Device for producing bright annealed line of non-annealed steel and production mode switching method thereof

Abstract

The invention discloses a device for producing non-annealed steel through a bright annealed line and a production mode switching method, and the production mode switching method comprises the following steps: cutting off strip steel: cutting off the strip steel on the bright annealed line near an inlet of an annealing furnace of the bright annealed line, the strip steel on the bright annealing line is cut off near an outlet of an annealing furnace of the bright annealing line, so that the strip steel is sequentially divided into a first section of strip steel, a second section of strip steel and a third section of strip steel from a starting point of the bright annealing line; by-pass turning rollers are arranged below the annealing furnace, the tail end of the first section of strip steel and the head end of the third section of strip steel are welded, the welded strip steel is supported by the by-pass turning rollers from the lower portion, and therefore the bright annealed wire is switched to be in a by-pass mode for producing non-annealed steel. According to the method, the production efficiency is remarkably improved while the product quality is guaranteed, and a more efficient and flexible solution is provided for production of the non-annealed steel.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a device for producing a bright annealing line for non-annealed steel and a production mode switching method thereof. Background Art

[0002] In the steel manufacturing industry, the versatility of the production line is crucial, and it needs to flexibly respond to the production needs of different grades of steel. The manufacture of each grade of steel requires precise process parameters, from temperature to time, and these subtle adjustments are related to the quality and performance of the final product. For example, a method is proposed in the Chinese invention application "A method for controlling switching between different grades of steel during the heating process of a continuous annealing furnace" with application number 202210868344.9. This method coordinately optimizes the adjustment time, adjustment amplitude, temperature compensation for strip thickness transition, and the use of transition coils to control the temperature of the radiant tube and the furnace temperature, to ensure that the heat treatment temperature of the strip is controlled within the process requirements during the entire switching process, thereby achieving accurate and stable temperature control in the non-stable working condition production process of steel grade switching.

[0003] The above patent can meet the production needs of switching from one type of steel to another in a certain extent. However, when the steel type is switched from annealed steel to non-annealed steel, not only parameter adjustment is required, but also a comprehensive production mode change. The traditional stainless steel bright annealing line production mode seems to be unable to cope with it. Due to its characteristics, non-annealed steel strip products do not need to go through the furnace annealing process. However, if the full production mode of the annealing line is used, it will not only increase energy consumption and cause unnecessary cost burden, but may also introduce quality defects and reduce product qualification rate. In addition, the plate production method with furnace prolongs the auxiliary switching time such as start-up and shutdown, temperature rise and fall, greatly reduces the start-up efficiency of the unit, and becomes a bottleneck for improving the efficiency of the production line. Summary of the invention

[0004] The technical problem to be solved by the present invention is to propose a device for producing a bright annealing line for non-annealed steel and a production mode switching method thereof, which can improve production efficiency, in view of the above technical status.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a production mode switching method for producing non-annealed steel in a bright annealing line, characterized in that the production mode includes a normal mode for producing annealed steel and a bypass mode for producing non-annealed steel, and the production mode switching method includes the steps of:

[0006] Cutting the steel strip: cutting the steel strip on the bright annealing line near the entrance of the annealing furnace of the bright annealing line, and cutting the steel strip on the bright annealing line near the exit of the annealing furnace of the bright annealing line, so that the steel strip is divided into a first section of steel strip having a starting point of the bright annealing line as a head end and a cut portion near the entrance of the annealing furnace as a tail end, a second section of steel strip having a cut portion near the entrance of the annealing furnace as a head end and a cut portion near the exit of the annealing furnace as a tail end, and a third section of steel strip having a cut portion near the exit of the annealing furnace as a head end and a terminal point of the bright annealing line as a tail end;

[0007] Bypass strip steel: A bypass turning roller is arranged below the annealing furnace, the tail end of the first strip steel section is welded to the head end of the third strip steel section and the bypass turning roller supports the welded strip steel from below, so that the bright annealing line is switched to the bypass mode for producing non-annealed steel.

[0008] Furthermore, the production mode switching method disclosed in the present invention also includes the steps of:

[0009] Switching the operation control program: switching the operation control program of the bright annealing line from a normal mode operation control program including an annealing furnace to a bypass mode operation control program without an annealing furnace, wherein the bypass mode operation control program includes a control program for tension and speed, thereby enabling the bright annealing line to operate stably without an annealing furnace.

[0010] In order to avoid the idle consumption of the annealing furnace when producing non-annealed steel, further, the production mode switching method further includes the steps of:

[0011] Shutdown of annealing furnace: When switching to bypass mode to run the control program, the operation of the main equipment of the annealing furnace process section is stopped at the same time.

