JP3411507B2 - Surface treatment method and apparatus for steel materials - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for surface treatment of steel materials, and more particularly to a technology for preventing rust from occurring again after the steel materials are subjected to pickling, water washing and chemical conversion treatment. is there.

[0002]

2. Description of the Related Art Scales are formed on the surface of steel materials such as steel plates, steel bars and wires during the manufacturing process. Normal,
This scale not only spoils the appearance of steel products,
Subsequent "plating", "painting", "chemical conversion treatment"
Since it interferes with the surface treatment, it is removed by washing with an acid solution in advance (called pickling). If this pickling is carried out, the acid solution remains on the surface of the steel material, so if it is left as it is, the steel material may later be rusted or corroded. Therefore, the steel material after pickling must be washed with water (hereinafter,
It is called "water washing" to remove the acid solution.

By the way, in recent years, in the surface treatment of steel materials such as pickling, the respective treatments are sequentially and continuously performed to improve work efficiency. For example, when the steel material is a wire material, the surface treatment apparatus suspends the wire material 1 bound in a hollow cylindrical shape (coil shape) on a hook 2 such as a crane, as shown in FIGS. Support each processing tank 7,8,
It is configured to be sequentially immersed in 9. That is,
A pickling tank 7 containing an acid solution, a water washing tank 8 containing water, and a chemical conversion treatment tank 9 containing a chemical conversion treatment liquid are arranged in series. Then, in such a surface treatment device, the surface of the acid solution in the pickling tank 7,
Since steam and acid components (hereinafter collectively referred to as fumes 10) are diffused from the surface of the wire rod 1 after the pickling treatment,
The space above the tank is covered with a so-called hood 3, and the fumes 10 are sucked and removed through the ducts 4, 5, and 6.

[0004]

However, in the surface treatment apparatus having the above-mentioned structure, as shown in FIGS. 4 (a) and 4 (b), steam is condensed on the inner surface of the hood ceiling, and the condensation is generated. The water droplets 11 absorb the fumes 10 (moving direction is indicated by an arrow) floating in the atmosphere above the tank. Then, it often happens that the water droplets 11 containing the fumes 10 fall on the wire 1 after being washed in the washing tank 8. For this reason, many wire rods 1 have a problem in that, at the point where the water droplets 11 have fallen, rust occurs later and the product fails.

In view of such circumstances, it is an object of the present invention to provide a method and an apparatus for surface treatment of a steel material capable of remarkably suppressing rusting after washing with water.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and do not allow water drops containing fumes to drop on the steel material after washing with water, or even if the drops contain fumes in water drops. The present invention is embodied with the idea of reducing the amount.

That is, according to the present invention, a pickling tank and a water washing tank are arranged in series, the upper space of these tanks is surrounded by a common hood, and a surface treatment apparatus for exhausting the exhausted steel material is used. It is characterized in that it is immersed in a washing tank and a water washing tank one after another, and when the surface is continuously treated, water is sprayed on the inner surface of the hood above the water washing tank to wash and remove water droplets that are condensed on the inner surface. It is a surface treatment method for steel materials.

Further, the present invention is the surface treatment method for a steel material, characterized in that the spraying is carried out so that the pH of the water falling from the hood becomes 3 to 7.

Further, according to the present invention, a pickling tank, a water washing tank and a chemical conversion treatment tank are arranged in series, a space above the tanks is surrounded by a common hood, and a surface treatment apparatus for a steel material for exhausting is used. When the material is successively immersed in a pickling tank, a water washing tank and a chemical conversion treatment tank for continuous surface treatment, water is sprayed onto the inner surface of the hood above the water washing tank or above the chemical conversion treatment tank. A surface treatment method for a steel material, which comprises spraying a treatment liquid.

In addition, the present invention is the surface treatment method for a steel material, wherein the steel material is a steel wire rod.

The present invention relating to the apparatus is a surface treatment apparatus for a steel material in which a pickling tank and a water washing tank are arranged in series, the upper space of these tanks is surrounded by a common hood, and exhausted, inside the ceiling of the hood. The surface treatment apparatus for steel material, further comprising a water injection nozzle for spraying water on the inner surface of the hood above the water washing tank.

