JP2007023323A - Steel plate production hybrid line with excellent productivity and method for separating steel plates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel plate production line that makes the best use of the annealing capacity of the annealing line, and a method for making steel plates by which various steel plates are made on the line.
SOLUTION: In a steel sheet production line including an annealing line 1, (a) an electroplating line 3, a hot dipping line 2, and an annealed steel sheet storage / shipment line 4 following the annealing line 1 are arranged in parallel with each other. And (b) the electroplating line 3, the hot dipping line 2, and the annealed steel sheet storage / shipment line 4 are in an array relationship with the annealing line 1, and (c) from the annealing line 1, The annealed steel sheet is distributed to an electroplating line 3, a hot dipping line 2, and an annealed sheet storage / shipment line 4 according to the demand for the steel sheet.
[Selection] Figure 1

Description

  The present invention relates to an electroplated steel sheet, a hot dip plated steel sheet, and a manufacturing line and a method for making a steel sheet as appropriate according to the steel sheet demand.

  Conventionally, hot-dip plated steel sheets are manufactured in a steel sheet manufacturing line equipped with an annealing line and a hot dipping line, and electroplated steel sheets are manufactured in a steel sheet manufacturing line equipped with an annealing line and an electric plating line (Patent Documents). 1 and 2).

  Patent Document 1 discloses that the delivery of a steel plate is controlled by a process computer in order to reduce the in-process between processes. Further, Patent Document 1 discloses that the rolling speed and the line speed of continuous heat treatment are synchronized in the case of passing through the subsequent continuous annealing line as it is without removing the strip after cold rolling.

  Patent Document 2 discloses a continuous processing line for cold-rolled strips connected in parallel via a strip winding device and a coil conveyor after cold rolling. The post-processing line described in Patent Document 2 is a line for processing a cold-rolled steel sheet, and is a continuous annealing line, a continuous plating line, or the like. In addition, this continuous plating line has heating furnaces, such as a preheating chamber and a reduction furnace.

  As disclosed in Patent Documents 1 and 2, each plated steel sheet production line includes an annealing line in the line, and anneals the steel sheet to be used for the next plating line.

  The productivity of the steel sheet production line depends on the speed at which the steel sheet passes through the plating line as the final line (plating line speed), but the plating line speed is slower than the annealing line speed.

  For example, the line speed of continuous annealing equipment for cold-rolled steel sheets is 180 to 600 mpm (see Non-Patent Document 1), while the line speed of hot-dip galvanizing equipment is 100 to 200 mpm (see Non-Patent Document 2). In addition, the line speed of the electrogalvanizing equipment is 100 to 200 mpm (see Non-Patent Document 3).

  Thus, the line speed of hot dip galvanizing equipment and electroplating equipment is smaller than the line speed of continuous annealing equipment.

  Therefore, when the in-line annealing equipment is attached to the hot dip galvanizing equipment, the line speed of the annealing equipment is controlled in accordance with the plating speed. Moreover, in order to adjust the production capacity of the electroplating equipment, the annealing equipment must be operated intermittently or the line speed of the annealing equipment must be reduced.

  In addition, a method of manufacturing a steel sheet that is subjected to pre-Ni plating (electroplating) after annealing and then hot-dip galvanized has been proposed (see Patent Document 3,), but in a plating line that performs this manufacturing method, It is necessary to adjust the line speed of the annealing equipment in accordance with the heating time before hot dip galvanization and the alloying time after hot dip plating.

  After all, the annealing line is always in line with the production capacity of the plating line, even if it has the required annealing capacity (maximum annealing capacity) apart from the in-line annealing equipment attached to the hot dip galvanizing equipment. The fact is that it is forced to operate at an annealing capacity below the maximum annealing capacity.

  In addition, when a new line for manufacturing a plated steel sheet is newly added, it has been naturally performed to provide a dedicated annealing line in front of the plating line in accordance with the conventional design concept (see Non-Patent Document 2). ).

  However, this is to establish a new annealing line that operates at an annealing capacity suitable for the plating equipment. As a result, the old line that operates at an annealing capacity below the maximum annealing capacity and a new one designed with a lower annealing capacity are designed. The new and old two-row annealing line with the line will coexist.

