JPS58128218A - Device for descaling hot rolled band steel - Google Patents

Abstract

PURPOSE:To perform perfect descaling at inexpensive running cost and at high speed by bending and pulling a hot rolled band steel repeatedly and spraying highly pressurized water on both sides of the band steel after pickling. CONSTITUTION:Cracks are formed on scales by applying repeated bending, pullling and rolling by a rolling mill 1 to a hot rolled band steel S1 immediately after hot rolling. After rolling down, the hot rolled band steel S2 is passed through a pickling tank 2 to permeate acid solution into cracks. Highly pressurized water is jetted onto the hot rolled band steel S3 that has been subjected to pretreatment for scale removal by a highly pressurized water jetting device 3 and scales are completely stripped off.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a descaling apparatus for hot rolled steel strip.

Conventional descaling methods for hot-rolled steel strips include (2) the sulfuric acid pickling method, in which multiple pickling tanks using acids such as sulfuric acid and hydrochloric acid are installed, and the copper strip is run between them; Mechanical descaling methods such as blasting with a grid or denting using a grinding tool, ultrasonic pickling tanks that increase pickling efficiency by applying ultrasonic waves to the pickling tank,
There is an electrolytic pickling method in which electrodes made of high-silicon steel, lead, etc. are disposed in a pickling tank to generate an electrolytic action and the acid solution is stirred by the generated hydrogen, thereby increasing the pickling efficiency.

By the way, as a recent trend in descaling technology, there is a shift from the conventional chemical treatment method using an acid to a mechanical descaling method. An example of this is a method in which the copper strip is subjected to a light reduction (skin pass) and then pickled. However, this method has the disadvantage of inferior descaling performance. Another example is a method in which the pickling process and the cold rolling process are directly connected. In this method, it is difficult to match the processing speeds of both steps.

Therefore, the purpose of the present invention is basically to
The object of the present invention is to provide a hot-rolled steel strip descaling device that utilizes the descaling method, has extremely low running costs, is capable of high-speed processing, and (3) provides a complete descaling effect.

The descaling device of the present invention performs the following steps after the scale removal pretreatment:
Its unique feature is that it sprays high-pressure water to completely remove scale.

Next, the descaling apparatus of the present invention will be explained with reference to the drawings. The equipment shown in FIG. 1 includes a rolling mill 1, a pickling tank 2,
It even has a high-pressure water injection device.

This descaling device has 1. Features include that each component device is arranged approximately horizontally in the descaling line 10, that a rolling mill 1 with staggered rolls 11 is used, and that a pickling tank 2 is used. There is.

In this descaling apparatus, first, the rolling mill 1 applies repeated bending and tensile reduction to the hot rolled steel MS1 immediately after hot rolling. As a result of this rolling, cracks are created in the scales occurring in the hot rolled steel strip S1.

The hot-rolled steel strip $2 after rolling is passed through a pickling tank 2 to infiltrate the cracks of the scale with an acid solution. The hot-rolled copper strip S3 that has undergone such scale removal pretreatment is then injected with high-pressure water (pressure 100 to 60%) by high-pressure water injection device B.
0Kg/crn2) to completely remove the scale.

The apparatus shown in FIG. 2 is characterized in that an acid injection device 6 is provided in place of the pickling tank 2, and a brush roll 7 is provided on the outlet side of the acid injection device 6. The acid solution is then sprayed onto the hot rolled steel strip S using a brush roll 7.
The reason for brushing step 3 is to allow the crack roll 7 to sufficiently penetrate the scale of the steel strip S6 with the acid solution and to squeeze out excess acid solution adhering to the scale.

The apparatus shown in FIG. 3 is characterized in that a leveler 5 is provided on the exit side of the rolling mill 1. The residual stress of the copper strip S2 which has been subjected to repeated bending and tensile compression by the leveler 5 is removed, and the copper strip S2 is flattened.

The rolling mill 10 and staggered arrangement rolls 11 are normally all driven at different circumferential speeds. However, in order to facilitate roll driving, it is preferable to drive only the upper or lower roll 11.

<Example 1> The following article (5) is carried out using the descaling device shown in Figure 1. We descaled the issue.

