JPH03504572A - Method and apparatus for continuously producing steel strips or steel plates by continuous casting - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention Method and apparatus for continuously producing steel strips or steel plates by continuous casting Technical field The present invention is a flat product manufactured by a curved continuous casting method with a horizontal discharge direction. This invention relates to a method for continuously producing steel strips or steel plates from steel.

Background technology Whether due to general trends or due to operators of equipment that has become too old over the past few years, Whether it is for the purpose of overcoming the crisis facing the steel industry, operating costs and lower investment costs, while at the same time reducing There is a strong need to improve product quality and increase flexibility with respect to Existing steel mill New steel plants by modernizing or with new technical configurations and equipment'' Increase productivity and optimize availability by planning and realizing Efforts are being made to allow large play in the unit product dimensions of the final product in order to provide width. It has been.

One of the new technologies currently being promoted regarding the actual requirements for steel production is the process of melting steel and the process of winding steel strip into a coil shape or the process of laminating steel plates. This new technology requires only a small number of subsequent holes, i.e. The thickness is close to the final size so that the desired final product can be produced in the forming step. This includes the casting of thin sheet slabs, in particular permanent molds and corresponding immersion molds. Continuous casting technology has been improved with respect to the structure of the Tauchausguss. Roll stand and mill arrangement to achieve desired molding with as few holes as possible The structure of has been improved.

150 to 320 rc- Continuous casting method produces thin plate slabs with a thickness of about 50-1 compared to conventional slabs. A steel strip production apparatus is known. In this case, these thin sheets can be processed in different ways. The roll passes through successive rolling/processing stages.

The final product is a number-thick plow strip. Immediately after intermediate heating in the furnace, e.g. It is proposed to roll cast products on a tandem rolling line with two roll stands. It was proposed. The casting speed does not significantly exceed approximately 5s/gain, so this at the last roll stand of the rolling line corresponding to at least about 865°C. This results in a rolling speed that is too low to maintain the final rolling temperature of . In other words, the rolling ladle Due to the same low speed as the casting speed during the entry into the belt, two successive bands Excessive cooling occurs between the rolling stages. Therefore this solution was not adopted, what Therefore, installing a thermal protection device is an economical solution to this problem even if the roll is heated. is not possible, because such solutions reduce investment costs and operational costs. This is because the cost increases significantly.

In another solution, the strip is then heat treated (temperature compensated) over the entire cross section. The band is then cut in front of the heating furnace. This can be considered, for example. approximately 100 °C at the furnace outlet, independent of the casting speed to be applied, i.e. during the subsequent rolling process. It can also be a gas-heated roll furnace that adjusts the zone temperature to the optimum temperature for the be. The strip has a standard length, which may be, for example, 50 mm for a given coil weight. and, taking into account the required damping effect, a corresponding furnace length of approximately 150 m for this purpose. is necessary.

By separating the rolling line from the actual casting process, thin plate slabs or 1' 1 rolling can be carried out at higher speeds, thus reducing the temperature for the final rolling stage. temperature may drop below the minimum allowable temperature. In this case, the partial band The excessive length of the furnace, which is about three times the length of the furnace, increases the equipment investment cost. It requires a large amount of space that many steel mills cannot provide.

In addition to this, the dimensions of the equipment and thus of the furnace limit the length of the sub-strips that can be processed in succession. , which in turn limits the final coil weight and therefore concerns the production of coils with maximum diameter. to limit the range of play. Correspondingly, this type of equipment uses a continuous casting method. If further technological development makes it possible to manufacture even thinner plain slabs. does not provide a way to use such thin bare slabs, already instead of 501 Assuming an initial thickness of 25− as assumed, we achieve the same final coil weight. In order to For this reason, a length of the order of approximately 300 mm must be provided, which is practical and economical. It is economically unfeasible.

It is an object of the present invention to solve the problem of flat castings coming from a curved casting machine without the above-mentioned drawbacks. A method of the type mentioned at the beginning by which continuous steel strips can be produced from products and this method The object is to provide a corresponding device for implementing the invention.

In particular, the continuous casting material is cut between the casting process and at least the first roll stand. The continuous casting material enters the hole mold in the first roll stand. is carried out at the speed at which the rolled stock leaves the curved section of the continuous casting device. Therefore this The method can be implemented with unlimited flexibility in practice and therefore Coils of any weight and length without changing the dimensional parameters of the device or It is possible to produce sheet stock, since the rolled strip must be cut at least once. After the first rolling step or after all working steps have been carried out, the winding device or This is because it is performed directly in front of the laminating device.

the above! Il! ! is solved by a method characterized by the following steps.

a) Continuous casting of blanks in the first forming stage at temperatures higher than 1100°C After complete solidification, flat products are formed.

b) Approximately 1100°C with the best possible temperature compensation over the entire cross section of the flat product Induction heat again to temperature.