  In this way, in the current steel plate production line in which the plating line is simply arranged in series with the annealing line, it is the actual situation that the annealing capacity of the annealing line is minimized, and in the newly installed steel plate production line However, as long as each line is arranged in series according to the conventional design concept, the annealing capacity of the annealing line cannot be fully utilized.

JP-A-56-122611 JP-A-57-58905 JP 2003-183798 A "The 88th and 89th Nishiyama Memorial Lecture" Advances in Continuous Strip Annealing Technology ", page 291 “138th and 139th Nishiyama Memorial Lecture“ Surface Treatment Technology Progress and Future Trends ”, p. 6 "138.139th Nishiyama Memorial Lecture" Surface Treatment Technology Advances and Future Trends ", p. 53

  In view of the above circumstances, the present invention is a steel plate production line capable of making the best use of the annealing capacity of the annealing line, and a steel plate capable of appropriately making various steel plates according to the demand of the steel plate in the steel plate production line. The purpose of this is to provide a method of making different types.

  The present inventor has conducted earnest research on a steel sheet production line that can make the most of the annealing ability of the annealing line, based on the design philosophy opposite to that of the conventional steel sheet production line.

  In order to make the best use of the annealing capacity of the annealing line, it is necessary to continuously feed the steel sheet after annealing to the next line, but as a result of earnest research, the present inventor has conducted a final line following the annealing line. If the hot-dip plating line, electroplating line, and annealed steel sheet storage / shipment line are arranged in parallel and the lines that cooperate with each other are configured, the steel sheets after annealing are continuously It was found that the annealing ability of the annealing line can be maximized because it can be distributed and sent to any of the lines, and productization and product shipment can be carried out without any hesitation.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

(1) In a steel sheet production line equipped with an annealing line,
(A) The electroplating line, the hot dipping line, and the annealed steel sheet storage / shipping line following the annealing line are in parallel with each other, and
(B) The electroplating line, the hot dipping line, and the annealed steel sheet storage / shipment line are in a serial relationship with the annealing line,
(C) A steel plate production hybrid line with excellent productivity, characterized in that an annealed steel sheet is distributed from an annealing line to an electroplating line, a hot dipping line, and an annealed sheet storage / shipment line according to the demand for the steel sheet.

  (2) In the said arrangement | positioning relationship, an annealed steel plate storage / shipment line, an electroplating line, and a hot dipping line are mutually connected, The steel plate excellent in productivity as described in said (1) characterized by the above-mentioned. Production hybrid line.

  (3) The steel plate manufacturing mixed line having excellent productivity according to (1) or (2), wherein the annealing line is operated to the maximum to anneal the steel plate.

(4) A method of making steel sheets separately in an annealing line and a steel plate production mixed line comprising an electroplating line, a hot dipping line, and an annealed steel sheet storage / shipping line, which are in parallel with the annealing line. ,
(A) Operate the annealing line to the maximum to anneal the steel sheet,
(B) A method for producing steel sheets with excellent productivity, characterized by allocating annealed steel sheets to an electroplating line, a hot dipping line, and an annealed steel sheet storage / shipment line according to the demand for steel sheets.

  (5) In the steel plate production hybrid line, the annealed steel plate storage / shipment line, the electroplating line, and the hot dipping line are in a cooperative relationship with each other, and the productivity according to (4) is excellent. Steel sheet making method.

  According to the present invention, in the steel sheet production line, the annealed steel sheets are continuously distributed and fed to any one of the final lines, ie, the hot dipping line, the electroplating line, and the annealed steel sheet storage / shipment line. Since product production and product shipment can be carried out without difficulty, various steel plates can be appropriately made according to the demand for steel plates by making full use of the annealing capacity of the annealing line.

  The present invention will be described with reference to the drawings. FIG. 1 shows a basic steel plate production hybrid line of the present invention.

  The basic line configuration of the present invention includes an annealing line 1, a hot dipping line 2, an electroplating line 3, and an annealed steel plate that are arranged in series with each other and are arranged in parallel with each other. A storage / shipping line 4 is included.

  The annealing line 1 is basically (i) mainly including a payoff reel, a welding machine, a cleaning device, an inlet side device including an inlet side looper, and (ii) mainly including pre-tropical zone, heating zone and soaking zone. A furnace, a cooling zone (which may include an overaging furnace and a secondary cooling zone after the cooling zone), and (iii) mainly an exit side looper, a temper rolling mill, a cutting machine, a tension reel, a side trimmer, Consists of a delivery facility including a surface inspection unit and an oiling machine.

