RU2114708C1 - Process and plant for casting intermediate-thickness slabs and slab receiver - Google Patents

Abstract

FIELD: metallurgy, namely rolling strips and thick sheets. SUBSTANCE: plant includes continuous casting unit, cutting member, station for storing slabs, one or two heating furnaces, unit for alternating slabs, roller table, reversing hot rolling mill with furnace coilers. Plant may include in addition conveyer for transporting slabs. Station for storing slabs may include heat-insulated receiver for vertically stacking slabs. It is possible to realize different variants of cooperation of plant units. Process includes steps of casting, cutting slab and hot rolling it to finish product. If it necessary after cutting slab may be placed for storage. Process may comprise step of rolling heated slabs removed out of storing station or from outside or step of rolling slabs without heating them. EFFECT: minimized heat and power consumption, lowered investment, minimal space of working shop, flexible manufacturing process, enlarged assortment, enhanced efficiency. 10 cl, 21 tbl, 8 dwg

Description

 The invention relates to the continuous casting of a strip of cutting slabs and subsequent rolling of products of finite thickness, in particular to a plant that combines means for continuous casting of a strip of intermediate thickness and a reversible hot rolling mill, means for receiving, in order of sequence, slabs cut from the strip and their storage.

 The combination of a strip hot rolling mill with continuous casting by mounting in one combined line or a single installation allows you to maximize productivity and minimize the necessary equipment and necessary capital investments.

 However, currently known such combined installations with high investment are extremely unsuitable in relation to rolling the mixed product and modern generally accepted market requirements. Also significant disadvantages of plants known from the prior art are difficulties in achieving the required product quality and limitations associated with casting devices for thin strips, for example, limiting the life of a casting ladle (about seven heats).

 More significantly, thin slab casting plants inevitably must operate at high speed to prevent metal cooling in modern ladle devices and when they are located. This, ultimately, makes it necessary to solve the problems associated with the length of the tunnel kilns, ensuring the supply of heat to the poured thin two-inch (50.8 mm) strip, which, in turn, quickly loses heat. The rolling mill must also be adapted to the rapid movement of the casting strip when rolling it to final thicknesses. Moreover, in the known systems significant loss of scale. For long ovens, intensive maintenance of the roller hearth is also necessary.

 This also causes problems in achieving the required microstructure of the rolled steels, which are often solved by special heat treatment.

 The aforementioned and other problems, such as providing adequate rolling mill stands, eliminating bandwidth and surface defects, ensuring synchronization and continuity of casting and rolling in an integrated system, are solved by the present invention.

 An object of the present invention is to combine or integrate a medium-thickness strip casting means with a reversible hot rolling mill. In addition, the object of the invention is the selection and adoption of a system that balances the casting speed with the rolling speed and provides for the separation of the means for casting and the mill, if necessary. An object of the present invention is also to select a system using less thermal and electric energy. Another objective is the choice of an automated system with small capital investments, moderate requirements for the space of the workshop’s work site, moderately energy-consuming rolling equipment and low operational cost. An additional objective is to provide flexibility in the use of slab sources, flexibility in establishing the sequence and storage of slabs, and economic adaptation and coordination with growing requirements for a wide band of small caliber.

 The present invention consists of a group of inventions comprising two versions of slab casting plants of intermediate thickness with a hot-rolled strip and thick sheet line, a method for producing metal strips carried out in the above-mentioned plants, and a slab receiver in a slab casting machine with a hot-rolled strip line and sheets.

 The closest analogue of the installations for casting slabs of intermediate thickness with a hot rolling line of strips and thick sheets is a prior art device for casting slabs of intermediate thickness with a hot rolling line of strips and thick sheets [1].

 The analogue device comprises means for continuous casting of a strip of intermediate thickness, a line cutter located downstream of the casting means and intended for cutting a continuously cast strip into slabs of the required length, means for storing slabs, at least one heating furnace located below downstream of the slab storage facility, the supply and working roller table located behind the outlet end of at least one furnace, a hot rolling reversing mill installed in line with the feed a working roller table and intended for rolling slabs heated in the furnace into an intermediate product with a thickness sufficient for winding into a roll, and a pair of furnace winders, one of which is located upstream of the reversing mill and the other is located downstream, while the furnace winders are made with the ability to receive and unwind the intermediate product sent between the furnace winders through a reversing mill for hot rolling into a product of finite thickness.

 The closest analogue of the method for producing metal strips is the prior art method for producing strips, including continuous casting of a slab of intermediate thickness, cutting it into slabs of a given length, reversible hot rolling of slabs to form an intermediate product with a thickness sufficient to wind it into a roll, and wind it into the intermediate product roll by a furnace winder and further reverse hot rolling with winding - unwinding the intermediate product roll into a strip [1].

 The closest analogue of the receiver for slabs in the installation according to the invention is a thermos storage device known from the prior art, located between the continuous casting installation and the hot rolling mill and made with heat insulation and with the possibility of receiving slabs from the casting installation [2].

 The aforementioned known method for producing strips and a casting plant with a hot rolling line have disadvantages associated with ensuring synchronism and continuity of the process in an accident and stable operation, and also does not allow to manufacture advanced varieties of products and other previously mentioned problems.