C) At least one rolling speed corresponding to the respective removal from the groove. A subsequent forming stage forms a flat product.

In one embodiment of the invention, the strip is wound between the first forming step and the subsequent forming step. It is proposed that

The rolled strip is then wound into a flat product according to the desired coil weight. , or after forming the flat product to a predetermined length and subsequently cutting the rolled strip. After cooling and straightening as necessary, the steel sheet is laminated into a sheet steel laminate. Therefore flat products First, in the first roll stand, the initial stage when emerging from the curved casting machine is The rolling stage is entered at speed=, and the successive rolling stages correspond to forming within each mold. Pass at the appropriate speed each time.

The strip rolled in this way is then wound up after reaching the desired coil weight. One important feature of the invention is that the strips are divided into desired lengths and laminated into plates. The important point is that after descaling, flat products can be reduced to approximately 1100″ with the best possible temperature compensation. The point of heating to a temperature of This is because it can be resisted.

One or more stages are provided for inductively heating the flat product. This intermediate heating The stages can also resist excessive cooling of the rolled stock and therefore the last forming stage The required rolling temperature must be constantly adjusted so that the temperature does not fall below the limit value of 860"C. I can do it.

Another proposal of the invention provides the following steps.

- adjusting the forming stage after the dummy bar provided in the casting process has passed;

- cutting the dummy bar immediately before winding the strip or laminating the plates;

- Individual heating adjustment in successive stages/zones after the dummy bar has passed. .

Dummy bars were originally provided to divide the rolled strip after it passed through the roll stand. The dummy bar can also be cut using a device that is It can also be cut with one cutting device.

The apparatus for carrying out the method of the present invention shall be provided with the following apparatus parts in the order listed. It is characterized by

a) Permanent mold for continuous casting of flat products followed by a guide device into a curved shape.

b) a first step in which the flat product is formed in the guiding device and/or directly following it; Molding equipment.

C) A device that performs induction heating and temperature compensation across the cross section of a flat product.

d) At least one further roll stand.

e) Cutting device.

The cutting device is provided after the first forming device and between the first forming device and another forming device. , a device for winding and unwinding the flat product may be provided in front of the cutting device. biased in favor A device for winding and unwinding flat products is installed after the induction heating device and before another forming device. .

Optionally, according to the invention, this device is followed by a rolling band cutting device and at least one band wrapping. Provided with a cutting machine, or rolling strip cutting equipment, cooling equipment, straightening machine and cut plate A laminating device will be provided for this purpose.

In another embodiment of the invention, the device provides intermediate heating between subsequent roll stands. and at least one induction heating device for heating.

Preferably each of these devices includes a separately controlled heating stage.

In one embodiment of the invention, the apparatus includes a 13i1 dummy in the head of the continuous casting stock. allow the dummy par to pass, and redo the cross section directly after the dummy par has passed. The rolls of the first forming device and the following, making it possible to return to normal pass running values. A device that adjusts the passing cross section between the roll stand and a device that adjusts the passing cross section after passing the dummy par. and a device for sequentially controlling the individual heating stages of the furnace and cutting the dummy par. The cutting device is a cutting device that is also used to cut the rolled strip, i.e. the cutting device of this device. This is a cutting device installed at the final stage.

Next, the present invention will be explained in detail based on examples and using figures.

Figure 1 is a schematic diagram of the device of the present invention, Figure 2 is a diagram showing temperature changes in sheet steel, and Figure 3. is one modified embodiment of the invention.

BEST EMBODIMENT OF THE INVENTION The drawing schematically shows a device according to the invention, on the basis of which a corresponding method can be carried out. Starting from the continuous casting permanent mold, indicated by 1 in the drawing, A flat product 2 is formed. Flat product 2 guided and conveyed through conventional support rolls from the initial vertical direction through the curved section formed by the supporting rolls. Move to upright position. After complete solidification, i.e. solidification up to the end region of the curved section, the main The flat product according to the invention passes through a first forming stage 3 in which the flat product is e.g. It is molded to a thickness of 25mm. The forming stage 3 has one or more rolling units, advantageously It consists of four sets.

For temperature compensation, a furnace 5 is then provided, which furnace 5 is preferably equipped with an induction heating device. ing. Temperature compensation is carried out simultaneously in this furnace 5 over the entire cross section of the flat product 2, Therefore, flat products must be rolled at a sufficient rolling temperature for the first roll stand in the subsequent forming equipment. reach in degrees.