  The annealing line may be connected to the cold rolling line, and in this case, the payoff reel is omitted.

  The hot dip plating line 2 basically includes (i) an inlet side apparatus (including an acid pickling apparatus and an Ni plating apparatus) mainly including a payoff reel, a welding machine, an inlet side looper, and a cleaning device, and (ii) Heating equipment that heats up to the temperature at which hot dip plating is performed, hot dip plating furnace, alloying furnace, and (iii) mainly including temper rolling mill, coater, exit looper, side trimmer, cutting machine, tension reel It consists of a processing device.

  The electroplating line 3 includes (i) an entrance side device mainly including a payoff reel, a welding machine, an entrance side looper, a cleaning device, and a pickling device, (ii) a plating device mainly consisting of a plating tank, and ( iii) Mainly composed of post-treatment equipment including phosphate treatment, chemical treatment, etc., delivery looper, oil coater, delivery device including tension reel.

  The annealed steel plate storage / shipment line 4 includes a packing line, a storage place, and a shipping yard.

  The hot dipping line 2, the electroplating line 3, and the annealed steel sheet storage / shipment line 4 are in a parallel arrangement with each other and in a cooperative relationship. These lines are in series with the annealing line 1.

  From the annealing line 1 to the hot-dip plating line 2, the electroplating line 3, and the annealed steel sheet storage / shipment line 4, the annealed steel sheet coils are conveyed by a coil conveyor, a coil car, a crane, and the like.

  Further, the stored annealed steel sheet coil can be moved from the annealed steel sheet storage / shipment line 4 to the hot dipping line 2 and / or the electroplating line 3 by a coil conveyor, a coil car, a crane or the like (see “ (See dotted line).

  In addition, the annealing steel plate storage place may be one place or many places as long as the existence place of the coil is recognized and the coil can be moved as shown in FIG.

  A steel plate is supplied to the annealing line 1 from a hot rolling line or a cold rolling line 5. The hot rolled steel sheet rolled to a predetermined thickness in the hot rolling process is supplied to the cold rolling line 5. The steel sheet rolled to a predetermined thickness in the cold rolling process is supplied to the subsequent annealing line 1. In the annealing line 1, in order to make the material of the steel plate, the steel plate is heated and held at a necessary temperature, and then cooled.

  The steel plate manufactured in the annealing line 1 is supplied to the hot dipping line 2 and the electroplating line 3.

  When producing galvanized steel sheets or electroplated steel sheets having the same thickness, cold-rolled steel sheets having the same thickness may be used. Moreover, when manufacturing the galvanized steel plate or electroplated steel plate of the same material, the heating-cooling pattern in the same annealing process may be sufficient.

  Therefore, usually, from the stage of hot-rolled steel sheets, product specifications are determined and manufactured in a planned manner.For example, when a hot-dip galvanized steel sheet is required from an electroplated steel sheet for the convenience of the customer, When the steel sheet is cold-rolled, the manufacturing object can be changed from the electroplated steel sheet to the hot-dip galvanized steel sheet, and the annealing process is not vacated.

  This change from the electroplated steel sheet to the hot dip galvanized steel sheet is possible even when the steel sheet enters the annealing line 1.

  Also, when the temper rolling ratio of the electroplated steel sheet and hot dip galvanized steel sheet is the same, even after exiting the annealing line 1, after the annealed steel sheet is temporarily stored, the electroplated steel sheet is changed to the hot dip galvanized steel sheet. It is also possible to do.

  In this case, since there is no change in the steel sheet supplied to the annealing line, the annealing process can be operated without changing the plan, so that the production capacity is not reduced.

  After the conventional cold rolling process, an electroplated steel sheet is manufactured through an annealing line-electroplating line, and a hot dip galvanized steel sheet is manufactured through a hot dip galvanizing process having an inline annealing process. After passing through the rolling process, when the change from electroplated steel sheet to hot dip galvanized steel sheet occurs as described above, the annealing line leading to the electroplating line is vacant, and the part to the in-line annealing process in the hot dip galvanizing process. The load will increase.

