JPH078420B2 - Equipment for continuous production of rolled thin metal sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention continuously flattens wide flat thin cast pieces continuously cast by a thin cast continuous casting machine such as a twin belt caster. The present invention relates to an apparatus for producing a rolled metal thin plate having a good degree.

[Prior art and its problems]

Twin belt type, twin roll type, etc. are available as casting means for wide and thin slabs. In recent years, the twin belt type continuous casting method as shown in Fig. 1 has been put to practical use not only for non-ferrous metals but also for ferrous metals. However, when the cast slab is used as it is as a rolled material, the slab itself is originally thin, so even if there is a slight unevenness in wall thickness, a slab produced by a conventional continuous casting machine (for example, wall thickness 150 to 250 mm ) Has a greater effect on the thickness uniformity and flatness of the final rolled product,
Uniformization of the wall thickness of the slab material has been a very important issue.

On the other hand, large-width thin slabs produced by the twin-belt continuous casting method at high speed and stably are subjected to large preliminary processing such as hot rolling and hot forging simply by light rolling in the next step. It is extremely effective in labor saving and energy saving to produce a rolled metal sheet material with good flatness at high efficiency without cost, and in related industries, this type of continuous casting technology is used. Currently, we are focusing on development.

In the continuous casting machine, reducing the thickness of the slab more than necessary is, for example, in the case of a twin belt type continuous casting machine,
Due to the influence of the hot water supply flow from the hot water supply device, the growth of the solidified shell of the slab tends to be non-uniform, and the surface properties of the slab are also adversely affected. Furthermore, in terms of productivity, if the thickness of the slab is reduced, it is necessary to increase the casting speed by that amount, but there is a limit in the current casting technology, and for example, in the case of steel, maximum 15 m / mi
It is about n. Therefore, in order to satisfy these requirements, a thin slab with a slab thickness of about 40 to 50 mm is cast at a speed of 15 m / min or less at the maximum.

From the viewpoints as described above, the inventors of the present invention, in the twin-belt type continuous casting method, simply perform light rolling as it is in the next step of the continuous casting machine, omit the large preliminary processing step, and have good flatness, We have developed a method for manufacturing a rolled sheet material with good workability with high efficiency and low cost, and have already applied for it (Japanese Patent Application Laid-Open No. Sho 60-96).
60-87904).

The present invention aims to provide an apparatus for effectively implementing such a method.

[Means for solving problems]

The apparatus according to the present invention is a twin-belt type or twin-roll type thin slab continuous casting machine on the downstream side, continuously squeezing a thin slab having an unsolidified layer inside to obtain a good flatness. An apparatus for producing a rolled thin metal sheet, wherein the rolling apparatus roll group is divided into a rolling zone in the former stage for rolling down the solidified shell of the slab and a parallel zone in the latter stage for stabilizing the thickness of the slab after rolling, The frames of the reduction zone and the parallel zone are connected to each other, and these frames are moved in and out in a direction orthogonal to the moving direction of the slab in synchronization with the slab.

〔Example〕

Hereinafter, the present invention will be described based on an illustrated embodiment.

This is a twin belt caster 3 as shown in Figs.
This is an example of using the twin belt caster 3
A mold is formed from an endless belt 3B that is forcibly cooled from the inner surface side while rotating by the rotation of the upper and lower pulleys 3A, and a dam block (not shown) that moves in synchronization with the endless belt and forms left and right sidewalls. Then, the molten metal M that is constructed by casting the molten metal M from the tundish 1 and the water heater 2 into such a mold is an endless belt.
It moves together with 3B, is cooled, and is pulled out by the pinch roll 6 while forming the solidified shell S.

In such equipment, the reduction device 5 according to the present invention is
The thin slab Sb, which is arranged downstream of the twin belt caster 3 via the slab support roll group 4 and has the unsolidified layer S ′ therein, is continuously pressed as shown in FIG.

This reduction device 5 is composed of a large number of upper and lower roll groups 8Ai, 8Bi, 9i. The roll group 9i on the lower surface side of the slab is arranged on the lower roll frame 7 so that the pass line becomes a straight line, and the rolls on the upper surface side of the slab are arranged. The groups 8Ai and 8Bi are divided into a front-stage reduction zone A for reducing the solidified shell S of the slab and a parallel zone B in the rear stage for stabilizing the thickness of the slab after the reduction.

The roll group 8Ai in the reduction zone A has a thickness T of the slab Sb before reduction.
Arranged in the reduction zone frame 10 are pass lines such that ₀ and the thickness T ₁ after reduction are continuous on a smooth curved surface.

For example, this pass line is formed by two arcs having radii of curvature R ₁ and R ₂ whose centers are opposite to each other, as shown in FIG.

Here, the radius of curvature R is set so that the bending strain amount εi on the inner surface of the solidified shell calculated by the equation (1) is equal to or less than a limit value that causes a serious defect such as internal cracking of the slab. It

However, t: thickness of solidified shell The roll group 8Bi in the parallel zone B is arranged in the parallel zone frame 11 so that it is always at the same level as the final roll 8A ₇ of the roll group in the reduction zone A and has a linear pass line. ing.

