JPS62972B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to an in-furnace path switching method and device for steel strip in a continuous annealing furnace, in which the thermal cycle is appropriately switched in the same annealing equipment line, and the changed in-furnace path is used. It is an object of the present invention to provide a method and an apparatus for appropriately obtaining steel strips made of different quality materials.

When a steel strip is annealed in a continuous annealing facility, the material quality of the product obtained is determined by its thermal cycle. For example, direct cooling or indirect cooling is performed using a refrigerant such as water, and whether there is a reheating zone, overaging treatment zone, quenching zone, etc. after cooling, or by omitting a part of the furnace. As a result, the materials of the specific products obtained will differ. However, conventional continuous annealing equipment of this type is generally designed to be compatible with each material, and therefore requires multiple equipment to quickly respond to various types of products. If you try to change the line or change the processing time for processing, the atmosphere inside the furnace will change significantly, and production in this type of equipment may have to be stopped for a long time to change the connecting duct. This may hinder the smooth running of its operations, especially if the conversion is made to coincide with the repair date, otherwise it may reduce its processing output, and it may also reduce the quality of the material for the desired purpose. This inevitably comes with disadvantages and disadvantages, such as difficulty in obtaining

The present invention was developed through research to eliminate the disadvantages and shortcomings of the conventional products as described above. That is, in the present invention, when switching the pass line of the steel strip in the above-mentioned continuous annealing equipment, a sealing material is applied to keep the atmospheric gas on the furnace body side and the cooling mechanism side in an unchanged state, and then a predetermined material is obtained. This proposal proposes switching the path of the cooling section according to the thermal cycle of the
As an example, we will explain a device in which a cooling mechanism (direct cooling with water) is installed in the same line, and the path switching of the steel strip corresponding to a predetermined thermal cycle can be performed within a short time without changing the atmosphere inside the furnace. Then,
The general equipment relationship is as shown in Figure 1, and consists of a front stage consisting of a heating zone 1, a soaking zone 2, and a precooling zone 3, a reheating zone 6, an overaging zone 7, and a quenching zone 8. A roll cooling mechanism section 4 and a water cooling mechanism section 5 are incorporated between the rear stage section. However, the more specific structure of the roll cooling mechanism section 4 and the water cooling mechanism section 5 is as shown in FIG. After passing through the mechanism section 4, the water is guided from the outlet section 4a to the water cooling mechanism section 5, and from this water cooling mechanism section 5, via the inlet 4b, it is again guided to the roll cooling mechanism section 4, and then the inlet section of the reheating zone 6. 6a
In this case, a plurality of clamp-type seal mechanisms 9 are provided at the outlet section 3a and the inlet section 6a, and at the outlet section 4a and the inlet section 4b, respectively.

The roll cooling mechanism section 4 is provided with horizontally movable rolls 14, 14 into which a refrigerant such as water passes, and an elevating roll 14a, which prevents the passage and reheating from the pre-cooling zone 3. The path to the tropical zone 6 is formed by the horizontal movable rolls 14 on both sides, and the lifting roll 14a is located between them, forming a curved path line as shown by the solid line in the figure. When the roll cooling mechanism 4 is not used, the rolls 14 are moved inward, and the roll 14a is moved downward, so that the water cooling mechanism 5 is cooled without contacting the rolls 14, 14a. It is becoming more and more popular. A removable lid 13 is provided in the opening 13a of the casing of the roll cooling mechanism section 4 so that threading or inspection can be performed.

Although the roll cooling mechanism section 4 shown in the figure is composed of three cooling rolls 14, 14a, 14, it is clear that more cooling rolls may be employed as appropriate; It goes without saying that the roll 14 may be a tensioned bridle roll. However, regarding this roll 14, a snubber roll or the like may be attached for purposes such as when switching pass lines.

The water cooling mechanism section 5 mainly includes a cooling roll 5, to which a bent pass line section 5a is attached, and a seal roll 15 is provided for the inlet section 4b. The furnace atmosphere gas in the reheating zone 6 is sealed when the reheating zone 6 is used.

