,
Lubrication is performed during rolling.

When it comes to lubrication for aluminum hot rolling, it is known that the oily film that forms on the surface of the work rolls and rolled aluminum material has a large effect on the lubrication performance, so it is necessary to improve the lubrication performance. In order to improve the productivity and surface quality of rolled products, it is known that it is effective to stabilize the formation of an oily film on the surfaces of these work rolls and rolled aluminum materials. It is also known that in order to stabilize the formation of an oily film on the work roll surface, it is effective to increase the concentration of the rolling oil emulsion and increase the adhesion of the oily components of the rolling oil emulsion to the work roll surface. It is being

However, in order to increase the concentration of the rolling oil emulsion to stabilize the formation of an oily film on the work roll surface and thereby improve the lubrication performance during rolling, it is possible to increase the concentration of the rolling oil emulsion by adding it to the lubricant to improve the lubrication function. Additives such as fatty acids and esters are difficult to dissolve in water, making it difficult to increase the concentration of the rolling oil emulsion, and increasing the concentration of the rolling oil emulsion may affect the cooling performance of the rolling oil. The reality is that it cannot be expected to exceed a certain level because there is a problem that it decreases by that amount and becomes more likely to cause burn-in.

On the other hand, the reality is that the formation of an oily film on the surface of rolled aluminum materials cannot be expected for the following reasons. The reality is that little improvement can be expected.

In other words, the surface temperature of the rolled aluminum material during aluminum hot rolling is usually as high as 300°C or higher, so when a rolling oil emulsion is sprayed onto the rolled aluminum material, a large amount of evaporated water vapor causes the surface temperature of the rolled aluminum material to be high. A film of water vapor is formed on the surface, and this water vapor film prevents the rolling oil emulsion from coming into direct contact with the surface of the rolled aluminum material, and prevents the oily components of the rolling oil emulsion from adhering to the surface of the rolled aluminum material. This will lead to For this reason, even if the concentration of the rolling oil emulsion is increased, almost no oily film can be formed on the surface of the rolled aluminum material, and therefore lubrication based on the formation of an oily film on the surface of the rolled aluminum material. Almost no improvement in performance can be expected.

In addition, if a large amount of oil-based lubricating oil is sprayed onto the rolled aluminum material instead of the rolling oil emulsion, an oily film will be reliably formed on the surface of the rolled aluminum material.
It is possible to reliably improve the lubrication performance during rolling, but in aluminum hot rolling, it is common for rolling oil emulsions to be used repeatedly and recirculated, so oil-based lubrication is required for the rolled aluminum material. If a large amount of oil is sprayed, there is a problem that excess lubricating oil mixes into the rolling oil emulsion, increasing the concentration of lubricating oil components in the rolling oil emulsion, and having an adverse effect on the rolling oil emulsion. There is, therefore,
A lubrication method in which a large amount of oil-based lubricating oil is sprayed onto the rolled aluminum material in the same way as a rolling oil emulsion cannot be adopted.

(Problem to be solved) The present invention has been made against this background, and the problem to be solved is to improve the concentration of the rolling oil emulsion without increasing the concentration of the rolling oil emulsion. without reducing cooling performance.
In addition, it effectively improves the lubrication performance during rolling without causing excessive mixing of oily components of the lubricating oil into the rolling oil emulsion, and advantageously improves the productivity and surface quality of rolled products. The object of the present invention is to provide a method of lubrication in hot rolling of aluminum.

(Solution Means) In order to solve this problem, the present invention includes:
Spraying compressed gas onto at least the upper surface of the rolled aluminum material located on the entry side of the rolled material near the rolling stand, and causing the rolling oil emulsion sprayed onto the rolling stand to flow and spread toward the upstream side of the rolled aluminum material. To prevent this, drain areas are formed on the upper and lower surfaces of the rolled aluminum material on the inlet side of the rolled aluminum material near the rolling stand, and drain areas on the upper and lower surfaces of the rolled aluminum material are formed. , the lubricating oil is sprayed in a mist form to form an oily film on the upper and lower surfaces of the rolled aluminum material, respectively, and before the oily films disappear, the rolled aluminum material is placed on the rolling stand. It was then rolled.

