JPS58128217A - Device for descaling hot rolled band steel - Google Patents

Abstract

PURPOSE:To perform perfect descaling at high speed and at inexpensive running cost by applying small rolling down force to a hot rolled band steel immediately after hot rolling and spraying highly pressurized water on both side of the band steel after pickling. CONSTITUTION:Cracks are formed on scales by applying small rolling down force to a hot rolled band steel S1 by a rolling mill 1 immediatey after hot rolling. After light rolling down, the hot rolled band steel S2 is passed through a pickling tank 2 to permeate acid solution into cracks of the scales. 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 perfectly 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 strip include sulfuric acid pickling, in which multiple pickling tanks using acids such as sulfuric acid and hydrochloric acid are installed, and the copper strip is run between them, and blasting using shots, grids, etc. Alternatively, mechanical descaling methods such as grinding using a grinding tool, ultrasonic pickling tanks that increase pickling efficiency by applying ultrasonic waves to the pickling tank, and high-silicon steel, lead, etc. There is an electrolytic pickling method in which electrodes are provided to generate an electrolytic action and the acid solution is stirred by generated water to improve 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 guoka belt is subjected to light pressure reduction (skin pass) and then pickled. However, this method has the disadvantage of poor 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 a descaling method, has extremely low running costs, can perform high-speed processing, and can provide 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 is made up of a high pressure water injection device 6.

The present descaling apparatus is characterized in that each component device is arranged substantially horizontally in the descaling line 10 and that a pickling tank 2 is used.

In this descaling apparatus, first, a rolling mill 1 applies a light reduction to the hot rolled steel strip S1 immediately after hot rolling.

By this light reduction, cracks are created in the scale generated in the hot rolled steel strip S1. The hot-rolled steel strip S2 after being lightly rolled is passed through a pickling tank 2 to infiltrate the cracks of the scale with an acid solution. High-pressure water (pressure 100 to 300 kg/cm2) is sprayed by the high-pressure water injection device 6 to the hot-rolled copper strip $3 that has undergone such scale-removal pretreatment to completely remove the scale.

The equipment shown in FIG. 2 includes a rolling mill 1, a vertical pit 4, a steam injection device 5, an acid injection device 6, and a brush roll 7. It is made up of a high pressure water injection device 5. This descaling device is equipped with a vertical pit 4 that descends in a direction substantially perpendicular to the rolling direction in a descaling line 10, and a steam injection device 5, an acid injection device 6, a brush, etc. It is characterized in that the roll 7 and the high-pressure water injection device 6 are arranged in sequence, and that the acid injection device 6 is provided in place of the pickling tank 2.

The reason for arranging each device in the vertical pit 4 is to improve the environment and ensure work safety. The reason why steam is sprayed onto the hot-rolled steel strip S2 after light reduction is to heat the hot-rolled steel strip S2 to a high temperature and hasten the acid reaction during pickling in the next step. The reason why the acid solution is sprayed and then brushed with the plan roll 7 is that the crack roll 7 allows the acid solution to sufficiently penetrate the scale of the copper strip S3, and at the same time squeezes out the excess acid solution adhering to the scale.

Example 1 Descaling was carried out using the descaling apparatus shown in FIG. 1 under the following conditions.

(11 Processing material: Thickness 3.0mm x width ln00m
, hot rolled steel strip (2) Processing speed: 500m/m1
n(3) Rolling mill: Type 4 rolling mill (4) Reduction rate = 10% (5) Acid solution concentration: 10% HCl (6) High pressure water injection device: Pressure 10 Qkg/crn2 Flow rate = 20 l/m1n ( (1 nozzle, per 100m+++ board width) (7) Descaling results: Scale was completely removed.

Example 2 Descaling was carried out using the descaling apparatus shown in FIG. 2 under the following conditions.

(1) Processing material: thickness 4.5 mrp x width 1300
My hot rolling intermediate phase (2) Processing speed: 650m/m1
n(3) Rolling mill: Type 4 rolling mill (4) Reduction rate = 8% (5) Steam injection device: Pressure = 3 kg/cIn2 (
6) Acid solution concentration = 15% HCl (7) Brush roll: Diameter = 300mm Rotation speed 10
00 rpm (8) High pressure water injection device: Pressure = 150 kg/cm2 Flow $ = 25 l/m1n (1 nozzle, per 10 gmn plate width) (9) Descaling result: Scale was completely removed.

[Brief explanation of the drawing]

Claims (1)

[Claims] (1) In the hot-rolled steel strip descaling line, a rolling mill that applies light reduction to the hot-rolled steel strip immediately after hot-rolling, and a rolling mill that applies light reduction to the hot-rolled steel strip immediately after hot-rolling, and a hot-rolled steel that is placed on the exit side of the rolling mill and that applies light reduction to the hot-rolled steel strip. Hot-rolled steel comprising a pickling tank for immersing the strip in an acid solution, and a high-pressure water injection device disposed on the outlet side of the pickling tank for spraying high-pressure water onto both sides of the hot-rolled steel strip after pickling. Band descaling device. (2+ In the hot-rolled steel strip descaling line, there is a rolling mill that applies a light reduction to the hot-rolled steel strip immediately after hot rolling, and a pit that descends on the exit side of the rolling mill in a direction perpendicular to the rolling line. , a steam injection device disposed above the pit and spraying steam onto the hot rolled steel strip after light reduction; and a steam injection device disposed below the steam injection device within the pit and spraying steam onto both sides of the hot rolled steel strip. an acid injection device that sprays an acid solution; a brush roll that is disposed below the acid injection device in the pit and brushes both sides of the hot rolled copper strip after pickling;
A hot-rolled steel strip descaling device comprising a high-pressure water injection device disposed below the brush roll in the pit and spraying high-pressure water onto both sides of the hot-rolled steel strip after brushing.