Further, in the present invention, in a surface treatment apparatus for a steel material in which a pickling tank, a water washing tank and a chemical conversion treatment tank are arranged in series, and the space above these tanks is surrounded by a common hood and exhausted, Inside the ceiling, a water injection nozzle for spraying water on the inner surface of the hood above the water washing tank and / or a liquid injection nozzle for spraying a chemical conversion treatment solution on the inner surface of the hood above the chemical conversion treatment tank are provided. It is a processing device.

Further, according to the present invention, the ceiling of the hood is
It is also a surface treatment apparatus for a steel material, characterized in that it is tilted with respect to the horizontal plane in the range of 10 to 50 degrees to the left and right with the central axis in the longitudinal direction as a boundary.

According to the present invention, water droplets containing fumes adhering to the inner surface of the hood are removed or the content of fumes is reduced, so that rusting is less likely to occur even if the fumes fall on steel materials. Also, in some cases, water drops do not adhere. As a result, the passing rate of steel material products has improved significantly compared to the past.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, the apparatus according to the present invention is basically installed above a pickling tank 7 containing a pickling solution of a steel material and a washing tank 8 for washing in series. That is, the water drop 11 containing the fumes 10 generated from the acid solution is removed from the inner surface of the ceiling of the hood 3 necessary for exhausting the space above it, or
Or because it is installed to make it harmless. Specifically, it is a water injection nozzle 14 provided inside the ceiling of the hood 3, as shown in FIG. As a result, the water droplets 11 containing the fumes 10 attached to the hood 3 are blown away, that is, washed and removed to prevent the water droplets 11 that are problematic from falling on the steel material existing below. Further, even if the water drops 12 fall, the content of the fumes 10 is reduced, so that the steel material 1 does not rust later. By the way, an example of trial with a steel wire rod is shown in FIG. As is clear from FIG. 2, in the case of the steel material, when the pH exceeds 3, the effect of reducing rusting is shown. Therefore,
In the present invention, it is preferable to spray water so that the pH of the water falling from the hood is in the range of 3 to 7.
Further, according to the investigation by the inventor, the water injection nozzle 14 may be any one as long as the water injection pressure is 2 kg / cm ² or more, and the shape of the opening does not matter. Furthermore, the installation position of the nozzle 14 is preferably above the washing tank 8. This is to prevent the sprayed water from entering the pickling tank 7 and affecting the composition of the acid solution.

Further, in the apparatus according to the present invention, the chemical conversion treatment tank 9 is arranged on the downstream side of the water washing tank 8, and the chemical conversion treatment liquid is sprayed on the inner surface of the ceiling of the upper hood 3 of the chemical conversion treatment liquid in the same manner as water. It is also the nozzle 14. Since the situation is the same in this case as well, the description is given by substituting it in FIG. This is because, when the steel material 1 is subjected to chemical conversion treatment, the liquid used does not cause rusting of the steel material 1, and this device is also effective in preventing rusting.

Further, in the present invention, the ceiling of the hood 3 on which the water and the liquid are sprayed is inclined with respect to the central axis in the longitudinal direction with respect to the horizontal plane in the range of 10 to 50 degrees to the left and right. As a result, harmful water droplets 12 are removed from the steel material 1
This is because it is possible to promote the prevention of rusting of the steel material 1 by moving the steel material 1 to a position where it does not fall. The reason for limiting the angle is that, according to the research conducted by the inventor, if the angle is less than 10 degrees, the drop still occurs, and if the angle exceeds 50 degrees, the design of the hood 3 is inconvenient.

Next, points to be noted when the surface treatment method according to the present invention is carried out by using these apparatuses will be described.

It is the time of spraying water or the chemical conversion treatment liquid on the inner surface of the ceiling of the hood 3, but it may be sprayed during the actual surface treatment of the steel material 1, that is, during the operation or at all times. It may be stopped, that is, the time when the steel material 1 is not on the tank. However, the effect is slightly larger when the operation is performed. This is because water droplets due to dew condensation do not adhere when constantly sprayed.

[0021]

EXAMPLE A water jet nozzle 14 according to the present invention was attached to the conventional surface treatment apparatus for a wire 1 shown in FIG. 1, and water 15 was constantly sprayed from the nozzle 14 to the inner surface of the ceiling of the hood 3 during operation. The surface treatment was actually performed. The conditions for surface treatment and the conditions for spraying water are as follows.

