JPS611455A - Continuous casting equipment - Google Patents

Abstract

PURPOSE:To prevent the breakdown and crack of a strip and to improve production efficiency by dividing transversely the pouring part of a casting mold into >=3 chambers, forming respectively the chambers into a hermetic construction, inserting tundish nozzles into the pouring parts, introducing an inert gas into the chambers and casting the strip. CONSTITUTION:Two sets of intermediate partition plates 2c parallel with side seals 2b are fixed to the inside of a gate flask 2 to form three chambers in the flask 2. The three nozzles 10a, b, c are provided to the tundish 3 so that a molten metal 4 can be supplied separately to the chambers. Bellows 13 are provided between a supporting frame 12 and the bottom end of skirts 11 to close respectively hermetically the chambers 14a, b, c. Inert gas introducing pipes 16a, b, c provided with control valve 15a, b, c are provided to the hermetic chambers. The molten metal 4 is supplied from the tundish 3 to the respective hermetic chambers and is cast while the internal pressure of the inert gas in each hermetic chamber is controlled by the valves 15a, b, c.

Description

[Detailed description of the invention] [Industrial application field 1 The present invention relates to a continuous casting device for strips.

[Prior art 1 There are various types of devices for continuously spinning metal strips, such as a twin roll type, a bell type, and a caterpillar type. For example, a twin roll type continuous casting device is shown in Fig. 4 and As shown in FIG.

1 is a pair of left and right cooling rolls, 2 is a crusher, 3 is a tandyer l for supplying molten metal 4 to the crusher 2, and the crusher 2 is composed of a barrel seal 2a and a side seal 2b.

The lC molten water supplied from the tundish 13 to the crusher 2 is cooled by the cooling roll 1 rotating in the direction of arrow X, and a solidified shell 5 is formed from the surface side of the C cooling roll 1, and the solidified shell 5 gradually It grows and is pulled out from the top 6 in the direction F, and the strip 7 is cast.

However, in the conventional apparatus, the molten metal 4 is cooled from the central part on the side of the site seal 211 and covered by the hot metal, so that the semi-solidified material 8 abnormally grows on the inner surface of the side seal 2b at the upper part of the roll gap. The semi-solidified material 8 falls off and is rolled into the roll gap 6. Therefore, the semi-solidified material 8
If it gets caught in the roll chute 6, there is a risk that the plate will break or break during casting. Furthermore, since the semi-solidified material 8 is rolled into the roll gap 6, unevenness may occur on the surface of the strip 7, which may result in uneven thickness distribution of the product.

[Problem to be Solved by the Invention 1] The present invention provides a continuous casting device that can prevent plate breaks and plate cracks from occurring during casting and can obtain products with uniform plate thickness distribution. /υ.

[Means for Solving the Problems] The present invention provides an apparatus for pouring molten metal into a mold, cooling it, and continuously casting a strip, in which the moldability) t111 is divided into three or more chambers in the width direction. Each pouring part has a sealed structure, and a tundish and a nozzle are inserted into each pouring part, and an inert gas is introduced into each pouring part so that the internal pressure of each pouring part can be adjusted individually. It is composed of

[Function] Therefore, the pressure applied to the surface of the molten metal can be distributed in the width direction.

[Example] Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

As shown in FIGS. 1 and 2, two sets of intermediate partition plates 2C parallel to the side seals 21) are fixed inside the crusher 2 to form three chambers within the crusher 2. In Tanditsushi 73,
3 so that 1q of molten metal 4 is separately supplied to each chamber in the crusher 2.
Book nozzle 10a.

10b and 10c are provided, and a skirt 11 is provided at a position surrounding each nozzle 10a, 101], 10c on the bottom surface of the tundish 3, and a crushing plate 2 and a partition plate 2C are provided.
A support frame 12 is extended and fixed to the upper end, and a bellows 1 is provided between the support frame 12 and the lower end of the skirt 11.
3 is installed () each room in C1 weir frame 2 is sealed room 14a,
+4b, 14c. Furthermore, each sealed chamber 14a, 14b
.

