JPS61238402A - Rolling method by multi-stages cluster rolling roll for cold rolled metallic strip having good surface gloss and shape - Google Patents

Abstract

PURPOSE:To produce a product having high surface gloss and good shape with high efficiency by subjecting a metallic strip to high-speed rolling with large-diameter work rolls up to an intermediate pass than changing the rolls with small-diameter work rolls and subjecting the strip to low-speed rolling in at least the final pass. CONSTITUTION:The 1st lubricating system 6 and the 2nd lubricating system 7 are provided as the lubricating oil system for cooling the work rolls 5 of a 12-stages cluster rolling mill. The large-diameter rolls are incorporated together with intermediate rolls 2 and backup rolls 3 for the work rolls up to the intermediate pass. The soluble type lubricating oil is supplied from the 1st lubricating oil tank 8 and is circulated by the 1st pump 9 and is injected from nozzles 10 to lubricate and cool the rolls in order to improve the cooling effect by the 1st lubricating oil system 6. The strip is thus rolled at a high speed. The work rolls are exchanged with the small-diameter rolls 5 in order to improve the surface gloss in at least the final pass. The straight type lubricating oil is supplied and circulated from the 2nd lubricating oil tank 11 to the 2nd lubricating oil system 7 by the 2nd pump 12 in order to obtain the high surface gloss. The oil is injected from the nozzles 10 and the strip is rolled at a low speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to an improvement in a cold rolling method using a multi-stage cluster rolling mill for producing cold rolled metal strip with a high degree of surface gloss and good shape. be.

(Prior Art) Many studies have been conducted on cold rolling methods for improving the surface gloss of cold rolled products such as stainless steel and aluminum products, which have traditionally had strong demands for good surface gloss. As a result of this research, the cold rolling conditions for improving the surface gloss of cold-rolled metal strips include using low-viscosity lubricating oil and performing cold rolling with as thin an oil film between the rolls and the material as possible. It has been shown that good gloss can be obtained. Further, the work roll diameter and rolling speed have also been studied, and it has been experimentally revealed that the smaller the work roll diameter and the lower the rolling speed, the better the surface gloss can be obtained.

Taking cold rolling of stainless steel strip as an example, a 20-high cluster rolling mill with small diameter work rolls is generally used, and by adopting the aforementioned rolling conditions, i.e., small diameter rolls, low speed rolling, low viscosity lubricating oil, etc. A cold-rolled IJ tube with high surface gloss is obtained.

(Problems to be Solved by the Invention) However, the conventional rolling method for obtaining cold-rolled metal slabs with good surface gloss and shape does not involve rolling operations as is clear from the above-mentioned rolling conditions. It has been difficult to produce thin stainless steel sheets with high surface gloss at a high efficiency due to poor efficiency. In addition, the 20-high cluster rolling mill has the drawback that it tends to produce a complex elongation shape, making it difficult to obtain a good plate shape.

(Means for Solving the Problems) An object of the present invention is to solve the above-mentioned problems and to provide a rolling method that makes it possible to produce cold-rolled metal strips with high surface gloss and good shape with high efficiency. This is what we are trying to provide.

According to the present invention, as shown in FIG. 1 as an example of a 12-high cluster rolling mill, a large-diameter work roll 1 is incorporated into a multi-stage cluster rolling mill together with an intermediate roll 2 and a backup roll 3 to produce cold-rolled metal strips. 4 is rolled at high speed with a high reduction rate and rolled with high efficiency up to the intermediate bath, the large diameter work roll 1 is transferred to the small diameter work roll 5 as shown in FIG.
and then low-speed rolling.

(Function) According to the present invention, a metal strip having a high surface gloss and a good shape is rolled at high speed with a large diameter work roll up to the intermediate bath and then at a low speed with a small diameter work roll. ) IJ tubes can be rolled efficiently.

(Example) Figure 3 shows an example of rolling equipment for carrying out the present invention. A second lubrication system 7 is provided, and up to the intermediate bus, a first lubrication oil tank 8 is provided to improve the cooling effect of the first lubrication oil system 6.
High-speed rolling is made possible by supplying and circulating the sori-pull type lubricating oil by the first pump 9 and injecting it from the nozzle 10 for lubrication and cooling.

At least in the final bus rolling, the work roll is replaced with a small diameter roll 5 to improve the surface gloss, and the second lubricant system 7 is supplied with a second lubricant tank 11 to a second pump 12 to obtain a high surface gloss. Straight type lubricating oil is supplied and circulated and injected from the nozzle 10 to perform low speed rolling.

Next, an example of cold rolling a stainless steel (IJ) tube requiring a high degree of surface gloss according to the present invention will be described.

From the first bus to the fourth bus, a large-diameter work roll 1 with a diameter of 300 mm is used, and in order to enhance the cooling effect of the lubricant, the first lubricant oil system 6 is filled with solipull type lubricant oil at a concentration of 4.
Used at ~8%, with a diameter of 150m at the final bus (5th bus)
A straight type lubricant was used in the second lubricant system 7 to achieve high surface quality as a lubricant.

In order to roll 5US304 stainless steel pickled and annealed hot rolled steel strip from 3.5mm to 0.8mm, a large work roll with a diameter of 300u is used to roll the strip.
Perform reversible 4-bath rolling from mm to 0.91 mm,
The fifth bus was rolled from 0.91 mm to 0.8 mm using a small work roll with a diameter of 150 mm. The rolling bus schedule in this case is shown in Table 1 in comparison with the bus schedule of a conventional 20-high cluster type rolling mill.

While the conventional method required 9 baths, the method of the present invention made it possible to perform rolling in 5 baths. The surface quality of the rolled material after cold rolling obtained by the present invention was equivalent to that of the conventional method.

(Effects) According to the present invention, a metal strip having a high surface gloss and a well-controlled shape can be produced with high efficiency.

[Brief explanation of drawings]

Fig. 1 is a route diagram showing a state in which a large-diameter work roll is installed in a 12-high cluster rolling mill for rolling, and Fig. 2 is a state in which the work roll in a 12-high cluster rolling mill is replaced with a small-diameter work roll for rolling. Fig. 3 is a schematic diagram showing a lubricating oil system connected to a nozzle header of a 1.2-high cluster rolling mill. ■...Large diameter work roll 2...Intermediate roll 3...Park up roll 4...Metal strip 5...Small diameter work roll 6...First lubricating oil system 7...Second Lubricating oil system 8...first lubricating oil tank 9...first pump 10...nozzle 11...
Second lubricating oil tank 12...second pump

Claims (1)

[Claims] 1. A multi-stage cluster rolling mill is equipped with a large-diameter work roll, and after the metal strip is rolled at high speed to an intermediate bus by the large-diameter work roll, it is replaced with a small-diameter work roll and at least the final bus is rolled at low speed. A method of rolling a cold-rolled metal strip with good surface gloss and shape using a multi-stage cluster rolling mill.