(1) Processing material: Hot-rolled steel strip with a thickness of 6.8 mm x @ 1214 mm (2) Processing speed: 200 m/m1n (31 rolling mill = 5 staggered roll rolling mill (4) Reduction rate:
10% (5) Acid solution concentration = 10% HC6 (6) High pressure water injection device: Pressure = 150 Kq/1m2 Flow rate = 50 t/mrn (1 nozzle, per 100 fighting board width) (7) Descaling result Niscale is Completely removed.

<Example 2> Descaling was performed using the descaling apparatus shown in FIG. 2 under the following conditions.

txt processing material: Hot rolled steel strip with thickness 68mm x width 1214y (2) Processing speed: 300 m/m1n (3) Rolling mill =
5 staggered roll rolling mill (4) Reduction rate = 6% (51 acid solution concentration - 8 cm Hct (6) Brush roll: diameter = 600 mm (6) Number of revolutions = 150 Orpm (7) High pressure water injection device : Pressure - 150Kg/1yn2 Flow rate 5017m 1n (1 nozzle, per 100 mm board width) (8) Descaling result Niscale was completely removed.

<Example B> Descaling was carried out under the following conditions using the descaling apparatus shown in FIG.

fi+ processing material: thickness 3.8ma x width 1214+++s
Processing speed of hot rolled steel strip (2): 400 m/m1n (3
) Rolling mill: (4) Reduction rate: 3% (5) Leveler: Elongation rate: 5% (6) Acid solution concentration: 6% (7) Brush roll: Diameter = 600, rotation speed = 15
0 Orpm (8) High-pressure water injection device: Pressure = 150 kg/cm2 Flow rate 5077 m1n (7) (1 nozzle, per 100 plate width) (9) Descaling result Niscale was completely removed.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of the descaling apparatus of the present invention. FIG. 2 is a schematic explanatory diagram of another descaling device of the present invention. FIG. 6 is a schematic explanatory diagram of still another descaling device of the present invention. 1: Rolling mill 2: Pickling tank 3 = High-pressure water injection device, 5 Nilevera 6: Acid injection device 7: Brush roll 10: Descaling line 11: Roll patent applicant Sumitomo Metal Industries, Ltd. (8)

Claims (3)

[Claims] (1) In a hot-rolled steel strip descaling line, there is a rolling mill equipped with staggered rolls that apply repeated bending and tension to the hot-rolled steel strip immediately after hot rolling, and a rolling mill located on the exit side of the rolling mill. a pickling tank for immersing the hot-rolled steel strip after repeated bending and tensile reduction in an acid solution; A descaling device for hot-rolled steel strips consisting of a high-pressure water injection device. (2) In a hot-rolled steel strip descaling line, there is a rolling mill equipped with staggered rolls that apply repeated bending and tension to the hot-rolled steel strip immediately after hot rolling, and a rolling mill located on the exit side of the rolling mill. an acid injection device that sprays an acid solution onto both sides of the hot-rolled steel strip after repeated bending and tensile reduction; and a brush that is disposed on the outlet side of the acid injection device and brushes both sides of the hot-rolled steel strip after pickling. A hot-rolled steel strip descaling device comprising a roll and a high-pressure water injection device disposed on the exit side of the brush roll (1) for spraying high-pressure water onto both sides of the brushed hot-rolled steel strip. (3) In a hot-rolled steel strip descaling line, there is a rolling mill equipped with staggered rolls that apply repeated bending and tension to the hot-rolled steel strip immediately after hot rolling, and a rolling mill located on the exit side of the rolling mill. a leveler for straightening the flatness of the hot rolled steel strip after repeated bending and tensile rolling; an acid injection device disposed on the exit side of the leveler for spraying an acid solution onto both sides of the hot rolled steel strip after the flattening; a brush roll disposed on the outlet side of the acid injection device for brushing both sides of the hot-rolled steel strip after pickling; and a brush roll disposed on the outlet side of the brush roll for brushing both sides of the hot-rolled steel strip after brushing. A hot-rolled steel strip descaling device consisting of a high-pressure water injection device that sprays high-pressure water onto both sides.