JPH06226325A - Cooling method for rolled wire rod and device therefor - Google Patents

Abstract

PURPOSE:To provide a method and a device by which cooling control and uniform cooling can be attained at the same time when foam fluid is supplied to a hot rolled wire rod which has received final finish rolling for adjusting cooling. CONSTITUTION:When a non-concentric annular wire rod S is cooled by foam fluid on a conveyor 1, to uniformize the flow of foam supplied to a cooling tank without receiving influence of the steam generated in a cooling time, the foam fluid F having a water content W(1/m<3>) is supplied to the cooling tank 2 at q(1/min.m<2>) per a unit floor area, and when the wire rod is cooled keeping this relation as 10<=q.W<=900 (1/min.m<2>), cooling speed control and uniform cooling can be attained at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a foaming fluid to a hot-rolled wire rod after final finish rolling to adjust and cool the hot-rolled wire rod, and an apparatus for carrying out the method. In addition, in the present invention, "foam" refers to a state of aggregation of a large number of bubbles separated by thin liquid films.

[0002]

2. Description of the Related Art As a method for directly adjusting and cooling a steel wire rod after hot rolling in a hot rolling line, a wire blower is used to wind the wire rod after hot rolling into a non-concentric ring shape and convey it on a conveyor. Stelmore method of cooling by cooling (for example, Japanese Patent Publication No.
No. 15463) or a method of cooling a steel wire rod after hot rolling by immersing it in a hot water tank as it is (for example, JP-B-46-46).
-8089), a method of immersing in a molten salt tank and cooling (Japanese Patent Publication No. 59-37725), and the like.

However, since these cooling methods are limited in the cooling rate within a narrow range, it is necessary to properly use them depending on the purpose of manufacture, which leads to enlargement and complexity of equipment, and
There is a problem that the equipment cost also increases. Therefore, the applicant of the present invention has proposed a cooling method using foam as a medium capable of controlling a wide range of cooling rates with a single cooling medium (Japanese Patent Application No. 61-20).
6716 and Japanese Patent Application No. 62-88876).

However, these methods focus on the cooling rate in the case of cooling with foam, and are unsatisfactory from the viewpoint of uniform cooling due to the influence of the flow of foam supplied and the generated steam.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate these problems of the prior art and to provide a method and apparatus capable of simultaneously achieving cooling control and uniform cooling.

[0006]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors have found that when non-concentric ring-shaped wire is foam-cooled on a moving conveyor, it is affected by steam generated during cooling. In order to make the flow of the foam supplied to the cooling tank uniform without receiving the water, a foam fluid of water W (l / m ³ ) is added per unit floor area of the cooling tank to q (l / min, m ² ).
Supply, and the relationship is 10 ≦ q · W ≦ 900 (l / m
It is confirmed that the cooling rate control and the uniform cooling can be achieved at the same time by cooling as in, m ² ), and in practicing the present invention, the foam supply nozzle should be set so as not to interfere with the steam generated during cooling. The injection angle of the foam supply nozzle is set to be below or on the side of the concentric ring-shaped wire or on both sides thereof, or 10 to 6 so as to sufficiently penetrate the overlapping portion of the rings so as to face the traveling direction of the ring-shaped wire.
It has been confirmed that uniform cooling can be achieved by installing it at 0 °, and the present invention is constituted by the gist of the present invention.

(1) Winding into a non-concentric ring shape after hot rolling
Move the wire rod on the conveyor installed in the cooling tank.
The water content W (l
/ M ³) Foam fluid per unit floor area of the cooling tank q (l /
min, m²) Is supplied and the relation is 10 ≦ q · W ≦
900 (l / min, m²) As a cooling
Cooling method for rolled wire rods.

(2) In the cooling tank, a conveyor for conveying the wire placed in a non-concentric ring shape is housed, and the non-concentric ring-shaped wire moving on the conveyor is cooled by a foam fluid. In the rolling wire cooling device configured, a foam supply nozzle is arranged at a lower position or a lateral position or both of the wire, and a foam injection angle of the nozzle is set to 10 to 60 ° opposite to the traveling direction of the wire. A cooling device for a rolled wire, which is characterized in that

An embodiment of the present invention will be described with reference to the drawings. In the figure, 10 is a laying head, 12 is a carrier belt in the atmosphere, 1 is a conveyor accommodated in a cooling tank 2, S is a wire rod wound on the conveyor 1 in a ring shape, 3
Are side guides provided on both sides of the conveyor 1,
Is the focus tab. A foam supply header 5 is arranged immediately below the conveyor 1, and the header 5 is provided with a plurality of foam injection nozzles 6a in the width direction and the longitudinal direction at appropriate intervals. Further, both side guides 3 are provided with foam supply nozzles 6b at appropriate intervals in the length direction thereof. 7 is a foam generator, 8 is a foaming liquid tank, and 9 is an air tank. The foaming liquid is prepared by adding 1.0% of a surfactant to water.

