JP5198126B2 - Cooling apparatus and cooling method for rod-like or tubular metal material - Google Patents

Description

  The present invention relates to a cooling device and a cooling method for a rod-like or tubular metal material.

  Specifically, the present invention relates to a cooling device and a cooling method for cooling by spraying water spray onto a rod-like or tubular metal material placed on a support base.

  A rod-like or tubular metal material is generally cooled by being immersed in a cooling water tank. However, since immersion cooling causes a difference in the flow state and boiling state of the cooling water at the upper and lower parts, warpage occurs without uniform cooling. There was a problem.

  Various proposals have been made regarding methods for cooling rod-shaped or tubular metal materials.

  For example, in Japanese Patent Laid-Open No. Hei 8-20821 (the following Patent Document 1), an inlet and an outlet of a high-frequency induction heater are formed in a straight line, and a steel bar feed opening and a feed opening are formed on the side wall of the cooling liquid tank. The coolant is constantly supplied to the coolant tank, and is held on the coolant level in the tank higher than the feed opening and the feed opening. The steel bar is continuously sent from the inlet to the outlet of the high-frequency induction heater and induction heated, and then sent out from the inlet of the cooling liquid tank and sent to the opening to cool down. A method of heat-cooling treatment is described.

  However, the method described in Patent Document 1 requires a sufficient cooling time when immersed in the cooling water tank while conveying the steel bar, so it is necessary to reduce the conveying speed or enlarge the water tank. Therefore, the equipment cost is high, and if the rolling and cooling are continuously synchronized at a low conveyance speed, the production efficiency is remarkably impaired. Since the morphological difference cannot be sufficiently relaxed, there is a problem that uniform cooling cannot be performed and warpage occurs.

  JP 2004-332089 A (the following Patent Document 2) discloses that a steel bar to be hardened is rapidly cooled (high temperature region rapid cooling) while being restrained by a press from a quenching temperature to a temperature just above the Ms point, and immediately above the Ms point. The steel bar to be hardened is reciprocated in the longitudinal direction from this temperature, and gradually cooled (medium temperature range cooling) while repeatedly pressing and releasing the press straightening load. This middle temperature region cooling is performed to a temperature of at least (Ms-50) ° C. Then, the hardened steel bar is rapidly cooled (low temperature region rapid cooling) while being restrained by a press from a temperature of at least (Ms-50) ° C. In the case of flat bar steel quenching, a quenching method is described in which the amount of warpage after quenching is reduced in quenching of the bar steel by quenching so that the square bar steel bends in a small amount of arc shape on the front and back surfaces in the high temperature region quenching Yes.

  However, the method described in Patent Document 2 is a method in which the steel bar is reciprocated in the longitudinal direction and cooled while repeatedly pressing and releasing the press straightening load, and requires a reciprocating function and a press straightening machine. Therefore, the equipment cost is high, and complex residual stress is generated due to press correction and non-uniform cooling, so there is a concern that shape problems such as warping may occur during secondary processing such as cutting.

  Japanese Patent Laid-Open No. 10-263687 (the following Patent Document 3) provides a first spray nozzle above the traveling line of the welded pipe, and the first spray nozzle has a long diameter refrigerant liquid at the welded portion of the welded pipe. It sprays in the shape of an ellipse so that the direction may coincide with the direction of the weld, and the weld is cooled linearly. Cooling to cool the welded steel pipe by providing a second spray nozzle around the travel line of the weld pipe to cool the base metal part of the weld pipe around the travel line of the weld pipe. A method for shortening the device length of the device to save the amount of refrigerant liquid is described.

However, in the method described in Patent Document 3, spray nozzles are arranged in the circumferential direction with respect to the steel pipe, and uniform cooling is performed by adjusting the amount of water in each spray nozzle. Therefore, there is a problem that the equipment cost becomes high.
Japanese Patent Laid-Open No. 8-20821 JP 2004-332089 A Japanese Patent Laid-Open No. 10-263687

  Therefore, the present invention solves the problems of the prior art as described above, and sprays water spray onto a rod-like or tubular metal material placed on a support base to cool it uniformly and bends after heat treatment. It is an object of the present invention to provide a cooling device and a cooling method capable of reducing the above.

