JPS5816756A - Broadening method for ingot in continuous casting - Google Patents

Abstract

PURPOSE:To prevent breakout accidents such as steel leakage with quick and simple operations by accelerating the cooling of a broadened ingot by the use of a joint of which the lower half part is embedded into the terminal part of the ingot prior to broadening and engaging members engaged therewith. CONSTITUTION:At the point of the time when charging of molten metal is stopped temporarily and the terminal 16 of an ingot 16 is not fully solidified, a metallic joint 7 of a rail shape having an I-type section is embedded in the terminal 16 down to the depth of a stopper 12 by positioning the same in parallel longitudinally with the long sides 2a, b of the mold and horizontally. The solidified shell of the ingot 15 is perfectly formed by the cooling effect of the joint 7 of which the lower half part is embedded in the molten metal. The short sides 1a, b of the mold are moved outward to form clearances between said sides and the ingot 15. Engaging members 17 are mounted in the clearance parts and cooling materials 21 and refractory materials 22 are packed on the bottom plates thereof. After the slide plates 10a, b of the joint 7 are slided toward the short sides 1a, b, the next molten steel 25 is charged into a cavity 3.

Description

DETAILED DESCRIPTION OF THE INVENTION In continuous casting, the width of the mold is expanded while the end of the previous slab is in the mold, so that wider slabs can be successively cast. This invention relates to a method for expanding slab width during casting.

The conventional slab width changing method involves changing the width of the mold after pulling out the slab from the mold, inserting a dummy par, and then starting casting, which results in a large loss of preparation time. For this reason, many methods have been proposed to change the width at one end during casting.

In the slab width expansion method during continuous casting of bent steel,
As a jig to prevent steel from leaking at that time, for example, Japanese Patent Application Laid-Open No. 55-33871 and Japanese Patent Application Laid-Open No. 54-94436
The proposal described in the publication has been completed. Both jigs,
Filling the gap between the enlarged mold and solidified shell (charging coolant)
In the former case, a receiving bottom with a part that engages with the upper edge of the solidified shell is used to support the coolant, and in the latter case, the coolant is supported by the receiving bottom. A closure piece that engages with a joint (steel pipe) embedded in the upper surface of the shell is used to support the coolant.

The objects of the present invention are to further ensure the prevention of wave harmonics between the expanded mold and the solidified shell, to further strengthen the bond between the preceding slab and the succeeding slab, and to The purpose of the present invention is to make it possible to adjust the bonding strength according to the degree of width, and to provide a method and jig for expanding the width of a slab during casting that is simple to operate and completely avoids breakout accidents such as wave harmonics. It is to provide.

The present invention was made for these purposes, and while pouring into a continuous casting mold consisting of a pair of short sides of the mold and a pair of long sides of the mold is temporarily stopped, And the end of the front slab is stationary within the mold.・While moving up and down at Tt, a metal joint with a ■-shaped longitudinal section and a similar rail shape is made so that its longitudinal direction is substantially parallel and horizontal to the long side of the mold, and its lower body is placed within the end of the front slab. After the end of the front slab has solidified, the short mold piece is moved outward, and in the gap between the slab and the short mold piece created by the movement of the short mold piece, an area slightly smaller than the cross section of this gap is created. installing a member having a bottom plate so as to fit into the joint; loading cooling and/or sealing material into the gap on the bottom plate; and then restarting pouring. This is a method for expanding slab width during casting, which is characterized by:

In this case, if the slide plate 1 is attached to the metal joint and the slide plate is moved and operated, the above object can be more advantageously achieved.

The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a plan view showing an example of a continuous casting mold for molten steel to which the present invention is applied, in which a rectangular cavity is formed by a pair of mold short sides 1a and 1b and a pair of mold long sides 2a and 2b. 3, and the short sides 1a and 1b of the mold form the long sides 2a and 2 of the mold.
The width of the slab is changed by the movement of the short sides 1a and 1b of the mold, which can be moved in parallel by the movable members 4a and 4b while sliding on the inner wall of the mold. In the present invention, by using such a continuous casting mold, the width is expanded during casting compared to the previous slab.

FIG. 2 shows an example of the appearance of the joint body according to the present invention. As shown in the figure, the joint body 7 according to the present invention has a rail shape with a type 1 cross section. The material for this joint is preferably substantially the same as the cast metal. city,
It is also possible to use existing rails or Type 1 steel by cutting them to a predetermined length. In any case, the joint body 7 with
is a metal member with a ■-shaped cross section having overhanging parts 8 and 9 extending horizontally upward and downward, and its length -St is shorter than the width of the front slab, but is about 10 cIrL shorter than the width of the front slab. It is best to use a shorter version. The height h is a height that allows sufficient joining of the front slab and the rear slab, and in the case of a normal slab, it is preferably about 15 to 6 ocrn. The width W of the overhanging parts 8 and 9 is narrower than the thickness of the slab, but it is better if it is 4 (7 m) or more shorter than the thickness of the slab.