The final roll 8A _{7 in the} reduction zone A is the required cast piece thickness T after reduction.
_{For 1} , T ₁ ≈t ₀ + t ₀ ′ or slightly unsolidified layer S ′
It is most desirable that the rolling condition be such that the residual amount remains.
(T ₀ and t ₀ ′ represent the upper and lower solidified shell thicknesses at the position of the final roll 8A ₇ ) until the solidified shell S of t ₀ and t ₀ ′ is completely pressed. When the thickness is reduced, the thickness of the cast piece is unconditionally determined to be the solidified shell S of t ₀ and t ₀ ′, and when a non-uniform solidified shell thickness occurs,
This is to prevent nonuniformity up to the cast piece thickness T ₁ after reduction.

Also, the casting speed is too high and the final roll in parallel zone B
When unsolidified portion extends 8B ₄ after the upper roll for pressing the bulging of the slab also is required for parallel zone after B, equipment cost is undesirable.

Next, as shown in FIGS. 3 to 5, the reduction zone frame 10 and the parallel zone frame 11 move forward and backward in a direction orthogonal to the moving direction of the slab, that is, in the vertical direction, always in synchronization with the slab. When a solidified shell thicker than a predetermined solidified shell thickness is pressed down, the roll gear cup is expanded so as not to damage the device, and further, the thickness is not uniform in the slab width direction due to twisting of the frame. It is configured so that it is not uniform.

That is, the upstream side of the reduction zone frame 10 is a support frame.
A support bracket 13 provided on 12 is pin-connected so as to be rotatable about a point a, and a downstream side is supported by a reduction jack 14 installed on a support frame 12 via a damper 15 for reduction. The centers of the jack 14, the damper 15 and the final roll 8A _{7 in} the rolling-down zone A are arranged on a substantially straight line.

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

The pair of pinions 17 are respectively meshed with the racks 18 provided on the legs of the support base 12, and when the reduction zone frame 10 makes a rotational movement about the point a by the elevation of the reduction jack 14, the width direction The torsional rigidity of the tuning shaft 16 is compensated so that it does not tilt at. Such a width-direction tuning mechanism prevents uneven thickness in the width direction of the slab.

The upstream side of the parallel zone frame 11 is pin-connected to the common bracket 20 of the reduction zone frame 10 via a pair of left and right connecting arms 19. This pin connection point b is also considered to be located on the center line of the above-described reduction jack 14 or the like.

Here, the turning radius L from the turning center point a to the rolling force point b
Compared with the above, the rolling stroke = T ₀ -T ₁ is very small, and the displacement of the point b in the longitudinal direction of the slab due to the rotation is negligibly small. The rolling jack 14, the damper 15, the final roll 8
It can be considered that A ₇ and the pin connection point b are always in the same plane.

The downstream side of the parallel zone frame 11 is a reduction zone frame.
As with the downstream side of 10
Is supported through.

The reduction jacks 14 and 21 are connected by a connection shaft 23, and are always moved up and down with the same stroke by a reduction drive motor 24. Therefore, the parallel zone frame 11 always moves up and down together with the reduction zone frame 10 and moves up and down in parallel with the pass line of the lower roll group 9i.

The dampers 15 and 22 function as relief mechanisms for the reduction strokes of the reduction jacks 14 and 21, and when the solidified shell thickness exceeds a specified value due to some trouble during casting, it is used for reduction. It is provided in order to prevent damage to the device due to an excessive force acting on the jacking force.

Therefore, the safety valve pressure set value P of the dampers 15 and 22 is F _S + Fm <P · A <Fa (2) where F _S : Rolling force on both sides of the solidified shell Fm: Overhanging force due to static pressure of molten metal Fa: Rated load of reduction jack A: It is set to satisfy the cylinder cross-sectional area of the damper.

The above-described structure operates as follows.

(I) The slab Sb that has been supplied with hot water from the water heater 2 to the twin-belt caster 3 and has started to solidify from the outer periphery passes through the slab support roll group 4 with the unsolidified molten layer S ′ remaining inside. , The slab tip ₁₀ and the dummy bar 25 need to be connected with sufficient strength at the start of casting, and the slab is completely transferred to the inside of the slab at a low casting speed. Since it has solidified, this part cannot be rolled down by the ability of the jacks 14 and 21 for rolling down.

(Ii) Therefore, after the start of casting, the casting speed is gradually increased, and after the tip has passed through the reduction device, the reduction drive motor 24 is driven to start the reduction of the slab Sb.

At this time, since the thicknesses t ₀ and t ₀ ′ of the solidified shell S of the slab vary depending on the casting conditions and the cooling conditions, the casting conditions are set in advance so as to have a predetermined thickness.