[0012] In order to enable the bright annealing line to freely switch between the two production modes, further, the production mode switching method further includes the steps of:

[0013] Cutting the strip steel again: Cutting the strip steel in the bypass section so that the strip steel on the bright annealing line is divided into the first strip steel section and the third strip steel section again;

[0014] Welding the steel strip: welding the tail end of the first steel strip to the head end of the second steel strip, welding the tail end of the second steel strip to the head end of the third steel strip, and establishing tension;

[0015] Switching the operation control program again: switching the operation control program of the bright annealing line from the bypass mode operation control program without the annealing furnace back to the normal mode operation control program with the annealing furnace;

[0016] Restart annealing furnace: Restart annealing furnace.

[0017] Specifically, when the strip is cut in the above step, the strip is cut between the entrance of the annealing furnace of the bright annealing line and the dancing roller group of the bright annealing line, and the strip is cut between the exit of the annealing furnace of the bright annealing line and the 3# tension roller group of the bright annealing line.

[0018] In order to ensure that the strip steel can perform normal transition operation when passing through the bypass steering roller, preferably, the strip steel between the dancing roller group and the 3# tension roller group is the bypass section strip steel, and the bypass steering roller is arranged between the dancing roller group and the 3# tension roller group. The bypass steering roller supports the bypass section strip steel from below and makes the bypass section strip steel form an operating wrap angle ranging from 115° to 125°.

[0019] Specifically, the bypass steering roller is a passive roller.

[0020] Furthermore, the bypass steering roller is made of rubber, and the bypass steering roller is common with other rollers of the bright annealing line. This design has the advantage of common management of spare parts.

[0021] Preferably, an inlet looper is provided outside the inlet of the annealing furnace, and an outlet looper is provided outside the outlet of the annealing furnace. The design of the inlet and outlet loopers can keep the inlet section of the bright annealing line running continuously without stopping during the shutdown of the exit section of the production line (unloading coils, quality inspection and related shutdown inspection), and ensure the continuous operation of the following degreasing section equipment, thereby ensuring the degreasing quality of the strip surface.

[0022] Specifically, the bright annealing line also includes an uncoiler, a degreasing section and a coiler, wherein the uncoiler is located at the starting point of the bright annealing line, the degreasing section is located between the uncoiler and the inlet looper, and the coiler is located at the end of the bright annealing line. The degreasing section is used to ensure the removal of impurities such as residual oil on the surface of the cold-rolled bright coil.

[0023] The present invention also discloses a device for producing a bright annealing line for non-annealed steel, characterized in that it includes an annealing furnace and a bypass turning roller, the annealing furnace has an inlet and an outlet, the bypass turning roller is arranged below the annealing furnace, and the bypass turning roller is located between the inlet and the outlet of the annealing furnace.

[0024] Compared with the prior art, the present invention provides a bypass mode for the efficient production of non-annealed steel. This mode uses the bypass turning rollers provided below the annealing furnace to enable the strip steel to bypass the annealing furnace and realize direct short-circuiting, thereby switching to the bypass mode. This switching method only requires the process of disconnecting and re-welding the strip steel, and the entire process can be completed within 2 hours. However, it takes at least 8 hours to produce non-annealed steel strips in the normal mode of the conventional belt furnace. When switching from non-annealed steel to the normal mode of the belt furnace, due to the heating of the furnace and the destruction of the atmosphere in the furnace caused by the production of non-annealed steel, a recovery time of at least 48 hours is required. The switching method disclosed in the present invention provides a basis for avoiding the consumption of this recovery time. When switching from the bypass mode to the normal mode, because the annealing furnace can be heated synchronously during the production of non-annealed steel, and the bypass mode has no effect on the atmosphere of the annealing furnace, switching from the bypass mode to the normal mode also only consumes the time required for strip steel welding. In summary, the bypass mode of the present invention not only simplifies the production process and shortens the switching time, but also significantly improves the production efficiency while ensuring product quality, providing a more efficient and flexible solution for the production of non-annealed steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of a bright annealing line in a normal mode according to an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A in the enlarged view;

[0027] Figure 3 A schematic diagram of a bright annealing line in a bypass mode according to an embodiment of the present invention;

[0028] Figure 4 for Figure 3 Enlarged view of point B in . DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings.

[0030] like Figures 1 to 4 FIG. 1 is a preferred embodiment of a method for switching production modes of a bright annealing line for producing non-annealed steel according to the present invention. This embodiment enables the bright annealing line to have two production modes, one of which is a normal mode containing an annealing furnace for producing annealed steel (see FIG. 1 ). Figure 1 and Figure 2 ), the other is a bypass mode without annealing furnace for the production of non-annealed steel (reference Figure 3 and Figure 4 ). The production mode switching method of this embodiment enables the bright annealing line to switch back and forth between the normal mode and the bypass mode.

