Manufacturing method of hot rolling laminar cooling device and hot rolling laminar cooling method

Abstract

The invention discloses a manufacturing method of a hot rolling laminar cooling device and a hot rolling laminar cooling method, and relates to the field of steel rolling machinery and processes. A cooling water main pipe of the cooling device is connected with the pneumatic ball valve; the pneumatic ball valve is connected with a turbid circulating water pipeline; the cooling water branch pipe vertical pipe is connected with the cooling water main pipe; the manual ball valve is connected with the vertical pipe of the cooling water branch pipe and the metal hose; the metal hose is connected with the horizontal pipe of the cooling water branch pipe; the cooling water branch pipe transverse pipe is fixed on the cooling water transverse pipe bracket; and nozzles are arranged on the transverse pipes of the cooling water branch pipes. The control modes in the hot rolling laminar flow cooling method include (1) a steel belt whole-course cooling mode, (2) a steel belt head and tail non-cooling mode, (3) a manual start-stop mode, (4) a steel belt head non-cooling mode and (5) a steel belt tail non-cooling mode. The problems that in the prior art, after-rolling on-line cooling is conducted on the hot-rolled stainless steel band, the temperature of the hot-rolled stainless steel band cannot be effectively controlled, and the uniformity of the cross section structure and the mechanical property of the band steel is difficult to guarantee and improve can be solved.

Description

Technical Field

[0001] The invention relates to the field of steel rolling machinery and technology, and in particular to a device for laminar cooling of hot-rolled stainless steel strips after finish rolling in a stainless steel hot rolling production line and a cooling method for laminar cooling of hot-rolled stainless steel strips. Background Art

[0002] Hot rolling laminar cooling is a post-rolling online controlled cooling process for hot rolled steel plates or strips using laminar water flow. The common laminar cooling method is to place several headers equipped with U-shaped tubes above the output roller to form a cooling belt to cool the upper surface of the plate and strip.

[0003] If there is no laminar cooling facility after the stainless steel hot rolling production line, the temperature of the steel strip after finishing rolling cannot be effectively controlled, the uniformity of the cross-sectional structure and mechanical properties of the strip cannot be effectively guaranteed and improved, and it will also affect the subsequent processing procedures such as the loss of solution annealing and the pickling rewash rate. The existing laminar cooling equipment is relatively complex and expensive, and it is difficult to effectively control the temperature of the steel strip after finishing rolling by laminar cooling. If a new set of laminar cooling devices is installed with the latest equipment configuration and control method, the initial one-time investment and subsequent maintenance costs are too high, which is not conducive to the lean control of production costs, and it also cannot solve the problem that the laminar cooling method is difficult to effectively control the temperature of the steel strip after finishing rolling. Therefore, it is necessary to make a simple stainless steel hot rolling laminar cooling device to perform laminar cooling on the stainless steel strip after finishing rolling to solve the above problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for manufacturing a hot rolling laminar cooling device and a hot rolling laminar cooling method, which can solve the problems that the post-rolling online cooling of the hot rolled stainless steel strip in the prior art cannot effectively control the temperature of the hot rolled stainless steel strip, it is difficult to ensure and improve the uniformity of the cross-sectional structure and mechanical properties of the strip, as well as the problems of high equipment configuration and maintenance costs and backward control methods.

[0005] In order to solve the above problems, the technical solution of the present invention is: the manufacturing method of the hot rolling laminar cooling device comprises the following manufacturing steps: 1. The cooling water pipe is connected to the turbid water pipe beside the roller table and welded with a DN100 elbow.

[0006] 2. Use a pneumatic ball valve with a specification of DN100 to install behind the elbow, use flange connection, and install metal gaskets between the flanges to prevent water leakage.

[0007] 3. Use a seamless pipe with a diameter of 114mm, specification model DN100 and length of 10 meters as the cooling water main pipe, connect it to the pneumatic ball valve through a flange, and the center line of the pipe is parallel to the turbid ring water pipe.

[0008] 4. Use DN40 seamless pipe to make 20 cooling water branch risers with a length of 1000mm, cut 20 circular holes with a diameter of 45mm on the cooling water main pipe, and weld the cooling water branch risers to them respectively, with the center line of the pipe perpendicular to the main pipe.

