JPS62270257A - Apparatus for producing continuously rulled stock for metal sheet - Google Patents

Abstract

PURPOSE:To obtain a rolled stock for metal sheet having uniform thickness and good flatness at high efficiency by dividing roll group for rolling reduction apparatus into a rolling reduction zone and a parallel zone, shifting two zones as synchronizing and also continuing the pass line of the roll group for the rolling reduction zone by smooth curved face. CONSTITUTION:The rolling reduction apparatus 5 is composed of plural upper and lower roll groups 8i, 9i and the roll group 9i for the lower side of cast slab is arranged on a lower roll frame 7, so as to make the pass line a straight line. The roll group 8i for the upper side of case slab is divided into the rolling reduction zone A at the front stage and the parallel zone B. The roll group 8Bi of the parallel zone B is arranged on the parallel zone frame 11, so as to become always the same level as the end roll 8A7 of the roll group for the rolling reduction zone A and also the linear pass line. The rolling reduction zone frame 10 and the parallel zone frame 11 are constituted, so as to shift always as synchronizing according to the cast slab size.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention is a method for producing wide thin slabs that are continuously cast by a thin slab continuous casting machine such as a twin belt caster. The present invention relates to an apparatus for continuously rolling down a rolled metal sheet material with good flatness.

[Prior art and its problems]

There are twin belt casting methods, twill roll casting methods, etc. for casting wide thin slabs, and in recent years, the twin belt continuous casting method shown in Fig. 1 has been put into practical use not only for non-ferrous metals but also for ferrous metals. However, when a cast slab is used as a rolling material as it is, the slab itself is thin to begin with, so even slight unevenness in wall thickness may cause the slab to be rolled using a conventional continuous casting machine (for example, a slab with a wall thickness of 150 to 2,501 mm). ) has a greater influence on the uniformity and flatness of the wall thickness in the final rolled product, and making the wall thickness of the slab material uniform has been a very important issue.

On the other hand, wide thin slabs manufactured rapidly and stably using the twin-belt continuous casting method are simply lightly rolled in the next process, without the need for large-scale preliminary processing such as hot rolling or hot forging. The production of rolled metal sheets with good flatness at high efficiency and low cost is extremely effective in terms of labor and energy savings, and related industries are working hard to develop this type of continuous casting technology. This is what we are currently focusing on.

In addition, in a continuous casting machine, making the thickness of the slab unnecessarily thinner, for example, in the case of a twin belt type continuous casting machine,
The growth of the solidified shell of the slab tends to be uneven due to the influence of the flow of hot water from the hot water heater (and also has a negative effect on the surface properties of the slab. Furthermore, in terms of productivity, if the thickness of the slab is reduced, It is necessary to increase the minute casting speed, but current casting technology has its limits; for example, in the case of steel, the maximum casting speed is 15 m/min.
It is about min. Therefore, in order to satisfy these requirements, a thin slab with a thickness of about 40 to 50 nm must be used at a maximum of j5
Casting is performed at a speed of m/min or less.

From the above-mentioned viewpoints, the present inventors have proposed that in the twin-belt continuous casting method, the next step after continuous casting is just light rolling, omitting the large preliminary processing step, and achieving good flatness and workability. We have developed a method for manufacturing rolled thin sheets with high efficiency and low cost, and have already filed an application (Japanese Patent Application Laid-Open No. 1983-1999).
No. 87904@).

An object of the present invention is to provide an apparatus for effectively implementing such a method.

[Means for solving problems]

The apparatus according to the present invention continuously reduces thin slabs having an internal unsolidified layer on the downstream side of a twin-belt type or twin roll type continuous casting machine for thin slabs to form a metal with good flatness. This is an apparatus for manufacturing thin plate rolled material, and the rolling device roll group is divided into a rolling zone at the front stage where the solidified slab shell is rolled down and a parallel zone at the rear stage where the thickness of the slab after rolling is stabilized. There is no K so that the frame in the zone and the parallel zone move forward and backward in synchronization with the slab, and the roll group in the rolling zone is set so that the thickness before rolling of the slab and the thickness after rolling are continuous on a smooth curved surface. By arranging them along pass lines, it is possible to produce rolled thin sheets with uniform wall thickness and good flatness with high efficiency and at low cost.

〔Example〕

The present invention will be described below based on an illustrated embodiment.

This is an example using a twin belt caster 3 as shown in Fig. 1. This twin belt caster 3 is an endless bell (3B) that is forcibly cooled from the inside while rotating and moving by the rotation of the upper and lower pulleys 3A. A mold is formed from dam blocks (not shown) that move in synchronization with the endless belt and form left and right side walls, and molten metal M is cast from the tundish 1 and the water heater 2 into the mold. The molten metal M that is configured and cast is an endless bell)
It moves together with 3B and is cooled, and is pulled out by pinch rolls 6 while forming a solidified shell S.

In such equipment, the rolling down device 5 according to the present invention,
It is disposed on the downstream side of the twin belt caster 3 via a slab support roll group 4, and as shown in Figures 1-2, continuously rolls down a thin slab sb having an unsolidified layer S' inside.

