JPS589710A - Cold rolling mill having descaling function - Google Patents

Abstract

PURPOSE:To perform a descaling and a cold rolling of a hot rolled sheet in the same line and to reduce workers and construction cost, by providing a pre- treating mill for crushing oxidized scale of said sheet and a pair of grinding rolls to the pre-stage of a cold rolling line. CONSTITUTION:A pre-treating rolling mill 2, consisting of dull rolls 7 and supporting rolls 8, crushes oxidized scale down into fine pieces and powder by rugged surfaces of the rolls 7. Next, a descaling device 3 is constituted of a water washer 10, grinding rolls 11 and 11 made of base flexible-synthetic resin mixed with granular grinding medium, and a cover 12. Then water is jetted from nozzles 13 against the inside and outside surfaces 14 and 15 of a hot rolled sheet and against the rolls 11 and 11 to wash away the fine pieces and the powder stuck to the sheet and together to remove clogging of the rolls 11 and 11, and scraping off the scal and washing with a washing device 4. Thereafter, the hot rolled material is fed to a cold rolling installation 5 to be rolled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cold rolling facility having a descaling function, which includes a device for removing oxide scale generated on the surface layer of hot rolled material and a cold rolling facility in the same rolling line.

As a pre-process to cold rolling, it is necessary to remove oxidized scale from hot-rolled materials. Conventionally, pickling has been widely used as a method for removing scale. However, this method requires expensive pickling equipment; Since the pickling process is still an independent line, it is necessary to have operating personnel separate from the rolling line, which has the disadvantage of increasing operating costs.

The present invention uses a mechanical descaling device in place of the conventional pickling, eliminates the above-mentioned drawbacks associated with pickling, and also installs the descaling device and the cold rolling mill in the same rolling line to save operating personnel. This was developed with the aim of providing a cold rolling facility with a descaling function that can reduce the amount of oxidation scale on the surface layer of hot rolled materials and directly cold roll hot rolled materials. A pre-treatment rolling mill with crushing dull rolls and a grinding roll made mainly of flexible synthetic resin and mixed with a granular abrasive are installed at the front stage of the rolling line, and cold rolling equipment is installed at the rear stage of the rolling line. It is characterized by the fact that it is provided in

Embodiments of the present invention will be described below with reference to the accompanying drawings. The idea of the present invention is as shown in the process diagram of FIG. The oxidized scale on the surface layer is crushed and made into small pieces or powder, and then the descaling device (3) is used to polish the previously crushed scale, and then the cleaning device (3) using water etc. 4), and finally cold rolled in cold rolling equipment (5),
A thin coil material (6) is obtained.

Next, each step will be explained in detail. As shown in Figure 2,
The pre-treatment rolling mill (2) consists of dull rolls (force and support rolls).
8), and the hot rolled material (1) is rolled to a predetermined elongation rate which will be described later. The dull roll (7) used has a roughness larger than that of a normal roll, and it is preferable that the roughness is about the same as the thickness of the scale or slightly larger. As a result of this pretreatment, the oxide scale (9) becomes thinner, causes cracks, and is crushed into fine pieces and powder by the unevenness of the roll surface of the dull roll (force). This state is shown in Figure 3C. .In addition, Figure 3^ shows the state of oxide scale adhesion before rolling.
FIG. 0 shows the case of rolling with a smooth roll, and the oxide scale is pressed onto the base material by the smooth roll, and the surface becomes smooth and mirror-like. According to experiments, the oxide scale is rolled out as shown in FIG. The hardness of the scale decreases, but the greater the elongation rate due to rolling, the greater the decrease in hardness. It has also been found that when rolling scales of the same thickness, if a dull roll is used instead of a smooth roll, the scale hardness decreases significantly for the same elongation rate. This has an important significance for workability in the cleaning process described later, and by setting the elongation rate in the pretreatment rolling to 3 to 20%, oxide scale can be easily and completely removed. .

The hot rolled material (1) leaving the dull roll (7) enters a descaling device (3) provided on the same line.