The present invention solves the problems of the prior art as described above, and sprays water spray onto a rod-like or tubular metal material placed on a support base to cool uniformly, and reduces warpage after heat treatment. The present invention provides a cooling device and a cooling method that can be performed, and the gist thereof is as follows.
(1) A cooling device in a cooling bed for cooling by spraying water spray on a rod-like or tubular metal material placed on a support table,
The nozzle for spraying the water spray is disposed asymmetrically above and below the rod-like or tubular metal material, and is a vertical plane parallel to the axial direction that is the longitudinal direction of the material and / or perpendicular to the axial direction. A rod-shaped or tubular metal material cooling device, which is arranged in a zigzag pattern on a vertical plane parallel to a conveying direction which is a horizontal direction .
(2) The rod-shaped or tubular metal material cooling device according to (1) , wherein the lower nozzle that sprays the water spray is disposed directly below the support base.
(3) Cooling by spraying water spray on the rod-like or tubular metal material placed on the support using the cooling device in the rod-like or tubular metal material cooling bed described in (1) or (2) Cooling method
A method for cooling a rod-like or tubular metal material, wherein the upper and lower nozzles are uniformly cooled by adjusting the water amount ratio of the upper and lower nozzles spraying the water spray based on the amount of warping during and after cooling. .
<Action>
According to the invention of (1), since the nozzle for spraying water spray is disposed asymmetrically above and below the rod-shaped or tubular metal material, the upper and lower portions of the rod-shaped or tubular metal material are each uniformly in the axial direction. Since it can be cooled and the amount of bending of the metal material can be minimized, there is no problem in the manufacturing process after the heat treatment.
Further , according to the invention of (1), since the nozzles for spraying are arranged in a staggered manner on a vertical plane parallel to the axial direction and / or a vertical plane parallel to the conveying direction, a rod-shaped or tubular metal The upper and lower parts of the material can be cooled more uniformly in the axial direction.
Further, according to the invention of (2), since the lower nozzle for spraying water spray is arranged directly under the support base, the water spray blocking range by the support base is minimized, so the number of spray nozzles is small. The upper and lower portions of the rod-like or tubular metal material on the support table can be uniformly cooled over a wide range.
On the other hand, according to the invention of (3) , the upper and lower portions can be uniformly cooled by adjusting the water amount ratio of the upper and lower nozzles that spray water spray based on the warpage amount during and after cooling.

According to the present invention, a cooling device and a cooling method capable of cooling uniformly by spraying water spray onto a rod-like or tubular metal material placed on a support base and reducing the bending after the heat treatment are provided. Specifically, the following industrially useful remarkable effects can be obtained.
According to the invention of (1), 1) A sufficient cooling time can be ensured regardless of the rolling speed by performing water spray cooling in the cooling bed after heating, rolling and cutting.
2) The spray nozzles are arranged at the upper and lower parts so that the water spray is evenly sprayed on the entire cooling floor, and the lower nozzles are asymmetrically arranged in a staggered manner with respect to the upper nozzles. By improving the cooling capacity deviation in the axial direction due to interference water, uniform cooling in the axial direction can be realized, and then the upper and lower water volume ratios are adjusted to adjust both the upper and lower parts and the axial direction. Uniform cooling is possible, and the amount of bending after heat treatment can be minimized.
According to invention of (2), the spray which generate | occur | produces with a support stand (Lake) by arrange | positioning a lower nozzle directly under the support stand (Lake) installed in the cooling floor in order to support a stationary metal material. Since the non-collision range can be minimized, the number of nozzles can be reduced.
According to the invention of (3) , the upper and lower portions can be uniformly cooled.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.
1 to 9, 1 is a rough rolling mill, 2 is an intermediate rolling mill, 3 is a finish rolling mill, 4 is a cooling bed, 5 is a support base (lake), 6 is a water spray nozzle (upper side), and 7 is water. Spray nozzle (lower side), 8 is a rod-shaped or tubular metal material, WB furnace is a walking beam furnace (heating furnace), IH is an induction heating device, R / S is a cutting machine, and the same symbols are used for the same elements Thus, a duplicate description is omitted.

  FIG. 1 is a diagram illustrating a steel bar manufacturing facility to which the present invention is applied.

  First, a steel bar is heated to 1125 ° C. in a WB furnace, heated to a required heating temperature, for example, to 1200 ° C. using an induction heating apparatus IH, and kept in a heat retaining furnace. Further, by performing rolling with a total reduction of 88 to 98% by the intermediate rolling mill 2 and the finishing rolling mill 3 and cooling in the cooling bed 4, steel bars having various outer diameter sizes can be manufactured.

Cooling device and cooling method of the metal material of the present invention, for example, is placed on the contact Keru support table to cooling bed 4 in FIG. 1 (Lake), a cooling device and a cooling method for cooling a rod-like or tubular metal member Is to provide.

