JPH11156404A - Method for wet skinpass rolling of cold rolled metal strip and row of installations - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for wet skinpass rolling of cold rolled metal strip and a row of installations as well which save cost of refining liquid and do not generate remaining liquid possibly taken for a flow after rolling. SOLUTION: In a method for wet skinpass rolling of cold rolled metal strip in which a metal strip S is subjected to skinpass rolling while supplied with refining liquid and a rust preventing oil is applied to the metal strip after liquid is removed off the upper ad rear surfaces of the metal strip, water 2A is supplied instead of the refining liquid. Preferably, a drying device 6 is arranged between the skinpass rolling mill 11 and an oil applying device 7, and thus the metal strip is dried after liquid revomal by a liquid removing device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for wet-temper rolling a cold-rolled metal strip.

[0002]

2. Description of the Related Art Temper rolling of a cold-rolled metal strip is performed for the purpose of improving the shape of the metal strip after cold rolling or continuous annealing, and giving desired surface roughness and mechanical properties. There, metal powder generated during the cold rolling in the previous process and the temper rolling in the current process adheres to the work roll and intermediate roll (back-up roll) of the temper rolling mill, causing surface defects such as dull baldness and roll marks. In order to prevent
Generally, so-called wet temper rolling in which temper rolling is performed while supplying a temper liquid and performing roll cleaning is performed.

Conventionally, a 3-10% aqueous solution of an organic amine or an organic acid, which is effective in preventing rusting from temper rolling to rust-preventive oiling, has been used as a heat treatment liquid. As shown in FIG. 4, the upper and lower work rolls 3, 3 or metal strips (cold rolled metal strips) S are formed on upper and lower surfaces of the liquid supply nozzles 1, 1 arranged on the upper and lower sides of the temper rolling mill 11, respectively. A method of spraying a large amount of the refining liquids 2, 2 is used. In addition, on the exit side of the temper rolling mill 11, the upper and lower surfaces of the metal strip are drained by air injection from air wipers 4 and 4 provided above and below in order to keep moisture of the temper liquid as little as possible.

[0004]

In wet pass tempering, a large amount of temper is used, but it is desired to reduce the supply of temper in order to reduce costs. On the other hand, the continuous annealing line for the thin steel strip is provided with an automatic surface inspection device for monitoring the metal strip subjected to wet temper rolling after continuous annealing and automatically detecting the surface flaw thereof. This device emits light to a surface to be inspected by a metal strip and recognizes the presence or absence of a flaw from the form of the reflected light.

However, the tempering liquid sometimes remains on the surface of the metal strip after the wet temper rolling in the form of a thin spot pattern 8 or a black dripping pattern 9 as shown in FIG. Such a pattern is likely to be mistaken for a flaw because its reflected light form is similar to a flaw, due to its surface gloss, form of the residue, contour, and the like. There is a problem that loss occurs and cost increases. In the investigation by the present inventors so far, about 40% of the surface patterns determined to be surface flaws were those in which the above-mentioned liquid residue was erroneously recognized.

[0006] It is considered that if the supply amount of the refining liquid is reduced, the cost can be reduced, and at the same time, the residual liquid is reduced and the false recognition rate is reduced. However, in this case, when the temper rolling is performed at a high speed, the probability of occurrence of liquid film breakage increases, and there is a problem that the surface quality and shape of the metal strip are often poor. As a measure to prevent liquid film breakage when the supply amount of the refining liquid is reduced, as shown in FIG. Of the metal band S before and after entering the deflector rolls 5 and 5 and trying to uniformly spread the conditioning liquids 2 and 2 on the surface by the deflector rolls 5 and 5, The occurrence of poor surface quality and poor shape of the band was reduced.

