JP4044206B2 - Wire rod cooling system - Google Patents

Description

【００３１】
尚、本発明は、前記実施の形態や実施例に示されるものに限定されるものではない。例えば、規制装置を、加熱装置のヒータの両側部を幅方向中央部を指向するように傾斜配置させることにより構成してもよい。加熱装置のヒータは、幅方向に分割して独立制御されるものに限定されない。
【００３２】
【発明の効果】
本発明によれば、非同心コイル状線材の全長にわたって、所定の冷却速度で冷却することができる。
【図面の簡単な説明】
【図１】図１は、本発明の実施の形態を示し、その（Ａ）は概略側面図、（Ｂ）は拡大断面図である。
【図２】図２は、本発明の実施の形態を示し、全体レイアウトを示す平面図である。
【図３】図３は、本発明の実施の形態の作用効果を説明する断面図である。
【図４】図４も、本発明の実施の形態の作用効果を説明する断面図である。
【図５】図５は、遮蔽部材の長さと冷却速度の比Ｒｓの関係を示すグラフである。
【図６】図６は、本発明の他の実施の形態を示す断面図である。
【図７】図７は、非同心コイルの疎部と密部を示す平面図である。
【符号の説明】
９ コンベア
１０ 加熱装置
１４ 規制装置
Ｌ 層厚コイル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire cooling apparatus, and more particularly, to an apparatus for gradually cooling a non-concentric coiled wire following hot rolling.
[0002]
[Prior art]
In the technique of gradually cooling a hot-rolled wire rod in a ring-like state (hereinafter referred to as “non-concentric coil shape”) that is non-concentric with each other on a conveyor after rolling. As shown in FIG. 7, since the overlapping condition of the wire in the conveyor width direction of the non-concentric coiled wire is different, both sides in the conveyor width direction are dense parts and the central part is a sparse part. And since a cooling rate differs in a dense part and a sparse part, it was difficult to perform uniform cooling over the full length of a wire.
[0003]
Therefore, a cooling technique for performing uniform cooling over the entire length of the non-concentric coiled wire is disclosed in, for example, Japanese Patent Publication No. 56-28973.
This prior art pays attention to the wire mass distribution in the conveyor width direction of the non-concentric coiled wire in order to perform uniform cooling over the entire length of the wire, and the radiant heat that is approximately inversely proportional to this mass distribution is applied to the non-concentric coiled wire. Or a radiant heat control device that dissipates and suppresses radiant energy substantially corresponding to the mass distribution.
[0004]
It is also known that it is desirable to use a so-called “layer thickness coil” in which the density of the wire ring on the transfer conveyor is increased, particularly when the thin wire rod is gradually cooled (see Japanese Patent Publication No. 59-52214). ).
[0005]
[Problems to be solved by the invention]
However, in the prior art disclosed in the above Japanese Patent Publication No. 56-28973, the radiant heat control device is installed over the entire length in the width direction of the conveyor, so that the device becomes complicated and control is very difficult. It had deficiencies in cold uniformity and operability.
[0006]
Therefore, in order to simplify the apparatus and control, it is conceivable to control only the sparse part at the center without controlling the entire length in the width direction of the conveyor.
However, for thin wire rods with a wire diameter of 9 mm or less, when performing slow cooling with a slow cooling rate, the layer thickness coil (when the ring pitch is P and the wire diameter is d, (3/4) · d ≦ P ≦ (5/4) · d is a non-concentric coiled wire in the range of d, but is not limited to this range.) In this layer-thickness coil, the heater is located above the sparse part. Even if it is installed and gradually cooled, the cooling rate may exceed the target cooling rate depending on the part of the sparse part.
[0007]
That is, because the radiant heat from the heater is different between the upper part (side closer to the heater) and the lower part (side closer to the conveyor surface) of the layer thickness coil, the cooling rate of the wire material in the lower part of the sparse part is locally There was a problem that it was faster and it was difficult to keep the sparsely spaced region within the required slow cooling rate range.
To solve this problem, the heater temperature can be set higher to increase the amount of radiant heat to the sparse part. However, if the temperature is set above the normal temperature (up to about 800 ° C), the heater life will be significantly shortened. , Not economical. In addition, it is possible to increase the amount of radiant heat to the sparse part by increasing the heater width, but this method also increases the amount of radiant heat to the dense part, so the cooling rate of the dense part becomes slower than necessary. When the slow cooling ends on the conveyor delivery side, the dense portion does not reach the predetermined slow cooling end or the slow cooling cutoff temperature.
