Hot continuous rolling roughing mill unit and operation method thereof

Abstract

The invention relates to a hot continuous rolling roughing mill unit and an operation method thereof, and belongs to the technical field of strip steel production. The hot continuous rolling roughing mill unit comprises a flat rolling mill, a vertical rolling mill, and cooling water spray heads, top spray heads and side spray heads which are respectively arranged on an inlet side and an outlet side; each cooling water spray head is connected with a collecting pipe for introducing rolling line cooling water; descaling spray head groups are respectively arranged on two sides of the flat rolling mill; and the spraying directions of the top spraying nozzle and the cooling water nozzle are opposite to the spraying direction of the descaling nozzle group. The operation method comprises the steps of inlet side cooling, outlet side cooling, inlet side descaling, outlet side descaling, inlet side cooling and descaling and outlet side cooling and descaling. During odd-number-pass rolling, a rolled piece enters the vertical rolling mill from the inlet side; and during even-number-pass rolling, the rolled piece enters the flat rolling mill from the outlet side. Cooling is carried out between passes, the rolling rhythm is improved, the temperature difference between the core and the surface of the rolled piece is increased, core deformation of the rolled piece is promoted, and the mechanical property of the rolled piece is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of strip steel production and relates to a hot rolling roughing mill group and an operating method thereof. Background Art

[0002] As one of the core equipment in the hot rolling production line, the roughing mill is composed of a flat roll mill and a vertical roll mill. They work together and are arranged between the heating furnace and the finishing mill. They are responsible for the important task of converting heavy slabs into intermediate billets that meet specific specifications. This process is not a simple change in physical form, but through multiple passes of reciprocating fine rolling, the slab is gradually thinned and adjusted to the required width, while strictly controlling the temperature drop to ensure that the intermediate billet can meet the high temperature and specification requirements of the finishing mill.

[0003] The heating furnace plays a vital role in this process, and it is responsible for heating the slab to the appropriate rolling temperature. In order to meet the heating requirements of different types of steel in the same batch, the heating furnace usually adopts the strategy of "higher rather than lower temperature out of the furnace" to ensure that all rolled products can achieve sufficient plasticity and avoid scrap due to insufficient heating. However, with the steel industry's continuous pursuit of rolling line capacity and efficiency, the rolling time of rolled products in the rough rolling area has been greatly compressed, and this change has brought new challenges.

[0004] The shortening of the rolling time of the rolled piece in the rough rolling area directly leads to the continuous reduction of the actual temperature drop in the rough rolling area.

[0005] In addition, the reduction in temperature drop may also have a negative impact on the rolling process. In the finishing mill, there are strict requirements for the temperature of the intermediate billet. If the temperature drop in the rough rolling area is not properly controlled, the temperature of the intermediate billet may be too high or too low, which in turn affects the smooth progress of the finishing process and the dimensional accuracy and surface quality of the final product.

[0006] Therefore, faced with the challenges of shorter and shorter rolling time and smaller temperature drop in the rough rolling area, it is particularly necessary to add temperature control measures in the rough rolling mill area to ensure the smooth progress of the rolling process and the steady improvement of product quality. Summary of the invention

[0007] In view of this, the object of the present invention is to provide a hot rolling roughing mill group and an operation method thereof, so as to realize cooling of the roughing mill between passes and improve the rolling rhythm. At the same time, cooling between passes is adopted to increase the temperature difference between the core and the surface of the rolled piece, promote deformation of the core of the rolled piece, and improve the mechanical properties of the rolled piece.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A hot rolling roughing mill group comprises a flat roll mill and an upright roll mill which are sequentially arranged on a rolling line, wherein the side of the upright roll mill away from the flat roll mill is an inlet side, and the side of the flat roll mill away from the upright roll mill is an outlet side; cooling water nozzles are both provided on the inlet side and the outlet side, and top spray nozzles are provided on the near-machine side and far-machine side of the cooling water nozzles on the outlet side, and top spray nozzles are provided on the near-machine side and far-machine side of the cooling water nozzles on the inlet side; side spray nozzles are provided on the side of the rolling line on the inlet side, and side spray nozzles are provided on the side of the rolling line on the outlet side.