  In the cooling floor, rod-shaped or tubular metal materials cut to an appropriate length are aligned horizontally in parallel in the longitudinal direction (axial direction), placed on a support base (lake), and axially oriented. It is conveyed in a horizontal direction (conveying direction) perpendicular to.

  2 to 4 are diagrams illustrating a first embodiment of the cooling device of the present invention, in which FIG. 2 is a front view, FIG. 3 is a side view, and FIG. 4 is a plan view.

  The cooling device of the present invention is a cooling device that cools a bar-like or tubular metal material 8 placed on a support base (lake) 5 by spraying a water spray, the nozzle 6 spraying the water spray. 7 is characterized by being disposed asymmetrically above and below the rod-like or tubular metal material 8.

  As shown in FIG. 2, on the vertical plane parallel to the axial direction, the upper and lower nozzles are asymmetrically arranged in a staggered arrangement. Further, as shown in FIG. 3, the upper and lower nozzles are also asymmetrically arranged in a staggered manner on a vertical plane parallel to the transport direction. Therefore, as shown in FIG. 4, when the cooling floor is viewed from above, the nozzles appear to be arranged in a checkerboard pattern. However, the transport direction is more densely arranged than the axial direction.

  Since the nozzles 6 and 7 for spraying water spray are disposed asymmetrically above and below the rod-like or tubular metal material 8, the upper and lower portions of the rod-like or tubular metal material 8 can be uniformly cooled in the axial direction. In addition, since the amount of bending of the metal material can be minimized, there is no problem in the manufacturing process after the heat treatment.

In this embodiment, as shown in FIGS. 2 to 4, the water spray nozzles 6, 7 arranged above and below the metal material 8 are vertically asymmetrical and parallel to the axial direction that is the longitudinal direction of the material. Since it is arranged in a staggered position on the vertical plane and / or the vertical plane parallel to the conveying direction which is the horizontal direction perpendicular to the axial direction , the metal material 8 can be uniformly cooled in the axial direction from above and below. .

  FIGS. 5 and 6 are diagrams illustrating heat transfer coefficient distributions in the comparative example in which the first embodiment of the cooling device of the present invention and the nozzle positions are arranged oppositely in a vertically symmetrical manner, and FIG. FIG. 6 is a diagram in which a front view and a heat transfer coefficient distribution are superimposed.

  6A shows a case where the water spray nozzles 6 and 7 arranged above and below the metal material 8 are arranged in a zigzag pattern so as to be shifted forward and backward on the horizontal plane and left and right, and FIG. The case where the water spray nozzles 6 and 7 arranged in the above are arranged at positions facing each other vertically is shown.

  FIG. 5A shows a case where the water spray nozzles 6 and 7 arranged above and below the metal material 8 are arranged in a zigzag pattern so as to be shifted forward and backward on the horizontal plane and left and right, and FIG. The change of the heat transfer coefficient according to distance from right under a spray nozzle is shown about each when the water spray nozzles 6 and 7 arrange | positioned to are arrange | positioned in the position facing up and down.

  In the case of facing arrangement as shown in FIG. 5 (b), the heat transfer coefficient of the upper and lower parts of the metal material 8 decreases as it moves away from directly below the nozzle, and this tendency is particularly remarkable in the lower part. As shown in a), in the zigzag arrangement, the heat transfer coefficients of the upper and lower parts of the metal material 8 are uniform in the axial direction, and it was confirmed that the zigzag arrangement is more effective for uniform cooling.

  In Fig. 6 (a), the nozzle positions are staggered in the upper and lower parts, the part directly below the upper nozzle is farthest from the lower nozzle position, and the part just above the lower nozzle is farthest from the upper nozzle position. In this way, it can be seen that the influence of the interference water of the sprays in the upper and lower portions is alleviated and the cooling ability is uniform in the axial direction.

  On the contrary, in Fig. (B), since the lower nozzle is placed directly below the upper nozzle, the interference water of the spray on the upper and lower parts has a large effect, and the cooling capacity has changed uniformly and greatly in the axial direction. I understand.

  7 and 8 are front views showing the second row in the depth direction of the cooling device of the present invention. FIG. 7 shows an invention example illustrating the first embodiment, and FIG. 8 shows a comparative example.

  As shown in FIGS. 7 and 8, the upper and lower water spray nozzles 6, 7 are all arranged in a staggered pattern shifted in the front-rear and left-right directions on the horizontal plane. In FIG. 8, the lower water spray nozzle 7 is disposed in the middle of the support base (lake) 5.

