JPS58125345A - Tundish for horizontal and continuous casting - Google Patents

Abstract

PURPOSE:To make the continuous casting of ingots of small sections having various shapes stably in a tundish consisting of a crucible and a mold joined horizontally to the lower part on the side surface of the crucible by making the central axis of the crucible sharp at specific angles with respect to a horizontal plane. CONSTITUTION:In this tundish 10, a crucible 2 thereof is disposed by inclining the central axis O-O thereof at a certain angle lower than 90 deg. with respect to a horizontal plane X-X. Since an induction heating coil 3 can be wound down to the bottom part of the crucible 2 as compared with vertical type crucibles, the efficiency of induction heating is improved. The length l of a nozzle part 4 can be made shorter and at the same time, a magnetic flux phi covers the part of the nozzle 4 as well; therefore, the entire part of molten metal 8 is maintained at a specified temp. Thus, the troubles with the cooling of the nozzle part 4 after starting of the continuous casting operation are eliminated and the stable continuous casting operations are accomplished.

Description

[Detailed description of the invention] It is about improvement.

In recent years, steel. *As stock system and continuous casting method for special alloys,
The horizontal continuous casting method is applied to the chest.

The reasons for this are that the construction cost is low, installation can be done in a small space, and it can be installed as a replacement for idle equipment, and the slab has fewer defects such as center borosity and non-metallic inclusions, and is of high quality. Examples include being excellent in terms of quality. Moreover, this casting method allows for a cross-sectional area of kits that was considered impossible to cast using the conventional vertical continuous casting method in which the tundish and mold are separated.
It also has the advantage of being able to cast slabs with the following small cross-sections. However, when it comes to slabs with a small cross-sectional area of SO1 or less, depending on the commonly used burner-heated vertical crucible-shaped tundish or vertical crucible-shaped induction-heated tundish, respectively,
Not only does the heating not reach the nozzle part (in such slabs, the cross-sectional area is small and the length of the nozzle part is long, so the molten metal is cooled in the nozzle part,
The coagulation extended to the nozzle area, leading to breakage or nicks leading to cessation of drawing color. Furthermore, the molten metal is injected into the mold in a semi-molten state, and it is not completely welded to the initially solidified shell, resulting in cracks.

The present invention is directed to the above-mentioned casting point 1 in the conventional horizontal continuous casting method, especially in the case of casting slabs with small cross-sections such as round, square, rectangular, irregular shape, etc. with a cross-sectional area of So- or less. The objective is to obtain an improved horizontal continuous casting machine that can solve the problem.

In order to achieve this target sound, the present invention forms a T-crucible high-frequency induction furnace or a low-frequency induction furnace, and the angle θf of the center axis of the crucible with respect to the horizontal direction! The entire feature is to select an angle less than or equal to 00, preferably from jθ'' to ?O'llC.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the first and second figures of the accompanying drawings showing embodiments thereof.

As shown in Part 1, inside the side wall l of the tundish 101i made by the present invention 1111rc, there is a cylindrical crucible whose central axis 0-0 is 0 with respect to the horizontal plane X-XVC.
arranged inclined with an angle It less than or equal to
An induction heating coil J is wound around the lining that constitutes the crucible 1, and the crucible t! Lower SW
A nozzle is connected to the surface in the direction of the horizontal plane is deposited, and the induction coil 3 is supplied with high frequency or low frequency. In addition, in the figure, 4 is the slab pulled out from the mold j, ri is the bottom wall of the tundish, and t is the molten metal. In this way, the tundish 10 according to the present invention has a central axis of the crucible. 0-0 is 90" to horizontal plane X-X
Although it is arranged inclined with a certain angle θ as follows,
This inclination angle θ is.

It varies depending on the molten metal holding weight, heating capacity, etc., and generally,
By selecting this angle between θtno' and 70°, the induction heating coil Jt
- It is possible to wrap the crucible to the bottom of the crucible, so that not only can the induction heating efficiency be increased, but also the length of the nozzle part shown in FIG. 1 can be shortened. In addition, this angle 0 also changes depending on the size of the inner diameter d of the crucible.If the inner diameter d of the crucible is small, the inclination angle 6t approaches Oo, and conversely, the inner diameter of the crucible 1 approaches Oo. If it is large, the inclination angle [#i;jj
By selecting the angle # to such a value, the length jt of the nozzle portion can be shortened. Thus, according to the present invention, the crucible
The angle between the central axis 0-0 and the horizontal @X-X is 0t; Oo
By selecting between Oo and Oo, the length 1 of the nozzle part can be shortened as described above. After the fermentation heating coil 3 and the center axis 〇-〇 of the fermentation heating coil 3 and the melting coil are filled with
Since the angle -tm of Therefore, the trouble caused by the cooling of the nozzle parts after the start of continuous casting operation is eliminated, and stable continuous casting operation can be performed.

