JPH03210903A - Method for giving surface roughness on hot rolled metallic material and line of hot rolling stand for it - Google Patents

Abstract

PURPOSE:To give surface roughness on a hot rolled metallic material by installing a rolling stand for giving surface roughness independently behind a rolling mill for forming. CONSTITUTION:The metallic material is forming rolled into a desired dimensions with the finish mil of the rolling mill 6 for forming. Next, desired conditions of roughened surface is given on the surface of the metallic material 5 with the rolling stand 7 for giving surface roughness which is installed behind that finish mill. At this time, small rolling-down of 1 - 10 % draft is taken to transfer the conditions of roughened surface of the rolling roll 1 on the surface of the metallic material 5 and successively that metallic material is cooled to a desired completion temp. at a desired speed with a control cooling device 8. In this way, uniform surface roughness can be given on the surface of hot rolled metallic material.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method and apparatus for imparting a constant roughness level and roughness profile to the surface of hot rolled metal materials. In particular, the present invention relates to a method and apparatus for preventing temperature dispersion that occurs during the cooling process in heat-processing steel materials, and uniformly cooling the material to obtain a heat-processed metal material with a good cooling shape and no material dispersion.

(Prior art) In recent years, in the controlled piezoelectric/controlled cooling process for thick plates or hot strip mills, which have been rapidly put into practical use in Japan, the steel plate is Temperature dispersion (deviation) within the material occurs, resulting in shape defects and material variations. Therefore, correction work is required, and the reality is that the cost thereof is significantly higher than that of conventional processes.

There are many causes of temperature dispersion that occurs during the cooling process, but it has been revealed that a major factor is uneven surface roughness caused by roughening and wear of the rolling rolls being transferred to the surface of the hot rolled steel sheet.

To solve this problem, Japanese Patent Publication No. 63-54046, Japanese Patent Application Publication No. 62-54507, and Japanese Patent Application Publication No. 63-149315
As disclosed in US Pat.

(Problems to be Solved by the Invention) However, regarding the technology for forming a uniform rough surface on the surface of a hot rolled steel sheet, there is no technology known as on-fin roll dressing (hereinafter referred to as ORD), which continuously grinds the roll surface during rolling operation.
The application of the law (abbreviated as ")" was only pointed out, and there were few concrete and detailed proposals, leaving the matter unresolved.

The ORD method is being used on a trial basis in lip mills (Holatos), but its main purpose is to remove local wear at the roll position, which corresponds to the edge of the steel plate, and the reason why the local wear increases is due to the rolling reduction rate. This is because a large stress concentration occurs at the ends under a pressure of 20 to 40%/bath. In other words, the purpose of the conventional ORD method is not to control the surface roughness of the steel sheet, and because the roll surface temperature increases (increases) in roll-by F, roll cooling devices are required on the front and rear surfaces of the roll, and the pressure Ill. There were problems such as the roll cooling and other equipment being crowded around the rolls, making it impossible to install the ORD device.In this way, the main purpose of the existing thick plate presses and holatos)')-/pumil is rolling. Therefore, there were problems such as surface roughness control not functioning sufficiently.

In view of the importance of surface roughness control in the online controlled cooling heat treatment process of steel materials, the present invention provides a method and apparatus for adding a surface roughness control function to a hot rolling stand (row) at the same time as rolling capacity.

(Means for Solving the Problems) The present invention provides a rolling stand that is installed separately behind the forming press me and is equipped with a roll processing device that imparts roughness to the surface of the rolling roll. A method for imparting surface roughness to a hot piezoelectric metal material characterized by transferring the rough surface conditions of a roll onto the surface of the metal material, and a surface roughening method that transfers the rough surface conditions of a rolling roll to the surface of the metal material. A rolling stand for imparting surface roughness, which is equipped with a roll processing device for imparting roughness to the surface of a rolling roll, is referred to as a rolling stand for forming. This is a row of hot rolling stands characterized by being separately installed behind the hot rolling stand. Note that the rough surface conditions here refer to the roughness level and roughness profile.

(Operation, Examples) The operation of the present invention will be explained below with reference to the drawings.

Figure #1 is a diagram showing an embodiment of the present invention. To explain the controlled rolling/controlled cooling process of a thick plate as an example, firstly, forming rolling is performed to desired dimensions with finishing pressure IHjl of forming rolling mill 1j16.Next, rolling stand for surface roughening installed behind it is used. In step 7, desired roughness conditions are imparted to the surface of the metal material 5. In order to transfer the rough surface conditions of the rolling roll 1 to the surface of the metal material 5, a light rolling reduction of 1 to 10% is sufficient.

Subsequently, the controlled cooling device 8 cools at a desired cooling rate to a desired cooling end temperature. At this time, since a uniform roughness condition is imparted to the surface of the metal material before cooling, temperature dispersion does not occur during the cooling process, and a flat steel plate is produced. In addition, the same effect can be obtained using a hot strip mill using the same process. As the roll machining device 4 for imparting roughness to the surface of the rolling roll 1, an electrical discharge machining device, a laser machining device, or the like can be employed in addition to a grindstone grinding device. With the latter two methods, a surface profile different from that of the grinding surface can be formed.

(Effect of the invention) A light reduction with a rolling reduction ratio of 1 to 10% is sufficient to transfer the surface roughness of the rolling roll onto the surface of the steel sheet, so the rise in roll temperature during roll bite of the rolling roll is reduced,
Spraying of roll cooling water is only required on the outlet side and is not required on the inlet side. Therefore, there is enough space to install the ORD device. In addition, since roll wear and surface roughness are reduced, the amount of grinding (amount of cut) on the roll surface is also reduced, and the life of the roll is longer than when used in combination with a rolling function.

The biggest advantage is that by separating the wear removal at the root end of the rolling roll and the surface roughness control, the range of selection of roll processing equipment such as grinding wheels is expanded, and the desired roughness conditions can be freely adjusted to the rolling roll by the equipment used. It is now possible to apply it to the surface, and temperature dispersion in controlled cooling can be easily prevented.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. 1... Rolling roll, 2... Backup roll, 3
... Roll cooling device, 4... Roll processing device, 5.
...Metal material, 6.. Rolling machine for forming processing, 7.. Rolling stand for imparting surface roughness, 8.. Controlled cooling device.

Claims (2)

[Claims] (1) A rolling stand for surface roughening, which is installed separately behind the rolling mill for forming processing and is equipped with a roll processing device that imparts roughness to the surface of the rolling roll, is used to adjust the roughness conditions of the rolling roll to the surface of the metal material. A method for imparting surface roughness to a hot-rolled metal material, the method comprising transferring surface roughness to a hot-rolled metal material. (2) A rolling stand for imparting surface roughness that transfers the rough surface conditions of a rolling roll onto the surface of a metal material, the rolling stand for imparting surface roughness comprising a roll processing device that imparts roughness to the surface of the rolling roll. A row of hot rolling stands characterized in that they are separately installed behind a rolling mill for forming processing.