Further, in the final roll 8A _{7 of the} rolling zone A, the rolling condition is such that T ₁ ≈t ₀ + t ₀ ′ or a slight uncoagulated layer remains as described above.

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

The force required for the rolling at this time is the total force of the force for rolling both side surfaces of the solidified shell S and the force for counteracting the static pressure of the molten metal acting on the remaining portion of the molten metal. Unlike the above, the drawing torque of the pinch roll 6 required for drawing the slab is greatly reduced and a large capacity is not required.

(Iv) When the casting speed does not reach the steady value at the initial stage of casting and the solidified shell thickness of the slab is thicker than the planned value, or during the steady casting, the cooling capacity of the slab due to some trouble, etc. The casting conditions are different and the thickness of the solidified shell changes accordingly, and if it becomes thicker than the planned value, the roll group 8i in the reduction zone and the parallel zone is pushed up by the slab Sb. All the displacement is absorbed by the dampers 15 and 22.

(V) The reduction amount in the width direction should not be different due to the elastic twist of the reduction zone frame 10 due to the non-uniform thickness of the solidified shell in the width direction and the non-uniform thickness of the short sides. Since the pinion 17, the rack 18, and the tuning shaft 16 are arranged and the reduction zone frame 10 is not always twisted, the cast slab after reduction has a uniform thickness in the width direction.

(Vi) The upstream support point b of the parallel zone frame 11 is compared with the support point a of the reduction zone frame 10 by the reduction jack 14.
, And the downstream support point c is supported on the vertical line via the damper 22 by the reduction jack 21 that moves up and down in synchronization with the reduction jack 14, so that the rolls in the parallel zone B are grouped together. 8Bi can move up and down in parallel to the pass line of the lower roll group 9i.

Although the twin belt caster has been described above, the present invention is not limited to this, and a twin roll type continuous casting machine, a belt / casting wheel type continuous casting machine (rotary caster) or the like continuous casting machine for wide and thin cast pieces. It goes without saying that it can also be applied to.

Furthermore, although an example in which a roll down zone and a parallel zone are provided in the upper roll group is shown, the lower roll group or the upper roll group
It is also included in the present invention to provide a rolling zone and a parallel zone in both lower roll groups.

〔The invention's effect〕

As described above, according to the present invention, the rolling apparatus roll group is divided into the front-stage rolling zone and the rear-side parallel zone, the rolling zones and the parallel zone frames are connected to each other, and these frames are synchronized with the slab. Since the slab is moved forward and backward in a direction perpendicular to the moving direction of the slab, it is possible to manufacture a rolled thin plate material having a uniform wall thickness and good flatness with high efficiency and at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an example of a thin slab continuous casting facility according to the present invention, and FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3, and FIG.
5 and 5 are a front view showing a rolling-down device according to the present invention, a view taken along the line III-III in FIG. 3, and a plan view. 1 ... Tandishyu, 2 ... Hot water supply device, 3 ... Twin belt caster, 3A ... Pulley, 3B ... Endless belt, 4 ... Cast support roll group, 5 ... Rolling down device, 6
…… Pinch roll, 7 …… Lower roll frame, 8Ai ……
Rolling zone roll group, 8Bi ... Parallel zone roll group, 9i
...... Lower roll group, 10 …… Suppression zone frame, 11 …… Parallel zone frame, 12 …… Support frame, 13 …… Support bracket, 14 …… Screw down jack, 15 …… Damper, 16 ……
Tuning shaft, 17 ... Pinion, 18 ... Rack, 19 ... Coupling arm, 20 ... Common bracket, 21 ... Reduction jack, 22 ... Damper, 23 ... Connection shaft, 24 ... Reduction drive motor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inujie Yuji Inoue 5-15 Kitahama, Higashi-ku, Osaka, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Setsuo Ishimatsu 5-15 Kitahama, Higashi-ku, Osaka, Osaka Sumitomo Metal Industries Co., Ltd. (72) Inventor Katsuji Honda, 5-15 Kitahama, Higashi-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries Co., Ltd. Kashima Steel Works (72) Inventor Yukazu Koide 3rd Hikari, Kashima-cho, Kashima-cho, Kashima-gun, Ibaraki Sumitomo Metal Industries, Ltd. Kashima Steel Works

Claims (1)

[Claims] 1. A thin casting having a non-solidified layer inside which is arranged downstream of a thin casting continuous casting machine for producing thin castings and continuously cast by the thin casting continuous casting machine. A piece
It is an apparatus that continuously rolls down rolled metal sheet with good flatness, and the rolling mill roll group stabilizes the thickness of the cast strip after rolling and the rolling zone in the previous stage that rolls down the solidified shell of the cast strip. It is divided into a parallel zone of the latter stage to be made into a solid, and the frames of the reduction zone and the parallel zone are connected to each other, and these frames are made to move forward and backward in a direction orthogonal to the moving direction of the slab in synchronization with the slab. An apparatus for continuously producing a rolled thin metal sheet.