KR100218643B1 - Method and apparatus for production of steel strip - Google Patents

Abstract

In the manufacturing method of the steel strip, the continuously cast steel strip 2 composed of the solidified steel strip 3 and the liquid core 4 is reduced in thickness by roll forming and subsequently rolled.

Cast a 40 to 80 mm thick steel billet to avoid undesired thicknesses, improve the structure and simplify the roll forming apparatus, and the thickness of 15 to 40 mm and the remaining liquid cores to 2 to 15 mm Roll forming up to three stages and guide to complete solidification.

Description

Method and equipment for manufacturing steel strip

1 is a principle diagram of steel strip manufacturing equipment.

2 is a schematic view of the first section of the installation from the mold to the drive.

3 is a schematic view of a variant of FIG. 2 with two forming roller pairs.

4 is a schematic view of another variant in which a support roller is arranged at the front end of the forming roller pair.

5 is a partial view of a pair of forming rollers provided with a lateral support member and an adjusting and positioning device.

6 is a partial view of a pair of support rollers equipped with a support frame and an adjustment and positioning device.

* Explanation of symbols for main parts of the drawings

1: Template 2, 2 ': Kangdae Billet, Gangdae

3: epidermis 4: liquid core

5,6: forming roller pair 7: guide roller

8: driving roller 9: bending roller

10: drive adjustment device 11: cutting machine

12: No 13: Additional Cutting Machine

14: descaling device 15: roll stand

18: laminar flow cooling zone 19: winder

21: support roller 24, 25, 37, 38: bearing

27, 28: aspect ratio 29, 42: spindle drive

30, 43: motor 31, 44: screw spindle

32, 45: Distance nut 33, 46: Spring

34, 47: stopper plate 35: internal cooling furnace

36, 48: adjustment cylinder 36a, 48a: tow bar

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a steel strip, wherein a continuously cast steel strip consisting of a solidified steel strip skin and a liquid core part is reduced in thickness to roll forming (roll deformation) and subsequently rolled.

In this method known by EP-A1 0 286 862, the rolled steel sheet is 40 to 50 mm thick and cast from the casting mold after the steel sheet is discharged from the mold, so that the inner walls of the steel sheet formed in the mold are welded together. Squeezed.

In continuous casting in a pass-through mold of a given length, the thickness of the steel strip formed is in fact dependent on the casting speed.

To ensure that the clearance between the rollers is kept constant, the rolling force must be adapted to the instantaneous outer skin thickness. If the casting speed is too low, the available rolling force is no longer sufficient, so the thickness of the produced steel strip will exceed the set thickness. On the other hand, when the casting speed is too high, fusion of both strip skins can be achieved only under the set thickness of the production strip.

It is an object of the present invention to provide a method and a facility for carrying out the method which can avoid undesired thickness biases of the produced steel strip and obtain good structure. On top of that, it is intended to simplify the molding apparatus and to reduce the energy demand.

The purpose of the setting is to cast a steel billet with a thickness of 40 to 80 mm, roll forming the coil to a maximum of three stages up to a thickness of 15 to 40 mm and a residual liquid of 2 to 15 mm, and then solidify the steel sheet. It is achieved by the present invention by conveying without deformation (molding) to (cure hardening).

In this way, casting speed and strip thickness can be freely selected between each other to achieve high productivity.

Also, in terms of quality, a dense nucleus and no segregation can be obtained.

Structural simplification and energy savings can be achieved by reducing the rolling force (adjustment force) of the molding apparatus.

It is preferable that the thickness of the stripped skin portion is 6 to 19 mm before roll forming.

According to a further preferred embodiment of the invention the roll forming degree (strain) is 10 to 60% and can vary during casting.

When the casting speed is 2 to 10 m / min, the roll-formed steel strip is guided in parallel over the length of 1 to 5 m.

The steel strip is adjusted to the rolling temperature after the solidification and rolled.

In the embodiment of the apparatus according to the present invention, in the facility for carrying out the method of the steel casting mold, the solidification zone and the driving device composed of the support rollers (guide rollers) are arranged at the rear end of up to three pairs of the molding rollers.

In addition, the forming roller and / or the support roller are equipped with a mechanical positioning device and a hydraulic pressure device.

Further aspects of the invention are indicated in the claims subclaims (claims 9 to 16) of the claims.

The drawings illustrate embodiments with features and advantages of the invention.

The equipment of FIG. 1 consists of a mold 1, a forming roller pair 5, a guide roller 7 and a drive roller 8 for casting a steel billet 40 to 80 mm thick. A bending roller 9 is arranged to change the direction of the steel strip. The strip 2 'may then be reached by the drive adjuster 10 and cut by the cutter 11. The steel strip then passes through the furnace 12 for temperature control, after which an additional cutter 13 and a descaling device 14 are installed.

The stackel rolling machine arranged in the material advancing direction is constituted by a roll stand 15 in which winding paths 16 and 17 are installed before and after.

The rolling strip 2 ″ leaving the stacker rolling mill passes through the laminar flow cooling zone 18 and is then wound up in the winder 19.

2 to 4 show the steps of manufacturing steel strips 2, 2 'in a continuous casting apparatus.

The molten steel injected into the mold 1 produces a cast steel strip 2 having a liquid core 4 by cooling and solidifying the strip skin 3.

The steel strip skin 3 on the width side of the steel strip under the mold 1 is shortened by its forming rollers 5 and 6 with an internal cooling path 35.