 The well-known thermos flask in the prior art is not used as part of the above integrated plant and does not have sufficiently developed solutions to the problems of simultaneous heat storage and optimal reception and delivery of stored slabs.

 The aforementioned disadvantages are eliminated by the present group of inventions that make up a single inventive concept.

 According to the present invention, an apparatus for casting slabs of intermediate thickness with a hot-rolling line of strips and thick sheets comprises means for continuously casting strips of intermediate thickness, a line mounted cutter located lower in the ceiling from the casting means and designed to cut continuously cast strips into slabs of the required length, means for storing slabs, at least one heating furnace located downstream of the means for storing slabs, feeding and working roller table, located beyond the outlet end of at least one furnace, a reversible hot rolling mill installed in line with the feed and working roller table and designed to roll slabs heated in the furnace into an intermediate product with a thickness sufficient to be wound into a roll, and a pair of furnace winders, one of which is located upstream of the reversing mill, and the other is located downstream, while the furnace winders are arranged to receive and unwind an intermediate product sent between the furnace winders through the reversing mill En for hot rolling into a product of finite thickness. And also, according to the first embodiment, the installation comprises means for alternating slabs for selectively feeding slabs or for bypassing at least one heating furnace. Also, according to this embodiment, the installation may comprise a slab conveyor mounted in line with the cutter, and the slab alternating means includes slab transfer means adjacent to the slab conveyor and acting across the conveyor. In this case, the slab transfer means communicates with the feeding and working roller tables, adjoins the slab storage means and is adapted to selectively receive slabs from the slab storage means. Also, the installation may contain a pair of heating furnaces. Moreover, the first furnace is located between the feed and working roller table and the conveyor for slabs, and the second furnace is located downstream and adjoins the first furnace. Moreover, the input end of the second furnace is combined with a conveyor for slabs, and the output end is combined with the feed and working roller table.

 Also, according to the first installation option, the feed and working roller table can be installed in line with the cutter and adapted to receive slabs directly from the cutter, while the slab alternating means may include slab transfer means adjacent to the feed and working roller table and acting across the roller table for selective removal of slabs from the rolling table, as well as a conveyor for slabs adjacent to the transmission medium of the slabs and adapted to receive slabs from the transmission medium. In this case, the slab storage means adjoins the conveyor and is adapted to receive slabs from the conveyor.

 According to the second embodiment, the installation for casting slabs of intermediate thickness with a line for hot rolling of strips and thick sheets, in addition to the above, also contains a conveyor for slabs mounted in line with the cutter, and the storage means for the slabs contains at least one vertically stacking slab receiver, located adjacent to the conveyor for the slabs and containing a vertically movable trolley to support the stack of slabs.

 The method of producing metal strips carried out at the above installation in two variants of the invention according to the present invention includes continuous casting of a slab (or strip) of intermediate thickness, cutting it into slabs of a given length, reversible hot rolling of slabs to form an intermediate product with a thickness sufficient to wind it into a roll, winding into a roll of an intermediate product by a furnace winder and further reverse hot rolling with the winding-unwinding of a roll of an intermediate product into the floor Su, each piece slab is selectively fed either directly into the reversing hot rolling mill, or in an intermediate heating and after heating to hot rolling, a slab to a storage means with further heating and subsequent rolling into strip. Also, the slab supplied for heating and rolling from the storage means is preliminarily or continuously poured and cut at the beginning of the production line or fed from the side. In this case, the slabs are stacked in the storage medium. And for subsequent heating, slabs from the storage medium are served selectively in one of the two furnaces of the installation.

 Also, according to the present invention, a slab receiver arranged in a slab casting machine with a strip and sheet hot rolling line is disposed between the continuous casting means and the hot rolling reversing mill. The receiver is configured to selectively receive slabs from continuous casting means. The receiver comprises a vertically movable trolley adapted to mesh with the lowest slab from a stack of slabs directly in contact with each other installed inside the receiver. The receiver is insulated at least around the sides and top of the stack.

 The present invention provides for the use of continuous casting equipment for casting equipment having a mold with a fixed or adjustable width, with a clean straight, rectangular cross-section with a central gate. The casting agent must provide a sufficient amount of metal to be cast to change the intermediate casting ladle, as a result of which the operation of the installation is not limited by the service life of the intermediate casting ladle. Our invention provides a continuously cast strip with a thickness of two to three thicknesses of casting a thin slab, as a result of this much less heat is lost and much less input power is required. The invention provides a slab having a smaller scale of losses due to reduced surface area per volume, and makes it possible to use one or two heating or leveling furnaces with the minimum necessary maintenance and care. In addition, the invention provides a means for casting, which can operate at generally accepted speeds for these tools and conventional descaling technology.

 The invention has the ability to separate casting and rolling, if there is a delay or delay at either end. The invention provides for the storage of hot slabs if a delay or delay occurs during the rolling phase. The invention provides for the easy removal of unsteady intermediate slabs formed by changing the chemistry of the molten metal or changing the width in the means for casting. In addition, the invention provides easy delivery of cold slabs to the processing line. These slabs may be from an external source (i.e., not formed on the casting plant) and may be thicker than slabs, which may be different on the casting plant. Such flexibility will allow the production line to operate with the corresponding throughput of the individual components and also allows different sections of the line to operate independently. Such availability of external sources makes it possible to include steel grades in excess of the capabilities of steel equipment forming part of any given integrated process in the mixture of manufactured products.

