JPH01180754A - Method and apparatus for continuously casting strip - Google Patents

Abstract

PURPOSE:To uniformize the quality of a cast strip and to improve the yield by arranging as facing endless metallic belts shifting while circulating between rollers, arranging the similar metallic belts at the bottom part and executing continuous casting in the U-shaped casting space. CONSTITUTION:The metallic belts 1, 1 forming side wall are arranged while parting the interval and shifted while circulating with rollers 2, 2'. Belt supporting rollers 3 and nozzles 4 for cooling are arranged at back face of the belts 1 between the rollers 2, 2', respectively. Further, the metallic belts 5 and driving rollers 6, 6' are arranged at the bottom part of the casting space over the prescribed range and the rolls 7 and the nozzles 8 are arranged at the back face of the upper side belt. By this method, at the time of continuously casting the cast strip A, as the height of the molten steel is sufficiently obtd., impurity is floated and the quality of the cast slab is uniformized. Further, as the development of defect in the cast slab is reduced, the yield is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for continuously manufacturing thin cast slabs and an improvement in the apparatus used therein.

(Prior art) In recent years, in order to omit the hot rolling process as much as possible,
The following methods of directly casting thin slabs have been studied, one of which is a method using a twin-belt continuous casting device (Japanese Patent Laid-Open No. 61-253150, etc.).

The method using this twin-belt continuous casting device involves arranging endless metal belts, which are circulated by drive rollers, vertically facing each other with a predetermined interval between them. A casting space is formed by providing a dam block that is held between the dam blocks and circulates along with the metal belt, and molten steel is supplied to this casting space, and the supplied molten steel is cooled and sequentially solidified to form a thin slab. .

(Problems to be Solved by the Invention) According to the method using the twin-belt continuous casting apparatus described above, it is possible to continuously produce thin slabs with a thickness of 50 mm or less, which is the intended purpose. According to research and experiments conducted by the present inventor, it has been found that the following problems exist.

■ Since the twin belt type continuous casting equipment has metal belts arranged vertically facing each other, there is no height of molten steel, and therefore impurities cannot be floated up. Therefore, it is not suitable for improving quality.

■ With twin-belt continuous casting equipment, the thickness of the slab can be changed by changing the spacing between the metal belts.
The width of the slab cannot be changed.

The present invention aims to provide a method for continuously casting thin slabs and an apparatus for use in the method that can solve these problems.

(Means for Solving the Problems) A first aspect of the present invention is to arrange endless metal belts that circulate between rollers in a facing manner, and also to provide similar support within a required area at the bottom of these metal belts. A continuous process of thin slabs in which a metal belt is arranged to form a casting space with a cross-sectional opening, and molten steel is supplied from the upstream side of this casting space to continuously produce F# slabs. This is a casting method.

The second aspect of the present invention also provides endless metal belts arranged vertically to form a casting space having a U-shaped cross section, metal belts arranged within a required area at the bottom of these metal belts, and A pair of rollers that circulate and move each metal belt, and a cooling nozzle group that cools the rollers from the back side thereof;
The gist includes a water-cooled mold installed upstream of the casting space, and a pinch roller group and a secondary cooling zone installed downstream of the casting space formed by the metal belt. This is a continuous casting device for thin slabs.

(Function) The present invention provides endless metal belts that are arranged vertically to form a casting space with a U-shaped cross section, metal belts that are arranged within a required area at the bottom of these metal belts, and A pair of rollers that circulate and move each metal belt, a group of cooling nozzles that cool the metal belts from their back surfaces, a water-cooled mold that stands upright on the upstream side of the casting space, and a downstream side of the casting space formed by the metal belts. This is a continuous casting device for thin slabs, which is equipped with a group of pinch rollers and a secondary cooling zone, and a method for continuously casting thin slabs using this device. As a result, the height of the molten steel is sufficiently high, which allows impurities to float to the surface. Furthermore, according to the present invention, not only the thickness but also the width of the slab can be easily changed.

(Example) The present invention will be described below based on an example shown in the accompanying drawings.

In the drawings, ■, 1 is an endless metal belt that is placed vertically facing each other at a required interval to form a side wall, and is shown by an arrow in FIG. 1 (A) by a roller 2.2°. It is designed to move circularly in the direction. A plurality of belt support rolls 3 are disposed on the back side of the metal belt 1 on the opposite side between the rollers 2.2° for reinforcing the metal belt 1 and rolling the slab A to be cast. .

Further, a cooling nozzle 4 is interposed between these belt support rolls 3.3 and between the belt support roll 3 and the roller 2 or 2° to cool the slab A and the metal belt 1.

Reference numeral 5 denotes the metal belt 1 which is arranged upright to form a side wall.
．． This metal belt 5 is an endless metal belt disposed at the bottom of the required upstream region of the metal belt 1, that is, the region until the lower part of the supplied molten steel B solidifies. As shown by the arrows in FIG. 1(B), the belt support roll 7 and a plurality of cooling nozzles 8 are arranged alternately on the upper back surface thereof.

9 is a water-cooled mold installed at the bottom of the downstream row region of the metal belt 1.1 following the metal belt 5;
The metal bells 1.1 and 5 or the metal belts 1 and 1 and the water-cooled mold 9 form a casting space with a U-shaped cross section.

10 is a water-cooled mold installed upstream of the casting space formed by the metal belts 1.1 and 5, and a sliding nozzle and a casting nozzle 12
is supplied to the casting space through? It serves as a weir to prevent 8 Steel B from flowing out from the upstream end.