In this figure, the water cooling mechanism section 5 mainly consists of a roll 5b immersed in a cooling body, but it can be attached to a cooling body such as a jet nozzle or immediately before entering the cooling body. The bent path line portion 5a may be subjected to pickling, neutralization, surface treatment, hot water washing, dehydration, drying, etc. during liquid cooling.

The details of the sealing mechanism 9 as described above are shown separately in FIGS. 3 and below. That is, FIG. 3 is a cross-sectional plan view of the sealing mechanism in an open state, FIG. 4 is a vertical cross-sectional side view thereof, FIG.
Although the figure is a longitudinal side view of the same, a clamp seal member 19 having a thickness sufficient to close the passage of the steel strip 10 is moved forward and backward by the operation cylinder 18, and the clamp seal member 19 is designed to be moved forward and backward by the operating cylinder 18, and also has an inlet/outlet portion or an inlet as described above. A receiving member 17 is used on the opposing inner surface of the cylinder, and in order to further improve the sealing performance during cylinder operation, the sealing part is provided with an N ₂ gas pipe 16, as described above. The clamp seal member 19 and the receiving member 17 are each covered with a heat insulating material such as ceramic fiber, and in any case, as shown in FIGS. 5 and 6, they are operated by a cylinder 18 to clamp the steel strip 10 and It is designed to seal.

To specifically explain the switching of the method of the present invention using the above-mentioned device, first, in the case of a cooling cycle using the water cooling mechanism section 5, the precooling zone 3 and the water cooling mechanism are changed as already described with reference to FIG. The steel strip 10 is sent to the reheating zone 6 through the seal roll 15 and the seal mechanism 9 provided in the roll cooling mechanism section 4, and the clamp seal member 19 is released by the cylinder 18. It is in the state shown in FIGS. 3 and 4 in which it does not come into contact with the steel strip 10. To switch from this state, the line is stopped, the sealing member 19 is moved forward to clamp the steel strip 10 as shown in Figures 5 and 6, and the sealing member clamps _N2 gas to ensure the sealed state. 19 is sealed to shut off the atmosphere inside the furnace and the outside air. In this state, the lid 13 provided on the roll cooling mechanism section 4 is opened to cool this part and prepare for threading. That is, the second side is the charging side to the water cooling mechanism section 5 and the second side is the drawer side thereof.
The steel strip 10 is cut at the outlet section 4a and the inlet section 4b in the figure, and the steel strip for threading prepared in advance in the roll cooling mechanism section 4 is attached to the rolls 14, 14 and 14a, and the pre-cooling strip 3 is placed at the above-mentioned cutting position.
Then, the steel strip is connected to the steel strip 10 on the reheating zone 6 side, and the steel strip is pulled out to the opposite side using a threading perm or a threading chain. Note that before such work, the lifting rolls 14a are opened to a position where it is easy to pass through the steel strip, and the ends of the remaining steel strip are connected by spot welding or the like, and the rolls 1 on both sides forming the pass line are connected.
4 and 14 to the normal operating position, and after checking that each roll is wrapped, close the lid and purge the inside with inert gas such as N ₂ gas. After this purge is completed, the pre-cooling zone 3 side of the roll cooling mechanism section 4 and the reheating zone 6
The sealing mechanism 9 for the side is opened, and the supply of inert gas for sealing is stopped to restart the operation. Note that instead of cutting the steel strip 10 directly above the inlet portion 4b, it is cut at a position further into the water cooling mechanism 5 side as shown by arrow C in FIG. Depending on the size of the steel strip 10, it may also be possible to pull up the part that is in the side to the inlet part 4b and pass it through and connect it to the outlet part 4a side using a threading bar or a threading chain. If this is done, the number of connections made by spot welding or the like can be halved, and in any case, the completely instantaneous cooling conditions of the water cooling mechanism can be switched to the moderately slow cooling of the roll cooling mechanism.