 Thus, all of the above advantages are realized while maintaining the advantages of a thin casting installation, which include a low ferrostatic head, low slab weight, straight crystallizers with shorter lengths, shorter radii, low cooling requirements, low burn-through or cut-off power and simplified design of mechanisms.

 The mill of the present invention can roll a slab to a thickness of about one inch (25.4 mm) or less in a minimum number of flat gauges, about three or four flat gauges. The combination of the finishing line of coils, coils of plate, coiled sheets or discrete plates runs in one line and downstream of the reversing hot rolling mill and furnace coilers. Finishing equipment may include a cooling section, a multi-roller coiler, a thick sheet roller, scissors, a transition cooler, edge trimming and end shears for plate cutting and a stacker.

 Moreover, the method for producing strips according to the invention also provides that some rolls of continuously cast strips can be directed around the heating furnace along the bypass roller table if the temperature of the strips is sufficient for rolling, in addition, some of the slabs can be supplied to the heating furnace from an external source ( i.e., these are slabs that are not cast by means for casting slabs of intermediate thickness). These slabs from an external source may have a thickness greater than the thickness of the slabs obtained by means for casting slabs of intermediate thickness and / or have a chemical composition different from the chemical composition that can be obtained in a melting or refined furnace associated with the installation.

 Thus, the method of producing strips provides greater flexibility in the use of sources of slabs, in establishing the sequence and processing of slabs.

 In FIG. 1 and 2 schematically show a means for casting a strip of intermediate thickness and a reversible hot rolling mill with furnace winders integrated in one line with it according to the first embodiment of the invention; in FIG. 3 shows the location of the means for casting a strip of intermediate thickness and integrated in one line with a reversing hot rolling mill with furnace winders and with multiple heating and leveling furnaces according to the first embodiment of the invention; in FIG. 4 and 5, a second embodiment of an apparatus for casting a strip of intermediate thickness with a reverse hot rolling line comprising a receiver for slabs with thermal insulation; in FIG. 6 is a sectional view of one embodiment of a slab receiver shown schematically in FIG. 4 and 5; in FIG. 7 is a side view of another embodiment of a slab receiver shown schematically in FIG. 4 and 5; in FIG. 8 is a front view of the slab receiver of FIG. 7.

 In FIG. 1 shows an apparatus for rolling slabs of intermediate thickness with a hot-rolling line of strip and plate metal of the first embodiment of the invention. At the inlet end of the apparatus 25, one or more electric furnaces are provided for producing molten metal. The molten metal is fed into the casting ladle 28 before being fed to the casting means 30.

 The tool 30 feeds the metal into the mold (curved or rectilinear) 32 with a rectangular cross section.

 At the outlet end of the mold 32, there is a gas cutter (or scissors) 34 for cutting a continuously cast strip of hardened metal into a slab of intermediate thickness from about 3 to 6 inches (from about 76 to about 152 mm) and the desired length, the width of which is from 24 to 120 inches (from 610 to 3048 mm).

 Then, the slab is fed by the feed and working discharge roller 52 to the slab discharge or removal section, where the latter can be removed from the feed and discharge roller table 52 by the transfer means (slapper) 35 slabs acting across the feed and discharge roller table 52. The slabs are transferred by the slapper 35 to the roller table 36 for loading into the furnace 42 or removal from a combined processing line and placement in the collection and storage section of slabs 40, which usually contains equipment of one type or another for conditioning slabs. The creation of an easily accessible site for the collection and storage of slabs makes it possible to separate the means for casting and the subsequent processing line. For example, if the mill is idled during the casting process, the remaining castings can be sent to the slab collection and storage area. In addition, if the casting plant is turned off or idled, then the downstream processing can continue with slabs from an external source. The collection and storage section of slabs 40 provides the ability to collect individual slabs for individual surface treatment of defects of individual slabs.

 The preferred furnace is a walking beam hearth furnace, although a roller hearth furnace may be used in some cases. Slabs of natural size 44 and slabs of discrete length 46 for some plate products are shown inside the furnace with a walking beam 42. Slabs 38 located in the collection and storage section of slabs 40 can also be fed into the furnace 42 by means of an ingot ejector 48 or a loading lever device designed for continuous loading by slabs 38 of a walking beam hearth furnace 42. It is also possible to load slabs from other slab warehouses or storage areas. When slabs are introduced from the slab collection and storage areas 40 or external sources, the furnace 42 should be able to increase the capacity to bring the slabs to rolling temperatures.

 Since slabs of intermediate thickness retain heat much longer than thin slabs, temperature equalization is all that is required for many operating modes. In addition, the internal temperature of some slabs when they enter the supply and discharge working roller table 52 may be sufficient for immediate rolling. In this situation, the slab can be fed directly to the subsequent processing, bypassing the furnace 42. A second furnace can be located upstream from the first furnace 42 to increase flexibility and control the systems in circulation.