[0008]
Then, an object of this invention is to provide the cooling device of the wire which solved the said problem.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has taken the following measures. That is, the present invention is characterized by a conveyor for placing and transporting a heated wire as a layer thickness coil, a heating device provided corresponding to a sparse part of the layer thickness coil on the conveyor, and the heating And a regulating device that restricts supply of heat from the device to the dense portion of the coil.
[0010]
Further, the regulating device is configured by a radiant heat shielding member provided on both the left and right sides of the heating device.
This restriction device limits the amount of heat of the heating device to the dense part of the layer thickness coil, so that the cooling rate of the dense part is not unnecessarily slowed, and as a result, only the temperature of the sparse part is reduced. Since it only has to be considered, the temperature control becomes easy. That is, it is not necessary to control the temperature over the entire width direction of the conveyor as in the prior art .
[0011]
It is preferable that the radiant heat shielding member is made of a reflective material that inputs a part of the radiant heat from the heating device to a sparse part of the layer thickness coil.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows the layout of the entire equipment, and the object of the present invention through the heating furnace 1, the heat retaining furnace 2, the rough rolling mill 3, the first and second intermediate rolling mills 4, 5 and the finishing rolling mill 6, respectively. A hot-rolled wire rod cooling device 7 is provided.
[0013]
The details of the cooling device 7 are shown in FIGS. The cooling device 7 includes a winding machine 8 that forms a hot-rolled wire into a coil shape, and a conveyor 9 that forms and moves the wire discharged from the winding machine 8 into a layer thickness coil L. Above this conveyor 9, there is provided a slow cooling cover 11 that has a heating device 10 and surrounds the transfer path of the layer thickness coil L, that is, forms a cooling chamber 11A. At the end of transfer of the conveyor 9, a softened wire rod converging device 12 is provided.
[0014]
In the present embodiment, the conveyor 9 for placing and transferring the layer thickness coil L is a roller conveyor. The heating device 10 is provided on the inner surface of the center portion in the width direction of the slow cooling cover 11. A heat insulating material 13 is provided on both the left and right sides of the heating device 10 in the slow cooling cover 11.
The heating device 10 is configured by, for example, an electric resistance heater, and is installed at a position facing the sparse portion L1 in the layer thickness coil L on the conveyor 9, that is, the central portion in the width direction of the conveyor 9. The heating device 10 and the heat insulator 13 are not flush with the cooling chamber 11A but are flush with each other.
[0015]
Further, the heater constituting the heating device 10 is divided into a central portion 10A and left and right side portions 10B and 10C so that the temperature can be individually controlled in the width direction of the conveyor 9, and in a temperature range of 600 ° C to 900 ° C. The cooling rate of the sparse portion L1 can be adjusted, and the inner surface of the gradual cooling cover 11 is in the range of 25% to 85%, preferably 50% to 80% of the coil diameter centering on the sparse portion L1. is set up.
[0016]
That is, the heating apparatus 10 is not installed over the entire width of the layer thickness coil L, but is installed in a range of 25% to 85% around the sparse part L1 having the lowest layer density at the center of the coil. Temperature control from ℃ to 900 ℃ is easy and can reduce wasteful energy, depending on the wire diameter, coil pitch, and target cooling rate, that is, it is not necessarily proportional to the wire mass distribution. There is no need for control.
[0017]
Here, the temperature range of the heating device 10 is set to 600 ° C. to 900 ° C. The temperature of the wire rod formed on the layer thickness coil L and placed on the conveyor 9 by the winding machine 8 is 750 ° C. to 800 ° C. The layer thickness coil L being transferred on the conveyor 9 (for example, at a transfer speed of 10 to 15 m / min) has a heat release of the retained heat, and since this heat release is intense in the sparse part L1, the effect of slow cooling is 600 ° C. or less. In addition, it is not practical at 900 ° C. or higher.
[0018]
Further, the use of an electric resistance heater as the heating device 10 makes maintenance easier than a gas heater or the like, and the type of the heater 10 is a planar heater (panel heater) or a sheathed heater. It doesn't matter.
Furthermore, as the heat insulator 13, the following types can be adopted.