[0010] Optionally, the cooling water nozzles are all arranged above the rolling line, a cooling water nozzle is arranged below the inlet side rolling line, and a cooling water nozzle is arranged below the outlet side rolling line.

[0011] Optionally, the cooling water nozzles are all connected to separate headers, and surplus cooling water of the rolling line is introduced into each of the headers.

[0012] Optionally, a flow regulating valve is provided on the header.

[0013] Optionally, a descaling nozzle group is arranged on a side of the flat roll mill close to the vertical roll mill, and a descaling nozzle group is arranged between the flat roll mill and the top spray nozzle.

[0014] Optionally, the descaling nozzle group includes two descaling nozzles respectively arranged above and below the rolling wire.

[0015] Optionally, the spraying directions of the top spray nozzle and the cooling water nozzle are both toward the flat roll mill; and the spraying direction of the descaling nozzle group is away from the flat roll mill.

[0016] An operating method of a hot rolling roughing mill according to any of the above items, comprising:

[0017] A. Inlet side cooling: the rolled piece enters the vertical rolling mill from the inlet side, and the side spray nozzles on the inlet side, the top spray nozzles on the remote side and the cooling water nozzles are turned on for cooling;

[0018] B. Exit side cooling: the rolled piece enters the exit side from the flat roll mill, and the side spray nozzles, cooling water nozzles and top spray nozzles on the remote machine side are turned on to perform post-rolling cooling on the exit side;

[0019] C. Descaling on the inlet side: the rolled piece enters the vertical rolling mill from the inlet side, and the descaling nozzle near the inlet side, the side spray nozzle near the machine side, and the top spray nozzle are turned on for descaling;

[0020] D. Descaling at the exit side: When the rolled piece enters the exit side from the flat roll mill, the descaling nozzles near the exit side, the side spray nozzles near the machine side, and the top spray nozzles are turned on for descaling.

[0021] Optionally, the cooling and descaling processes are performed simultaneously, and the operation method includes:

[0022] E. Cooling + descaling at the inlet side: the rolled piece enters the vertical rolling mill from the inlet side, and the descaling nozzle, side spray nozzle, top spray nozzle and cooling water nozzle near the inlet side are turned on for cooling and descaling;

[0023] F. Cooling and descaling at the outlet side: When the rolled piece enters the outlet side from the flat roll mill, the descaling nozzles, side spray nozzles, cooling water nozzles, and top spray nozzles at the far side are turned on for cooling and descaling.

[0024] Optionally, during rolling with an odd number of passes, the workpiece enters the vertical rolling mill from the inlet side; during rolling with an even number of passes, the workpiece enters the flat rolling mill from the outlet side.

[0025] The beneficial effects of the present invention are:

[0026] The present invention adds cooling water nozzles, top spray nozzles, and side spray nozzles on the basis of descaling water in the rough rolling area. Through the combination of opening and closing of each process cooling water, the cooling water volume and the retention area of ​​descaling water are controlled, thereby enhancing the temperature control capability of the rolling mill in the rough rolling area. The excess cooling water on the rolling line is utilized to accurately control the flow, pressure, and spraying method of the cooling water, which can effectively adjust the temperature drop of each rolled piece in the rough rolling area, and also help to improve the energy utilization efficiency of the entire rolling line, reduce unnecessary energy waste, and achieve green and sustainable production goals. By optimizing the use of cooling water, not only can the uniformity of the rolled piece temperature be ensured and the purpose of temperature control be achieved, but also the differences in organizational properties caused by local overheating or overcooling can be avoided, and the furnace discharge temperature of the rolled piece can be flexibly adjusted according to actual needs to better meet the requirements of the finishing mill.

[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It is a schematic diagram of the layout of the hot rolling roughing mill group of the present invention.