[0031] This embodiment includes the following steps:

[0032] Cutting the steel strip: the steel strip on the bright annealing line is cut near the entrance 41 of the annealing furnace 4 of the bright annealing line, and the steel strip on the bright annealing line is cut near the exit 42 of the annealing furnace 4 of the bright annealing line, so that the steel strip is divided into a first section of steel strip 11 with the starting point of the bright annealing line as the head end and the cut portion near the annealing furnace entrance 41 as the tail end, a second section of steel strip 12 with the cut portion near the annealing furnace entrance 41 as the head end and the cut portion near the annealing furnace exit 42 as the tail end, and a third section of steel strip 13 with the cut portion near the annealing furnace exit 42 as the head end and the end end of the bright annealing line as the tail end. The cutting position of the strip near the entrance 41 is preferably between the entrance 41 of the annealing furnace 4 and the dancing roller group 8 of the bright annealing line, and the cutting position near the exit 42 is preferably between the exit 42 of the annealing furnace 4 and the 3# tension roller group 9 of the bright annealing line; the strip between the dancing roller group 8 and the 3# tension roller group 9 is the bypass section strip 14, and the bypass steering roller 7 is arranged between the dancing roller group 8 and the 3# tension roller group 9. The bypass steering roller 7 supports the bypass section strip 14 from below and makes the bypass section strip 14 form an operating wrap angle α in the range of 115° to 125°, preferably 120° to ensure that the strip can be normally transitioned when passing through the bypass steering roller 7;

[0033] Bypass steel strip: A bypass turning roller 7 is arranged below the annealing furnace 4. The bypass turning roller 7 can be arranged in advance and does not need to be removed after the arrangement. The tail end of the first steel strip 11 is welded to the head end of the third steel strip 13 and the bypass turning roller 7 supports the welded steel strip from below, so that the bright annealing line is switched to the bypass mode for producing non-annealed steel, such as Figure 1 and Figure 2 shown.

[0034] Switching operation control program: The bright annealing line has two sets of operation control programs at the same time. After bypassing the strip steel, the operation control program of the bright annealing line is switched from the normal mode operation control program with annealing furnace 4 to the bypass mode operation control program without annealing furnace 4. The bypass mode operation control program includes the control program for tension and speed, so that the bright annealing line can run stably without annealing furnace 4.

[0035] Shut down the annealing furnace: When the control program is switched to bypass mode, the operation of the main equipment of the process section of the annealing furnace 4 is stopped at the same time, thereby avoiding the idle consumption of the annealing furnace 4 when producing non-annealed steel;

[0036] Cutting the steel strip again: when the production of non-annealed steel is completed and the bright annealing line needs to be switched back to normal mode, the bypass section steel strip 14 is cut again, so that the steel strip on the bright annealing line is divided into the first section steel strip 11 and the third section steel strip 13;

[0037] Welding steel strips: Weld the tail end of the first steel strip 11 to the head end of the second steel strip 12, and weld the tail end of the second steel strip 12 to the head end of the third steel strip 13, and establish tension, such as Figure 3 and Figure 4 As shown;

[0038] Switch the operation control program again: switch the operation control program of the bright annealing line from the bypass mode operation control program without the annealing furnace 4 back to the normal mode operation control program with the annealing furnace 4;

[0039] Start the annealing furnace: restart the annealing furnace 4, so as to switch the production mode of the bright annealing line back to the normal mode. When it is necessary to produce non-annealed steel again, it is only necessary to repeat the production mode switching method disclosed in this embodiment starting from the step of "cutting the strip steel".

[0040] In this embodiment, the bypass steering roller 7 is a passive roller made of rubber. The bypass steering roller 7 is common with other rollers of the bright annealing line, which facilitates the common management of spare parts.

[0041] An inlet looper 3 is provided outside the inlet 41 of the annealing furnace 4 of the bright annealing line, and an outlet looper 5 is provided outside the outlet 42 of the annealing furnace 4. The design of the inlet and outlet loopers can keep the inlet section of the bright annealing line running continuously without stopping during the shutdown of the exit section of the production line (unloading coils, quality inspection and related shutdown inspection), and ensure the continuous operation of the equipment of the degreasing section 2 described below, thereby ensuring the degreasing quality of the strip surface.

[0042] In addition, the bright annealing line also includes an uncoiler 1, a degreasing section 2 and a coiler 6. The uncoiler 1 is located at the starting point of the bright annealing line, the degreasing section 1 is located between the uncoiler 2 and the inlet looper 3, and the coiler 6 is located at the end of the bright annealing line. The degreasing section 2 is used to ensure the removal of impurities such as residual oil on the surface of the cold-rolled bright coil.