The lubricating oil used in the method of the present invention may be oil-based or a water-soluble emulsion as long as it has a lubricating function.

(Example) Hereinafter, in order to clarify the present invention more specifically,
Embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 schematically shows an example of an aluminum hot rolling mill equipped with a lubrication system suitable for use in practicing the present invention. There, reference numeral 10 denotes a rolling stand of a rolling mill, which includes a pair of work rolls 14.14 for rolling an aluminum sheet material 12, which is an aluminum material to be rolled, and a roll stand pressed against the back of the work rolls 14.14. It is equipped with a pair of backup rolls 16, 16 for applying a reduction blade to these work rolls 14.14, and an aluminum plate 1 is placed between the work rolls 14.14.
2 is caught and rolled while being sent out to the right in the figure. A large number of rolling oil spouting nozzles 2° attached to the rolling hydraulic pressure pipe 18 are arranged in a plurality in the width direction of the aluminum plate 12 in correspondence with appropriate positions of the rolling stand 10. A predetermined rolling oil emulsion introduced through the pipe 18 is sprayed onto corresponding portions of the rolling stand 10 from the rolling oil spouting nozzles 2o.

Here, as shown in the figure, on the input side of the rolled material, the work roll 14.14, the backup rolls 16, 16, and the biting portions of the aluminum plate material 12 of each work roll 14.14 respectively correspond to In this state, a rolling oil injection nozzle 20 is provided, and the work roll 14.14 and the backup roll 16,
The rolling oil emulsion is sprayed from the corresponding rolling oil spouting nozzle 20 onto the surface of each of the 16 rolls and the biting portions of the aluminum plate 12 of the work rolls 14 and 14, respectively.

Further, here, the rolling oil emulsion sprayed onto the rolling stand 10 from the rolling oil spouting nozzle 20 is the same as the conventional one having both a lubricating function and a cooling function;
For example, lubricants are made by adding additives such as fatty acids and esters to base oils that act as lubricity improvers.
A product prepared by mixing water with an emulsifier will be used.

Incidentally, a large number of air nozzles 22 are arranged in the width direction of the aluminum plate 12 facing the upper surface (upper surface) of the aluminum plate 12 at a portion near the rolling stand 10 on the entry side of the material to be rolled. Compressed air at a predetermined pressure introduced through the compressed air introduction pipe 24 is blown onto the upper surface of the aluminum plate 12 from the air nozzles 22. The rolling oil emulsion sprayed onto the rolling stand 10 from the rolling oil spouting nozzle 20 is prevented from flowing further upstream of the aluminum plate material 10 by the compressed air blown from the air nozzle 22. As a result, on the upper surface of the aluminum plate 12 on the upstream side of the part corresponding to the location where the air nozzle 22 is disposed,
A draining area 26 is formed in a nearly dry state.

On the other hand, on the other hand, the above-mentioned air nozzle is not provided on the lower surface (lower surface) side of the aluminum plate material 12 on the inlet side of the material to be rolled near the rolling stand 1o. However, on the lower surface side of the aluminum plate material 12 to be bent, the flow rate of the rolling oil emulsion that flows and spreads along the plate surface of the aluminum plate material 12 is small, and the aluminum plate material 12
Since the rolling oil emulsion is constantly moved to the side of the rolling stand 10, the area where the rolling oil emulsion flows and spreads toward the upstream side of the aluminum sheet material 12 is significantly restricted. A draining area 28 in a state similar to that of the first embodiment will be realized in the vicinity of the rolling stand 10.

Here, in the portions of the upper and lower surfaces of the aluminum plate material 12 corresponding to the draining areas 26 and 28, a large number of them are arranged in the width direction of the aluminum plate material as close as possible to the rolling stand 10 side. A spray nozzle 30.32 is arranged. The lubricating oil introduction pipe 34 and the compressed air introduction pipe 36 are connected to these spray nozzles 30.32, and the compressed air guided by the compressed air introduction pipe 36 is passed from the spray nozzles 30.32 to the drainage area of the aluminum plate 12. 26. When spraying on 28, the lubricating oil introduction pipe 34
A predetermined lubricating oil introduced through the compressed air is dispersed in the form of a mist and is sprayed from each spray nozzle 30.degree. 32 onto the drainage regions 26.degree. 28 of the aluminum plate 12.