[0030] Reference numerals:

[0031] 1 flat roll mill, 2 vertical roll mill, 31 cooling water nozzle, 32 cooling water nozzle, 33 cooling water nozzle, 34 cooling water nozzle, 41 top spray nozzle, 42 top spray nozzle, 43 top spray nozzle, 44 top spray nozzle, 51 side spray nozzle, 52 side spray nozzle, 53 side spray nozzle, 54 side spray nozzle, 61 descaling nozzle group, 62 descaling nozzle group, 7 rolling line. DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0033] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0034] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] See also Figure 1, is a hot rolling roughing mill group, comprising a flat roll mill 1 and a vertical roll mill 2 arranged on a rolling line 7 in sequence, the side of the vertical roll mill 2 away from the flat roll mill 1 is the inlet side, and the side of the flat roll mill 1 away from the vertical roll mill 2 is the outlet side; the inlet side and the outlet side are both provided with cooling water nozzles 31 and 32, the near machine side and the far machine side of the cooling water nozzle 31 on the outlet side are both provided with top spray nozzles 41 and 42, and the near machine side and the far machine side of the cooling water nozzle 32 on the inlet side are both provided with top spray nozzles 43 and 44; the side of the rolling line 7 on the inlet side is provided with side spray nozzles 53 and 54, and the side of the rolling line 7 on the outlet side is provided with side spray nozzles 51 and 52. The cooling water nozzles, side spray nozzles, and top spray nozzles are all independently controlled nozzles. Each cooling water nozzle can independently adjust its flow rate to control the cooling water volume.

[0036] The cooling water nozzles 31 and 32 are both arranged above the rolling line 7 , two cooling water nozzles 34 are arranged below the rolling line 7 on the inlet side, and two cooling water nozzles 33 are arranged below the rolling line 7 on the outlet side.

[0037] The cooling water nozzles 31, 32, 33, 34 are all connected to separate headers, and surplus cooling water of the rolling line 7 is introduced into each of the headers. A flow regulating valve is provided on the header to compensate for the cooling intensity of the upper and lower surfaces of the rolled piece to be consistent.

[0038] A descaling nozzle group 62 is provided on a side of the flat rolling mill 1 close to the vertical rolling mill 2 , and a descaling nozzle group 61 is provided between the flat rolling mill 1 and the top spray nozzle 41 .

[0039] The descaling nozzle groups 61 and 62 each include two descaling nozzles respectively arranged above and below the rolling line 7.

[0040] The spraying directions of the top spray nozzles 41 , 42 , 43 , 44 and the cooling water nozzles 31 , 32 , 33 , 34 are all toward the flat rolling mill 1 ; the spraying directions of the descaling nozzle groups 61 , 62 are away from the flat rolling mill 1 .

[0041] During the roughing mill rolling, when the descaling water needs to be turned on in this pass, the side spray nozzles and top spray nozzles on the descaling side are turned on at the same time to suppress the rebound of the descaling water and control the impact area of ​​the descaling water on the surface of the rolled piece.

[0042] When it is necessary to lower the temperature of the rolled piece in this pass, open the cooling water nozzle on the descaling side to further increase the water volume on the surface of the rolled piece; the corresponding header of the lower surface cooling water can be opened to compensate for the cooling intensity of the upper and lower surfaces of the rolled piece; when descaling is not required in this pass, open the upper and lower cooling water nozzles, and adjust the upper and lower cooling water volumes to control the temperature of the rolled piece.

[0043] When it is necessary to lower the temperature of the next pass of the rolled piece, open one or two groups of cooling water nozzles on the outlet side of this pass, adjust the upper and lower cooling water volumes, and open the side spray nozzles and top spray nozzles on the outlet side at the same time.

[0044] The arrangement principle of the unit nozzles is: the top nozzles close to the rolling mill side serve the descaling water, the top nozzles far from the rolling mill side serve the descaling water and cooling water; the side nozzles serve the cooling water and descaling water. The present invention can perform three functions of inlet cooling, inlet descaling and outlet cooling on the rolled piece, and the three functions can be selected to be combined.

