JPH04200844A - Cooling method for continuous casting of steel beam blanks - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cooling method for continuous beam flank casting of steel.

[Prior Art] In the continuous casting method for steel beam blanks, a continuous casting device as shown in Fig. 5 is used, and the slab is cooled while being pulled out between a group of guide rolls provided at the bottom of the mold. It is being done.

In FIG. 5, molten steel poured from a ladle 6 into a tundish 7 is injected into a mold 1 through an immersion nozzle 8. The solidified shell formed in the mold 1 is solidified while being cooled by a group of spray nozzles 4 between a group of guide rolls 3 provided next to the bottom of the mold, and is drawn out as a slab 2. 5 is a pinch roll. Cooling by the spray nozzle 4 is very important from the viewpoint of controlling the solidification structure and preventing cracking of the slab. Depending on the spray shape, the spray nozzle 4 may be a flat nozzle, full cone nozzle, elliptical nozzle, square nozzle, etc. (Steel Handbook I [p.64
1. (1981).

FIG. 6 is a plan view of an example of a group of guide rolls provided following the mold in continuous beam blank casting, and FIG. 7 is a partial cross-sectional view taken along line A-A in FIG. 6. FIG. 8 is a partial cross-sectional view taken along line B--B in FIG. 6. In FIGS. 6 and 8, large arrows indicate the running direction of the slab in the cooling zone. In the figure, 9
a, 9b, 9c are flat nozzle spray tips,
10 is a French roll, 11 is a chip roll, ] 2 is a web roll. In FIG. 6, the guide roll group is provided with cooling zones such as a cooling zone 1, a cooling zone 2, etc. in sequence following the mold 1. There, a web roll 12, a chip roll 11, a franchise roll jO, and a guide roll group are lifted. In order to prevent the slab from breaking out, a large number of non-water-cooled small-diameter rolls are used to narrow the roll spacing, and a spray tip 9a is placed on top of each roll pitch at each roll pitch.
9b and 9c are provided so that they can be cooled with spray water as shown by the dotted lines.

In Fig. 7, the slab 2 of the beam flank is supported by chip rolls at its lower end 21, supported by web rolls 12 at its upper and lower center parts 2a, and supported by flannel rolls at its left and right parts 2C. It runs while being cooled while being supported by 10.

As a cooling means, a spray chip 91] is provided on each roll pitch of a chip roll], and a spray chip 91 is provided on the tip roll.
A spray tip 9c is provided thereon for every roll pitch of 2, and a spray tip 9C is provided thereon for every roll pitch of the flange roll 10, and the slab 2 is cooled as shown by the dotted line. The spray nozzle group on the side of [web roll] 2 is one flat nozzle with three spray tips 9a attached thereto, and the spray angle A is about 80°.

In Figure 8, the slab 2 of the beam blank is upper 1! II
The positive end 21) is supported by the tip roll 11, and the positive end 21) is supported by the web roll 12 while running. During this time, the spray tips 9a provided on the chip roll 11 at each roll pitch, and the spray tips 9a provided on the tip roll 11 at each roll pitch, and the spray chips 9a provided thereon at each roll pitch of the web roll 12.

As shown by the dotted line, the spray depth 9b provided at
Spray and cool. The chip roll 11 and web roll] 2 that support the lower side of the slab 2 of the beam flank are symmetrical with respect to the - dotted chain line as the axis, so
Omitted.

[Problems to be Solved by the Invention] However, in the above-mentioned spray nozzle group, as shown in FIG. Since 14 spray tips are arranged on the left and right sides, the amount of water per tip is as low as 15 to 43 p/min, causing problems such as nozzle clogging. If the nozzle is clogged, the slab will not be cooled uniformly, and the solidified structure will not be able to be properly rolled, causing problems such as cracking of the slab.

The present invention is an attempt to solve the problems mentioned in section 2 above, and it is an object of the present invention to provide a method for cooling slabs that does not cause nozzle clogging.

In order to achieve the object described in [Means and effects for solving the problem], the present invention cools the slab with spray water between a group of guide rolls provided subsequent to the mold for continuous casting of steel beam blanks. In the method 5, a plurality of spray nozzles are provided at the position of the guide roll group, and one spray nozzle forms a spray water carper area spanning the slab and the rolls of the guide roll group. This is a cooling method for continuous casting of steel beam blanks, which is characterized in that the rolls are simultaneously and directly cooled with water.

In the present invention, it is necessary to form a spray water covering region spanning the slab and the rolls of the guide roll group with one spray nozzle. As a result, in the present invention, the slab and the rolls of the guide roll group can be simultaneously and directly cooled with water, and the amount of cooling water required for this is an amount of water that does not clog the spray nozzle.

The spray nozzle used in the present invention is preferably a flucon nozzle. Flucon nozzles can provide an appropriate amount of cooling water by appropriately selecting the flucon tip. However, the present invention is not limited to the flucon nozzle, and any nozzle may be used as long as it can form a spray water carper region that can directly water-cool the slab and the rolls of the guide roll group at the same time.