The descaling device (3) includes a water washer Ql, at least one grinding roll αυ for cleaning scale, and a cover az.
It is composed of various parts. The water washer a1 has a nozzle (13 (13
A jet of water is applied to the front side 11 back side α$ and the grinding wheel (11) (II) of the hot rolled plate, and the rolled base material is
In addition to washing away the scale particles and powder adhering to the base material after peeling off, it also removes the clogging of the grinding roll aυαυ to restore the grinding function, and also removes scale powder etc. during grinding. Prevent scattering.

The grinding roll αυ is made of a flexible synthetic resin with a certain strength, such as synthetic rubber, or a soft base material mainly made of vinyl mixed with sand, iron sand, alumina, green carborundum, etc., or the above-mentioned material. A synthetic rubber or vinyl roll in which the abrasive material is embedded near the surface of the roll may be used, or a puff or brush roll similar to this may also be used. The grinding roll Uυ is mainly made of flexible synthetic resin, so rather than scraping off scale,
Rather, it has the effect of scrubbing, wiping, and cleaning scale. Therefore, the scale is completely removed, and there is no loss caused by scraping off the base material, and the ground surface is still uniform and has a good gloss.

The cover 02 includes the above-mentioned water washer (101) and the grinding roll 0.
υ and a cleaning device (4), which will be described later, to prevent water splashes and scale powder from scattering.

The cleaning device (4) cleans the front side α4 and the back side (α4) of the hot rolled material.
A nozzle αsae that sprays a cleaning liquid toward the hot rolled material (1) is provided, and water is used as the cleaning liquid to wash away scale powder, dust, etc. that adhere to the hot rolled material (1). cover 0
The bottom of No. 3 is inclined as shown in the figure, and the scale and washing water collected at the bottom are sent to the water treatment equipment Q81 using a sludge pump αη, where they are separated into sludge and water. Pull it out as shown by arrow a and recirculate it for cleaning, etc. Sludge is discharged from the arrow.

1. Remove the scale using a mechanical method as described above,
Furthermore, since no acid is used in the cleaning solution, there is no need to provide an independent pickling line or expensive pickling equipment. Therefore, equipment costs can be reduced and the number of operating personnel can be reduced.

The hot-rolled material from which oxide scale has been removed through the above steps finally enters the cold rolling facility (5), where it is rolled into a thin sheet coil material (6) that is wound up by the winder (II). As mentioned above, a descaling device was installed at the front stage of the same rolling line, and a cold rolling mill was installed at the rear stage, so that the hot rolled coil that was first placed in the unwinding machine 4 was descaled and then rolled into the unwinding machine 4. > Directly cold rolled and continuously wound on a winder (a).

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

The cold rolling equipment having a descaling function of the present invention has the above-described configuration, and therefore exhibits the following excellent effects.

(1) We installed a mechanical descaling device that crushes oxide scale using a pretreatment rolling mill equipped with dull rolls and then grinds it with a grinding roll made mainly of flexible synthetic resin. There is no need to install a pickling line, and the number of operating personnel can be reduced.

(11) For the same reason as in the previous section, pickling equipment is not required, and equipment costs can be reduced.

(in) Since the descaling equipment and cold rolling mill are installed on the same rolling line, hot rolled material from which oxidation scale has not been removed can be directly fed into the cold rolling line and work can proceed continuously. So,

[Brief explanation of drawings]

FIG. 1 is a working process diagram of a cold rolling facility showing an embodiment of the present invention, FIG. 2 is a schematic side view of the cold rolling facility shown in FIG. 1, and FIG.
Figures 1, 2, and 0 are cut side views showing the state in which oxide scale adheres to the rolled material. FIG. 4 is an explanatory diagram showing the relationship between elongation rate and scale hardness in pretreatment rolling. In the figure, (1) is a hot rolled material, (2) is a pre-treatment rolling mill, (
5) is a cold rolling equipment, (7) is a dull roll, (9) is an oxidized scale, and aυ is a grinding roll. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1) A pretreatment rolling mill with dull rolls for crushing oxidized scale on the surface layer of hot-rolled materials and a grinding roll made mainly of flexible synthetic resin and mixed with granular abrasive are installed in the front stage of the rolling line. A cold rolling facility having a descaling function, characterized in that the cold rolling facility is provided at a subsequent stage of the rolling line.