Powder / particulate insulation (perlite, diatomaceous earth, alumina powder, carbon balun, etc.), fiber / flame insulation (asbestos, cut paper, etc.), solid insulation (foam glass, foamed concrete, foamed styrene, foamed urethane, etc.) ), Cotton-like insulation (glass fiber, silica / alumina fiber, cotton, etc.), layered insulation (multi-layer glass, etc.), structural insulation (honeycomb structure, corrugated cardboard, etc.), composite insulation (insulation castable, etc.), The one formed by adding powder and particles is desirable.
[0019]
Moreover, you may utilize the insulation body of the sandwich structure etc. which laminated | stacked glass wool and shield plates, such as a stainless plate, alternately.
The cooling device 7 is provided with a regulating device 14 that restricts heat supply from the heating device 10 to the dense portion L2 of the coil. The regulating device 14 is constituted by radiant heat shielding members 15 provided on both the left and right sides of the heating device 10. The radiant heat shielding member 15 is made of a reflective material that inputs a part of the radiant heat from the heating device 10 to the sparse part L1 of the layer thickness coil.
[0020]
The shielding member 15 made of the reflective material is formed in a plate shape and is provided so as to protrude downward from the lower surface of the heater 10 by a length ls. The shielding member 15 reflects the amount of radiant heat from the heater 10 in the direction of the dense portion L2 of the layer thickness coil L, changes the direction to the sparse portion L1, and increases the amount of radiant heat to the sparse portion L1, This is to slow down the cooling rate.
[0021]
Hereinafter, the shielding member 15 will be described in detail.
In FIG. 3, by installing the shielding members 15 on both sides of the heater 10, generally, the radiant heat energy is released to the entire hemisphere space, so that it reaches the sparse part L <b> 1 directly below the heater 10 and the heater 10. A part of the radiant heat is reflected by the shielding member 15 as shown by an arrow, changes its direction, and reaches the sparse part L1. Moreover, since the temperature of the shielding member 15 also rises to some extent by the radiation heat from the heater 10, a secondary radiation effect from the inner surface to the sparse part L1 can be expected.
[0022]
On the other hand, as shown in FIG. 4, the heat input to the outer end E in the left-right direction of the coil L is taken as an example with respect to the dense portion L2 where the cooling rate is slow. Although the radiant heat from the central portion 10A of the heater 10 reaches the outer end E by the member 15, the radiant heat from the left portion B of the figure is blocked. Since the left part B of the heater is closer to the dense part L2 than the central part A and the incident angle α of the radiant heat is large (α3>α2> α1), the form factor between the dense part L2 and the heater 10 When the shielding member 15 is not provided, the amount of radiant heat to the end E is greater from the left part B than the heater central part A. As shown in FIG. 4, since the radiant heat from the heater side B is blocked by the shielding member 15 at the coil end E, the shielding effect to the dense portion L2 having a low cooling rate is great.
[0023]
FIG. 5 is based on the measured values of the coil L and the ambient temperature in the apparatus shown in FIG. 1 when the wire diameter of the wire is 8 mm and the width of the heater 10 is 800 mm (approximately 0.7 times the coil diameter). Calculated by temperature analysis, the cooling rate of the sparse part L1 when the length of the shielding member 15 is ls is indicated by Rs with respect to the cooling rate when there is no shielding member.
[0024]
From FIG. 5, it can be seen that as the length ls of the shielding member 15 is longer, the rate of heat input to the sparse part L1 due to the reflection of radiant heat from the heater 10 increases, and the cooling rate decreases. At the same time, the shielding effect of the radiant heat from the heater 10 to the dense portion L2 is also increased. However, if the length ls of the shielding member 15 is too long, it becomes an obstacle to the running of the layer thickness coil L, which is not preferable. In general, the coil rear end portion of the coil L placed on the conveyor 9 by the winder 8 may locally increase in coil height due to jumping at the start and end of winding. The cold cover 11 is installed at a certain distance H from the upper surface of the conveyor 9, and an appropriate value of H is about 400 to 500 mm. Corresponding to the target slow cooling conditions, the thickness of the layer thickness coil L differs depending on the wire diameter and the ring pitch P (distance between adjacent coil ring centers) at the time of winding. The distance to the cover 11 inner surface (heater 10 surface) is different. However, as can be seen from FIG. 4, the length ls of the shielding member 15 is about 100 mm, and it can be seen that the cooling rate of the sparse part L1 of the thin wire rod can be reduced by about several percent. This decrease in the cooling rate for the sparse portion L1 corresponds to the same effect as extending the width of the heater 10 by about 25% in total on both sides.