  And when the hot dip galvanizing process is in full operation, if there is an increase in the load described above, the input plan for the hot dip galvanizing process must be changed, and the production of steel sheets by other orders will be delayed accordingly. become.

  Furthermore, in the case of producing an electroplated steel sheet through an annealing line-electroplating line and in the case of producing a hot dip galvanized steel sheet through a hot dipping process having an in-line annealing process, a steel material having the same material and thickness range. Even so, the plated steel sheet may be manufactured from materials whose component adjustment methods are different.

  Such component adjustment at the material stage is necessary because the temperature history in the annealing line before electroplating is different from the temperature history in the in-line annealing furnace before hot dipping.

  In this case, after cold rolling, it is difficult to turn back the steel sheet, for example, from electroplating to hot dipping, and a change from the steelmaking stage is necessary. In preparation for such a change, having two annealing furnaces having different temperature histories affects the production capacity of the entire manufacturing process.

  The previous example is easy to understand and has been described by taking a short-term order change as an example. However, such an order change may occur even in a long-term order.

  However, even when an order change from electroplated steel sheet to hot dip galvanized steel sheet occurs over a long period of time, as shown in FIG. 1, hot dip galvanizing line 2 and electroplating line 3 are arranged in parallel after annealing line 1. If the formed line is configured, it is possible to efficiently produce the plated steel sheet by changing the hot dip galvanized steel sheet from the electroplated steel sheet without reducing the production capacity of the annealing line 1. .

  On the other hand, according to the conventional line configuration, after the cold rolling process, an electroplated steel sheet is manufactured through an annealing line-electroplating line, and a hot dip galvanized steel sheet is manufactured through a hot dip galvanizing process having an inline annealing process. In this case, when a long-term order change as described above occurs, the production capacity of the annealing line that leads to the electroplating line is reduced.

  Therefore, when the steel plate production mixed line of the present invention (the present invention mixed line) is used, even if the product composition changes in the short or long term, the productivity of the annealing line is not lowered, and the entire production process is changed. Thus, a plated steel sheet can be efficiently produced.

  When manufacturing a steel plate using the hybrid line of the present invention, the operator prepares an operation plan in consideration of sending the cold-rolled steel plate (or hot-rolled steel plate) to the annealing line 1 and operating the annealing line to the maximum extent. be able to.

  At this time, in the hybrid line of the present invention, the temperature history in the annealing line can be made the same, and can be adjusted according to the material characteristics, so the material of the same component system can be fused with the electroplated steel sheet. It is also possible to manufacture plated steel sheets, that is, to make these steel sheets separately.

  In this case, the annealed steel sheet coil exiting the annealing line may be supplied to the electroplating line or the hot dipping line as it is, or the annealed steel sheet coil stored in the annealed steel sheet storage / shipping line 3 is electroplated. You may supply to both plating lines from the said line 3 according to the operating condition of a line and a hot dipping line.

  By creating a production plan in this way, it is no longer necessary to consider the optimization of productivity in consideration of the operation mode and operation status of the two lines as in the past, so that the production plan can be simplified and the production plan can be simplified. Efficiency can be easily achieved.

  Further, by creating a production plan in this way, it is considered that cold-rolled steel sheets (or hot-rolled steel sheets) are divided into an annealing-electroplating line and an in-line annealing-hot-dip plating line as in the conventional line configuration. Since it becomes unnecessary, the storage amount of the cold-rolled steel sheet after the cold-rolling line required for adjusting the allocation by looking at the operating conditions of both lines can be significantly reduced as in the conventional case.

  Conventionally, steel plate coils have been stored after the cold rolling line as a buffer when the cold rolling line is stopped due to periodic repairs or sudden failures, for an annealing-electroplating line and an in-line annealing-hot-dip plating line.

  The main reason for this is that the two lines are operating independently of each other. Conventionally, the temperature history is different between annealing before electroplating and inline annealing before hot dipping, For this reason, the component composition of the supplied material is often different.

  On the other hand, in the hybrid line of the present invention, it is only necessary to store the annealed steel sheet coil as a buffer only for the annealing line 1, so the amount of storage coil after the cold rolling line is reduced.

  Furthermore, in the hybrid line of the present invention, the temperature history in the annealing line can be adjusted to be the same or adapted to the material characteristics, and the electroplated steel sheet and the hot dip plated steel sheet are manufactured with the same component system material. That is, since it is possible to make these steel plates separately, the storage amount of the steel plates after the cold rolling line can be reduced accordingly.

