JPS59159254A - Belt type continuous casting machine - Google Patents

Abstract

PURPOSE:To obtain a billet having a normal shape by forming hydrostatic bearings in the position opposite to a charging part for a molten metal into a linear shape in a vertical direction and forming the hydrostatic bearings to be disposed below the same into a curved shape. CONSTITUTION:A belt type continuous casting machine has a pair of belts 8, 9 which move and circulate in roughly synchronizing with a billet 12 formed approximately into a rectangular section while cooling and conveying continuously a molten metal 6, a pair of casting molds 11 which maintain the space between the belts 8 and 9, regulate the sectional size of the billet 12 and are disposed on both longitudinal directions of the belts 8, 9 and hydrostatic bearings 13-26 which guide respectively the belts 8, 9. The bearings 13, 20 in the position opposite to the charging part for the molten metal are formed into a linear shape in a vertical direction and the hydrostatic bearings disposed thereunder are formed into a curved shape. The sectional shape of the billet 12 on the molten metal surface is thus made rectangular and the billet 12 having a good shape is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a belt type continuous casting machine for manufacturing slab material, and particularly to its mold structure.

[Prior art]

BACKGROUND ART Conventionally, a continuous casting machine for manufacturing hot strip materials has been constructed with a rectangular mold and a roller guide connected to the rectangular mold. In this method, a thin solidified shell formed in a mold is slidably pulled out from the mold by a guide roller at the bottom of the H shape, so the solidified shell is likely to break and it is difficult to increase the speed.

In order to solve this drawback, a synchronous continuous casting machine was proposed in which a belt is used on the opposing long sides of a rectangular mold, and the solidified shell moves almost synchronously with the belt. It has become possible to achieve speeds several times faster than continuous casting. Furthermore, this type of belt type continuous casting machine is advantageous not only in forming solidified shells in a stable state at the initial stage but also in supporting the static pressure load of molten steel. In other words, a planar hydrostatic pressure bearing is installed on the back of the belt, which not only performs υ cooling but also prevents solidification shells between the rollers that occur when guiding and supporting slabs with conventional rollers. This prevents the phenomenon of bulging due to the static pressure of molten steel, that is, bulging deformation, and enables the production of high-quality products.

In such a belt-type continuous casting machine, it is important to accurately maintain the shape of the mold near the surface of the poured slab, and if this shape is poor, the shape of the cast slab may change. It gets worse after this.

Generally, continuous casting machines are formed into a curved shape to reduce the height of the equipment, and in belt-type continuous casting machines in particular, the belt is supported by hydrostatic pressure bearings, but since tension is applied to the belt on the inside surface of the curve, the belt The belt moves following the hydrostatic pressure bearing, so the belt does not deform.On the other hand, on the curved outer surface, the tension of the belt is supported by the short side of the mold in the direction perpendicular to the hydrostatic pressure bearing, and the belt does not deform due to the static pressure of the molten metal. The static pressure of the molten steel is supported by the hydrostatic bearing only after it increases and overcomes the belt tension.

FIG. 1 is a side sectional view showing the state of upper i1.2, and
The figure is a sectional view taken along the line AA. Measurements have revealed that when tension is applied to the belt 1 on the curved outer surface in FIGS. 1 and 2, this tension is not distributed uniformly in the belt width direction but is concentrated on the contact surface 3 with the short side member 2. Ta. On the other hand, the length a of the contact portion 3 of the short side member 2 with the belt 1 cannot be made too long in order to obtain good contact with the bell l-1, and is usually about 30 mm. ing. Also, when measuring the degree of concentration of tension at the contact area between the curved short side member 2 and the belt 1, it was found that the tension of the belt 1 was
It became clear that the tension was concentrated on a portion approximately twice as large as , and no tension was applied to other portions.

When the width of the belt 1 is assumed to be uniformly loaded on the B1 belt 1, and the unit tension is σfo, the tension σf of the belt 1 in this portion can be calculated using the following equation (1).

Therefore, the belt 1 at the contact portion with the short side member 2 is stretched, and the belt 1 is deformed toward the molten metal 4 as shown in FIG. When the radius of curvature of the mold is 1 and the Young's modulus of the belt 1 is E, the amount of deformation δ can be calculated using the following equation (2).

Here - as an example, σf O=5 to 4/rrrmz
% B = 210 ox9/run2, R = 2500m
++, a==30 rran, and B=1500. In other words, in Fig. 2, the center part of the belt 1 is 7
It is recessed toward the light-phase molten metal 4 side, and has an acute-angled shape near the short side member 2.

When the belt 1 is deformed in this way, the static pressure of the molten steel is close to zero at the surface where the molten metal 4 first solidifies, so the molten metal 4 shown in Figure 2 is shaped into the outer shell of the slab as shown in this figure. As a result, slabs with poor shapes are manufactured.

In addition, the gap between the hydrostatic bearing 5 and the belt 1 becomes a dog,
The amount of cooling water required to cool this portion of the belt increases.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned facts, and provides a belt type continuous casting machine having a mold structure that can obtain fishing pieces of normal shape.

[Summary of the invention]

The present invention consists of a pair of belts that circulate almost in synchronism with the slab to be shaped, a pair of molds for regulating the cross-sectional dimensions of the slab, which are provided on both sides of these belts, and a mold for controlling the cross-sectional dimensions of the slab. In a belt-type continuous casting machine that continuously cools molten metal and forms the cross section into a nearly rectangular shape, the top of the hydrostatic bearing, that is, the molten metal injection part, is placed vertically. The hydrostatic pressure bearing is formed in a straight line in the direction, and the hydrostatic pressure bearing starts curving at a position where the static pressure of the molten steel is large to a certain extent, so as to prevent the deformation of the belt on the outside of the curve and obtain a slab of normal shape. This is what I did.

