JPS5867855A - Apparatus for preparing steel plate having one surface hot-dipped with zinc - Google Patents

Abstract

PURPOSE:To perfectly eliminate the generation of press flaw even if zinc particles slightly remain on an inhibitor coating surface, by a method wherein the inhibitor coating surface of a steel strip is plated in a line for preparing the titled steel plate for an automobile by an inhibitor method and, after plating, the plated steel plate is advanced so as not to contact with the plated surface thereof with a rigid member until an inhibitor coating peeling process. CONSTITUTION:A steel strip 1 is passed through a roll coater 2 to coat one surface 5 thereof with a plating inhibitor and, after baking, drying and cooling, plated with zinc in a molten zinc bath 4. The plated steel strip 1 is successively treated by a frame wiper 6 and a wiper 8 to prevent zinc from adhesion onto the inhibitor coating and to adjust a plating adhesion amount and, according to necessity, subjected to alloying treatment in a furnace 9 and passed through a peeling apparatus 12 to peel the inhibitor coating while cooled by an apparatus 10 and receives post-treatment. Herein, by employing the constitution shown by the drawing, because the surface of the steel strip 1 is not contacted with a rigid member such as deflector roll until introduced into the apparatus 12 from the path 4, the formation of dents on the surface of the steel strip 1 can be perfectly prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing single-sided hot-dip galvanized steel sheets used as steel sheets for automobiles, etc. C. As steel sheets for automobile bodies, severe local corrosion on the inner surface of the car body can be prevented; It is well known that single-sided galvanized steel sheets are used to obtain a good painted appearance on the exterior of the car body. 60 The manufacturing method of single-sided galvanized steel sheets includes
There are hot-dip plating methods and electroplating methods, and in general, the former has a faster plating speed and is advantageous for thicker plating, while the latter is conversely more advantageous for thinner plating.0 However, with either method, single-sided plating becomes double-sided plating. Because it is technically more difficult to manufacture, manufacturing costs are not necessarily low, even though the amount of plated metal is half that.

For this reason, research has been conducted in search of a single-sided plating method with low manufacturing costs, and various proposals have been made. Typical manufacturing methods include α) single-sided grinding method, ■ meniscus method, and ■ plating inhibitor method.

The single-side grinding method is a method in which zinc is removed from one side after double-sided plating, which is inefficient and costly, and the quality of the removed surface is poor. The meniscus method is a method in which molten zinc is brought into contact with only one side of the stub, and examples include the ultrasonic method and the electromagnetic pump method. In this method, because the material is exposed to the atmosphere before the lag temperature drops, temper casing occurs on the cold rolled surface.Therefore, pickling is performed to remove this tempering force. For this reason, the quality is not stable, and moreover, when the zinc surface is alloyed, even more severe temper color occurs, and the method for removing this becomes another problem.

Many proposals have been made regarding plating inhibitor methods, but none have yet been put to industrial production. The reason for this is that the line speed cannot be increased sufficiently because dotted zinc particles remain on the surface where the plating inhibitor is applied, and the remaining zinc particles adhere to the surface of the roll that supports intermediate strip conveyance, and the copper strip This is due to the fact that it is the cause of the push marks.

Recently, the frequency of zinc particles remaining on the surface coated with the plating inhibitor has decreased due to improvements in the removability of the plating inhibitor and the adoption of flame wipers. The object of the present invention is to provide an apparatus for manufacturing single-sided hot-dip galvanized steel sheets that completely eliminates the occurrence of scratches caused by this.

Hereinafter, in order to make it easier to understand the present invention, a conventional apparatus will be briefly explained with reference to FIG. The strip 1 is coated with a plating inhibitor on one side of the slip by a roll booster 2, and then baked and dried in an annealing furnace 3 to form a coating film containing the plating inhibitor. Immediately above this bath, the anti-plating agent coated surface 5 of the strip 1 is wiped with a lame wiper 6 to remove the zinc deposited on the IkHz, and the galvanized surface 7 is wiped with a wiper 8 to reduce the plating thickness. Adjustments are made. Subsequently, if necessary, alloying is performed in an alloying furnace 9, cooled by a cooling device 10, introduced into a peeling device 12 via a deflector roll 11, the plating inhibitor coating is peeled off, and the single-sided surface is washed. Galvanized steel sheets are produced. Furthermore, it goes without saying that the coating and drying of the plating inhibitor may be carried out in advance on a separate line.