 Various slabs are fed through the furnace 42 in the usual way and removed by slab ejectors 50, placed on the feeding and working roller table 52. For slabs of intermediate thickness, a scale breaker 53 and / or vertical edger 54 can be used. A vertical edger cannot usually be used for slabs with a thickness of 2 inches (50.8 mm) or less.

 Downstream of the feed and discharge roller table 52 and vertical edger 54 is a single-chamber hot rolling reversing mill 56 with front and rear furnace winders 58 and 60, respectively. A discharge roller 61 and a cooling station 62 are located downstream of the furnace coiler 60. Downstream of the cooling station 62 is a coiler 66, which acts in conjunction with a trolley 67, followed by a roller table for thick sheets, acting in connection with scissors 68 The finished product is either wound up on coils 66 and removed by a trolley 67 in the form of a sheet, strip or rolled thick metal, or cut into thick metal sheets for subsequent processing in a line. The plate product is transferred by the slapper 70 to the finishing production line 71. The finishing production line 71 includes hook-shaped shears for plate metal 72, end shears of thick sheets 74 and a sheet stacker 76. Of course, the equipment of the plate product is not used when it is only necessary to produce a rolled product or a rolled sheet and sheet product.

 The casting thread should have an intermediate thickness, typically from about 3 inches (from 76 to 152 mm), more preferably from 3.5 to 5.5 inches (from 88.9 to about 139.7 mm). The width can usually vary from 25 inches to 100 inches (610 mm - 2540 mm) to produce a product up to 1000 PIW and above.

 The slab is passed flat and back through the hot rolling mill 56, in the minimum number of passes of the flat rolled, reaching the slab thickness of about 1 inch (25.4 mm) and below. The intermediate product is then wound up in a suitable furnace winder, which should be flat downstream of the furnace winder 60 in case of three passes, and then the intermediate product will be passed back and forth between the hot rolling mill 56 and between the furnace winders. sheet thicknesses in the form of a roll, a roll of a thick sheet or a plate product. The number of passes to achieve the thickness of the finished product can vary, but can usually be done in nine passes, which include the original passes flat. In the final pass, which usually comes from the front furnace winder 58, a strip of the required thickness is rolled on a reversible hot rolling mill and pulled through a cooling station 62, where it is suitably cooled for winding on a winder 66 or for feeding onto a rolling table for thick sheets 64. If the product should be made in the form of a roll of sheet or thick sheet, it is wound on a coiler 66 and removed by a trolley 67. If it must go directly in the form of a thick sheet, it enters a roller conveyor 64, where it is cut by the scissors 68 on the proper length. After that, the thick sheet enters the Schlapper 70, which acts as a refrigerator, so that the sheet can be finished clean on the final processing line 71, which includes a descaler 73, edge trimming shears 72, end scissors 74 and stacker 76.

 An apparatus for casting slabs of intermediate thickness and a hot rolling line of strip and thick sheets combined with it according to a modified version of the first embodiment of the invention are shown in FIG. 2. The combination of the casting means and the strip and plate line 25 is identical to line 25 described in connection with FIG. 1, except that the single-cage reversible hot-rolling mill is replaced by a two-cage reversible hot-rolling mill 56 '. The provision of a double stand increases the throughput of the mill. In addition, the two-stand mill 56 'allows the processing of slabs from external sources that are thinner than the slabs of intermediate thickness that can be produced by the casting means 30. With a two-stand mill 56', four are usually required to achieve a thickness at which it can be wound into rolls crimp passes flat on the feed and working table 52 (with two passes occurring at each pass of the slab along the feed and working table 52).

 An apparatus for casting slabs of intermediate thickness with a hot-rolling line of strip and thick sheets including multiple furnaces and / or a multi-cell reversible hot-rolling mill according to another version of the installation of the first embodiment is shown in FIG. 3. The production line of FIG. 3 is in many aspects similar to the line of the version depicted in FIG. 1. One or more electric furnaces provides molten metal at the inlet end of a combination of a means for casting slabs of intermediate thickness and a strip and plate processing line. The molten metal is fed into the casting ladle 128 before being fed to the casting means 130 slabs of intermediate thickness. The casting means 130 feeds a curved or straight crystallizer 132 with a rectangular cross section. A gas cutter or scissors 134 are located at the outlet end of the mold 132 for cutting a strip of hardened metal into slabs of intermediate thickness of a desired length, which may have a width of 24 to 120 inches (310 to 3048 mm). The slab of intermediate thickness is then fed to the roller table for slabs 136. Above the roller table for slabs 136, a slab fire-cleaning machine 137 may be located to process the surface of the slabs. The slab can be removed from the combined production line and stored in the collection and storage area of slabs 140 or it can be loaded directly from the slab to the inlet of a leveling or heating furnace 142. The preferred furnace is a walking beam hearth furnace, although in some cases it can be used hearth heating furnace. Various slabs are fed through the furnace 142, removed in the usual way and placed on the feeding and working roller 152 located at the outlet of the furnace 142. The feeding and working roller 152 is located in line with the casting means in the technological sense, but is not physically located on the same line with the means for casting, as in FIG. 1 and 2.