F is a foam fluid, and the foam that has been supplied to the cooling tank 2 and has not been broken down flows toward the lacking part of the foam. In the present invention, the lower limit of the relational expression q · W between the water content W (l / m ³ ) in the foam and the supply amount q of the foam fluid is 10 (l / m).
in, m ² ) is a value in which the foam fluid uniformly penetrates the overlapping portion of the ring-shaped wire in a range where the latent heat of vaporization of water in the foam that gives the cooling rate hardly contributes, and the upper limit is 900 ( 1 / min, m ² ) is a value selected with some allowance for the value that the foam supplied to the cooling tank flows uniformly around the ring-shaped wire in a state where the water content in the foam is high.

In the present invention, the reason why the position of the foam supply nozzle and the angle of the foam injection direction are defined is that the steam generated by the foam cooling becomes an upward flow, so that it does not interfere with this, that is, the non-concentric ring-shaped wire. This is because a foam supply nozzle is installed below or on the side or both of them so that the foam fluid can easily penetrate the overlapping portion of the ring-shaped wire. The angle of the foam injection direction is 10 to 60 ° with respect to the traveling direction of the ring-shaped wire. Specifically, it is preferably 25 to 35 ° opposite to the traveling direction of the ring-shaped wire.

The effects of the present invention will be specifically described with reference to examples.

[0013]

[Example] Steel type JIS G 3506 SWRH 8
2A equivalent steel (C: 0.82%, Si: 0.27%, M
o: 0.78%, P: 0.013%, S: 0.006
%) Steel pieces are hot-rolled into a wire having a diameter of 5.5 mm,
While moving the same wire wound in a non-concentric ring shape on a conveyor installed in a cooling tank, a nozzle is provided at a foam injection angle of 30 ° facing a temperature range of 820 to 400 ° C in the traveling direction of the wire. 6a and 6b were arranged and foam-cooled. In addition,
The transport conditions such as the ring diameter were the conditions in an ordinary wire rod mill.

As a result, as shown in Tables 1 and 2 (continued from Table 1), although the tensile strength of the wire varies depending on the water content W in the foam and the foam supply amount q, it is at the same level as the Stelmore method (conventional example). The variation σ under these conditions can be reduced by about 30 to 60%. Further, the mechanical descaling property evaluated by the ratio to the residual scale amount after applying 6% strain to the wire in the tensile test is also excellent. Also, the water content in the foam W
And the product q · W of foam supply amount q is less than 10, or 900
If it exceeds, the mechanical properties of the wire deteriorate as shown in the comparative example.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

According to the present invention, when a non-concentric ring-shaped wire is cooled with a foam fluid, extremely uniform cooling is possible, and mechanical strength such as tensile strength of the wire is higher than that of the conventional method. The variation can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a state where a wire rod placed in a ring shape is conveyed on a conveyor.

FIG. 2 is a vertical sectional view of a wire rod cooling facility.

FIG. 3 is an explanatory view showing a mode in which the jetting direction of the foam supply nozzle is opposed to the traveling direction of the ring-shaped wire to be angled.

FIG. 4 is a schematic explanatory view of an apparatus for carrying out the present invention.

[Explanation of symbols]

 1: Conveyor 2: Cooling tank 3: Side guide 5: Foam supply header 6a, 6b: Foam supply nozzle 7: Foam generator 8: Foam liquid tank 9: Air tank 10: Laying head 11: Focusing tab 12: Atmosphere Conveyance zone S: Ring-shaped wire F: Foam fluid

Claims (2)

[Claims] 1. When cooling a wire rod wound into a non-concentric ring shape after hot rolling with a foam fluid while moving on a conveyor installed in a cooling tank, the wire rod has a water content W (l / m).
³ ) The foam fluid of q) (l / mi per unit floor area of the cooling tank)
n, m ² ) are supplied and the relationship is 10 ≦ q · W ≦ 90.
A method for cooling a rolled wire rod, which comprises cooling as 0 (l / min, m ² ). 2. A cooling tank is provided with a conveyor for transporting a wire placed in a non-concentric ring shape, and the non-concentric ring-shaped wire moving on the conveyor is cooled by a foam fluid. In the apparatus for cooling a rolled wire rod, a foam supply nozzle is arranged at a lower position or a lateral position or both of the wire rod, and a foam jet angle of the nozzle is set to 10 to 60 ° opposite to the traveling direction of the wire rod. A cooling device for a rolled wire, which is characterized in that