JPH05146818A - Hot rolling method - Google Patents

Abstract

PURPOSE:To provide a hot rolling method capable of preventing the scattering of fine powder of oxidized scale 91 generated when a material to be rolled such as stainless steel, etc., is hot rolled. CONSTITUTION:Scattering prevention water 1 is ejected onto a roll 8 and the stainless steel to prevent the scattering of the oxidized scale 91 generated on the surface of the stainless steel 9 when the stainless steel 9 is hot rolled as a material to be rolled by the roll 8. Surface active water consists of water containing a small quantity of surfactant is used as the scattering prevention water 1. Since the surface tension of the surface active water is low, the water sufficiently permeates into the inside of the fine powder of the oxidized scale having surface which has fine recessed part and projection part and flocculates the powder and the blowing up of the powder is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling method capable of preventing scattering of fine oxide scale powder that occurs when hot rolling a material to be treated such as stainless steel.

[0002]

2. Description of the Related Art For example, when a stainless steel material is formed into a desired plate shape or the like, it is drawn and formed by hot rolling using a rolling roll. Then, in the rolling process, the stainless steel is drawn to a predetermined thickness with a rolling roll at a high temperature of 900 to 1200 ° C. Also, at this time,
As shown in FIG. 2, because of the high temperature, in the stainless steel 9 as the material to be treated, iron (Fe) as the main component is combined with oxygen in the air to form an oxide scale 91 on the surface thereof.

When passing through the rolling roll, as shown in FIG. 3, the oxide scale 91 becomes fine oxide scale powder 910, which is scattered on the rolling mill and its peripheral equipment, ceiling, floor, etc. To pollute. The oxide scale fine powder 910 has a fine particle diameter of 0.5 to 3 μm.
Therefore, it is difficult to remove the oxide scale fine powder 910 scattered on the rolling mill and the floor around the rolling mill. Further, since the oxide scale fine powder 910 is a weak magnetic substance, it cannot be collected by the magnetic collector during the scattering. Therefore, conventionally, in order to prevent the scattering of the oxide scale fine powder, the stainless steel 9 coming out of the rolling roll is
Water was being sprayed.

[0004]

[Problems to be Solved] However, as described above, it is difficult to completely prevent the oxide scale fine powder from scattering even if water is sprayed onto the rolled stainless steel. For example, even when water is sprayed as described above, in the case of hot rolling of austenitic stainless steel, at the upper part of the rolling mill provided with the above-mentioned rolling roll,
A large amount of oxide scale fine powder of 4 cc per 1 m ² is scattered and accumulated in 1 hour. Such scattering of fine oxide scale powder is remarkable especially in austenitic stainless steel, but there is a similar problem in hot rolling of general steel such as structural steel. The present invention has been made in view of these problems.
An object of the present invention is to provide a hot rolling method capable of preventing the oxide scale fine powder from scattering.

[0005]

Means for Solving the Problems The present invention provides a hot rolling method in which a material to be treated is hot-rolled by a rolling roll while spraying anti-scattering water for preventing the dispersion of fine oxide scale powder. A hot rolling method is characterized in that surface-active water composed of water and a surface-active agent is used. What is most noticeable in the present invention is that surface-active water composed of water and a surface-active agent is used as the anti-scattering water.

As the surfactant, nonionic or cationic surfactants are used. Also, anion system,
An amphoteric surfactant may be used. And the surfactant is
It is preferable to mix 0.02 to 0.2% (weight ratio) with respect to water. If the amount of the surfactant is less than 0.02%, it is difficult to sufficiently prevent the oxide scale fine powder from scattering. Further, when the content of the surfactant exceeds 0.2%, problems such as concentration regulation and pollution of the drainage of the surface-active water after use occur.

The surface-active water is also preferably used as cooling water for cooling the rolling rolls. That is, in hot rolling, cooling water is sprayed onto the rolling rolls to prevent overheating of the rolling rolls. Therefore, when the surface-active water is also used as the cooling water, it is possible to further improve the prevention of scattering of the oxide scale fine powder. In addition to stainless steel, heat-resistant steel, structural steel, etc., can be used as the material to be treated.