 When the slabs are transferred to the collection and storage section of slabs 140, they can be removed from the slab conveyor for slabs using a slapper 138 operating across the production line. The slapper for slabs 138 transfers the slab from the roll table for slabs 136 to the feeding and working roller table 152. The second slapper for slabs 144 is located adjacent to the feeding and working roller table 152 for transferring slabs from the feeding and working table to the collection and storage section of slabs 140. An alternative layout should combine the first and second slappers for slabs 138 and 144 into a single slapper, passing from the roller table for slabs to the storage medium of slabs 140, while the feed and working roller table 152 passes and receives slabs from the middle part of the combined Lepper for slabs.

 The furnace 146 is located between the rolling table for slabs 136 and the feeding and working roller table 152 and is adjacent to the furnace 142. The furnace 146 may have an entrance to the feeding and working roller table 152 and an output end to the rolling table for slabs 136. The storage section for slabs further includes a slab conditioning section 148, where, if necessary, additional surface treatment of the slabs is performed.

 The described dual arrangement of the furnace and the device for loading and unloading slabs provides greater flexibility when choosing sources when processing slabs. As noted above, the slab from the casting means 130 can be fed directly through the furnace 142 to the feed and working roller table 152 and further to the production line. Since slabs of intermediate thickness retain heat much longer than thin slabs, the leveling temperature is usually the same as that required in many operating modes.

 This arrangement, moreover, ensures the transfer of the slab from the line position on the slab conveyor 136 to the medium, to the slab collection and storage area or section 140 via slappers 138 and 144. Such a storage or warehouse may be required to enable continuous casting to continue when an accident occurs downstream in the processing line, or alternatively, to ensure removal of a single slab for further processing in the conditioning section of the slabs 148 due to any undesirable defects on top awns. The present arrangement provides greater flexibility in the delivery of slabs from the area or site of collection and accumulation of slabs 140 back to the production line.

 Without delay, the slab can be passed directly onto the feeding and working roller table 152 with a slapper 144 for further processing. A second alternative would be to transfer the slab to the slab conveyor 136 through both slappers 138 and 144. The slab can then follow through the kiln 142 and to the feed and working roller table 152 for processing. When cold slabs are reintroduced into the processing line, this arrangement provides the ability to transfer slabs to the slab conveyor 136 through a heating furnace 146, which should be able to increase power to bring the slabs to the appropriate processing temperature.

 An alternative version of the installation is also considered, in which the input side of the furnace 146 is located on the conveyor for slabs 136, and the output side is on the supply and working conveyor 152. With this arrangement, slabs from the area for collecting and accumulating slabs 140 should usually be fed to the conveyor for slabs 136 and then through one of the suitable furnaces 142 or 146. In this alternative arrangement, both furnaces usually should work the same. In the embodiment depicted in FIG. 3, furnace 146 can be used and act as a preheating furnace, while furnace 142 can typically act as a leveling furnace.

 The present arrangement also provides for direct transfer of the corresponding slab from the conveyor for slabs 136 to the feed and feed roller table 152 for subsequent processing without passing through any of the furnaces 142 or 146.

 Slabs located on the feed and working roller table 152, for subsequent processing are passed through descaling 153 known type. As noted above, the process can be harmful and unprofitable for thin slabs with a thickness of 2 inches (50.8 mm).

 On the line with the feed and working roller table 152 downstream of it there is a reversible hot rolling mill, including a pair of four-roll stands of the mill 156, located so as to act in tandem. An adjustable vertical edger 154 is located between the pair of stands 156 of the rolling mill. The vertical edger 154 is designed to be used in the usual way or to refine the front and rear ends, respectively, of the slab in the first pass through the mill in order to compensate for the widening of the extreme ends that occurs during subsequent rolling. Such refinement can be controlled, and the vertical edger can be passively driven from the twin stands of the mill. The effectiveness of the thinning of the ends can be controlled by the width of the side ruler at the output end, located downstream of the reversing stand of hot rolling, in which the index of the imprint of the width is set, and regulation is carried out by means of the feedback loop with the vertical edger, when necessary.

 The front and rear furnaces with coilers 158 and 160 are respectively located at each side of the pair of stands 156 of the reversible hot rolling mill. The discharge roller 161 is further downstream of the furnace with the coiler 160. The cooling station 162 for cooling by laminar flow is located downstream of the rear furnace with the coiler 160 and runs along the discharge roller 161. Downstream from the cooling station 162 is an overhead coiler 166, which can work in conjunction with a trolley 167. A subsequent finishing line can be provided, essentially the same as that shown previously in FIG. 1 and 2, which includes scissors 68, a schlepper 70, an end production line 71, edge trimming shears for thick sheets 72, end scissors for thick sheets 74 and a stacker of thick 76.

 The installation for casting a slab of intermediate thickness and the combined strip and plate hot rolling line of the second embodiment of the present invention is shown in FIG. 4 and 5. The second option is similar to the first option, including an electric melting furnace 226 located at the inlet end of the strip and plate line 225, a casting ladle 228, casting means 230, a mold 230, and a cutter 234 located at the output end of the hardening metal cutting mold 232 into a slab with a thickness of 3.5 to 6 inches (88.9 - 152.4 mm) (intermediate thickness) of the required length and a width of 24 to 120 inches (6.09 - 3048 mm).