FIG. 3 shows a state in which two slide plates 10a and 10b are slidably attached to the upper projecting portion δ of the joint main body 7 in FIG. These slide plates 10a and 10b have a length t) of the joint body 7 as shown in FIG.
It is designed to be able to extend beyond. In addition, 3rd to 4th
In the figure, 11a and 11b are slide plates 10.
It is a knob attached to a and 10b, and this knob 1
1a and 11b are used to slide the slide plates 10a and 10b in the mold as shown in FIG. 4, and also serve as suspension metal fittings when the entire joint is installed in the mold. Reference numeral 12 denotes a plate or rod extending horizontally from the middle of the joint body, and is used to accurately perform the embedding operation when embedding the lower half of the joint body in the terminal end of the front slab.

FIG. 5 shows a state in which the lower half of the aforementioned joint is embedded in the terminal end 16 of the front slab 15 existing in the mold, and a locking member 17 is attached to this joint. This IF member 17 has an upper end 18 and a lower end 20 bent in opposite directions, and the upper end 18 has a notch 19 that fits into the side edge of the joint. How this locking member 17 and the joint are used will be described later.

As shown in FIGS. 2 to 5, the method of expanding the slab width during casting according to the present invention is such that the cross section perpendicular to the longitudinal axis is
A joint body 7 having a mold and having a certain length in the horizontal direction (in other words, a direction parallel to the width direction of the slab or the long side of the mold), and a joint body 7 that is slidable in the longitudinal direction. At least one slide plate 10 is added to the joint body 7 so that it can extend to a portion exceeding the length of the joint body 7, and one slide plate 10 whose ends are bent in opposite directions.
This is carried out using a jig consisting of a locking member 17 having a portion 19 at one end that engages with the joint body 7.

Below, steps 6 to 10 of the method of the present invention using this jig will be explained.
Let's explain according to the diagram.

6 and 7 show that the lower half of the joint 7 is inserted into the front slab 15 while the injection of molten steel into the mold is temporarily stopped and the end 16 of the front slab 15 remains in the mold. The stage is shown embedded within the terminal end 16 of. In this case, as shown in the figure, the lower half of the joint 7 is buried in the terminal end 16 with the longitudinal direction of the joint 7 substantially parallel to and substantially horizontal with the long side 2ζ2b of the mold. This embedding operation is performed when the terminal end 16 is incompletely solidified, and the tabs 11a and 11b are used as hanging hardware at that time.

Further, a plate or rod 12 protruding from the mid-abdominal part serves as a positioning and stopper function for accurately embedding the lower body of the joint 7. The dimensions and shape of this joint 7 are as described above, and solidification of the front slab is promoted by embedding the lower half of this joint 7, and after the solidified shell of the front slab is completely formed, the mold short side 1a and 1b is translated outward by a predetermined distance.

FIG. 8 shows an enlarged view of the short sides 1a and 1b of this mold. In the case of this example, the width of the subsequent drawing equipment and other parts is expanded with the shearing machine driven once, so in Fig. 8, the end of the front slab is slightly lowered than in the state shown in Figs. 6 and 7. There is.

The slab 15 produced by the movement of the mold short pieces 1a and 1b
The locking members 17a and 17b are attached to the gap between the two. This locking member 17, as shown in FIG.
It consists of an upper end 18 having a portion 19 that engages with the joint 7 and a lower end 20 serving as a bottom plate. In the illustrated embodiment, this locking member 17 is made of a steel plate whose width is slightly narrower than the thickness of the front slab 15, and when this steel plate is placed along the solidified wall on the shorter side of the front slab 15, it is moved. The bottom plate is formed by bending the lower part horizontally so that it extends near the short side of the slab.
On the other hand, the upper part is bent horizontally to the side opposite to the bottom plate so as to be aligned with the end surface of the front slab, and a notch is provided in the center of the front edge to fit into the thickness of the body of the joint 7. The notch is used as a means for securing the joint 7. By attaching the locking member made of this steel plate to the solidified surface on the short side of the exposed front slab in a fitting relationship with the joint 7, this steel plate itself functions as a coolant, allowing the injection of molten steel. This will also promote coagulation in this area when the treatment is restarted.

As shown in Fig. 5, the dimensions of the bottom plate 20 are as follows: its width Use one that is about 5 to 10 mm smaller than the distance traveled. and,
Above the bottom plate 20, a cooling material 21, 22 is loaded, such as a fine chill material such as a metal cushion material or nail scrap, or a refractory material 21,22. With this, preparations for restarting the injection of the next molten steel are substantially completed, but in order to ensure that the shallow pot is prevented from entering the widened portion, the slide plate 10 is moved to the side of the short side 1 of the mold. Slide it.