Reference numeral 13 denotes a pinch roll installed downstream of the casting space formed by the metal belt 1.1.5 and the water-cooled mold 9, and the pinch roll 13 is a pinch roll installed downstream of the casting space formed by the metal belt 1.1.5 and the water-cooled mold 9. The rollers are sequentially pulled out and rolled while being cooled by a cooling nozzle 14 interposed between these pinch rolls 13, and there are driven and non-driven types.

Reference numeral 15 denotes a lower roll disposed below the pinch roll 13 to support the slab A pulled out by the pinch roll 13, and a cooling nozzle 16 is also interposed between these lower rolls 15.

The continuous casting device for thin slabs according to the present invention has the above-mentioned configuration, and a method for manufacturing thin slabs using this continuous casting device will be described next.

First, a dummy bar is installed at a predetermined position on the downstream side of the metal belt 5, and molten steel B is poured into the space surrounded by the metal belts 1.1 and 5, the water-cooled mold 10, and the dummy bar through the casting nozzle 12 from the tan-dish 1). Pour hot water.

Then, both sides and the bottom surface layer of the poured molten f4B are cooled by the cooling medium from the cooling nozzles 4.8 disposed on the back surfaces of the metal belts 1.1 and 5, and solidified to the required thickness. At this point, the slab A, whose surface layer has solidified, is pulled out downstream through the dummy bar, and is further cooled by the cooling nozzle 4, the water cooling mold 9, and the cooling nozzle 14 forming a secondary cooling zone. At the same time, the belt support roll 3 and pinch rolls 13 are used to continuously roll the cast material to a desired thickness to produce a thin slab. At this time, the amount of molten steel B supplied from the tundish 1) and the drawing speed of the slab A are the same as in the conventional twin belt type continuous casting apparatus.

By the way, in the present invention, thin slabs are continuously manufactured in the above-mentioned order, and by controlling the cooling intensity during casting and sequentially solidifying the slab A from the lower part, the thin slabs A are solidified in the steel bath. Contaminated Sing and ^1. Impurities such as O1 rise and can be aggregated at the top of the slab, improving product quality and yield.

Further, according to the present invention, the thickness of the thin cast slab to be produced can be easily adjusted by adjusting the interval between the metal belts 1.1 which are arranged vertically in a facing manner. Note that when adjusting this interval, it is difficult to replace or change the width of the water-cooled mold 10, so in this embodiment, the upstream side of the metal belt 1.1 is A method is adopted in which the water-cooled mold 10 is moved back and forth in accordance with the adjustment of the opening by setting the mold in an open state with a required slope.

Furthermore, according to the present invention, when changing the width of the thin slab to be manufactured, it is possible to easily change the casting height by adjusting the amount of poured metal from the tundish 1) and the drawing speed. .

By the way, according to the present invention, 3.47
ON/min molten steel is poured into the casting space and pulled out at 15 m/sec to produce 20 thin slabs of uniform quality with a width of 950 mm and a thickness of 30 m.
TONi! ! could be manufactured continuously.

In this embodiment, the metal belt 5 is disposed only in a required area on the upstream side of the metal belt 1.1, but it may be provided in the same area as the metal belts 1 and 1.

(Effects of the Invention) As explained above, the present invention provides endless metal belts that are arranged vertically to form a casting space having a U-shaped cross section, and endless metal belts that are arranged within a required area at the bottom of these metal belts. a pair of rollers that circulate and move each of these metal belts, a cooling nozzle group that cools from the back side thereof, a water-cooled mold that stands upright on the upstream side of the casting space, and the metal belt. This is a continuous casting device for thin slabs, which is equipped with a pinch roller group and a secondary cooling zone, which are installed downstream of a casting space, and a method for continuously casting thin slabs using this device. Because width casting is carried out in the horizontal direction, the height of the molten steel is sufficient, which allows impurities to float to the surface, and thin slabs of uniform quality can be produced at a high yield.

Furthermore, according to the present invention, not only the thickness but also the width of the slab can be easily changed during the casting process, which is an extremely effective invention that can solve all of the problems that existed in the conventional continuous casting of thin slabs. .

[Brief explanation of the drawing]

FIG. 1(A) is a plan view of the device of the present invention, and FIG. 1(B) is a rolling view of FIG. 1(A). 1.5 is a metal belt, 2.2゛, 6.6° are rollers, l
O is a water-cooled mold, 13 is a pinch roll, 14.16 is a cooling nozzle, and 5 is a lower roll. Patent applicant: Sumitomo Metal Industries, Ltd.

Claims (2)

[Claims] (1) Endless metal belts that circulate between the rollers are placed in a standing arrangement facing each other, and a similar metal belt is also placed in a required area at the bottom of these metal belts to create a casting space with a U-shaped cross section. 1. A continuous casting method for thin slabs, characterized in that the thin slabs are continuously produced by forming a casting space and supplying molten metal from the upstream side of the casting space. (2) Endless metal belts arranged vertically to form a casting space with a U-shaped cross section, metal belts arranged within a required area at the bottom of these metal belts, and each of these metal belts. A cooling nozzle group that cools a pair of rollers that circulate and move from the back side thereof, a water-cooled mold that is installed upstream of the casting space, and a water-cooled mold that is installed downstream of the casting space that is formed by the metal belt. 1. A continuous casting apparatus for thin slabs, characterized in that the apparatus is equipped with a group of pinch rollers and a secondary cooling zone.