 The slab is then fed onto the slab conveyor 236 to the slab withdrawal zone, where it is loaded directly into the slab 242 or stored in the slab storage receiver 280, or alternatively removed from the integrated processing line and stored in the slab collection and storage area 240. If it is necessary to maintain the temperature slabs before rolling, for example during maintenance of the rolling mill, it is preferable that the slabs are stored in the receiver 280. The zone of slabs 240 is usually used when additional processing of the slab is required, for example superficial processing of a slab by manual fire stripping. Natural-sized slabs 244 and discrete length slabs 246 for some plate products are shown inside a walking beam 242 furnace. Slabs 238 located in the slab collection area 240 can also be fed into the furnace 242 by means of slab ejectors 248 or lever loading devices arranged for indirect loading slabs 238 into a walking-beam hearth furnace 242. You can also load slabs into a furnace 242 from a receiver 280 using a slab conveyor 236. As mentioned above, when slabs are inserted from external (i.e., off-line ASTK, the oven must be able to increase the thermal power to bring the slabs up to rolling temperature. Receiver for slabs 280 minimizes the need for loading such slabs from external portions, from the side.

 Different slabs are fed through the next oven 242.

 The installation according to the second embodiment includes slab ejectors 250, feeding and working roller 252, descaler 253, vertical edger 254 and a hot rolling reversing mill located downstream of the feeding and working roller 252, front and rear furnace winders 258 and 260, cooling station 262 , a coiler 266 downstream of the cooling station 262, a trolley 267, a roller table for thick sheets 264, scissors 268, a slipper 270 and an end production line including edge trimming shears for thick sheets 272, end scissors s for thick sheets 274 and stacker for thick sheets 276.

 In FIG. 5 shows a modified version of an embodiment of the casting means and the integrated rolling mill of FIG. 4, FIG. 5 is identical to FIG. 4, except that there are a plurality of receivers for storing slabs 280 and 280 ′ adjacent to the conveyor for slabs 236. The second receiver for slabs 280 ′ provides additional storage capacity for slabs in case of downstream delay. Adding a second container for storing slabs 280 'also provides the possibility of changes in the order of the slabs. This makes it possible to ensure a certain sequence and change in the sequence of slabs by sending them to the appropriate containers for storing slabs 280 and 280 ', from where the slabs can be selectively removed.

 In FIG. 6 shows a first embodiment of a slab receiver 280. The receiver 280 includes a trolley 282 supported by rollers 284 on guides 286 located inside the storage well for slabs 288. The walls 290 of the storage slab well 288 are suitably insulated, as is the upper surface 292 of the trolley 282, which catches and supports the lowest slab of the foot or stacks of slabs. An insulated movable cover 294 is provided for covering a storage well for slabs 288 and a stack of slabs, as shown by the dotted line in FIG. 6. There are 296 slab breakers in receiver 280.

 The slab receiver 280 operates as follows. The lowermost slab of the slab stack is pushed onto the upper surface 292 of the trolley 282 by the ejector slabs 296. The trolley 282 then descends a distance substantially equal to the thickness of the slab, whereby the second slab can be pushed by the ejector slabs 296 directly onto the first slab. When a stack of slabs is placed in the slab receiver 280, the lid can be placed on top of the storage slab well 288 to retain heat in the slabs.

 The configuration of the slab receiver 280 provides a simple and effective means for storing a stack of slabs, which minimizes the required space. In addition, stacking the slabs on top of one another and keeping the stacked slabs in contact with each other creates thermal advantages for thicker slabs. The temperature or heat loss of individual slabs is minimized with this arrangement.

 FIG. 7 is a side view of another embodiment of a slab receiver 280 ′ according to the present invention.

 The slab receiver 280 ′ includes a trolley 282 ′ supported by a frame 298. The trolley 282 ′ includes a front and rear pair of clinging slabs of levers 300. As shown in FIG. 8, the engaging ends 302 of each arm (rod) 300 engage the lateral edges of the lowermost slab in the stack of slabs to engage and maintain the stack of slabs. It is preferable that the levers (rods) for engaging the slabs operate from a hydraulic actuator and are movable to adapt to different slab widths. The side insulating plates 304 and the upper insulating plate 306 are secured in each bar to engage the slabs 300. As shown in FIG. 8, the upper insulating plates 306 of the opposite rods for engaging the slabs 300 must overlap to allow the rods to move to engage the slabs 300 and to match the different widths of the slabs.

 The slab receiver 280 ′ acts like the slab receiver 280 described above and provides similar advantages. In operation, the trolley 282 'is lowered to a position above the slab and the rods for engaging the slabs 300 are actuated to clamp the slab between them, then the trolley 282' again rises, holding the slab on it. To add a second slab to the stack of slabs, the trolley 282 'is lowered, being located above the second slab, which should be placed in the stack. The slab engaging rods are detached from the first slab, the trolley moves downward to set the engaging tips 302 at the same level as the new lowermost slab in the slab stack, and the slab engaging rods 300 mesh with the new lowermost slab in the slab stack. This process is repeated until all the slabs are stacked, and the process proceeds in the reverse order when removing the slabs from the stack.