This rolling down device 5 has a large number of upper and lower roll groups 8.

The roll group 91 on the lower surface side of the slab is arranged on the lower roll frame 7 so that the pass line is a straight line, and the roll group 81 on the upper surface side of the slab is a roll group 91 in the previous stage that rolls down the solidified slab S. It is divided into a reduction zone A and a subsequent parallel zone B that stabilizes the thickness of the slab after reduction.

The roll group 8Ai of the rolling zone A is arranged in the rolling zone frame 10 on a pass line such that the thickness To of the slab sb before rolling and the thickness T1 after rolling are continuous on a smooth curved surface.

For example, as shown in Figure 2, this path line is formed from two circular arcs with radii of curvature Rl + R2 whose centers are in one opposite direction.

Here, this radius of curvature R is set so that the amount of bending strain ε1 on the inner surface of the solidified shell, calculated by equation (1), is below the limit value that causes serious defects such as internal cracks in the slab. be done.

The roll group 8B1 of the parallel zone B is always at the same level as the final roll 8A7 of the roll group of the rolling zone A, and the pass line is straight, so that a parallel zone to' or a slight unsolidified layer remains. It is most desirable to have a rolling reduction condition of a certain degree.

This means that when the solidified shell S of flow tO' is rolled down until it is completely crimped, the thickness of the slab becomes unconditionally Kto.

This is to prevent the slab thickness TI after rolling from becoming non-uniform in the case where the solidified shell S is determined to be to' and the solidified shell thickness is non-uniform.

In addition, if the casting speed is too high and the unsolidified portion extends beyond the last roll 3B4 in the parallel zone B, an upper roll will be required to suppress the bulging of the slab even after the parallel zone B, which is unfavorable in terms of equipment cost. .

Next, as shown in Fig. 5 to Fig. 5, the reduction zone frame 10 and the parallel zone frame 11 are configured to always move forward and backward in synchronization with the slab, and are designed to achieve a solidified shell thicker than a predetermined solidified shell thickness. When the shell is rolled down, the roll gap widens to avoid damage to the equipment, and
The structure is such that the thickness does not become uneven in the width direction of the slab due to twisting of the frame, etc.

That is, the upstream side of the rolling down zone frame 10 is connected via a support bracket 13 provided on a support pedestal 12 so as to be rotatable around point a, and the downstream side is connected to a screw down jack 14 installed on the support pedestal 12. The center of the rolling jack 14, the damper 15, and the final roll 8A of the rolling zone A are arranged substantially in a straight line.

Further, a tuning shaft 16 that crosses the frame width direction is rotatably attached to the reduction zone frame 10 via a bush 16A, and binions 17 are attached to both ends of the tuning shaft 16.
is installed.

A pair of binions 17 are respectively engaged with racks 18 provided on the legs of the support frame 12, and when the rolling zone frame 10 performs a rotational movement about point a by raising and lowering the rolling jack 14, The torsional rigidity of the tuning shaft 16 is used to compensate for tilting in the direction. Such a widthwise tuning mechanism prevents the occurrence of uneven thickness in the widthwise direction of the slab.

The upstream side of the parallel zone frame 11 is pin-coupled to the common bracket of the reduction zone frame 10 via a pair of left and right connecting arms 19 .

This bottle connection point is also designed to be located on the center line of the aforementioned screw down jack 14, etc.

Here, compared to the rotation radius from the rotation center point a to the reduction blade point, the reduction stroke 3=T, -'r.

is very small, and the loss of position at point b in the longitudinal direction of the slab due to rotation is so active that it can be removed by the can master. It can be considered to be within the plane.

The downstream side of the parallel zone frame 11, like the downstream side of the rolling zone frame 10, is supported by a rolling jack 2] via a damper η.

The screw down jacks 14 and 21 are connected by a connecting shaft η, and are always moved up and down with the same stroke by the screw down drive motor 24. Therefore, the parallel zone frame 11 always moves up and down together with the rolling zone frame 10, and also moves up and down parallel to the pass line of the lower roll group 91.

The dampers 15 and 22 are the lowering jacks 14 and 21.
This is a relief mechanism for the reduction stroke of the reduction stroke, and if the solidified shell thickness exceeds a predetermined value due to some trouble during casting, an excessive force will be applied than the reduction capacity of the reduction jack. This is provided to prevent damage to the device.

Therefore, the safety valve pressure setting value P of the dampers 15 and 22 is Fs+Fm<P-A (Fa-...-(2), however, F8: Rolling force on both sides of the solidified shell Fm: Overhanging force due to molten metal static pressure Fa: Mini reduction jack load rating A: Set to satisfy the cylinder cross-sectional area of the damper.

In the above configuration, the operation is as follows.

(i) The slab Sb, which is supplied from the hot water supply device 2 to the twin belt caster 3 and starts to solidify from the outer periphery, passes through the slab support roll group 4 and is rolled down with unsolidified molten metal S' remaining inside. The slab is continuously transferred to the device 5, but at the start of casting, the tip end 1. and the dummy bar 5 must be connected with sufficient strength, and since the inside of the slab is completely solidified at a low casting speed, this part cannot be rolled down by the capabilities of the rolling down jacks 14 and 21.