[0045] An operating method according to the above hot rolling roughing mill group comprises:

[0046] A. Inlet side cooling: the rolled piece enters the vertical rolling mill 2 from the inlet side, and the side spray nozzles 53 and 54 on the inlet side, the top spray nozzle 44 and the cooling water nozzles 32 and 34 on the remote side are turned on for cooling;

[0047] B. Exit side cooling: the rolled piece enters the exit side from the flat rolling mill 1, and the side spray nozzles 51, 52, cooling water nozzles 31, 33, and top spray nozzle 42 on the remote side are turned on to perform post-rolling cooling on the exit side;

[0048] C. Descaling at the inlet side: the rolled piece enters the vertical rolling mill 2 from the inlet side, and the descaling nozzle 62 near the inlet side, the side spray nozzle 54 near the machine side, and the top spray nozzles 43 and 44 are turned on for descaling;

[0049] D. Descaling at the exit side: When the rolled piece enters the exit side from the flat roll mill 1, the descaling nozzle 61 near the exit side, the side spray nozzle 52 near the machine side, and the top spray nozzles 41 and 42 are turned on for descaling.

[0050] The cooling and descaling processes are carried out simultaneously, and the operation method includes:

[0051] E. Cooling and descaling at the inlet side: the rolled piece enters the vertical rolling mill 2 from the inlet side, and the descaling nozzle 62, the side spray nozzles 53 and 54 near the inlet side, the top spray nozzle 44 at the remote side, and the cooling water nozzles 32 and 34 are turned on for cooling and descaling;

[0052] F. Cooling and descaling at the outlet side: the rolled piece enters the outlet side from the flat roll mill 1, and the descaling nozzle 61, side spray nozzles 51, 52, cooling water nozzles 31, 33, and top spray nozzle 42 at the far machine side are turned on for cooling and descaling.

[0053] During the odd-numbered rolling passes, the workpiece enters the vertical rolling mill 2 from the inlet side; during the even-numbered rolling passes, the workpiece enters the flat rolling mill 1 from the outlet side.

[0054] Example:

[0055] The hot rolling roughing mill adopts a flat roll mill 1 and a vertical roll mill 2 attached arrangement, and the mill can reciprocate. The rolled material is fed from the vertical roll mill 2, and after multiple passes of rolling, it leaves the roughing area from the flat roll mill 1.

[0056] During odd-numbered rolling, the rolled piece enters the vertical rolling mill 2 from the inlet side, and the inlet descaling nozzle 62, the side spray nozzle 54, the top spray nozzle 43, and the top spray nozzle 44 are turned on to descale the rolled piece only; the inlet descaling nozzle 62, the side spray nozzle 54, the cooling water nozzles 32, 34, the side spray nozzle 53, and the top spray nozzle 44 can also be turned on to cool and descale the rolled piece before rolling; the cooling water can be turned on by the pipeline flow regulating valve to select the upper and lower surface cooling water nozzles 32, 34, and the lower surface cooling water nozzle 34, and the water volume can be controlled to control and compensate the temperature of the rolled piece. The side spray nozzle 52, the cooling water nozzles 31, 33, the side spray nozzle 51, and the top spray nozzle 42 on one side of the flat rolling mill 1 are turned on to cool the rolled piece after rolling and control the temperature of the next rolling pass. The descaling and cooling functions can be turned on independently and selectively.

[0057] During even-numbered rolling, the rolled piece enters the flat rolling mill 1 from the exit side, and the exit descaling nozzle 61, the side spray nozzle 52, the top spray nozzle 41, and the top spray nozzle 42 are turned on to descale the rolled piece only; the exit descaling nozzle 61, the side spray nozzle 52, the cooling water nozzles 31, 33, the side spray nozzle 51, and the top spray nozzle 42 can also be turned on to cool the rolled piece only before rolling and descaling; the cooling water can be turned on by the pipeline flow regulating valve to select the upper and lower surface cooling water nozzles 31, 33, and the lower surface cooling water nozzle 33, and the water volume can be controlled to control and compensate the temperature of the rolled piece. The side spray nozzle 54, the cooling water nozzles 32, 34, the side spray nozzle 53, and the top spray nozzle 44 on one side of the vertical rolling mill 2 are turned on to cool the rolled piece after rolling to control the temperature of the next rolling pass. The descaling and cooling functions can be turned on independently and selectively.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A hot rolling roughing mill, characterized in that: The invention comprises a flat rolling mill (1) and an upright rolling mill (2) which are arranged in sequence on a rolling line (7); the side of the upright rolling mill (2) away from the flat rolling mill (1) is an inlet side, and the side of the flat rolling mill (1) away from the upright rolling mill (2) is an outlet side; the inlet side and the outlet side are both provided with cooling water nozzles (31, 32); the near-machine side and the far-machine side of the cooling water nozzle (31) on the outlet side are both provided with top spray nozzles (41, 42); the near-machine side and the far-machine side of the cooling water nozzle (32) on the inlet side are both provided with top spray nozzles (43, 44); the side edge of the rolling line (7) on the inlet side is provided with side spray nozzles (53, 54); the side edge of the rolling line (7) on the outlet side is provided with side spray nozzles (51, 52).