  In the hybrid line of the present invention, the annealed steel sheet storage / shipment line 3, the hot dipping line 1 and the electroplating line 2 are linked to each other, and the annealed steel sheet coils are exchanged between these three lines (flexibility). can do.

  That is, while observing the operation status in the electroplating line or the hot dipping line, the annealed steel sheet coil can be supplied to either or both of the above lines from the storage line of the annealed steel sheet storage / shipment line.

  Furthermore, in the hybrid line of the present invention, the material characteristics can be adjusted by making the temperature history the same in the annealing line 1, so that the electroplated steel sheet and the hot dip plated steel sheet are manufactured with the same component materials, that is, these It is also possible to make steel plates separately, and the annealed steel plate coils can be moved and conveyed from the annealed steel plate storage / shipment line 4 to the hot dipping line 2 and the electroplating line 3 as necessary.

  Thus, in the hybrid line of the present invention, the steel plate coil that has been annealed can be supplied to the hot dipping line 2 and the electroplating line 3 and utilized between the two lines. Can be supplied to the next line without any waste.

  In this manner, since the annealed steel sheet coil can be exchanged (accommodated) between the plating lines, the annealing ability of the annealing line 1 can be further utilized to the maximum extent.

Next, examples of the present invention will be described. The conditions of the examples are one example of conditions adopted for confirming the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. Is not to be done. The present invention can adopt various conditions as long as the present invention is achieved without departing from the gist of the present invention.
(One line configuration example)
FIG. 2 shows a configuration example of the hybrid line of the present invention. An annealing steel sheet storage / shipment line 4 having a storage place and a product warehouse is arranged in series with the line 1 following the annealing line 1, and a hot dipping line 2 and an electroplating line 3 are arranged in parallel on both sides thereof. Yes. As shown in the figure, the lines in the parallel arrangement relationship are in a relationship of mutual cooperation. In the figure, 6 is a storage place and 7 is a product warehouse.

  In FIG. 3, the one aspect | mode of the annealing steel plate storage and shipment line in this invention hybrid line is shown. The annealed steel sheet storage / shipment line includes a transport facility 8 for discharging the annealed steel sheet coil from the annealing line 1, a packing line 9 connected thereto, a transport device 10 for transporting the packed annealed steel sheet coil, and a refining line 11 for refining the coil. The crane 12 conveys the annealed steel sheet coil, and the storage place 6 stores the coil.

  The flow of the annealed steel sheet coil in the annealed steel sheet storage / shipment line will be described with reference to this figure.

  First, the flow of the annealed steel sheet coil shipped as a product coil will be described.

  (1) A part of the steel sheet coil annealed in the annealing line 1 reaches the refining A ridge 13 by the exit side equipment of the annealing line 1 and is temporarily placed in the refining A ridge 13 by the crane 12.

  (2) This steel sheet coil is subjected to removal of defective portions and inner diameter adjustment in the finishing line 11 and further trimmed, and reaches the packing line 9 by the crane 12 and the transfer machine 15 in the finishing building B 14, and the conveying device 10. And the crane 12 is stored in the product warehouse 7 for shipment as a product.

  (3) Annealed steel sheet coil that is not processed by the routes (1) and (2) is transferred to the crane 12 through the transfer equipment 8, the transfer machine 15, the packing line 9, and the transfer device 10 on the exit side of the annealing line 1. In order to ship as a product, it is stored in the product warehouse 7.

  Next, the flow in the case of supplying an annealed steel plate coil to an electroplating line or a hot dipping line will be described.

  The steel sheet coil supplied to the electroplating line or the hot dipping line is unloaded from the transfer equipment 8 on the exit side of the annealing line, and when it needs to be adjusted, it passes through the adjusting line 11 and is adjusted. Is not stored in the storage place 6 by the transfer machine 15 and the crane 12 from the finishing building B 14 without going through the finishing line 11, or directly to the plating line. Supplied.

  For example, as shown in FIG. 2, the storage place 6 is provided on both the side for supplying the annealed steel sheet coil to the hot dipping line and the side for supplying the annealed steel sheet coil to the electroplating line.

  It is desirable that the storage amount of the coil stored in the storage location be at least a storage amount sufficient to cover the operation of the line for about two days in consideration of the periodic repair and sudden failure of each line.