Due to the hole entry speed being too slow in response to the traveling speed when exiting the curved section. The temperature drops significantly and therefore in the second roll stand 7 in the subsequent forming device. If the forming temperature is insufficient, a further intermediate processing in the form of a second induction furnace 8 A heating device can be provided between the roll stands 6 and 7, and the second induction furnace 8 5, but the second induction furnace 8 may be shorter than the furnace 5 with three roll stands. 6. During forming along another forming apparatus consisting of 7 and 9, the last roll Ensure that the temperature on entry into the hole mold of tand 9 is of sufficient order for good forming. is only necessary if it does not play a sufficient role in adjusting the corresponding temperature difference. Ru. Upon exiting the last roll stand 9, the flat product 2, referred to as strip 2'', is It has a thickness of

As shown in FIG. The desired coil weight! When the cutoff is reached, the cut is finished, or the cutting machine 10 cuts the desired The strips are cut to length and then deposited in the deposition device 14 to finish.

Start-up continuous casting (not shown) without the need for additional cutting equipment A device that cuts the strip 10 at the beginning of the process cycle is also used to cut the material. The dummy par passes through the induction furnace 5, which is shut off, and is transferred to the forming device 6. Pass through the open rolls at 7 and 9, provided as the case may be, and the same After passing through the intermediate heating device 8, which is cut off in the same way, it is cut. corresponds to this A position adjustment device is provided, and this position adjustment device allows the direct Afterward, the rolls are adjusted to the normal roll gap required for forming. Furthermore, there is a heating device 5. Benefits include the condition of a furnace that consists of zones that are independent of each other and are therefore isolated. The furnace zone through which the dummy par passes each time is sequentially connected Start heating.

FIG. 2 is based on a schematic diagram (with the same reference numerals) of the individual sections of the device of FIG. , shows the temperature change of the flat product 2 from the last roll stand until the strip 2' comes out. There is. Below the curve is a table from which you can determine the specific section of the device and , the respective speed at the corresponding thickness corresponding to the corresponding strip section is known. .

The values shown were obtained in tests on strips 100 w1 wide - 25 mm thick. another It is obvious that the dimensions and speeds of will result in different temperature changes.

From the figure, when the flat product 2 obtained by the casting and rolling process leaves the first forming stage 3, has a temperature of 1075°C, and this temperature reaches the descaling device 4. The temperature drops to 1049°C. This device is equipped with a high-pressure water spray set desk. Conditioned by the ring device, the temperature suddenly drops to 969°C and reaches furnace 5. The temperature further drops to 934°C.

In the furnace or in the induction heating device 5 the temperature rises again to 1134°C and temperature compensation Compensation is carried out over the entire cross section of the flat product. Flat products reach roll stand 6 The temperature drops to 1104°C before rolling, and this temperature is the temperature of the rolls in the roll stand. The temperature decreases further due to contact with the roll stand, reaching 1063°C by the time In the aforementioned case, the partially rolled strip is It is heated in the induction furnace 8 from 1020°C to 1120°C. Second roll stand 7 When entering the hole mold, the temperature is 1090℃, and when leaving the roll stand, the temperature is 1090℃. The temperature drops again to 1053 °C, and this temperature rises to 9 in the third and final roll stand. The temperature drops to 88°C. This temperature is sufficient as the groove entry temperature for the final rolling process. It is.

Roll stand 2' leaves the last roll stand 9 at 953°C and then further lowers. It can be cut to the desired length and deposited at a reduced temperature, or as shown in FIG. It is wound up like this.

Regarding the speed change, in the example, the traveling speed when leaving the first forming stage 3 is 0.08 m/sec, or 4.8 m/win.

This is a roll stand for subsequent forming equipment where the thickness of the flat product is still 25+am. Corresponds to the hole entry temperature upon entry into the board. Enter roll stand 7 The entrance speed of the hole mold is 10.2 m/sin, and at the same time the flat product is formed. The thickness changes from 25 mm to 12.3 mm. Pressure into the last roll stand The rolled material enters at a speed of 19.8 + w/sin and a thickness of 6.2 exit with a finished thickness of 4.05 a+m and a speed of 30.6 k/sin.

The subsequent Heating preceding the first roll stand of the forming device and optionally the first roll The intermediate heating that takes place between the stand and the subsequent roll stand refers to After that, the flat product or rolled strip is heated to about 1100°C and the final roll stand is heated. The temperature level is maintained so that the final rolling temperature in the inside does not fall below the limit of 860°C. Adjustments must be made so that

In the modified embodiment shown in FIG. 3, a winding and unwinding device 12 is used. In this case, the winding and unwinding device is located after the induction furnace 5, as shown in Figure 0. is incorporated into. This device is supplemented by a descaling device 4 A take-up and unwind device 12 winds the flat product until a desired amount of coils is reached. Ru.

After the wound coil is transported to the winding position (located on the right side in the figure) For further processing, the flat material is processed by a subsequent roller stand consisting of one or more roll stands. Supplied to molded W6.7 and 9. Rolls of subsequent forming equipment if required An additional induction furnace 8 can be installed between the stands. For example, the coil is in 11 For example, it can be finished with a down coiler.