2. The hot rolling roughing mill according to claim 1, characterized in that: The cooling water nozzles (31, 32) are both arranged above the rolling line (7), a cooling water nozzle (34) is arranged below the inlet side rolling line (7), and a cooling water nozzle (33) is arranged below the outlet side rolling line (7).

3. The hot rolling roughing mill according to claim 2, characterized in that: The cooling water nozzles (31, 32, 33, 34) are all connected to separate headers, and surplus cooling water of the rolling line (7) is introduced into each header.

4. The hot rolling roughing mill according to claim 3, characterized in that: The header is provided with a flow regulating valve.

5. The hot rolling roughing mill according to claim 1, characterized in that: A descaling nozzle group (62) is arranged on the side of the flat roll mill (1) close to the vertical roll mill (2), and a descaling nozzle group (61) is arranged between the flat roll mill (1) and the top spray nozzle (41).

6. The hot rolling roughing mill according to claim 5, characterized in that: The descaling nozzle groups (61, 62) each comprise two descaling nozzles respectively arranged above and below the rolling line (7).

7. The hot rolling roughing mill according to claim 6, characterized in that: The spraying directions of the top spray nozzles (41, 42, 43, 44) and the cooling water nozzles (31, 32, 33, 34) are all toward the flat rolling mill (1); and the spraying direction of the descaling nozzle group (61, 62) is away from the flat rolling mill (1).

8. An operating method of a hot rolling roughing mill according to any one of claims 1 to 7, characterized in that: include: A. Cooling on the inlet side: the rolled piece enters the vertical rolling mill (2) from the inlet side, and the side spray nozzles (53, 54) on the inlet side, the top spray nozzles (44) on the remote side and the cooling water nozzles (32, 34) are turned on for cooling; B. Cooling at the outlet side: when the rolled piece enters the outlet side from the flat roll rolling mill (1), the side spray nozzles (51, 52), cooling water nozzles (31, 33) and top spray nozzles (42) at the outlet side are turned on to perform post-rolling cooling at the outlet side; C. Descaling at the inlet side: the rolled piece enters the vertical rolling mill (2) from the inlet side, and the descaling nozzle (62) near the inlet side, the side spray nozzle (54) near the machine side, and the top spray nozzle (43, 44) are turned on to perform descaling; D. Descaling at the outlet side: When the rolled piece enters the outlet side from the flat roll rolling mill (1), the descaling nozzle (61) near the outlet side, the side spray nozzle (52) near the machine side, and the top spray nozzle (41, 42) are turned on to perform descaling.

9. The method for operating a hot rolling roughing mill according to claim 8, characterized in that: The cooling and descaling processes are carried out simultaneously, and the operation method includes: E. Cooling and descaling at the inlet side: the rolled piece enters the vertical rolling mill (2) from the inlet side, and the descaling nozzle (62), the side spray nozzles (53, 54) near the inlet side, the top spray nozzle (44) at the remote side, and the cooling water nozzles (32, 34) are turned on to cool and descale the rolled piece; F. Cooling and descaling at the outlet side: When the rolled piece enters the outlet side from the flat roll rolling mill (1), the descaling nozzle (61), the side spray nozzles (51, 52), the cooling water nozzles (31, 33) and the top spray nozzle (42) at the far side near the outlet are turned on to cool and descale the rolled piece.

10. The method for operating a hot rolling roughing mill according to claim 8, characterized in that: During the odd-numbered rolling passes, the rolled piece enters the vertical rolling mill (2) from the inlet side; during the even-numbered rolling passes, the rolled piece enters the flat rolling mill (1) from the outlet side.

Images