JPH0671328A - Controller for cooling hot rolled steel plate - Google Patents

Abstract

PURPOSE:To uniformize the quality of a product by measuring temperature distribution in the width direction of a steel plate, arranging cooling devices in the width direction of the steel plate based on the result and on-off controlling cooling water headers. CONSTITUTION:The temperature distribution of the steel plate P in the width direction is detected by temperature distribution sensors 3. The cooling headers 2 are provided on the upstream or the downstream of the line of temperature distribution sensors 3. The flow is controlled by the temperature distribution sensors 3 based on the measured temperature distribution and plural groups of cooling water supplying nozzles are arranged on the headers 2 in parallel or in an angle <=15 deg. to the advancing direction. Plural cooling water headers 2 are mounted on a width direction cooling control zone in the width direction of the steel plate P. In this way, ununiformity of temperature in the width direction of the steel plate can be dissolved. Improvement of the steel plate performance, reduction of restraint to an additive alloy element and saving of cooling water can be accomplished.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water cooling device in a continuous cooling treatment process of hot rolled steel sheets.

[0002]

2. Description of the Related Art In a hot-rolled steel sheet manufacturing process of steel, a thin plate having a thickness of several mm and a plate width of about 1 to 2 m is continuously manufactured.
After finish rolling of the steel sheet, forced continuous cooling is usually performed by water cooling in the final part of the process line as shown in FIG. 7 (a). The temperature-time pattern of the steel sheet during this cooling greatly affects the material quality.

FIG. 7B shows a perspective view of a conventional continuous cooling device. The header portion 1 of the cooling device has a structure that is long in the width direction of the steel plate, and a hairpin type nozzle 2 is arranged therein in the width direction. In such a cooling device, cooling water is uniformly supplied in the width direction, and it is considered that the cooling capacity in the width direction is uniform except for the influence of the end portion.

[0004]

These hairpin nozzles are on / off controlled for every one or several headers. Therefore, it is possible to control to make the temperature uniform in the length direction of the steel sheet. But the problem is
If temperature nonuniformity in the width direction as shown in FIG. 8 occurs due to nozzle clogging or heat generation during rolling, such a cooling device cannot control the temperature to be uniform.

Therefore, an edge heater for inductively heating the edge portion, or a masking device 14 for shielding the cooling water at the edge portion and its driving device as shown in FIG. 9 disclosed in JP-A-59-24511. 15
Have been put to practical use. With these edge temperature control devices, the effect of compensating for the temperature drop at the edge portion as shown in FIG. 10 can be obtained to some extent.

However, a further problem is that the conventional temperature control device for the width direction of the steel sheet cannot cope with the occurrence of the temperature extreme value at the central portion of the steel sheet as shown in FIG. The present invention aims to equalize the steel plate temperature in the very early stage of continuous cooling with respect to the occurrence of a temperature extreme value in the central portion of the steel plate, and the steel plate width caused by clogging of a part of the nozzle of the conventional continuous cooling device. It is an object of the present invention to provide a means for promptly eliminating the temperature non-uniformity in the direction.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a temperature distribution sensor for detecting a temperature distribution in the width direction of a steel plate in a continuous cooling line following a hot rolling mill for hot rolled steel plates, and a line upstream or a line of the temperature distribution sensor. On the downstream side, a plurality of cooling water supply nozzle groups were arranged linearly with the flow rate being controlled based on the temperature distribution measured by the temperature distribution sensor, parallel to the direction of travel of the steel plate or at an angle within 15 °. A cooling control device for a hot-rolled steel sheet, comprising: a width-direction cooling control zone in which a plurality of cooling water headers are installed in the steel sheet width direction.

[0008]

According to the present invention, the temperature distribution in the width direction of the steel sheet is measured by measuring the temperature distribution in the width direction of the steel sheet and controlling the cooling water headers arranged in the width direction of the steel sheet of the cooling device to perform on / off control. Non-uniformity can be made uniform in the initial stage of continuous cooling, and subsequent continuous cooling can take the same temperature history for each part of the steel sheet.

The present invention will be described below in more detail based on examples.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the structure of a cooling device of the present invention. The difference from the conventional device is the widthwise divided cooling header 2 in the figure. A temperature sensor 3 for width-direction temperature detection is provided before and after the width-direction divided cooling header 2.
The width direction divided cooling header 2 is 90 ° from the conventional cooling header.
It is installed by turning around and arranged side by side in the width direction. The line position where the widthwise divided cooling header 2 is provided is called a widthwise cooling control zone.