[0009] 5. Weld a DN40 straight connector to the cooling water branch pipe riser, followed by 20 DN40 manual ball valves, which can adjust the flow of the cooling water branch pipes respectively.

[0010] 6. Connect 20 metal hoses with a specification of DN40 to each of the manual ball valves.

[0011] 7. Use DN40 steel pipes and 50×5 angle steel to make cooling water cross pipe brackets with a height of 1000mm. Bolts are vertically welded on the horizontal surface of the roller side plate. The cooling water cross pipe bracket is sleeved on the bolts. The cooling water cross pipe bracket is split type for easy disassembly.

[0012] 8. Use DN40 seamless pipes to make 20 cooling water branch transverse pipes with a length of 2000 mm. Cut 19 holes with a diameter of 12 mm at intervals of 50 mm on the cooling water branch transverse pipes, and weld nozzles with a diameter of 12 mm to them. There are 19 nozzles in total.

[0013] 9. Connect the cooling water branch pipe cross pipe to the metal hose through a straight connector and fix it to the cooling water cross pipe bracket through bolts.

[0014] 10. Connect the solenoid valve of the pneumatic ball valve to the finishing rolling operation table through the PLC electronic control system.

[0015] A method for hot rolling laminar cooling using the hot rolling laminar cooling device is characterized in that the cooling method is as follows: 1. Connect the electrical signal of the solenoid valve of the pneumatic ball valve 4 from the digital output module (6ES7 322-1BL00-0AA0) of the finishing PLC1517 substation P302 to the coil terminals 13 and 14 of the intermediate relay KA14 (MYJ2N-G), connect the V+ and V- of the switching power supply (DRP-240-24) to the terminals 5 and 8 of KA14, and connect the terminals 9 and 12 of KA14 to the + and - plugs of the pneumatic solenoid valve.

[0016] 2. Use PLC programming software (TIA Portal v18) and configuration software (Wincc Runtime V7.5 +SP1) to develop control programs; define cooling water valve output variables (Q5.5) and delay instructions in the PLC program, including: create a new DB data block to define intermediate variables, create a new FC program block and use ladder diagrams for programming. Add button switches for control modes such as manual open, manual close, full cooling, no cooling at the head and tail, no cooling at the head, and no cooling at the tail to the wincc screen. Each control mode uses the corresponding control variables in the PLC to compile the program, and complete the switching and normal use of the above multiple control modes.

[0017] 3. According to the required steel strip cooling mode, adopt a specific control mode, the specific options are as follows: (1) Full cooling mode for steel strip: Click the full cooling button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when any of the F5, F6, F7, F8, and F9 racks bites steel, the simple laminar cooling water automatically starts; 5 seconds after the F5, F6, F7, F8, and F9 racks throw steel (the control time can be adjusted according to actual needs), the simple laminar cooling water stops.

[0018] (2) No cooling mode for the head and tail of the steel strip: Click the No cooling button for the head and tail of the steel strip on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when the F2 and F3 racks bite the steel, and the head of the strip reaches the pre-coil heat inspection, the simple laminar cooling water is turned on. At this time, the head of the steel strip is not cooled for about 100m; when any of the F2 and F3 racks throws the steel, 1s (the control time can be adjusted according to actual needs), the simple laminar cooling water stops. At this time, the tail of the steel strip is not cooled for about 100m.

[0019] (3) Manual start and stop mode: Click the manual start button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: simple laminar cooling water starts; click the manual close button on the wincc operation screen. When the button background color turns green, this mode takes effect; the control logic is: simple laminar cooling water stops.

[0020] (4) No cooling mode for the steel strip head: Click the no cooling button for the steel strip head on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when the F8 and F9 racks bite the steel, and the steel strip head reaches the pre-coil heat inspection, the simple laminar cooling water is turned on. At this time, the steel strip head is not cooled for about 100m. When any of the F8 and F9 racks throws steel for 3S (the control time can be adjusted according to actual needs), the simple laminar cooling water stops.

[0021] (5) No cooling mode for the tail of the steel strip: Click the no cooling button for the tail of the steel strip on the wincc operation screen. When the background color of the button turns green, this mode takes effect. The control logic is: when the F1 rack bites the steel and any of the F5, F6, F7, F8, and F9 racks bite the steel, the simple laminar cooling water is turned on; when the F1 rack throws the steel (the control time can be adjusted according to actual needs), the simple laminar cooling water stops, and the tail of the steel strip is not cooled for about 100m.