[0025]
According to the above apparatus, in the thin wire rod, the cooling rate of the sparse portion L1 is very close to the limit of the target speed, and thus the above cooling rate effectively acts on the intended softening of the tough steel.
Thus, by attaching the shielding member 15 having a reflection function to both ends of the heating device 10 installed in the upper area of the sparse portion L1 of the layered coil L on the inner surface of the slow cooling device 7, the heater width is substantially reduced on both sides. An effect equivalent to that obtained by the extension is obtained, and there is an effect that the amount of radiant heat from the heating device 10 to the layer thickness coil dense portion L2 is suppressed.
[0026]
In addition, the shielding member 15 does not necessarily need to be a perpendicular direction in the both ends of the heating apparatus 10, and as shown in FIG. It is desirable that θ is smaller than 45 °. Moreover, as a material of the shielding member 15, it is preferable that the reflectance is large, and a steel alloy or a copper alloy is desirable. As its structure, a heat insulating material is attached to the outer surface, that is, the surface on the dense portion L2 side so that the temperature of the surface is lower than that of a single metal plate, thereby preventing radiation from the outer surface to the dense portion L2 as much as possible. It is necessary to keep it.
[0027]
Further, from the viewpoint of facilitating maintenance, the shielding member 15 is preferably divided into a plurality of parts in the longitudinal direction of the cooling device 7.
[0028]
【Example】
A 155-square billet of JIS SCM435 is hot-rolled into a wire rod having a wire diameter of 8 mmφ, placed on the roller conveyor 9 while the wire rod is formed into a layer thickness coil L, and lengths at both ends of the heater 10 having a width of 800 mm. By controlling the surface temperature of the heater 10 with the cooling device 7 having the shielding member 15 made of a metal plate whose ls is 100 mm, the cooling rate of the coil sparse portion L1 and the dense portion L2 is controlled to be a predetermined value. The mechanical properties of the slowly cooled wire were measured.
[0029]
In addition, as a comparative material, by controlling the surface temperature of the heater in the conveyor length direction as in the case of having the shielding member 15, slow cooling was performed without the shielding member, and the mechanical properties were measured.
The mechanical properties of the rolled material were evaluated by performing a tensile test on a sample obtained by dividing one ring into 16 parts. The results are as shown in Table 1. When the shield member 15 of the present invention was provided, both the maximum value and the average value of the tensile strength were lower than when the shield member 15 was not provided.
[0030]
[Table 1]

[0031]
In addition, this invention is not limited to what is shown by the said embodiment and Example. For example, the regulating device may be configured by inclining and arranging both side portions of the heater of the heating device so as to face the center portion in the width direction. The heater of the heating device is not limited to one that is divided and controlled independently in the width direction.
[0032]
【The invention's effect】
According to the present invention, cooling can be performed at a predetermined cooling rate over the entire length of the non-concentric coiled wire.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention, in which (A) is a schematic side view and (B) is an enlarged cross-sectional view.
FIG. 2 is a plan view showing an overall layout according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view for explaining the function and effect of the embodiment of the present invention.
FIG. 4 is also a cross-sectional view for explaining the effect of the embodiment of the present invention.
FIG. 5 is a graph showing the relationship between the length of the shielding member and the cooling rate ratio Rs.
FIG. 6 is a cross-sectional view showing another embodiment of the present invention.
FIG. 7 is a plan view showing a sparse part and a dense part of a non-concentric coil.
[Explanation of symbols]
9 Conveyor 10 Heating device 14 Regulatory device L Layer thickness coil

Claims (2)

A conveyor for placing and transferring the heated wire as a layer thickness coil;
A heating device provided corresponding to the sparse part of the layer thickness coil on the conveyor;
The restricting device and for limiting the amount of heat supplied from the heating device to the dense portion of the coil possess,
The regulating device is a wire rod cooling device configured by radiant heat shielding members provided on the left and right sides of the heating device. The radiant heat shielding member, the heating device cooling apparatus of the wire part of claim 1, wherein and a reflective material to heat input to the sparse portion of the thickness coils radiant heat from.

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