All parameters of this equipment, casting speed, rolling speed and forming are adjusted accordingly It is obvious that these mutual adjustments can be made by doing this.

The foregoing description of the invention provides a method for linking materials with low equipment and energy costs. Method for carrying out continuous casting and finish rolling and for carrying out this method It was about the necessary equipment. The heating output required for induction heating exceeds the limit of approximately 8 MV. This is considered very economical for steel mills of the corresponding order. I found out that it is possible.

Regarding the method proposed by the invention and the equipment necessary for carrying out this method The configurations described and illustrated can be varied within the scope of the objectives of the invention; In this case, the heating device provided between the mill arrangement or the roll stand is The induction furnace can be replaced by another, for example a furnace with laser technology, a radiation A wire furnace etc. can be used.

Temperotur　C international search report 111 ■＾-mlII1. PCT/DE 89100332 International Search Report DE 8900332 SA　　　　2εε37

Claims (16)

[Claims] 1. From flat products manufactured by curved continuous casting method with horizontal discharge direction, strip steel or is a continuous manufacturing method for manufacturing sheet steel, which is characterized by the following steps: Continuous manufacturing method. a) After solidification of the continuous casting material, the first forming stage (3) is carried out at a temperature higher than 1100°C. A flat product (2) is formed inside. b) A temperature of approx. 1100 °C over the entire cross section of the flat product with the best possible temperature compensation. Induction heat again to 30°F. c) at a rolling speed corresponding to the removal of the flat product from the respective groove. In both cases, a flat product is formed in one subsequent forming stage. 2. The band is wound up between the first forming step and the subsequent forming step. A method for continuously manufacturing a steel band or a steel plate according to claim 1. 3. Following forming of the flat product, the rolled strip is wound into the desired coil. The steel strip or steel strip according to claim 1, which is cut according to weight. is a continuous manufacturing method for sheet steel. 4. Following the shaping of the flat product, the rolled strip is previously provided. Cut to length and optionally cooled and straightened before being laminated into sheet steel laminates. A method for continuously manufacturing a steel strip or a steel plate according to claim 1. 5. One or more stages are provided for induction intermediate heating of the flat product between subsequent forming stages. Any of claims 1 to 4, characterized in that A method for continuous production of steel strip or steel plate according to any one of the above. 6. Claim 1, characterized in that the following subsequent steps are provided: 5. The method for continuous production of steel strip or steel plate according to any one of Item 5. - The forming stage is adjusted after passing through a dummy bar provided in the casting process. process. − The dummy bar is cut immediately before the strip is wound or the plate is cut. process. − The heating is adjusted individually in successive steps or areas after passing through the dummy bar. process. 7. Claims characterized in that the following device parts are provided in the order of description: An apparatus for carrying out the method according to paragraph 1. a) Permanent continuous casting of flat products (2) followed by a guide device that guides them in a curved manner Mold (1). b) a first forming device for forming said flat products in and/or immediately after the guiding device; Place. c) A device (5) for induction heating and temperature compensation over the cross section of said flat product (2). d) at least one subsequent roll stand (6, 7, 9). e) Cutting device (5, 10). 8. characterized in that the cutting device (5) is provided after the first forming device (3). The apparatus according to claim 7. 9. Between the first forming device (3) and the following forming devices (6, 7, 9), a flat product is A winding and unwinding device (12) is provided, and a cutting device (5) is provided in front of this device. 9. The device according to claim 7 or 8, characterized in that: 10. A winding and unwinding device (12) is connected to the subsequent forming stage (6, 7, 9) The device according to claim 9, characterized in that it is provided before . 11. A cutting device (10) for the rolled strip (2') and a small device for winding said strip (2'). Claims characterized in that at least one winder (11) is arranged downstream. 7. The device according to paragraph 7. 12. After the device there is a cutting device (10) for the rolling strip (2), a cooling device, a straightening roller. and a laminating device (14) for the cut plates. The apparatus according to claim 7. 13. At least for intermediate heating between subsequent roller stands (6, 7, 9) Claim 1, characterized in that one induction heating device (8) is provided. The device according to item 7. 14. Each induction heating device (5, 8) has a heating stage that can be individually controlled. 14. The device according to claim 13, characterized in that: 15. Allows the dummy bar installed at the head of continuous casting material to pass through. In order to The rolls of the forming device (3) and the subsequent roll stands (6, 7, 9) are an additional passing cross-section adjusting device between the control of the individual heating stages of said induction heating device (5, 8) in order to switch on each time A control device is provided to cut the dummy bar from the rolling strip (2'). Claim 11, characterized in that the cutting device (10) is also used for cutting purposes. The device described. 16. characterized in that a cutting device (5) is used to cut the dummy bar; An apparatus according to claim 8.