[0022] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. After using the present invention, the post-rolling temperature of the hot-rolled stainless steel strip can be effectively reduced by more than 50°C, the temperature difference of the cross-section of the strip and the precipitation of carbides in the organization can be reduced, and the uniformity of the cross-section organization and mechanical properties of the strip can be improved. The uniformity of the yield strength of the cross-section of the strip can be improved by about 5%, and the uniformity of the tensile strength can be improved by about 4%.

[0023] 2. The use of the present invention can reduce the amount of oxide scale produced during the air cooling of steel coils, reduce the loss of solution annealing by more than 0.2%, and reduce the cost of steel by about 13 yuan / ton. At the same time, the pickling rewash rate can be reduced by about 0.9%.

[0024] 3. The use of the present invention can effectively reduce the strip breakage rate of black coils in the subsequent cold rolling process by about 5%.

[0025] 4. Under different production demand conditions, the present invention can be used to select and switch multiple cooling modes. Compared with the state where laminar cooling water is always on, 10m³ of cooling water can be saved per shift. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A three-dimensional schematic diagram of a laminar cooling device used in the present invention; Figure 2 A schematic diagram of a front view of a laminar cooling device used in the present invention; Figure 3 A schematic top view of a laminar cooling device used in the present invention; Figure 4 A left schematic diagram of a laminar cooling device used in the present invention; Figure 5 for Figure 4 The enlarged schematic diagram at A in the middle; Figure 6 This is the wiring diagram of the electric control system; Figure 7 This is a schematic diagram of the electrical control process of the pneumatic valve.

[0027] The numbers in the figure are as follows: 1-cooling water main pipe; 2-manual ball valve; 3-cooling water branch pipe riser; 4-pneumatic ball valve; 5-metal hose; 6-cooling water cross pipe bracket; 7-cooling water branch pipe cross pipe; 8-nozzle; 9-roller side plate; 10-turbid water pipe; 11-elbow; 12-roller. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments: Figures 1 to 5 The hot rolling laminar cooling device is manufactured by the following steps: 1. The cooling water pipeline is connected from the turbid water pipe 10 beside the roller table 12, and an elbow 11 of specification model DN100 is welded.

[0029] 2. Install the pneumatic ball valve 4 with specification model DN100 behind the elbow 11, use flange connection, and install metal gaskets between the flanges to prevent water leakage.

[0030] 3. Use a seamless pipe with a diameter of 114mm, specification model DN100 and length of 10 meters as the cooling water main pipe 1. After connecting it to the pneumatic ball valve 4 through a flange, the center line of the pipe is parallel to the turbid circulating water pipe.

[0031] 4. Use DN40 seamless pipe to make 20 cooling water branch risers 3 with a length of 1000mm, cut 20 circular holes with a diameter of 45mm on the cooling water main pipe 1, and weld the cooling water branch risers 3 to them respectively, with the center line of the pipe perpendicular to the main pipe.

[0032] 5. Weld the DN40 straight connector to the cooling water branch pipe riser 3, and then connect 20 DN40 manual ball valves 2. The manual ball valves 2 can adjust the flow of the cooling water branch pipes respectively.

[0033] 6. Connect the metal hose 5 with specification model of DN40 to the manual ball valve 2, a total of 20 hoses.

[0034] 7. Use DN40 steel pipe and 50×5 angle steel to make cooling water cross pipe bracket 6, with a height of 1000mm. Bolts are vertically welded on the horizontal plane of roller side plate 9. Cooling water cross pipe bracket 6 is sleeved on the bolts. Cooling water cross pipe bracket 6 is split type for easy disassembly.

[0035] 8. Use DN40 seamless pipes to make 20 cooling water branch transverse pipes 7 with a length of 2000 mm. Cut 19 holes with a diameter of 12 mm on the transverse pipes at intervals of 50 mm, and weld nozzles 8 with a diameter of 12 mm to them, for a total of 19 holes.

[0036] 9. Connect the cooling water branch cross pipe 7 to the metal hose 5 through a straight connector and fix it to the cooling water cross pipe bracket 6 with bolts.

[0037] 10. Connect the solenoid valve of the pneumatic ball valve to the finishing rolling operation table through the PLC electronic control system; and complete the production of the hot rolling laminar cooling device of the present invention.