By the way, as mentioned above, in the manufacturing process of this type of single-sided hot-dip galvanized steel sheet, densities were generated due to the zinc particles layered on the coating surface 5 of the steel sheet. We investigated the cause of this occurrence and found that it is due to the contact between the release agent coated surface 5 and the surface of the roll 11 in the deflector roll shown at 11 in FIG. When the inhibitor-applied surface 5 of the strip 1 comes into contact with the roll 11 in this way, the zinc particles remaining on the inhibitor surface are captured by the deflector roll 11, forming protrusions that cause scratches. It has been found.

Therefore, in the present invention, in order to eliminate the cause of this generation of densities, in the bath leading from the molten zinc bath 4 to the peeling device 12, It guides the user without contact.

An example of its structure is shown in FIG. 2. A plating inhibitor is applied to one side 5 of the strip 1 by a T0 roll coater 2, cooled after baking and drying, galvanized in a molten zinc bath 4, and coated with a 7 lame wiper. 6 and wiper 8 to prevent adhesion of zinc onto the inhibitor coating 2 and to adjust the plating weight, alloyed as required in an alloying furnace 9, cooled in a cooling device 10, and then coated with the plating inhibitor. The product is guided to the paint film stripper &12, and after the paint film is removed, post-treatment is performed. In the present invention, by using the configuration T shown in FIG. Avoid contact with rigid members. As a result, even if zinc particles adhere to the plating inhibitor coated surface 5 of the strip L, there is no member to press them against the IJ surface until the step of peeling off the plating inhibitor coating, so the strip surface The formation of dents (dents) is completely prevented.

The peeling device 2 can adopt various peeling methods such as water-cooled peeling, peeling by bending, and peeling by pushing, or a combination of these methods, and its installation position is not limited to the example shown in FIG. It can also be provided at the position of 1O or directly connected to the cooling device 1o.
A detailed explanation of the peeling device is also omitted as it does not constitute the gist of the present invention.In short, in the present invention,
It is important to configure the anti-plating agent application surface 5 so that it does not come into contact with rigid members such as deflector rolls from the time it leaves the zinc bath 4 to the time it reaches the stripping device X2. As described above, in the apparatus of the present invention, the surface coated with the plating inhibitor does not come into contact with rigid members such as rolls from the time it leaves the zinc dip bath until it reaches the stripping device, and therefore is not suppressed by these members. Therefore, even if zinc particles or balls remain on the anti-plating agent coated surface,
The occurrence of denso is prevented. As a result, effects such as an increase in line speed, relaxation of the usage conditions of the 7 lame wiper, and a wider selection of plating inhibitors (stripping agents) are brought about.
There are great benefits to the industrial production of single-sided galvanized steel sheets using a plating inhibitor method.

[Brief explanation of drawings]

FIG. 1 is a line diagram of a conventional single-sided galvanized steel sheet manufacturing line, and FIG. 2 is a partial line diagram of a single-sided hot-dip galvanized steel sheet manufacturing line according to the present invention. Explanation of symbols l..., strip, 2... roll coater 13.
... Annealing furnace, 4... Molten zinc bath, 5... Plating inhibitor coated surface, 6... Flame wiper, 7-- Plating surface, 8... Wiper, 9... Alloying furnace, 10... Cooling device, 11-Deflector roll, 12... Peeling Mi
Patent applicant: Kawasaki Steel Corporation

Claims (1)

[Claims] Hot-dip zinc: A copper strip with a plating inhibitor coating formed on one side is passed through a hot-dip galvanizing bath to galvanize the other side, and then the plating inhibitor M film is peeled off to produce a single-sided galvanized copper strip. In a plating line, the plating inhibitor-coated surface of the copper strip does not come into contact with a rigid member such as a deflector roll during the process of removing the plating inhibitor coating after passing through the hot-dip galvanizing bath. Manufacturing equipment for hot-dip galvanized steel sheets.