FIG. 9 shows a state in which the slide plate 10 is slid toward the short side 1 of the mold.

This sliding operation can be easily performed using the knob 11. As a result, the slide brakes 10a and 10b extend from the joint body at a position above the gap created by the width expansion (above the filling material 21), and when injection is restarted, the gap created by the width expansion cooling of the slide plates 10a and 10b
As a result of the presence of , the shallow pan can be reliably prevented from entering the gap.

FIG. 10 shows the state after restarting the injection of the next molten steel. The next molten steel 25 is the joint body 7, the slide plate 1
0, the locking member 17, the coolant 21, etc. start solidifying at the joint immediately after injection. In particular, in the width enlarged portion, in the embodiment of the locking member 17, this locking member suitably exhibits the effect as a coolant, and together with the coolant 21 and the slid slide plate 10, it works in the gap caused by the width expansion. In addition, the joint body 7 is buried half-by-half along the longitudinal direction of the front slab and the rear slab together with the slide plate 10, so that the molten steel solidifies quickly and reliably. The upper and lower overhangs 8 and 9 (Fig. 2) provide a wedge effect to maintain a strong connection between the front slab and the rear slab, making this joint safe even during extraction. Secured.

Furthermore, when the next injection of molten steel is resumed, the contact area with the front slab is covered by the joint 7, the locking member 17, etc., and solidification occurs quickly, so that the front slab and the rear slab have different compositions. Even in the case of steel types, mixing of components at joints can be effectively prevented.

As described above, according to the present invention, the above-mentioned objects are fully achieved, and the work of setting the jig and filling material into the mold is extremely simple, and accidents such as breakouts can be completely prevented. Width expansion casting was carried out 178 times according to the present invention, during which no accidents such as breakouts occurred, and joint slab loss could be kept to about 500 k19 per joint, and even in joints of different steel types. No mixing of ingredients occurred.

As a result of this operation, the operating rate of the continuous casting equipment was improved by approximately 25 tons compared to the previous width changing operation in which a dummy bar was inserted and injection was restarted.

[Brief explanation of the drawing]

Fig. 1 is a top plan view showing an example of a continuous casting mold to which the present invention is applied, Fig. 2 is a perspective view showing an example of a joint body according to the present invention, and Fig. 3 is a slide plate on the joint body of Fig. 2. FIG. 4 is a perspective view similar to FIG. 3 showing the slide plate in a slid state; FIG. 5 is a perspective view showing the jig according to the present invention attached to the front slab. , Figures 6 to 10 are all cross-sectional views of a mold showing the working procedure of the width expanding method according to the present invention, Figure 6 is a state in which the joint is embedded, and Figure 7 is a cross section taken along the line ■-■ in Figure 6. The same state as Fig. 6, Fig. 8 shows the state with the locking member and coolant installed after the width has been expanded, Fig. 9 shows the state with the slide plate slid, and Fig. 10 shows the state after restarting injection. This is what is shown. 1... Mold short side 2... Mold long side 3... Mold cavity 4... Variable member 7... Joint body 8.9... Overhanging part 10... Slide plate 11... Knob 15... Front slab 17... Locking member 19... Part that engages with the joint 20... Bottom plate 21... Coolant Fig. 6 Fig. 71A 1π 'It Fig. 8 Fig. 9 Figure 10

Claims (1)

[Claims] (I) While pouring into a continuous casting mold consisting of a pair of short sides of the mold and a pair of long sides of the mold is temporarily stopped, and While the end of the piece is stationary or descending into the mold, 1. Take a metal joint with a vertical cross section of ■ shape and resembling a rail shape, with its longitudinal direction substantially parallel and horizontal to the long side of the mold. The lower half of the body is buried in the end of the front slab, and after the end of the front slab has solidified, the short mold piece is moved outward, and this is inserted into the gap between the slab and the short mold piece created by the movement of the short mold piece. A member having a bottom plate having an area slightly smaller than the cross-sectional area of the gap is installed so as to engage with the joint, a material for cooling and/or sealing is loaded into the gap on the bottom plate, and then, A method of expanding slab width in continuous casting, which consists of restarting the hot water. (2) A joint body that has an I-shaped cross section perpendicular to the longitudinal axis and has a length in the horizontal direction, and that is slidable in the longitudinal direction of the joint body and exceeds the length of the joint body. at least one slide plate attached to the joint body so as to be able to extend up to the 4vc joint body; A slab connecting member used in continuous casting slab width expansion method.