However, since the organic amine and / or organic acid (collectively referred to as an organic component) in the liquid still leaves a pattern similar to the flaw on the surface of the metal strip after draining, misidentification of the surface flaw is completely eliminated. Could not be eliminated. In view of the above-mentioned problems of the prior art, the present invention provides a method and a series of equipment for cold-rolling a cold-rolled metal strip which can reduce the cost of a refining solution and which does not cause a liquid residue that can be recognized as a flaw after rolling. The purpose is to:

[0008]

SUMMARY OF THE INVENTION According to a first aspect of the present invention, a cold-rolled metal strip is temper-rolled while supplying a tempering liquid, and the upper and lower surfaces of the metal strip are drained. A wet temper rolling method for a cold-rolled metal strip, wherein water is supplied in place of a tempering liquid.

[0009] The second invention is the first invention, wherein
The gist of the invention is to dry the cold-rolled metal strip after draining and before rust-preventive oiling. A third aspect of the present invention is directed to the second aspect of the present invention,
The gist of the present invention is to conduct a surface inspection of a cold-rolled metal strip after drying and before rust-preventive oiling. According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the gist is that the cold-rolled metal strip before the temper rolling is continuously annealed.

According to a fifth aspect of the present invention, there is provided a temper rolling mill provided with a liquid supply device on the inlet side and a liquid drainer on the outlet side for wet temper rolling the cold-rolled metal strip, and drying the cold-rolled metal strip. A refining rolling equipment row for a cold-rolled metal strip, comprising a drying device and an oiling device for applying rust-preventive coating oil to the cold-rolled metal strip in this order. According to a sixth aspect of the present invention, in the fifth aspect, an automatic surface inspection device is arranged between the drying device and the oiling device.

According to a seventh aspect of the present invention, in the fifth or sixth aspect, the temper rolling mill is arranged on the outlet side of the continuous annealing equipment.

[0012]

According to the first aspect of the present invention, a cold-rolled metal strip is temper-rolled while supplying a tempering liquid, and the upper and lower surfaces of the metal strip are drained. In the wet temper rolling method for cold-rolled metal strips to be coated with rust preventive oil, water is supplied instead of the temper liquid, so that the temper liquid cost is significantly reduced to the level of water cost, At the same time, even if there is a liquid residue on the upper and lower surfaces of the metal strip after draining, since there is no organic component, a pattern having a reflection form similar to a flaw does not remain, so that it is not mistaken as a flaw. Further, by replacing the refining liquid with water, the cost can be afforded and the roll cleaning ability can be further increased, so that defects such as roll marks can be further reduced.

Incidentally, from the viewpoint of preventing the occurrence of false recognition of flaws,
Pure water is preferred as the water to be supplied to the temper rolling, and pure water is more preferred. However, if the water contains an organic component of 0.5% or less, the pattern due to the organic component does not remain. Water may be applied. According to the second aspect of the present invention, in the first aspect of the present invention, since the cold-rolled metal strip is dried after draining the liquid (water) and before applying the rust-preventive oil, the rust-preventing power of the organic component does not depend on the metal component. However, rust generation between draining and rust-preventive oiling can be sufficiently suppressed. In order to perform this drying, the upper and lower surfaces of the metal band may be heated to 60 ° C. or more.

According to the third aspect of the present invention, in the second aspect of the present invention, since the surface inspection of the cold-rolled metal strip is performed after drying and before rust-preventive oiling, the remaining liquid pattern is erroneously recognized as a flaw. Disappears. According to the fourth aspect of the present invention, in any one of the first to third aspects of the present invention, since the cold-rolled metal strip before the temper rolling is continuously annealed, the metal after the continuous annealing is formed. The strip can be subsequently subjected to a wet temper rolling efficiently without false recognition.

A fifth aspect of the present invention is a row of temper rolling equipment for cold-rolled metal strip suitable for carrying out the first and second aspects of the present invention. As shown in FIG. (Liquid supply nozzle)
1. A temper rolling mill 11 equipped with a draining device 4 on the outlet side for wet temper rolling a metal strip (cold rolled metal strip) S, a drying device (dryer) 6 for drying the metal strip S, and a metal strip An oiling device 7 for applying rust-preventive oiling to S is arranged in this order.

From the liquid supply nozzle 1, water 2A is jetted. Although the liquid removing device 4 in FIG. 1 is configured by an air wiper, it may be configured by a pinch roll. Drying device 6
Any type, such as an electric heating type, a radiant tube type, and a steam heat exchange type, can be applied as long as it has a capability of raising the surface temperature of the metal strip S to 60 ° C. or more.