[0043] In this embodiment, the bypass turning roller 7 provided below the annealing furnace 4 is utilized to enable the strip to bypass the annealing furnace 4, thereby achieving direct short circuit and switching to the bypass mode. This switching method only requires the process of disconnecting and re-welding the strip, and the entire process can be completed within 2 hours. However, it takes at least 8 hours to produce non-annealing steel strips in the normal mode of a conventional belt furnace. When switching from non-annealing steel back to the normal mode of the belt furnace, due to the heating of the furnace and the destruction of the atmosphere in the furnace caused by the production of non-annealing steel, a recovery time of at least 48 hours is required. When switching back to the normal mode from the bypass mode, because the annealing furnace 4 can be heated simultaneously during the production of non-annealing steel, and the bypass mode has no effect on the atmosphere of the annealing furnace 4, switching back to the normal mode from the bypass mode only consumes the time required for strip welding.

Claims

1. A method for switching production modes of bright annealing line for producing non-annealed steel, characterized in that: The production mode includes a normal mode for producing annealed steel and a bypass mode for producing non-annealed steel, and the production mode switching method includes the steps of: Cutting the steel strip: cutting the steel strip on the bright annealing line near the entrance of the annealing furnace of the bright annealing line, and cutting the steel strip on the bright annealing line near the exit of the annealing furnace of the bright annealing line, so that the steel strip is divided into a first section of steel strip having a starting point of the bright annealing line as a head end and a cut portion near the entrance of the annealing furnace as a tail end, a second section of steel strip having a cut portion near the entrance of the annealing furnace as a head end and a cut portion near the exit of the annealing furnace as a tail end, and a third section of steel strip having a cut portion near the exit of the annealing furnace as a head end and a terminal point of the bright annealing line as a tail end; Bypass strip steel: A bypass turning roller is arranged below the annealing furnace, the tail end of the first strip steel section is welded to the head end of the third strip steel section and the bypass turning roller supports the welded strip steel from below, so that the bright annealing line is switched to the bypass mode for producing non-annealed steel.

2. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 1, characterized in that: Also includes the steps: Switching the operation control program: switching the operation control program of the bright annealing line from a normal mode operation control program including an annealing furnace to a bypass mode operation control program without an annealing furnace, wherein the bypass mode operation control program includes a control program for tension and speed, thereby enabling the bright annealing line to operate stably without an annealing furnace.

3. The method for switching the production mode of non-annealed steel produced by a bright annealing line according to claim 2, characterized in that: Also includes the steps: Shutdown of annealing furnace: When switching to bypass mode to run the control program, the operation of the main equipment of the annealing furnace process section is stopped at the same time.

4. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 3, characterized in that: Also includes the steps: Cutting the strip steel again: Cutting the strip steel in the bypass section so that the strip steel on the bright annealing line is divided into the first strip steel section and the third strip steel section again; Welding the steel strip: welding the tail end of the first steel strip to the head end of the second steel strip, welding the tail end of the second steel strip to the head end of the third steel strip, and establishing tension; Switching the operation control program again: switching the operation control program of the bright annealing line from the bypass mode operation control program without the annealing furnace back to the normal mode operation control program with the annealing furnace; Restart annealing furnace: Restart annealing furnace.

5. The method for switching the production mode of a bright annealing line for producing non-annealed steel according to any one of claims 1 to 4, characterized in that: When the strip is cut in the above step, the strip is cut between the entrance of the annealing furnace of the bright annealing line and the dancing roller group of the bright annealing line, and the strip is cut between the exit of the annealing furnace of the bright annealing line and the 3# tension roller group of the bright annealing line.

6. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 5, characterized in that: The strip steel between the dancing roller group and the 3# tension roller group is the bypass section strip steel, and the bypass steering roller is arranged between the dancing roller group and the 3# tension roller group. The bypass steering roller supports the bypass section strip steel from below and makes the bypass section strip steel form a running wrap angle ranging from 115° to 125°.

7. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 6, characterized in that: The bypass steering roller is a passive roller.

8. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 7, characterized in that: The bypass steering roller is made of rubber and is common to other rollers of the bright annealing line.

9. The method for switching production modes of bright annealing line for producing non-annealed steel according to claim 8, characterized in that: An inlet looper is arranged outside the inlet of the annealing furnace, and an outlet looper is arranged outside the outlet of the annealing furnace.

10. A device for bright annealing line for producing non-annealed steel, characterized in that: The invention comprises an annealing furnace and a bypass turning roller. The annealing furnace has an inlet and an outlet. The bypass turning roller is arranged below the annealing furnace and is located between the inlet and the outlet of the annealing furnace.

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