[Embodiments of the invention]

An embodiment of a belt type continuous casting machine according to the present invention will be described below with reference to the drawings.

FIG. 3 is a side view showing an embodiment of the present invention.

FIG. 4 is a sectional view taken along line B-B in FIG. 3. The molten metal 6 in the tundish 5 is poured into the belt mold at the lower part of the nozzle 7.

As shown in FIG. 4, the bell l-mold is composed of opposing belts 8, 9 on the long sides and sub-moulds 10, 11 on the short sides. The bells I-8 and 9 are supported by a plurality of hydrostatic pressure bearings on their back surfaces, and while the molten metal 6 is poured from the nozzle 7 and the inside of the slab 12 solidifies, the upper static water・Ball bearings 13 to 19, lower hydrostatic pressure bearing 2
0 to 26 are arranged. These hydrostatic bearings 13 to 26
A cooling water supply hole 27 is formed in each of the holes, and cooling water is injected from the supply hole 27 between the surfaces of the belts 8 and 9 and the hydrostatic pressure bearings 13 to 26, and generates fluid resistance pressure along with cooling. It supports the static pressure of molten steel.

Each of these hydrostatic pressure bearings is provided with a roller at the bearing connection end. FIG. 5 is a front view showing the drive mechanism of this roller, in which the rows 228 respectively disposed on hydrostatic pressure bearings 19 and 26 are rotatably supported by bearings 29, and It is designed to be driven by a motor 31.

The hydrostatic bearings 13-19 are mounted on the upper support frame 32.3.
3.34, the hydrostatic pressure bearings 20 to 26 are respectively supported by lower support frames 35 and 36, and 37, and these support frames 32 to 37 are fixed to a frame 38.

The upper belt 8 is pressed against the upper surface of the slab 12 by the fluid pressure injected from the hydrostatic bearing, and is driven by the driving guide rollers 39, 40, 41 and the guide roller 42 in the direction of movement of the slab 12. In addition, it is driven and circulated at approximately the same speed as the slab 12. Like the upper belt 8, the lower belt 9 is also pressed against the lower surface of the piece 12, and is driven by drive guide rollers 43, 44, 45 and guide rollers 46.about.47.

The uppermost hydrostatic bearings 13 and 20 are arranged vertically, and the lower parts 14.15° 16 and 2
1, 22, 23 are arranged in a curved manner, and 17, 18, 19 and 24, 25, 26 are arranged horizontally.

In the embodiment of the present invention configured as described above, if the static pressure of molten steel is P1 depth and H1 specific gravity is r, the static pressure P increases in proportion to the depth H as shown in the following equation (3). do.

P= )−ir・・・・・・
(3) When the tension applied to the belt is applied uniformly in the widthwise direction, the apparent pressure pt generated in the radial direction in Fig. 1 is expressed by the following equation (4). .

p t = Cfo, h/l(,-・1 group=-(4)
However, σto is the unit tension of the belt, h is the thickness of the belt 1,
R is the radius of curvature of the mold.

After the pressures in (3) and (4) become equal, the static pressure of the molten steel overcomes the belt tension, so the depth 1■ of the molten steel when this happens is determined by the following equation (5). Become.

where - as an example h = 1.2 m1ll, r =
7200 Kg/depth 3, σfo = 5 Kf/m
m", R = 2500an, then H = 333 + 1. Therefore, if a vertical part of 333 or more angles is provided at the top of the mold, the deformation of the slab as shown in Fig. 2 will not occur over the entire length of the mold. A slab with a normal shape can be obtained.

In addition, in such a continuous casting machine, slabs with a thickness of 90 mm are
When manufacturing at a high speed of Q m /1 trip+,
Since it takes about 3 minutes to completely solidify the inside of the slab, a section (RI of about 30 m) is required to support the molten steel.

〔Effect of the invention〕

As mentioned above, the JJJ is a belt-type continuous casting system that has a pair of belts that circulate almost synchronously with the slab, a pair of molds that regulate the cross-sectional dimensions of the slab, and a hydrostatic bearing that guides the belt. In this machine, the hydrostatic pressure bearing of the molten metal injection part is formed in a vertical straight line, so the cross-sectional shape of the slab at the surface of the molten metal is almost rectangular, which makes it possible to obtain slabs with a good quality shape. It's large.

[Brief explanation of drawings]

Figure 1 is a side sectional view showing the main parts of a conventional belt type continuous casting machine.
2 is a sectional view taken along the line A-A in FIG. 1, FIG. 3 is a side view showing an embodiment of the belt-type continuous casting machine according to the present invention, and FIG. FIG. 5 is a front view showing the drive mechanism of the roller of the hydrostatic bearing. 1, 8.9... Belt, 2, 10.11... Short side mold, 6... Molten metal, 12... Slab, 13-26...
・Seishui ball calculation 10 20th

Claims (1)

[Claims] 1. A pair of belts move and circulate in almost synchronization with the slab, which continuously cools and conveys the molten metal and shapes the slab into a nearly rectangular cross-section, and a belt that maintains the distance between these belts and regulates the cross-sectional dimensions of the slab. In a belt-type continuous casting machine having a pair of molds disposed in the longitudinal direction on both sides of these belts and hydrostatic pressure bearings that guide each of the belts, the hydrostatic pressure bearings are placed at positions corresponding to the molten metal injection part. A belt-type continuous casting machine characterized by having a vertical straight line and a hydrostatic pressure bearing disposed below the belt having a curved shape.