Here, in the present invention, the inclination angle #t of the center axis 0-0 of the rucs with respect to the horizontal plane X-XK! Considering the benefits and losses when tilting from θ'' to the 70@ mark, Br in Figure 7
As shown by ri, when the amount of molten metal t decreases during continuous casting, a portion of the upper end of induction heating coil J protrudes beyond the interface of molten metal j, so that the induction heating efficiency decreases.

The horizontal plane X-X of the central axis 0-0 of
As the temperature increases from Oo to 10”K, induction heating coil J
The ratio of a portion of the upper end of the molten metal t coming out from the interface of the molten metal t increases, and the induced force efficiency further decreases. On the other hand, the heating due to the magnetic flux # reaching the nozzle part DA is caused by the horizontal plane X-! [Angle 0 increases as the angle 0 moves from 70° to N06. Therefore, the angle # of the central axis 0-0 of the crucible with respect to the horizontal plane The best angle can be determined from these glosses.

Next, the results of a comparative test between the tundish according to the present invention and a conventional one will be explained.

Comparative Example 0 According to the present invention Crucible-shaped high-frequency induction heating tundish with inclination angle #-40'' (crucible capacity 4I00Q, induction heating capacity JKE
Z, 2001W) Ii used, diameter lO from steel, special steel, special alloy (N1-C!r-Fe-'ri-AJ)
Continuous casting of ~701 m of round slabs was carried out, and it was confirmed that the molten metal was heated and kept at elevated temperatures as desired, and that stable operation was possible.

B. Conventional angle -=! O0, that is, vertical high-frequency induction heating tandem: L (crucible capacity * ooh, @ induction heating capacity JK
Hz, 20σrv), and as a result, the cross section was less than 0 square and the diameter was 300 mm. It has been observed that if the melt is below 100 mL, it will be poured into the mold in a semi-molten state and cracks will occur in the slab.

In addition, in the case where the cross section was less than a diameter UO2 circle, the molten metal was injected into the mold in a semi-molten state, cracking occurred, and eventually solidification reached the nozzle part, resulting in breakage or stopping of drawing.

As described above, according to the present invention, the angle It of the central axis of the melting hole with respect to the horizontal plane is determined by the inner diameter and the capacity of the melting hole.
-! By selecting a temperature between rO and Oo, tilting the crucible, and wrapping a high-frequency or low-frequency induction heating coil around the crucible, it is possible to increase the temperature of the molten metal and maintain a constant temperature, and further, Shorten the nozzle length t.

Therefore, according to the present invention, the cross-sectional area is IOam''.
This horizontal continuous casting method can be applied to a wider range of fields, as it can be used to produce horizontal continuous casting pipes of steel, special steel, and special alloys with small cross-section slabs in the following shapes: round, square, rectangular, irregular shapes, etc. It becomes possible to do so.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention. FIG. 1 is a schematic diagram showing the magnetic flux distribution 1. /... Side wall; Co... Crucible; J... Coil; Tei... Nozzle; S... Mold; 6... Slab; 7... Bottom wall; T...
Molten metal; lO...tanditshu. Patent applicant Mitsubishi Steel Corporation Figure 1

Claims (1)

[Claims] / A tundish for horizontal continuous casting, which consists of a mold horizontally joined to the lower side of a crucible and a crimp, and which continuously casts slabs by pulling the slabs horizontally from the mold. , the angle ef of the central axis of the crucible with respect to the horizontal plane is selected to be an angle smaller than 900 V
*Tanditshu as a sign. The tan dish according to claim 1, wherein the tan dish is formed as a crucible-shaped high-frequency or low-frequency induction furnace. 3 The cross-sectional area of the slab! In the case of a round, square, rectangular, or irregular shape of O- or less, the tundish according to claim 1 or claim 0, where the inclination angle is selected to be O.