JPS6156297B2 - - Google Patents

Description

[Detailed description of the invention]

In cooling the strip using a water-cooled roll, the present invention provides a roll crown and/or a water-cooled roll.
Or by changing the levelness of the water-cooled roll as appropriate,
This invention relates to a method for achieving uniform temperature in the strip width direction. A method is known in which a strip after heating and soaking is cooled by a water-cooled roll in a continuous annealing facility. These water-cooled rolls have traditionally been used in various shapes, such as those with a convex (+) crown as shown in Figure 1 (Figure A) and those with a concave (-) crown. (Fig. B) and a flat version (Fig. C) are known. Rolls with convex crowns provide good strip threadability, but the temperature difference in the width direction of the strip after cooling is large, and the temperature of the strip becomes particularly high at the edges (see Figure 2). The material quality in the width direction is not uniform, and in the case of a concave roll crown, the edges of the strip are cooled preferentially, which causes ear waves and, at the same time, increases meandering. In addition, the shape of the strip passed through a water-cooled roll is not necessarily uniform in the width direction, so even if the above-mentioned flat roll is used, the strip does not come into uniform contact with the roll in practice. It is difficult to achieve uniform cooling across the width of the strip. The present invention was proposed as a result of studies in view of the current situation, and in particular, by changing the roll crown and/or horizontality of the water-cooled roll according to the temperature distribution in the strip width direction at the entrance side of the water-cooled roll. , the aim is to cool the strip uniformly in the width direction, regardless of the shape, size, etc. of the strip. One embodiment of the present invention will be described below. Generally, the water-cooled roll disposed in continuous annealing equipment has a third
As shown in the figure, multiple water-cooled rolls #1...
#4 are arranged in parallel, and the strip 2 is passed between these water-cooled rolls while being in contact with the water-cooled rolls and being cooled. In such a cooling process, one feature of the present invention is that the roll crown of one or more water-cooled rolls is adapted to the temperature distribution of the entrance strip so that there is no temperature difference in the width direction. As a specific means for changing this roll crown, for example, as shown in FIG.
a, 12b...... to each section 11a, 11
b. A method of changing the bulge of shell 13 by controlling the water pressure sent to...
As shown in Fig. 4-b, there is a method of providing a plurality of hydraulic injection parts 14a, 14b divided in the width direction inside the roll and controlling the hydraulic pressure supplied by oil supply pipes 15a, 15b. . In the case of this hydraulic system, the cooling water enters from the supply port 16a, circulates inside the roll in a spiral shape, and is discharged from the discharge port 16b. On the other hand, in the present invention, the leveling of one or more water-cooled rolls may be changed instead of or in combination with the method of changing the roll crown. Figure 5 shows an example of a method for changing the leveling.The drive side Dr is set as a pivot, the operator side Op is provided with an appropriate height adjustment mechanism 3, and the operator side Op is moved up and down. This is what I did. As a result, the water-cooled roll R
The edge portion of the strip that comes into contact with the side that is higher than the horizontal level L (the operator side in FIG. 5) is particularly preferentially cooled.
Therefore, in order to uniformly cool the strip in the width direction by changing the leveling, for example, for water cooling roll #1 in Fig. 3, the operator side Op should be set higher than the horizontal level L. Then, the next water-cooled roll #2 is set lower (that is, the drive side is higher than the horizontal level). In addition, when changing this leveling, a flat roll may be used as the water-cooled roll, but a roll with a predetermined crown may be used as necessary. Example 1 As shown in Figure 6, the strip temperature after heating and soaking is higher at both edges in the width direction.
This was cooled to 400°C by adjusting the roll crown or leveling of the water-cooled roll according to the table below. As a result, the strip was cooled uniformly in the width direction, and a strip with a flat shape was obtained. Note that the dotted line in the figure is the result of the conventional method (when a roll with a +2 mm crown is used).

[Table] Example 2 When the temperature in the width direction of the strip on the entrance side of the water-cooled roll is uniform as shown in Fig. 7, according to the conventional method, the temperature in the width direction of the strip after cooling is equal to that of both edges, as shown by the dotted line. part becomes higher. Therefore, in this example, the amount of crown of the water-cooled roll was adjusted according to the table below, and the roll was cooled to 400°C. As a result, the same effects as in Example 1 were obtained (experimental conditions were the same as in Example 1).

[Table] Example 3 As shown in Fig. 8, when the temperature in the width direction of the strip on the entry side of the water-cooled roll is low at both edges, the crown amount and leveling were changed according to the table below. Similarly to the above, the strip temperature distribution after quenching became uniform (experimental conditions were the same as in Example 1).

[Table] As is clear from the above examples, according to the present invention, when cooling a strip with a water-cooled roll, the roll crown and/or horizontality of the water-cooled roll are adjusted by the temperature in the width direction of the strip on the entrance side of the water-cooled roll. By making appropriate changes according to the distribution, strips of all shapes and sizes can be cooled uniformly in the width direction, resulting in a good strip shape, uniform material quality, and various other excellent effects. It turns out. In addition, in the present invention, the temperature is measured at the center part and the edge part in the width direction of the strip on the exit side of the water-cooled roll.
It is also possible to automatically control the roll crown and/or levelness so that the temperature difference between the two becomes zero.

[Brief explanation of the drawing]

Figure 1 A, B, and C are schematic diagrams showing various shapes of water-cooled rolls. Figure 2 is a temperature distribution diagram in the width direction of the strip before and after cooling by the conventional method. Figure 3 is a typical water-cooled roll. 4-a and 4-b are schematic diagrams in the case of changing the roll crown in the present invention,
FIG. 5 is a schematic diagram in the case of changing the roll leveling, and FIGS. 6, 7, and 8 are temperature distribution diagrams in the strip width direction for explaining an embodiment according to the method of the present invention. In the figure, #1...#4, 10, R are water-cooled rolls, 12a, 12b...... are water supply pipes, 13 is a shell, 14a, 14b...... are hydraulic injection parts, 15
Reference characters a and 15b indicate oil supply pipes, and L indicates the horizontal level.

Claims (1)

[Claims] 1. When cooling the strip while it is in contact with a metal roll whose interior is water-cooled,
A method for cooling a strip, characterized in that the roll crown of the water-cooled roll and/or the horizontality of the water-cooled roll are changed in accordance with the temperature distribution in the strip width direction on the entry side of the water-cooled roll.