In this way, a steel strip having a thickness of 15 to 40 mm and a residual liquid core 4 of 2 to 15 mm is obtained. The roll-formed cast steel 2 is completely solidified while passing through the roller passages formed by the guide rollers 7 without being deformed. The steel strip feed is performed by the drive roller 8.

In the embodiment of FIG. 2, the cast steel strip 2 is roll-formed (roll deformation) in one stage between the pairs of forming rollers 5. Instead, two-stage roll forming takes place between the forming roller pairs 5 and 6 in the embodiment of FIG.

Two or three stage roll forming would be advantageous for steels that do not allow high forming speeds or high forming steps.

A fountain nozzle 20 is disposed between the guide rollers 7 for cooling the cast steel 2.

In the variant of FIG. 4, the cast steel is first guided without deformation between the support rollers 21 in order to adjust the temperature according to the quality at the bottom of the mold. The support roller 21 and the guide roller 7 have internal guideways 22 or 23.

In the case of the structure shown in FIG. 5, the forming rollers 5 are multiplely stored, and the bearings 24 and 25 are fixed to the side beams 27 and 28, and the side beams stand at opposite sides on both sides. May be moved at 26.

The spindle drive 29 is fixed to the stand 26 as a positioning device for the transverse members 27 and 28 and the forming roller 5. The spindle drive 29 connected to the motor 30 has one screw spindle 31 in the direction of the transverse members 27 and 28, respectively.

Each distance nut 32 screwed to the screw spindle 31 is reliably prevented from rotation by the insertion spring 33. In the side beams 27 and 28, stopper plates 34 are assigned to the respective distance nuts 32. The transverse beams 27 and 28 are mutually towed by the adjustment cylinder 36 with the respective towbars 36a, and the spacing between the two beams and thus the spacing of the forming rollers 5 is the spindle drive 29 Is determined by the distance nut 32 adjusted by

In this way, the pair of forming rolls 5 can be kept in center with the casting cavity of the mold 1 even when the distance is adjusted. Similar bearings and adjusters are provided for the additional forming roller pair 6 (FIG. 3).

In the case of the configuration shown in FIG. 6, the guide rollers 7 are also overlapped and the bearings 37 and 38 are supported on the frames 39 and 40.

Frames 39 and 40 are guided from stand 41 to both sides.

The spindle drive 42 is fixed to the stand 41 as a positioning device for the frames 39 and 40 and the guide roll 7. The spindle drive 42 connected to the motor 43 has one screw spindle 44 in the direction of the frames 39 and 40, respectively.

Each distance nut 45 screwed onto the screw spindle 44 is prevented from rotating by the insertion spring 46. In the frames 39 and 40, a stopper plate 47 is assigned to each of the distance nuts 45. Frames 39 and 40 are mutually towed by an adjustment cylinder 48 with a traction rod 48a, wherein the spacing between the two frames and the distance between the guide rollers 7 follows. It is determined by the distance nut 45 adjusted by.

In this way, the guide rollers 7 can remain in alignment with the corresponding forming roller 5 even when the gap is adjusted.

Claims (16)

In the method of manufacturing a steel sheet in which a continuous cast steel sheet consisting of a solidified steel sheet skin portion and a liquid core portion is reduced in thickness by roll forming and subsequently rolled, a steel sheet billet 2 having a thickness of 40 to 80 mm is cast and the steel sheet billet ( 2) roll forming up to three stages until the thickness is 15 to 40 mm and the residual liquid core part (2) is 2 to 15 mm, and the steel billets (2) are transported until solidification is completed. 2. Method according to claim 1, characterized in that the thickness of the outer skin (3) is 6 to 19 mm before roll forming. The method according to claim 1, wherein the roll forming degree (reduction rate) is 10 to 60%. The method of claim 1 wherein the roll forming characteristic is varied during casting. The method of claim 1 wherein the casting speed is between 2 and 10 m / min and the length of the parallel guide zone is between 1 and 5 m. The method according to claim 1, characterized in that the steel strip (2 ') is rolled after adjusting to a rolling temperature after solidification. An apparatus for carrying out the method according to any one of claims 1 to 6, comprising a steel casting mold and a forming roller arranged at a rear end thereof, wherein the solidification-completing zone and driving device composed of guide rollers 7 are provided. (8), characterized in that arranged at the rear end of a maximum of three pairs of forming rollers (5, 6). 8. The plant according to claim 7, characterized in that the forming rollers (5,6) are equipped with mechanical positioning devices (29-34) and an inlet pressurizing device (36,36a). 8. The installation according to claim 7, wherein the guide roller (7) is provided with a mechanical positioning device (42-47) and a hydraulic pressure device (48,48a). 8. Installation according to claim 7, characterized in that the forming rolls (5,6) are internally cooled and have a diameter of 150 to 300 mm. 11. Installation according to claim 10, characterized in that the forming rollers (5,6) are separated through the span and enclosed in the middle. 8. Installation according to claim 7, characterized in that the guide rollers (7) of the parallel guide zone are insulated. 8. The installation according to claim 7, characterized in that the guide rollers (7) separated through the span and formed in the middle form a solidification completion zone. 8. The installation according to claim 7, characterized in that a bending device (9) and a drive adjustment device (10) are arranged at the rear end of the solidification completion zone. 8. The plant according to claim 7, characterized in that the temperature adjusting zone (12) and the rolling mill (15) are arranged at the rear end of the drive adjusting device (10). 8. The installation according to claim 7, characterized in that a support roller (21) is arranged between the mold (1) and the forming roller pair (5).