(ii) Therefore, after starting casting, gradually increase the casting speed, and after the tip has passed, the rolling drive motor 2
4 to start rolling down the slab Sb.

At this time, since the thickness tQ + tO of the solidified shell S of the slab varies depending on the casting conditions and the cooling conditions, the casting conditions are set in advance so as to have a predetermined thickness.

Furthermore, in the final roll 8Ay of the reduction zone A, as mentioned above, T, ? The rolling conditions are set to to+t♂ or such that a slight unsolidified layer remains.

(iii) The solidified shell on the upper surface side of the slab is curved along the roll pass line of the reduction zone A with a smooth curved surface.

The force required for rolling at this time is the resultant force of the force rolling both sides of the solidified shell S and the force opposing the static pressure of the molten metal acting on the remaining molten metal. Unlike the conventional method, the pulling torque of the pinch rolls 6 required for pulling out the slab is greatly reduced, and the pulling torque of the pinch rolls 6 does not require a large capacity.

GV) At the initial stage of cutting, if the casting speed does not reach the steady value and the solidified shell thickness of the slab is thicker than the planned value, or during steady pouring, the cooling capacity of the slab may be affected due to rotational trouble. Other casting conditions vary, and the thickness of the solidified shell changes accordingly. If it becomes thicker than the planned value, the roll group 81 in the reduction zone and parallel zone will be pushed up by the slab Sb. All of the thickness displacement is absorbed by the damper 15.22.

(v) To prevent the amount of reduction in the width direction from varying due to elastic torsion of the reduction zone frame 100, etc. due to uneven thickness of the solidified shell in the width direction or uneven thickness of the short side; A binion 17, a rank 18, and a tuning shaft I6 are provided, and since the rolling zone frame 0 is always not twisted, the slab after rolling has a uniform thickness in the width direction.

(vil) The upstream support point of the parallel zone frame 11 is at the same distance iL as the reduction amount jack 14, etc. with respect to the support point a of the reduction zone frame 10, and the lower
Since the one-way rack C is supported on the vertical line via the damper η by the rolling jack 21 that moves up and down with the jack 14, the roll group 8B in the parallel zone B
i can move up and down parallel to the pass line of the lower roll group 91.

Although the twin belt caster has been described above, the present invention is not limited to this, but can also be applied to continuous casters for wide thin slabs such as twin roll continuous casters and belt/casting wheel continuous casters (rotary casters). Needless to say, it is applicable.

Furthermore, although we have shown an example in which the upper roll group is provided with a reduction zone and a parallel zone, the lower roll group or the upper roll group
The present invention also includes providing both lower roll groups with a reduction zone and a parallel zone.

〔Effect of the invention〕

As described above, according to the present invention, the rolling device roll group is divided into a rolling zone and a parallel zone, and the rolling zone and parallel zone are moved in synchrony, and the pass line of the roll group in the rolling zone is Since it is configured to have a continuous clear curved surface, a rolled thin plate material with uniform wall thickness and good flatness can be manufactured with high efficiency and at low cost.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of continuous casting equipment for thin slabs according to the present invention, Fig. 2 is a partially enlarged view of Fig. 1, Fig. 3, and Fig. 4.
FIG. 5 is a front view, a view taken along the line T in FIG. 1... Tanditshu, 2... Water heater, 3... Twin belt casters, 3A...
...F IJ-13B... Endless belt, 4.
... Slab support roll group, 5 ... Reduction device, 6 ... Vinci roll, 7 ... Lower roll frame, 8Ai ... Reduction Thor 70-
A/R, 8Bi...Parallel saw roll group, 91
...Lower roll group, 10... Rolling down zone frame, 11... Parallel zone frame, 12
......Support frame, 13...Support bracket, 14...Screwing jack, 15...
・Damper, 16... Tuning axis, 17...
・Binion, 18... Rack, 19...
・Connection arm, addition...Common bracket, 21
・・・・・・Jacket for rolling down, η・・・・・・Damper, Connection shaft, U: White: Drive motor for rolling down.

Claims (1)

[Claims] (1) A thin slab continuous caster that manufactures thin slabs is placed on the downstream side of the thin slab continuous caster, and thin slabs having an unsolidified layer inside are continuously cast and moved by the thin slab continuous caster. , is an apparatus for manufacturing thin metal sheet rolled material with good flatness by continuous rolling, and the rolling device roll group is divided into a rolling zone in the previous stage where the solidified slab shell is rolled down and a thickness of the slab after rolling. The rolling zone and the frame of the parallel zone move forward and backward in synchronization with the slab, and the roll group in the rolling zone is adjusted to the thickness before rolling of the slab. 1. An apparatus for continuously manufacturing rolled metal sheets, characterized in that the rolled metal sheets are arranged in pass lines such that the thickness after rolling is continuous on a smooth curved surface.