Surface treatment conditions Treatment amount of wire rod: 250 Coil wire rod steel type: Bearing steel wire rod moving speed: 12 m / min Pickling liquid: 25 wt% hydrochloric acid aqueous solution (pH 1 or less) Chemical conversion treatment liquid: Zinc phosphate Spraying conditions of mixed liquid of calcium phosphate and calcium Injection pressure: 3 kg / m ² Flow rate: 10 liters / min

As a result of carrying out this operation, the rust occurrence rate which was 30% in the past was completely eliminated, and it was confirmed that the present invention is extremely effective.

Although the above-mentioned embodiments are intended for steel wire rods, the present invention can also be applied to the surface treatment of general steel materials such as steel plates and bar steel. However, in that case, it goes without saying that the type of surface treatment and the shape of the material may be various.

[0025]

As described above, according to the present invention, it is possible to solve the problem that harmful water droplets containing acid gas, which have occurred in the surface treatment of steel materials, drop on the steel materials and rust later. It was As a result, the acceptance rate of the product has improved dramatically from the past.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a surface treatment apparatus according to the present invention.

FIG. 2 is a diagram showing a relationship between acid gas in water droplets and rusting of a steel material.

FIG. 3 is a vertical cross-sectional view of a general surface treatment apparatus for steel materials, in which a) shows a front surface and (b) shows a side surface.

4A and 4B are diagrams illustrating a mechanism for sucking fumes or vapor and generation of water droplets in an atmosphere above a processing tank, FIG. 4A is a front view, and FIG. 4B is a partially enlarged view of FIG. 4A.

[Explanation of symbols] 1 Steel material (wire material) 2 hooks 3 hood 4 suction duct 5 Air supply duct 6 suction duct 7 Pickling tank (several) 8 Washing tank (there are several) 9 Chemical conversion treatment tank (there are multiple) 10 fumes 11 Water drops (with acid) 12 Drops of water on the material 13 Water drop (decreased acidity) 14 Water jet or liquid jet nozzle 15 Water or chemical conversion treatment liquid

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C23G 1/08 C23C 22/73 C23G 3/02

Claims (7)

(57) [Claims] 1. A pickling tank and a water washing tank are arranged in series, the upper space of these tanks is surrounded by a common hood, and a surface treatment apparatus for the steel material is used for exhausting the steel material. Sequentially immersing in a tank, when performing a continuous surface treatment, above the water washing tank, spray water on the inner surface of the hood, wash and remove water droplets that have condensed on the inner surface of the steel material Surface treatment method. 2. The surface treatment method for a steel material according to claim 1, wherein the spraying is performed so that the pH of the water falling from the hood becomes 3 to 7. 3. A pickling tank, a rinsing tank and a chemical conversion treatment tank are arranged in series, the upper space of these tanks is surrounded by a common hood, and a surface treatment apparatus for the exhausted steel material is used to discharge the steel material.
In order to continuously perform surface treatment by successively immersing in a pickling tank, a water washing tank and a chemical conversion treatment tank, spraying water on the inner surface of the hood above the water washing tank,
Alternatively, a surface treatment method for a steel material, comprising spraying a chemical conversion liquid above a chemical conversion treatment tank. 4. The method for surface treatment of a steel material according to claim 1, wherein the steel material is a steel wire rod. 5. A surface treatment apparatus for a steel material in which a pickling tank and a water washing tank are arranged in series, and the space above these tanks is surrounded by a common hood and exhausted, wherein the inside of the ceiling of the hood is above the water washing tank. A surface treatment apparatus for steel material, comprising a water injection nozzle for spraying water on the inner surface of the hood. 6. A surface treatment apparatus for a steel material in which a pickling tank, a water washing tank, and a chemical conversion treatment tank are arranged in series, and a space above these tanks is surrounded by a common hood, and exhausted, in the ceiling of the hood, A surface treatment apparatus for a steel material, comprising: a water injection nozzle for spraying water on the inner surface of the hood above the water washing tank and / or a liquid injection nozzle for spraying a chemical conversion treatment liquid on the inner surface of the hood above the chemical conversion treatment tank. 7. The steel according to claim 5, wherein the ceiling of the hood is inclined with respect to a horizontal plane within a range of 10 to 50 degrees to the left and right with a central axis in the longitudinal direction as a boundary. Material surface treatment equipment.