In addition, the above-mentioned lubricating oil is one that has a lubricating function,
It may be an oil-based emulsion or a water-soluble emulsion similar to a rolling oil emulsion.

In order to roll the aluminum plate material 12 with such a rolling mill, a rolling oil emulsion is spouted from each rolling oil spouting nozzle 20, and the rolling oil emulsion is sprayed onto the appropriate place of the rolling stand 10 in the same manner as in the conventional method, while the air nozzle 2
While blowing compressed air from 2 onto the upper surface of the aluminum plate 12, the compressed air is blown from each spray nozzle 30.32, and the lubricating oil is turned into a mist and sprayed onto the drainage areas 26.28 on the upper and lower surfaces of the aluminum plate 12. .

By spraying the rolling oil emulsion at appropriate locations on the rolling stand IO in the same manner as in the past, an oily film can be formed on the roll surface of the work roll 1414 that rolls the aluminum plate material 12 with the same degree of stability as in the past. , based on the presence of an oily film formed on the roll surface.
At least the same level of lubrication performance as before can be obtained.

On the other hand, draining areas 26 on the upper and lower surfaces of the aluminum plate 12
．． If you spray a mist of lubricating oil on 28,
Of course, if the emulsion is oil-based, even if it is a water-soluble emulsion, the water evaporates earlier than the oil-based components that make up the emulsion, so the surface of the aluminum plate 12 is coated with oil. The components adhere favorably, and an oily film with a lubricating function is stably formed on the upper and lower surfaces of the aluminum plate 12, even if only temporarily.

Therefore, if the aluminum plate 12 is rolled between the work rolls 14 and 14 before the oily film evaporates or carbonizes due to the heat of the aluminum plate 12, Draining area 2
6.28 The oily film formed on the work roll 14.14
If a lubricating oil that does not disappear before rolling is used, lubricating performance during rolling can be obtained based on the presence of oily films formed on the upper and lower surfaces of the aluminum plate material 12. Accordingly, the lubrication performance during rolling can be improved compared to the conventional method.

In this embodiment, the rolling stand 10
It is possible to improve the lubrication performance during rolling by spraying the lubricating oil in the form of a mist onto the aluminum plate material 12 without increasing the concentration of the rolling oil emulsion that is sprayed on the aluminum plate material 12. In addition, for the same reason, an oil film can be formed extremely stably and uniformly on the surface of the aluminum plate 12 with the minimum amount of lubricating oil required. Therefore, the oily components of the lubricating oil do not become excessively mixed into the rolling oil emulsion that is circulated, and therefore the concentration of the oily components of the lubricating oil in the rolling oil emulsion does not become excessively high, causing the rolling oil emulsion to Any adverse effects can also be effectively avoided.

Incidentally, a rolling mill equipped with a lubrication device as shown in Fig. 1 was configured as a test mill, and oleic acid (fatty acid) was used as the lubricating oil, so that oleic acid was not sprayed from the spray nozzle 30°32. In the case where a predetermined aluminum plate material is hot rolled, and in the case where the aluminum plate material is hot rolled while spraying oleic acid in the form of a mist at a rate of 2 g/m2 from a spray nozzle 30.32. When we measured each allowable reduction rate, the allowable reduction rate when spraying oleic acid was 40 to 50%, compared to 30 to 40% when oleic acid was not sprayed.
An improvement of about 10% was observed. Also, before and after rolling, oleic acid was sprayed onto the aluminum plate from the spray nozzles 30 and 32, and the rolling stand 1o
When the concentration of oleic acid in the rolling oil emulsion sprayed onto the rolling oil was measured, it was found that there was almost no variation.