In addition, when switching from roll cooling to water cooling as obtained above, the steel strip is passed through the precooling zone 3 → roll cooling mechanism section 4 → reheating zone 6 during roll cooling. When switching from water cooling to roll cooling as described above, the steel strip is normally held in the position where it is cut at the outlet section 4a and the inlet section 4b by the sealing mechanism 9. In this state, as described above, the line undergoing cooling operation in the roll cooling mechanism section 4 is stopped, and the sealing mechanisms at the outlet section 3a of the precooling zone 3 and the reheating zone inlet section 6a are activated to clamp the steel strip 10. At the same time, N ₂ gas is contained to seal the furnace side, and then the lid 13 of the roll cooling mechanism section 4 is opened to cool the roll cooling mechanism. However, as mentioned above, the steel strip in the roll cooling mechanism section 4 is cut so that it can be connected to the steel strip ends left at the outlet section 4a and the inlet section 4b, respectively, and the steel strip thus cut is Take out the obi scraps and
The steel strips hanging down from the outlet section 3a and the inlet section 6a are connected to the steel strip ends on the outlet section 4a and inlet section 4b sides by spot welding or the like, respectively, and then the lid 13 is closed, and the roll cooling mechanism section 4 Purge the inside with an inert gas such as _N2 gas. After completion of this purge, the entire sealing mechanism 9 is opened and operation is resumed.
4 and 14 are set at positions where they do not contact the steel strip being threaded, and the roll 1 in the roll cooling mechanism section 4
4, 14a, and 14 are not formed.

According to the present invention as explained above, the in-furnace pass switching of the steel strip can be carried out in a short period of time under conditions where the in-furnace atmosphere does not change at all in response to a predetermined thermal cycle corresponding to the product to be obtained by annealing. In other words, by doing this, it is no longer necessary to change the in-furnace path according to the repair date, or to take a long time to change the path, as in the past. Path switching can be carried out as appropriate while the line is in operation, thereby allowing each product with its own performance to be obtained as appropriate, and reducing downtime for path switching to smoothly implement preferred production. This invention has the effect of significantly facilitating the process operation of this type of annealing equipment, and is a highly effective invention industrially.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention,
Figure 1 is an explanatory diagram showing the overall configuration of the annealing equipment, Figure 2 is a sectional view showing a more specific configuration around the roll cooling mechanism, and Figure 3 is a diagram showing the sealing mechanism in its open state. Cross-sectional plan, 4th
The figure is a longitudinal sectional side view of the same, FIG. 5 is a transverse plan view showing the closed sealed state, and FIG. 6 is a longitudinal sectional side view of the same. However, in these drawings, 1 is a heating zone, and 2 is a heating zone.
3 is a soaking zone, 3 is a pre-cooling zone, 4 is a roll cooling mechanism section,
5 is a water cooling mechanism, 6 is both heating zones, 9 is a sealing mechanism, 10 is a steel strip, 13 is a lid, 14 and 14a are cooling rolls, 16 is an inert gas pipe, 18 is an operating cylinder, 19 is a sealing member This shows that.

Claims (1)

[Scope of Claims] 1. A thermal cycle for obtaining a predetermined material quality after forming a seal to prevent changes in the atmospheric gas on the furnace body side and cooling mechanism side when switching the in-furnace pass line of the steel strip in a continuous annealing furnace. An in-furnace path switching method for a steel strip in a continuous annealing furnace, characterized in that the path of a cooling section is switched according to. 2 Equipment for continuous annealing of the steel strip in a continuous annealing furnace is equipped with multiple cooling mechanisms between heating, soaking zone, reheating, and overaging treatment zone, and an entrance/exit for the steel strip to one of these cooling mechanisms. An in-furnace path switching device for a steel strip in a continuous annealing furnace, characterized in that a sealing mechanism having a sealing member is provided in each section, and each of the sealing members is provided with an operating mechanism to clamp and seal the steel strip. .