FIG. 2 is a partial perspective view near the widthwise cooling control zone. In this way, the divided header in the width direction is configured, and as shown in FIG. 3, the water supply pipe 21 to the divided headers 2 is provided with the water supply on / off control valve 22 independently for each divided header. The temperature distribution signal of the temperature distribution sensor 3 is input to the width direction temperature extreme value detection block 4.
From the temperature extreme value data detected by the width direction temperature extreme value detection block 4, the width direction divided cooling header valve on / off control block 5 outputs a valve on / off control command signal 6 for correcting the temperature extreme value.

FIG. 4 is a diagram schematically showing the valve on / off control. When there is a temperature maximum detection position as shown in (a) of this figure, the cooling header at the width direction position that discharges the cooling water to that position is turned on as shown in (b) of the figure corresponding to that maximum position. . As a result, the temperature extreme value of the steel sheet is flattened as shown in FIG. Further, the widthwise divided headers in the widthwise cooling zone are preferably arranged and arranged at an angle of 15 ° or less with respect to the conveyance center line of the steel sheet P as shown in FIG. The reason is that cooling water from two adjacent headers may form an unexpected temperature minimum point if the same portion of the steel sheet is cooled.

As described above, it becomes possible to cope with the occurrence of the temperature extreme value at the central portion of the steel sheet, which cannot be achieved by the conventional steel sheet width direction temperature control device. By appropriately arranging such widthwise cooling control zones at several points in the middle of the continuous cooling line, it is possible to immediately eliminate the temperature nonuniformity in the widthwise direction of the steel sheet that occurs during cooling.

FIG. 6 is a diagram showing the logic of the valve on / off control block 5. The widthwise divided cooling header of the present invention can be commonly used for cooling the steel sheet in the longitudinal direction by conventional control, particularly for strong cooling. That is, in the case of strong cooling, it is possible to rapidly cool the entire surface of the steel sheet in the width direction by turning on all the plurality of width-direction divided cooling headers. When the temperature extreme value in the width direction is not detected as described above, it can be used by incorporating it into the conventional temperature control, so that the cooling header space is always effectively used and the line length is relatively short.

[0015]

According to the present invention, it becomes possible to eliminate the temperature nonuniformity in the width direction of the steel sheet, which has been impossible in the past, and the quality of the product is made uniform, and the performance is improved or the added alloying element is added. It was possible to obtain a very large effect, such as the restriction of the above and reduction of cooling water.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a line configuration of an embodiment incorporating a device of the present invention.

FIG. 2 is a perspective view showing a configuration of a width direction cooling zone and its vicinity.

FIG. 3 is an explanatory diagram showing a method of controlling a widthwise cooling zone.

FIG. 4 is an explanatory diagram of a method for uniformizing the temperature distribution in the width direction of the steel sheet by the device of the present invention.

FIG. 5 is an explanatory view illustrating an angle that the widthwise divided cooling header can take with respect to a steel sheet traveling direction.

FIG. 6 is an explanatory diagram of a logic of a valve on / off control block.

FIG. 7 is an explanatory diagram of a conventional continuous cooling device.

FIG. 8 is an explanatory diagram showing an example of a temperature distribution in a steel sheet width direction that cannot be made uniform by a conventional continuous cooling device.

FIG. 9 is an explanatory view of an apparatus for masking cooling of a steel plate end portion.

FIG. 10 is an explanatory diagram showing an effect of the masking device.

[Explanation of symbols]

 1 Cooling device header 2 Width direction division header 21 Water supply pipe to width direction division header 22 Width direction division header valve 3 Width direction temperature distribution sensor 4 Width direction temperature extreme value detection block 5 Valve on / off control block 6 Valve on / off command signal 10 Rolling Machine 11 Table roller 12 Pinch roll 13 Coiler 14 Masking device 15 Masking device drive unit P Steel plate

Claims (1)

[Claims] 1. A temperature distribution sensor for detecting a temperature distribution in a width direction of a steel plate in a continuous cooling line following a hot rolling machine for hot rolled steel plates, and the temperature distribution sensor on the upstream or downstream side of the temperature distribution sensor line. The flow rate is controlled based on the temperature distribution measured by the cooling water header in which a plurality of cooling water supply nozzle groups are arranged linearly at an angle of 15 ° or less in parallel with the traveling direction of the steel plate. A cooling control device for a hot-rolled steel sheet, comprising: a plurality of width-direction cooling control zones installed in the same.