14c, inert gas introduction pipes 16a, 16b, 16c equipped with control valves 15a, 15b, 15C are introduced through the crusher 2. Note that the same reference numerals as in FIGS. 4 and 5 indicate the same parts.

During casting, from the tundish 3 to the nozzle 10a,
Each sealed chamber 14a in the crushing 2 via 10b, 10c
, 14b, 14c, but at this time, each introduction pipe 16a, 1 is supplied to each sealed chamber 14a, 14b, 14c.
Inert gas is introduced from 6b and 16c, and each control valve 1
5a, 15b.

15c, the internal pressure P1 of the central sealed chamber 14b is
is set higher than the internal pressure P2 of the sealed chambers 14a and 14c at both ends. This is an IC for which the following was found as a result of various experiments conducted by the present inventors.

That is, as shown in Fig. 3, the heat transfer coefficient α (W/m2°C) between the cooling roll and the solidification shell, which is the moving mold C in the vertical chair 11, is
The horizontal axis is the contact time t between the molten metal and the cold 7J][J-ru.
(sec,), if the contact ffEP (ka) of the molten metal to the cooling roll is changed from small to large, the heat transfer coefficient α
The relationship between t and contact time t changes as shown by curves A and t. For the same contact time, the larger the contact pressure, the higher the heat transfer coefficient α
becomes larger. Therefore, if the internal pressure of the sealed chamber 14b is increased, the heat transfer coefficient α between the cooling roll 1 and the solidified shell 5 will increase, and the molten metal 4 will be more easily cooled, and the width direction (axial direction) of the cooling roll 1 will be increased. A solidified shell 5 is uniformly generated.

The molten metal 4 supplied to each closed chamber 14a, 14b, 14c of the crushing 2 is cooled by the cooling roll 1, and a solidified shell 5 is formed from the surface side of the cooling roll 1, and the solidified void 5 gradually grows until the roll It is pulled downward from the gap 6 and the strip plate 7 is cast, but as mentioned above, because the pressure is distributed across the width of the molten metal surface during casting, strips and cracks may occur during casting. Moreover, the thickness distribution of the strip plate 7 becomes uniform.

Further, by introducing an inert gas into each of the sealed chambers 14a, 14b, and 14c, oxidation of the surface of the molten metal 4 is prevented, and the formation of an oxide film is eliminated, further improving product quality.

Incidentally, in the above-described embodiment C, the inside of the crushed portion is divided into three parts, but it is of course possible to divide the inside of the crushed part into three parts or more, and various other changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the continuous casting apparatus of the present invention,
Since there is no breakage or cracking of the plate during casting, there is no risk of line stoppages, which improves production efficiency.Also, the thickness distribution of the plate can be made uniform, and the formation of oxide films can be prevented, so the product can be improved. Excellent effects such as improved quality can be achieved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the continuous casting apparatus of the present invention, and Fig. 2 is an explanatory diagram of the continuous casting apparatus of the present invention.
The ■-■ arrow view in the figure, Figure 3 is a graph showing how the heat transfer coefficient between the cooling roll and the solidified shell changes depending on the contact between the molten metal and the cooling roll or the contact pressure. An explanatory diagram of the conventional device, FIG. 5 is a plan view of FIG. 4. 1 is a cooling roll, 2 is a crusher, 3 is a tanditshi l, 4 is a molten metal, 10a, 10b, 10c is a nostle, 13
is bellows, 14a, 14b, 14c are sealed chambers, 1
5a, 15h. 15c is a control valve, 1 (3a, 16b, 16c is an inert gas introduction pipe.

Claims (1)

[Claims] 1) In a device that pours molten metal into a mold and cools it to continuously cast strips, the mold pouring section is divided into three or more chambers in the width direction, each of which has a sealed structure, and each pouring section is equipped with a tank. A continuous casting apparatus characterized in that a dish nozzle is inserted and an inert gas can be introduced into each pouring section so that the internal pressure of each pouring section can be adjusted.