  The annealed steel sheet coils stored in the storage locations of both plating lines can be moved to another plating line and used. That is, for example, an annealing coil stored in a storage place for electroplating is moved to a storage place for hot dipping, and an annealed steel sheet coil stored for electroplating is moved to a storage place for hot dipping. And can be used mutually. It should be noted that the storage locations can be integrated into one location in line configuration.

  The plated steel sheet coil produced in the electroplating line and the hot dipping line is once stored in the storage place or directly transported to the refining building B 14, and if refining is required, the crane 12 After being placed in the refining B building, it is moved from the refining B building 14 to the refining A building 13 by the inter-building carriage 16, and is transported to the packing line by the crane 12 and the transfer machine 15 through the refining line 11. .

  On the other hand, the plated steel sheet coil that does not require refining is conveyed to the packing line 9 by the crane 12 and the transfer machine 15 in the refining B building 14.

  These plated steel sheet coils are transported by the transport device 10 and the crane 12 and stored in the product warehouse 7 for shipment as products.

  In addition, when the plated steel sheet coil manufactured by the electroplating line and the hot dipping line is packed and shipped, it may be packed and shipped as it is without returning to the precision building B 14. This packing / shipping does not hinder the full use of the annealing capacity of the annealing line.

  In the hybrid line of the present invention, the annealing line may be a normal annealing line, and may be improved or devised so as to be compatible with the hybrid line of the present invention.

  An annealing furnace is generally composed of a payoff reel, a welding machine, a coil cleaning device (electric cleaning), an entrance looper, an annealing furnace, and an exit looper. In the annealing furnace, the temperature history can be changed according to the characteristics of the steel sheet.

  Following the annealing furnace, post-processing equipment, a temper rolling mill, a trimmer, a shear, and a tension reel are installed. Moreover, you may arrange | position a cold rolling mill and an annealing furnace continuously.

  FIG. 4 shows an embodiment of a hot dipping line incorporated in the hybrid line of the present invention. When the hot dipping line is arranged after the annealing line, it is sufficient to heat the steel plate to a temperature at which hot dipping can be performed, and it is not necessary to heat to the annealing temperature.

  In the hot dipping line shown in FIG. 4, after the unwinding machine 17 for rewinding the annealed steel sheet coil, the steel strip such as the inlet side equipment 18 including the shear and the welding machine, the inlet side looper 19 and the removal of the rolling liquid is washed. Pretreatment equipment 20 to perform, pre-plating equipment 21 for plating nickel, heating device 22 for heating the steel strip immediately before hot dipping, hot dipping equipment (pot) 23, alloying furnace equipment 24 for alloying the steel strip ( (Including heat insulation furnace 25, cooling zone 26, water cooling zone 27), skin pass mill (SPM) 28 for adjusting the thickness of the steel strip, post-treatment equipment 29 for surface treatment of the steel strip, outlet looper 30, trimmer, Euler A take-out facility 31 including a shear and a winder, and a winder 32 that winds up the plated steel sheet are sequentially arranged from the upstream side toward the downstream side.

  Next, the configuration of a heating device that performs heating immediately before hot dipping will be described. FIG. 5 shows one mode of the heating device.

  The heating device 33 shown in FIG. 5 employs a heating method by a transformer effect type heating method. In the heating device 33, a conductive roll 34 and a turn roll 35 are arranged in order from the upstream side along the steel strip H. The exit side of the turn roll 35 communicates with a turn roll 36 provided in a plating tank 38 of a hot dipping apparatus 37.

  The periphery of the steel strip from the seal roll 39 to the plating tank 38 is surrounded by an enclosure 40, for example. By this surrounding, the steel strip can be placed in a predetermined inert atmosphere between heating and plating.

  Between the conductive roll 34 and the turn roll 35, for example, a ring-shaped iron core 41 surrounding the steel strip H and the surrounding body 40 is provided. A primary coil is wound around the iron core 41, and an AC power source 42 is connected to the primary coil.

  The front end of the enclosure 40 is in contact with the plating metal accommodated in the plating tank 38. A bus bar 43 that is electrically connected to the conductive roll 34 is connected to the front end of the enclosure 40. Thereby, the secondary coil 44 that winds the iron core 41 is formed by the conductive roll 34, the steel strip H, the plating metal in the plating tank, the tip of the enclosure 40, and the bus bar 43.