A sixth aspect of the present invention is a row of cold-rolled metal strip temper rolling equipment suitable for implementing the third aspect of the present invention. As shown in FIG. An automatic surface inspection device 10 is arranged between the lubrication device 6 and the oiling device 7. The functions of the automatic surface inspection device 10 are as described above. This allows
The third invention can be efficiently implemented. The seventh present invention provides:
It is a row of temper rolling equipment for cold-rolled metal strips suitable for carrying out the fourth present invention. As shown in FIG. 3, in the fifth to sixth present invention, the temper rolling mill 11 is connected to a continuous annealing equipment. It is arranged on the 12 exit side. According to this, since temper rolling can be performed without winding the metal strip S after continuous annealing, productivity is further increased.

[0018]

EXAMPLE In the step of wet-temper rolling a cold-rolled thin steel strip having a thickness of 0.3 to 2.9 mm continuously annealed at a temper rolling elongation of 0.5 to 2.0%, the equipment row shown in FIG. Using the purified water in place of the bulk liquid, using a steam heat exchange type dryer capable of raising the surface temperature of a steel strip traveling at a maximum speed of 500 mpm to 60 ° C. or higher as a drying device, the temper rolling method of the present invention. As a result, erroneous flaw determination of the automatic surface inspection device based on the residual liquid pattern after draining was performed.
Has disappeared.

The cost of the refining liquid is remarkably reduced to the level of the water cost, and there is no rust between the drain and the rust preventive oil.

[0020]

As described above, according to the present invention, the refining liquid cost in wet temper rolling is remarkably reduced, and the remaining liquid pattern is erroneously recognized as a flaw in the surface defect inspection of the cold-rolled metal strip after the temper rolling. It has an excellent effect that no longer occurs.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a facility row according to a fifth invention.

FIG. 2 is a schematic diagram showing an example of an equipment row according to a sixth invention.

FIG. 3 is a schematic diagram showing an example of an equipment row according to a seventh invention.

FIG. 4 is a schematic diagram showing a conventional example of a wet passivation rolling method.

FIG. 5 is a schematic view showing a liquid remaining pattern which is easily mistaken for a surface flaw.

FIG. 6 is a schematic diagram showing another conventional example of a wet passivation rolling method.

[Description of Signs] S Metal Strip 1 Liquid Supply Nozzle (Liquid Supply Device) 2 Conditioning Liquid 2A Water 3 Work Roll 4 Air Wiper (Liquid Removal Device) 5 Deflector Roll 6 Drying Device (Dryer) 7 Oil Painting Device 8 Thin Spot Pattern 9 Black dripping pattern 10 Automatic surface inspection equipment 11 Temper rolling mill 12 Continuous annealing equipment

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Okamoto 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref. Chome (without address) Inside Kawasaki Steel Corporation Mizushima Works

Claims (7)

[Claims] 1. A cold-rolled metal strip which temper-rolls a cold-rolled metal strip while supplying a tempering liquid, performs liquid drainage on upper and lower surfaces of the metal strip, and applies rust-proof oil to the metal strip. The method of claim 1, wherein water is supplied in place of the tempering liquid. 2. The method according to claim 1, wherein the cold-rolled metal strip is dried after draining and before rust-preventive oiling. 3. The method according to claim 2, wherein the surface of the cold-rolled metal strip is inspected after drying and before rust-preventive oiling. 4. The method according to claim 1, wherein the cold-rolled metal strip before the temper rolling is continuously annealed. 5. A temper rolling mill provided with a liquid supply device on an inlet side and a drainer device on an outlet side for wet temper rolling a cold-rolled metal strip, a drying device for drying a cold-rolled metal strip, And an oiling device for applying rust-preventive oiling to the cold-rolled metal strip in this order. 6. The equipment line according to claim 5, wherein an automatic surface inspection device is arranged between the drying device and the oil coating device. 7. The equipment row according to claim 5, wherein the temper rolling mill is arranged on the outlet side of the continuous annealing equipment.