 As noted above, the slab receiver 280 'provides the advantages of minimal space and efficiency, effective thermal preservation of the slabs. In addition, the use of the slab receiver 280 ′ makes it possible to install it above the slab conveyor, further reducing the floor or platform space required for the entire system.

 The present invention will make it possible to produce at least 650,000, preferably more than 1 million, rolled clean tons (at least 589670, more preferably more than 987185 rolled clean metric tons) per year with an expanded variety of the resulting product. Such equipment or device can produce a product with a width of 24 to 120 inches (610 - 3048 mm).

 Moreover, in order to achieve the necessary balance between the reversible hot rolling mill and the casting means, it is preferable to produce slabs having a thickness of from about 4 to about 6 inches (from about 76 to about 152 mm), more preferably from about 3.5 to about 5.5 inches (from about 88.9 to about 139.7 mm). As used herein, the term intermediate or average thickness is intended primarily to define such slabs, although for some special steels, for example stainless steel, slabs of average thickness can be up to about 8 inches (about 203 mm). The slabs are crimped or rolled to a thickness at which they can be rolled up, usually about one inch (about 25.4 mm) or less in four flat gauges of a reversing hot rolling mill before cooling the intermediate product between the winding furnaces when it is additionally crimped to the required thickness of the finished product. To provide the possibility of obtaining rolled up thick metal and sheets in rolls, the width of the slab can vary from 24 to 120 inches (from 610 to 3048 mm).

 The basic design of the plant can predictly provide rolling of 150 tons (136 metric tons) per hour in a rolling mill. The requirements of the market should obviously dictate the manufacture of the mixed product, but subject to the calculation of the necessary casting speeds for the installation to produce 150 tons (136 metric tons per hour of rolling), it can be assumed that the bulk of the mixed product will be from 36 inches to 72 inches (from 914 mm to 1829 mm ) Casting of a 72-inch slab (1829 mm) at 150 tons (136 metric tons) per hour requires a casting speed of 61 inches (1549 mm) per minute. With a width of 60 inches (1524 mm), the casting speed increases to 73.2 inches (1859 mm) per minute, with a width of 48 inches (1219 mm), the casting speed increases to 91.5 inches (2324 mm) per minute and with a width of 36 inches (914 mm) casting speed increases to 122 inches (3099 mm) per minute. All of these speeds are within acceptable casting speeds.

 The annual tonnage of the structure can be based on 50 weeks of operation per year with an 8-hour work period and 15 periods or revolutions per week for 6,000 hours per year of available working time, assuming that 75% of the available working time is used and assuming 96% production on existing equipment, under these conditions, the annual tonnage of the output will be approximately 650,000 rolled clean tons (589,670 metric tons).

 Providing the current installation with double reversing stands 156 of the present invention increases the technological tonnage, as well as the possibility of obtaining rental of small calibers, for example, 0.040 inches (1.016 mm), the value of which is growing in many industries, for example in construction, where a hot-rolled product of small calibers is formed into racks , jambs, etc. for replacing logs. The additional rise in price due to the introduction of a reversing mill with a double stand instead of a single-chamber reversing mill is justified by an increase in productivity and flexibility and the possibility of introducing 140 slabs from external sources from the collection and accumulation zone, as noted above. As already noted, such slabs from external sources can have a thickness greater than the thickness of the strip from the casting plant 130, and can provide an even greater variety of products. The following examples illustrate this diversity.

 Example 1. A thick sheet with a width of 48.99 inches (1244 mm), a thickness of 0.040 inches (0.016 mm) in the form of a roll was obtained from a slab of 5 1/2 inches (139.7 mm) according to the following rolling process (see tables 1- 3).

 Example 1 illustrates a wide variety of types of products that can be rolled in the present system. As shown in this example, the present mill can economically perform hot rolling to a thickness of 0.040 inches (0.016 mm). The provision of double stands makes it possible to precisely roll to these small calibers, the need for which is growing on the market.

 Example 2. A thick sheet with a width of 55 inches (1397 mm) and a thickness of 0.060 inches (1.52 mm) in the form of a roll was obtained from casting a slab of 5 1/2 inches (139.7 mm) according to the following rolling process (see tables 4-6).

 Hot rolled products of small (reduced) gauge, for example about 0.040 inches (1.0 mm) and about 0.060 inches (1.5 mm), can be used as the final gauge in situations where the final gauge is usually not exposed (or open) and no surface finish is required. This, for example, the metal structure of the racks, for example, a thickness of 0.040 inches (1.0 mm), galvanized racks, are the final range. This is a clear advantage with respect to known methods: a hot-rolled product, usually having a thickness somewhere above 0.080 inches (2.0 mm), is then pickled and then finished clean on a cold rolling mill, followed by annealing and tempering.

 Example 3. A thick sheet with a width of 62 inches (1574 mm) and a thickness of 0.090 inches (2.3 mm) in the form of a roll was obtained from a 10-inch casting of a slab (254 mm) from an external source according to the following rolling process (see table 7 -ten).