[Example 1] The present invention is illustrated in the following examples and will be explained in detail below. Fig. 1 is a plan view of an embodiment of continuous casting of a beam blank in which the flucon nozzle used in the present invention is arranged, and Fig. 2 is a plan view of the spray water carper area of the flucon nozzle used in the present invention. It is a figure which shows an example. Figure 3 is A-A of Figure 1.
A diagram showing a partial cross section taken in the direction of the line arrow, Figure 4 is B of the first country.
It is a figure showing a partial cross section taken along arrows - and -B.

In Figure 1, 21. a and 21b are full cone nozzles, and 22 is a spray water carper area surrounded by a dashed line. In the figure, the guide roll group includes a cooling zone 1, a cooling zone 2, etc. following the mold 1, and a cooling zone with a spray nozzle group 4 (J, the guide roll group consists of a web roll 12, a chip roll 11, and a flange roll 10). Here, web roll 12 and franchise roll 1
Full cone nozzles 21 are arranged at every other position. A spray water carper area 22 is formed by the cooling water from the full cone nozzle 21 .

In FIG. 2, a full cone nozzle 21 can be used to form a suitable spray water cover area 22 by using a suitable full cone tip 23.

In Fig. 3, the slab 2 of the beam flank is located at the upper and lower ends 2.
1) is supported by the chip roll] 1, and the upper and lower central parts 2a
is supported by web rolls] 2, and runs on the left and right portions 2C without being supported by franchise rolls 10. web roll 1
2 full cone nozzle 21. A is provided, and a full cone nozzle 211 is provided at the second end of the French roll 10. In this case, shape the appropriate spray water cover area,
In order to achieve this, the spray angle A of the full cone nozzle 21a above the web roll 12 is adjusted to about 120 degrees. Also, the full cone nozzle 21 of the chip roll 1]. The injection angle B of b is adjusted to be about 100.

In FIG. 4, the slab 2 of the beam flank runs while being supported by a tip roll 11 at the upper end 2b and by a web roll 12 at the upper central part 2a. During this period, every other full cone nozzle 2 was installed on the web roll 12 ],
Cool by spraying with a. Here, the cooling state on the flange roll side is indicated by a two-dot chain line 22. 2
11) is a full cone nozzle. Note that the chip roll 11 and web roll 12 that support the lower side of the slab 2 of the beam blank are omitted because they are symmetrical with the - dotted chain line as the axis.

The results of an experiment in which a plurality of full-cone nozzles were installed in zones 1 and 2 as shown in FIG. 1 and continuous casting of steel beam blanks by the method of the present invention will be described. Here, the thickness is 250 m and the width is 200 to 4.90 m.
Continuous casting of bloom of m was performed for 100 charges. Full cone nozzle tip - Average amount of water per tip is 1st
The table is as follows.

Table 1 As shown in Table 1, in the present invention, there was no nozzle clogging of the full cone nozzle disposed in the zone 2 of the guide roll group.

For comparison, in the case of flat nozzles placed in zones 1 and 2 of the guide roll group in the conventional method, 100
As a result of charging, 33 charges caused nozzle clogging.

In addition, by forming a spray water carper area,
It is possible to obtain consistent cooling of the slab and the cooling of the rolls, and it is possible to perform uniform cooling, and a good solidification structure of the slab can be obtained.In addition, by direct water cooling from the outside of the rolls,
Traditionally, rolls lasted about June, but now we've found that they can last for 1 to 2 years.

[Effects of the Invention] According to the present invention, while forming a spray water covering region spanning the slab and the rolls of the guide roll group with one spray nozzle, the spray water covers the slab and the rolls of the guide roll group at the same time.
By the simple method of direct water cooling, nozzle clogging of the spray nozzle can be completely eliminated and the slab and the rolls of the guide roll group can be appropriately cooled.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the guide roll group used in the present invention, FIG. 2 is a diagram showing an embodiment of the spray water carper area of the full cone nozzle used in the present invention, and FIG. A diagram showing a partial cross section taken along the line A-A in Figure 1, No. 4
The figure shows a partial cross section taken along line B-B in Figure 1,
Fig. 5 is a diagram showing an example of a conventional casting machine for continuous beam blank casting, Fig. 6 is a diagram showing a plane of an example of a conventional guide roll group, and Fig. 7 is an arrow indicated by the line A-A in Fig. 6. 8 is a diagram showing a partial cross section taken along the line B--B in FIG. 6; FIG. 21a, 21b full cone tip, 22.22a
- Spray water cover area, 23-full cone tip.

Claims (1)

[Claims] In a method of cooling a slab with spray water between a group of guide rolls provided following a mold for continuous casting of steel beam blanks, a plurality of spray nozzles are provided at the position of the group of guide rolls, and casting is performed with one spray nozzle. A cooling method for continuous casting of a steel beam blank, characterized in that the slab and the rolls of the guide roll group are simultaneously and directly cooled with water while forming a spray water cover region spanning the slab and the rolls of the guide roll group.