In addition, in the above embodiment, if an aqueous emulsion is used as the lubricating oil, the disappearance of the oily film formed on the surface of the aluminum plate material 12 can be delayed by the amount that the water in the emulsion is evaporated first. (
Compared to the case of using oil-based lubricating oil, it has the advantage of being able to use an oil-based component that evaporates quickly, and also uses a slow-vaporizing oil-based component for the emulsion. This provides an advantage in that the period until rolling with the work rolls 14° 14 can be extended accordingly. In addition, when a water-soluble emulsion is used as the lubricant, as mentioned above,
The water in the emulsion will evaporate first, but
In this case, only a very small amount of the emulsion is sprayed onto the aluminum plate 12 in the form of a mist, so unlike the conventional case where a large amount of rolling oil emulsion is sprayed, the emulsion does not come into contact with the surface of the aluminum plate 12. There is no possibility that an inhibiting water vapor film will be formed on the surface of the aluminum plate 12, and therefore,
As mentioned above, the oily component adheres well to the surface of the aluminum plate material 12, and an oily film with a lubricating function is stably formed.

Although the embodiments of the present invention have been described in detail above, these are literal illustrations, and the present invention is not limited to the specific examples as described above, and within the scope of the spirit thereof,
It goes without saying that the present invention can be implemented with various changes, modifications, improvements, etc.

For example, in the embodiment described above, compressed air and lubricating oil are separately guided to the spray nozzles 30 and 32, and
．． By blowing compressed air from 32, the lubricating oil was dispersed in the compressed air in the form of a mist, so that the lubricating oil was sprayed onto the aluminum plate 12 by the action of the compressed air. However, an atomizing device that generates compressed air in which lubricating oil is dispersed in a mist form from compressed air and lubricating oil is provided separately from the spray nozzle 30, 32, and the compressed air in which lubricating oil is dispersed in a mist form is provided. The lubricating oil may be led from the atomization device to spray nozzles 30.32 via piping, and the lubricating oil may be sprayed onto the aluminum plate 12 from these spray nozzles 30.32.

Further, in the above embodiment, an air nozzle corresponding to the air nozzle 22 on the upper surface side was not provided on the lower surface side of the aluminum plate material 12, but a similar air nozzle was provided on the lower surface side of the aluminum plate material 12, and the air nozzle It is also possible to actively prevent the rolling oil emulsion from flowing upstream using compressed air blown from the draining area 28, thereby forming the draining area 28 more reliably and stably.

(Effects of the Invention) As is clear from the above description, the present invention sprays a rolling oil emulsion onto a rolling stand during hot rolling of aluminum material to be rolled, and at the same time, the material to be rolled near the rolling stand is Compressed gas is sprayed onto the upper and lower surfaces of the rolled aluminum material on the side, respectively, by spraying compressed gas against at least the upper surface of the rolled aluminum material to form drainage regions, and lubricating oil is sprayed onto the drainage regions in the form of a mist. An oily film with a lubricating function is formed on the upper and lower surfaces of the rolled aluminum material, and the rolled aluminum material is rolled on a rolling stand before the oily film disappears. without causing a decrease in the cooling performance of the oil emulsion, and without causing excessive mixing of the oily components of the lubricating oil into the rolling oil emulsion.
The lubrication performance during rolling can be advantageously improved, and therefore, there are advantages such as improved productivity of rolled products, improved surface quality, and various effects associated with improved lubrication performance. It is.

[Brief explanation of drawings]

FIG. 1 is an explanatory view schematically showing a rolling mill for aluminum hot rolling equipped with a suitable lubrication device for implementing the method of the present invention. lO: Rolling stand 12 Nialuminum plate material 14: Work roll 16: Backup roll 20: Rolling oil spout nozzle 22: Air nozzle 26.28
: Draining area 30.32: Spray nozzle

Claims (1)

[Claims] Spraying compressed gas onto at least the upper surface of the rolled aluminum material located on the entry side of the rolled material near the rolling stand, and causing the rolling oil emulsion sprayed onto the rolling stand to flow and spread toward the upstream side of the rolled aluminum material. To prevent this, drain areas are formed on the upper and lower surfaces of the rolled aluminum material on the inlet side of the rolled aluminum material near the rolling stand, and drain areas on the upper and lower surfaces of the rolled aluminum material are formed. , the lubricating oil is sprayed in a mist form to form an oily film on the upper and lower surfaces of the rolled aluminum material, respectively, and before the oily films disappear, the rolled aluminum material is placed on the rolling stand. A lubrication method for aluminum hot rolling, characterized by rolling.