  By applying a voltage to the primary coil with the AC power supply 42 and causing a current to flow, power can be induced on the secondary coil side and a high current can be caused to flow through the steel strip H. With this current, the steel strip H can generate heat and the steel strip can be heated.

  In the hybrid line of the present invention, a normal electroplating line can be adopted as the electroplating line, but improvements and devices may be added so as to be compatible with the hybrid line of the present invention.

  In the electroplating line, after the unwinder, usually the inlet side equipment such as shear and welder, the inlet side looper, the pretreatment equipment for cleaning the steel strip such as removing the rolling fluid, plating tank, phosphate Post-processing equipment including processing, chemical processing, and the like, outlet-side equipment including outlet-side loopers, trimmers, oilers and shears, and a winder are arranged.

(Operation mode and results)
Conventionally, the product composition was 50 annealed steel plates, 50 electroplated steel plates passing through the annealing line, and 0 hot-dip plated steel plates passing through the anneal line. However, according to the hybrid line of the present invention, the product composition changed. Based on the conventional amount, the annealed steel sheet was 50, the electroplated steel sheet passing through the annealing line was 30, and the hot dip plated steel sheet passing through the annealing line was 30.

  When a new in-line annealing-hot-dipping line was installed as in the prior art, the production of the annealing line was reduced by 20%.

  On the other hand, when the hybrid line of the present invention was used, the annealing line could be fully utilized. In addition, the total amount of steel required for annealing has increased from 100 to 110, which is essentially due to a partial modification of the annealing line with potentially high production capacity, thereby annealing the annealing line. It means that the ability was fully utilized.

  Further, even when a hot dip plating line is newly installed, it is not necessary to install an in-line annealing furnace in front of the hot dip plating facility, so that the construction cost is 30 compared with the case where a new in-line annealing-hot dip plating line is configured. % Reduction.

(Operation mode and metallurgical effect)
According to the hybrid line of the present invention, it will be described that an electrogalvanized steel sheet and a hot-dip galvanized steel sheet can be made separately using annealed steel sheet coils having the same component system.

  When producing an electrogalvanized steel sheet with aluminum killed steel containing about 0.03 to 0.05% C and about 20 to 30 ppm of B, it is heated to about 700 to 850 ° C. in an annealing furnace, and after cooling, An overaging treatment step for holding at about 400 ° C. was provided for annealing. By this annealing, the amount of dissolved C can be reduced and aging can be improved.

  On the other hand, when aluminum killed steel with the same composition is produced in an in-line annealing-hot-dipping equipment, there is no overaging treatment process, so the amount of solute C becomes slightly higher and the yield point after aging becomes higher, so electroplating In order to obtain the same material as the steel plate, it was necessary to finely adjust and reduce the C concentration.

  In the hybrid line of the present invention, since the annealing line is the same, when producing a hot-dip galvanized steel sheet, it is heated to about 700 to 850 ° C. in an annealing furnace, cooled, and then kept at about 400 ° C. A process can be provided, the amount of solid solution C can be reduced, and aging can be improved.

  Therefore, according to the hybrid line of the present invention, an electrogalvanized steel sheet and a hot-dip galvanized steel sheet having the same component composition are produced from an aluminum killed steel containing 20-30 ppm of B with a C concentration of about 0.03-0.05% ( Can be made separately).

  Conventionally, in the case of IF steel, the electrogalvanized steel sheet is produced with a Ti-SULC component (C: 30 ppm or less, Ti: 0.01% to 0.06%), and the hot dip galvanized steel sheet is Ti-Nb- It was manufactured with a SULC component (C: 30 ppm or less, Ti: about 0.01% to 0.04%, Nb: about 0.01 to 0.03%).

  The reason for using a Ti—Nb—SULC component steel sheet for the hot dip galvanized steel sheet is to improve the powdering property of the plating characteristics.

  Therefore, the component composition is different between the electroplated steel plate and the hot dip plated steel plate, and conventionally, the steel plate to be manufactured cannot be transferred from the electroplated steel plate to the hot dip plated steel plate during the production of the steel plate.