 Example 4. A thick sheet with a width of 48 inches (1219 mm) and a thickness of 0.125 inches (3.176 mm) of high carbon steel in the form of a roll was obtained from continuously cast slab with a thickness of 5 1/2 inches (139.7 mm) according to the following rolling process (see tables 11-17).

 Example 5. A thick sheet with a width of 60 inches and a thickness of 0.100 inches (1524 mm • 2.54 mm) in the form of a roll was obtained from a 5-inch slab (127 mm) of low carbon steel according to the following rolling process (see tables 18-21 )

 Examples 4 and 5 show the range of varieties produced by the present invention, providing the basic product mix required for a competing rolling mill.

Claims (10)

 1. Installation for casting slabs of intermediate thickness with a hot-rolling line of strips and thick sheets, containing means for continuous casting of strips of intermediate thickness, mounted in line with a cutter located downstream of the means for casting and intended for cutting continuously cast strips into slabs of the required length, means for storing slabs, at least one heating furnace located downstream of the means for storing slabs, a supply and working roller table located at the outlet end of at least at least one furnace, a hot rolling reversing mill installed in line with the feed and working roller table and designed for rolling slabs heated in the oven into an intermediate product with a thickness sufficient for winding into a roll, and a pair of furnace winders, one of which is located upstream of the reversing the mill, and the other is located downstream, while the furnace coilers are arranged to receive and unwind the intermediate product sent between the furnace coilers through a reversible hot rolling mill to the product finite thickness t, characterized in that it comprises means for selectively interleaving slab feeding slabs or for bypass of at least one preheating furnace.  2. Installation according to claim 1, characterized in that it contains a conveyor for slabs mounted in line with the cutter, and the means for alternating slabs includes means for transferring slabs adjacent to the conveyor for slabs and acting across the conveyor, while the means for transmitting slabs communicates with the feed and a working roller table, adjoins the slab storage means and is adapted to selectively receive slabs from the slab storage means.  3. The installation according to claim 2, characterized in that it contains a pair of heating furnaces, wherein the first heating furnace is located between the feed and working roller table and the conveyor for slabs, and the second heating furnace is located downstream and adjacent to the first heating furnace, its inlet end is combined with a conveyor for slabs and the outlet end is combined with a feed and working roller table.  4. The installation according to claim 1, characterized in that the feed and working roller table is installed in line with the cutter and is adapted to receive slabs directly from the cutter, while the means for alternating slabs includes means for transferring slabs adjacent to the feed and working table and acting across the feed and working roller table for selective removal of slabs from the roller table, the slab conveyor adjoins the slab transfer means and is adapted to receive slabs from the transfer means, and the slab storage means adjoins the conveyor and adapted for receiving slabs from the conveyor.  5. Installation for casting slabs of intermediate thickness with a line for hot rolling of strips and thick sheets, containing means for continuous casting of strips of intermediate thickness, mounted in line with a cutter located downstream of the means for casting and intended for cutting continuously cast strips into slabs of the required length, means for storing slabs, at least one heating furnace located downstream of the means for storing slabs, a supply and working roller table located at the outlet end of at least at least one furnace, a hot rolling reversing mill installed in line with the feed and working roller table and designed for rolling slabs heated in the oven into an intermediate product with a thickness sufficient for winding into a roll, and a pair of furnace winders, one of which is located upstream of the reversing the mill, and the other is located downstream, while the furnace coilers are arranged to receive and unwind the intermediate product sent between the furnace coilers through a reversible hot rolling mill to the product t of final thickness, characterized in that it contains a slab conveyor mounted in line with the cutter, and the slab storage means comprises at least one vertically stacking slab receiver located adjacent to the slab conveyor and containing a vertically movable trolley for supporting the stack slabs.  6. A method of producing metal strips, including continuous casting of a slab of intermediate thickness, cutting it into slabs of a given length, reversible hot rolling of slabs to form an intermediate product with a thickness sufficient to wind it into a roll, winding the intermediate product into a roll, winding it into a roll of an intermediate winder and further reversing hot rolling with the winding-unwinding of the intermediate product roll into a strip, characterized in that each piece slab is selectively fed either directly to a reversing hot rolling mill, or о for intermediate heating and after heating for hot rolling, or to a means for storing slabs with further heating and subsequent laying in a strip.  7. The method according to claim 6, characterized in that the slab supplied for heating and rolling from the storage means is preliminarily or continuously poured and cut at the beginning of the production line, or fed from the side.  8. The method according to claim 6, characterized in that the slabs are stacked in the storage medium.  9. The method according to claim 6, characterized in that the slabs from the storage means for subsequent heating are served selectively in one of two furnaces.  10. The receiver for slabs in the installation for casting slabs with a line for hot rolling of strips and sheets, made with heat insulation, characterized in that it is located between the means of continuous casting and a reversing mill of hot rolling, made with the possibility of selective reception of slabs from means of continuous casting, contains a vertically movable trolley adapted to mesh with the lowest slab from a stack of slabs directly in contact with each other, and the thermal insulation is made at least around the sides and top of the stack.

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