[0008]

In the hot rolling method of the present invention, surface-active water composed of water and a surface-active agent is used as the anti-scattering water. Therefore, the surface tension of the anti-scattering water decreases, and the anti-scattering water penetrates well into the inside of the oxide scale fine powder having fine irregularities and wets the entire surface sufficiently. Therefore, the oxide scale fine powder is well moistened, and these agglomerate with each other. Therefore, it is possible to prevent the oxide scale fine powder from rising. Therefore, the equipment around the rolling rolls, the ceiling, the floor, etc., will not get dirty. As described above, according to the present invention, it is possible to provide a hot rolling method capable of preventing the oxide scale fine powder from scattering.

[0009]

EXAMPLE A hot rolling method according to an example of the present invention will be described with reference to FIG. In the hot rolling method of this example, the stainless steel 9 as the material to be treated is hot rolled by the rolling mill 7 while spraying the anti-scattering water 1 for preventing the dispersion of the oxide scale fine powder. The shatterproof water 1 is stored in a water tank 11. The rolling mill 7 includes a housing 79, two rolling rolls 8 provided in parallel for rolling the stainless steel 9, and the stainless steel 9 coming out from the rolling roll 8.
And an injector 59 for injecting the anti-scattering water 1 and a cooler 58 for cooling the rolling roll 8. Then, the stainless steel 9 is inserted between the two rolling rolls 8 at a predetermined speed and hot rolled.

The stainless steel 9 used is an austenitic type, and immediately before it is inserted into the rolling roll 8,
The stainless steel 9 is heated to 900 to 1200 ° C. Therefore, an oxide scale 91 is formed on the surface of the stainless steel 9 as shown in FIG. The anti-scattering water 1 is a nonionic surfactant "Emar 20".
C "(Kao Corporation) is 0.05% (weight ratio) mixed with water.

The water tank 11 is provided with the scattering prevention water 1
Filled with the above-mentioned injector 59 through the pipe 18.
Further, it is connected to the cooler 58 via the pipe 19. A pump 17 is provided between the pipes 18 and 19.
To provide. The pump 17 delivers the splash prevention water 1 in the water tank 11 to the injector 59 and the cooler 58. The former sprays the anti-scattering water 1 of 0.1 to 0.3 liter / s onto the stainless steel 9, and the latter sprays 3 to 5 liter / s onto the rolling roll 8.

As described above, when the stainless steel 9 passes through the rolling rolls 8, the oxide scale 91 formed on the surface of the stainless steel 9 is crushed by the rolling rolls 8 to become oxide scale fine powder, but at the same time, it is scattered. The prevention water 1 is sprayed on the oxide scale 91. As described above, when the stainless steel 9 is hot-rolled by the rolling mill 7 while jetting the surface-active water, the upper portion 79 of the housing 79 is
At 0, an extremely small amount of oxide scale fine powder of 3 cc per 1 m ² was deposited in one month. This shows that the effect of the present invention is remarkable.

As described above, in the hot rolling method of this embodiment, the splash preventing water 1 is the surface active water composed of water and the surface active agent. Therefore, the above-mentioned splash prevention water 1
Surface tension is reduced. Then, the anti-scattering water 1 penetrates well into the oxide scale fine powder having fine irregularities,
Wet the entire surface thoroughly. Therefore, the oxide scale fine powder is well moistened, and these agglomerate with each other. Therefore, it is possible to prevent the oxide scale fine powder from rising. Therefore, the equipment around the rolling rolls, the ceiling, the floor, etc. will not be contaminated. In addition, the time and effort to remove fine oxide scale powder can be saved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a hot rolling method in an example.

FIG. 2 is a perspective view showing a state in which an oxide scale is generated on the surface of stainless steel in a conventional example.

FIG. 3 is a perspective view showing a state in which oxide scale fine powder is generated from the surface of stainless steel in a conventional example.

[Explanation of symbols]

 1. ． ． Shatterproof water, 11. ． ． Aquarium, 58. ． ． Cooler, 59. ． ． Injector, 7. ． ． Rolling mill, 8. ． ． Rolling roll, 9. ． ． Stainless steel, 91. ． ． Oxide scale, 910. ． ． Oxide scale fine powder,

Claims (1)

[Claims] 1. A hot rolling method of hot rolling a material to be treated with a rolling roll while injecting anti-scattering water for preventing scattering of fine oxide scale powder, wherein the anti-scattering water comprises:
A hot rolling method characterized by using surface active water comprising water and a surface active agent.