  On the other hand, according to the hybrid line of the present invention, since Ni pre-plating can be performed in the previous stage of the hot dip galvanizing line, the Ti-SULC component can be used without using a Ti-Nb-SULC component steel plate. The powdering property can be improved even in the case of a steel sheet.

  Therefore, in the hybrid line of the present invention, the component composition of the electroplated steel plate and the hot dip plated steel plate can be made the same, so that the steel plate to be manufactured can be transferred from the electroplated steel plate to the hot dip plated steel plate during the steel plate production. It became possible.

  Furthermore, after manufacturing an annealed steel sheet of IF steel having a predetermined composition, it is possible to store the annealed steel sheet coil in a storage line and supply the annealed steel sheet coil as a material for an electroplated steel sheet or a hot dip plated steel sheet. is there.

  In this way, in the hybrid line of the present invention, depending on the steel type, a hot-dip plated steel plate and an electroplated steel plate can be manufactured (separated) using steel materials of the same range components, so during steel plate manufacturing (before annealing, after annealing) Further, it is possible to transfer the steel plates to both plated steel plate lines, improve the productivity of the annealing line, and perform product manufacture and shipment without any trouble.

  As described above, according to the present invention, in the steel rice production line, various steel plates can be appropriately made according to demand by making the best use of the annealing capacity of the annealing line. Therefore, the present invention has high applicability in the steel industry.

It is a figure which shows one embodiment of this invention. It is a figure which shows one structural example of this invention line. It is a figure which shows the embodiment of the annealing steel plate storage and shipping line integrated in the hybrid line of this invention. It is a figure which shows the one aspect | mode of the hot dipping line incorporated in the hybrid line of this invention. It is a figure which shows the one aspect | mode of the heating apparatus integrated in the hot dipping line of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Annealing line 2 Hot dipping line 3 Electroplating line 4 Annealed steel plate storage and shipping line 5 Hot rolling line or cold rolling line 6 Storage place 7 Product warehouse 8 Transport equipment 9 Packing line 10 Transporting device 11 Refinement line 12 Crane 13 Refinement Building A 14 Refinement building B 15 Transfer machine 16 Inter-building cart 17 Rewinding machine 18 Entrance side equipment 19 Entrance side looper 20 Pretreatment equipment 21 Pre-plating equipment 22 Heating equipment 23 Hot dipping equipment (pot)
24 Alloying Furnace Equipment 25 Insulating Furnace 26 Cooling Zone 27 Water Cooling Zone 28 Skin Pass Mill (SPM)
29 Post-processing equipment 30 Outlet looper 31 Outlet equipment 32 Winding machine 33 Heating device 34 Conductive roll 35, 36 Turn roll 37 Hot dipping equipment 38 Plating tank 39 Seal roll 40 Enclosure 41 Iron core 42 AC power supply 43 Busbar 44 Secondary Coil H Steel strip

Claims (5)

In a steel sheet production line equipped with an annealing line,
(A) The electroplating line, the hot dipping line, and the annealed steel sheet storage / shipping line following the annealing line are in parallel with each other, and
(B) The electroplating line, the hot dipping line, and the annealed steel sheet storage / shipment line are in a serial relationship with the annealing line,
(C) A steel plate production hybrid line excellent in productivity, characterized in that, from an annealing line, an annealed steel sheet is distributed to an electroplating line, a hot dipping line, and an annealed sheet storage / shipment line according to the demand for steel sheets.   The steel plate manufacturing hybrid line with excellent productivity according to claim 1, wherein in the arrangement relation, the annealed steel sheet storage / shipment line, the electroplating line, and the hot dipping line are mutually linked.   The steel plate production hybrid line according to claim 1 or 2, wherein the steel plate is annealed by operating the annealing line as much as possible. An annealing line and an annealing line, followed by an electroplating line, a hot dipping line, and a steel sheet production mixed line equipped with an annealed steel sheet storage / shipping line in a parallel arrangement,
(A) Operate the annealing line to the maximum to anneal the steel sheet,
(B) A method for producing steel sheets with excellent productivity, characterized by allocating annealed steel sheets to an electroplating line, a hot dipping line, and an annealed steel sheet storage / shipment line according to the demand for steel sheets.   The steel sheet manufacturing and mixing line according to claim 4, wherein the annealed steel sheet storage / shipment line, the electroplating line, and the hot dipping line are mutually linked. Method.

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