  As shown in the comparative example of FIG. 8, when the lower water spray nozzle 7 is arranged in the middle of the support base (Lake) 5, the lower water spray interferes with the support base (Lake) 5 and the metal material 8 While the lower part cannot be cooled sufficiently, in FIG. 7 of the invention example, the lower water spray is less likely to be blocked by the support pedestal (Lake) 5, so the lower part of the metal material 8 is uniform with a small number of spray nozzles. Can be cooled to.

  FIG. 9 is a diagram showing an embodiment of the cooling method of the present invention.

  FIG. 9 shows a cooling method in which a water spray is sprayed on the rod-like or tubular metal material 8 placed on the support base (lake) 5 to cool the rod-like or tubular metal material 8 as described above. And the curvature amount of the metal material 8 can be adjusted by adjusting the water quantity ratio of the upper and lower nozzle which sprays the said water spray.

  As shown in FIG. 9, the amount of warpage of the metal material 8 can be controlled within an appropriate range by adjusting the water amount ratio between the upper and lower nozzles that spray water spray based on the amount of warpage during and after cooling. .

  The mechanism by which the amount of warpage of the metal material 8 can be controlled by the water amount ratio between the upper and lower nozzles is such that the water sprayed from above and below rebounds on the opposing spray water and improves the cooling effect of the metal material 8 (return water) and It is considered that the surface flow and boiling state of the metal material 8 are different from each other in the upper and lower parts, and this optimum water / water ratio is determined by the seasonal outside air temperature and water temperature fluctuation, the surface roughness of the target metal material 8 If the amount of water changes depending on the degree, etc., the water is not necessarily cooled vertically. However, the appropriate range can be determined based on the operating condition or the actual value of the warpage amount during and after cooling.

Experiments were performed under the following conditions using a staggered water-and-water spray nozzle shown in FIG. 7, and the amount of deformation at a position 35 mm from the center of the test piece was measured using a linear gauge. The effect of the present invention was confirmed.
<Experimental conditions>
・ Test piece: Φ60 × 540 mm, SUS304 material ・ Heating temperature: 1060 ° C.
・ Temperature retention time: 10 min.
-Water temperature: 22-29 ° C
-Upper nozzle water volume: 10-12L / min.
・ Lower nozzle water volume: 12L / min.
・ Spray nozzle: Full cone nozzle

It is a figure which illustrates the manufacturing equipment of the bar steel to which the present invention is applied. It is a front view which illustrates 1st Embodiment of the cooling device of this invention. It is a side view which illustrates 1st Embodiment of the cooling device of this invention. It is a top view which illustrates 1st Embodiment of the cooling device of this invention. It is a figure which shows the effect of 2nd Embodiment of the cooling device of this invention. It is a front view which illustrates 2nd Embodiment of the cooling device of this invention. It is a front view which illustrates 3rd Embodiment of the cooling device of this invention. It is a front view which shows the comparative example of 3rd Embodiment of the cooling device of this invention. It is a figure which illustrates embodiment of the cooling method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rough rolling mill 2 Intermediate rolling mill 3 Finish rolling mill 4 Cooling floor 5 Support stand (Lake)
6 Water spray nozzle (upper side)
7 Water spray nozzle (lower side)
8 Bar-shaped or tubular metal material WB furnace Walking beam furnace (heating furnace)
IH induction heating device R / S cutting machine

Claims (3)

A cooling device in a cooling bed for cooling by spraying water spray onto a rod-like or tubular metal material placed on a support table,
The nozzle for spraying the water spray is disposed asymmetrically above and below the rod-like or tubular metal material, and is a vertical plane parallel to the axial direction that is the longitudinal direction of the material and / or perpendicular to the axial direction. A rod-shaped or tubular metal material cooling device, which is arranged in a zigzag pattern on a vertical plane parallel to a conveying direction which is a horizontal direction . The rod-like or tubular metal cooling device according to claim 1 , wherein the lower nozzle for spraying the water spray is disposed directly below the support base. A cooling method in which a water spray is sprayed on a rod-like or tubular metal material placed on a support table to cool the rod-like or tubular metal material cooling bed according to claim 1 or 2. Because
A method for cooling a rod-like or tubular metal material, wherein the upper and lower nozzles are uniformly cooled by adjusting the water amount ratio of the upper and lower nozzles spraying the water spray based on the amount of warping during and after cooling. .

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