[0038] like Figure 6 and Figure 7 , using 1 to Figure 5 The hot rolling laminar cooling device uses the following laminar cooling method for stainless steel after finishing rolling in the hot rolling production line: 1. Connect the solenoid valve electrical signal of the pneumatic ball valve 4 from the digital output module (6ES7322-1BL00-0AA0) of the finishing PLC1517 substation P302 to the coil terminals 13 and 14 of the intermediate relay KA14 (MYJ2N-G), connect the switching power supply (DRP-240-24) V+ and V- to the terminals 5 and 8 of KA14, and connect the terminals 9 and 12 of KA14 to the + and - plugs of the pneumatic solenoid valve.

[0039] 2. Use PLC programming software (TIA Portal v18) and configuration software (Wincc Runtime V7.5 + SP1) to develop control programs; define cooling water valve output variables (Q5.5) and delay instructions in the PLC program, including: create a new DB data block to define intermediate variables, create a new FC program block and use ladder diagrams for programming. Add button switches for control modes such as manual open, manual close, full cooling, no cooling at the head and tail, no cooling at the head, and no cooling at the tail to the wincc screen. Each control mode uses the corresponding control variables in the PLC to compile the program, and complete the switching and normal use of the above multiple control modes.

[0040] 3. According to the required steel strip cooling mode, adopt a specific control mode, the specific options are as follows: (1) Full cooling mode for steel strip: Click the full cooling button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when any of the F5, F6, F7, F8, and F9 racks bites steel, the simple laminar cooling water automatically starts; 5 seconds after the F5, F6, F7, F8, and F9 racks throw steel (the control time can be adjusted according to actual needs), the simple laminar cooling water stops.

[0041] (2) No cooling mode for the head and tail of the steel strip. Click the No cooling button for the head and tail of the steel strip on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when the F2 and F3 racks bite the steel, and the head of the strip reaches the pre-coil heat inspection, the simple laminar cooling water is turned on. At this time, the head of the steel strip is not cooled for about 100m; when any of the F2 and F3 racks throws the steel 1s later (the control time can be adjusted according to actual needs), the simple laminar cooling water stops. At this time, the tail of the steel strip is not cooled for about 100m.

[0042] (3) Manual start and stop mode. Click the manual start button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: simple laminar cooling water starts; click the manual close button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: simple laminar cooling water stops.

[0043] (4) No cooling mode for the head of the steel strip. Click the No Cooling button for the head of the steel strip on the wincc operation screen. When the background color of the button turns green, this mode takes effect. The control logic is: when the F8 and F9 racks bite the steel, and the head of the steel strip reaches the heat inspection before coiling, the simple laminar cooling water is turned on. At this time, the head of the steel strip is not cooled for about 100m; when any of the F8 and F9 racks throws steel for 3S (the control time can be adjusted according to actual needs), the simple laminar cooling water stops.

[0044] (5) No cooling mode for the tail of the steel strip. Click the no cooling button for the tail of the steel strip on the wincc operation screen. When the background color of the button turns green, this mode takes effect. The control logic is: when the F1 rack bites the steel, and any of the F5, F6, F7, F8, and F9 racks bite the steel, the simple laminar cooling water is turned on; when the F1 rack throws the steel (the control time can be adjusted according to actual needs), the simple laminar cooling water stops, and the tail of the steel strip is not cooled for about 100m.

Claims

1. A method for manufacturing a hot rolling laminar cooling device, characterized in that: The production steps include:

1. The cooling water pipe is connected from the turbid water pipe (10) beside the roller table (12) and welded with an elbow (11) of specification model DN100; 2. A pneumatic ball valve (4) with a specification of DN100 is installed on the elbow (11) and connected with flanges. Metal gaskets are installed between the flanges to prevent water leakage; 3. Use a seamless pipe with a diameter of 114 mm, a specification of DN100 and a length of 10 meters as the cooling water main pipe (1) and connect it to the pneumatic ball valve (4) through a flange, so that the center line of the pipe is parallel to the turbid water pipe (10); 4. Use DN40 seamless pipes to make 20 cooling water branch pipe risers (3) with a length of 1000 mm, cut 20 circular holes with a diameter of 45 mm on the cooling water main pipe (1), and weld the cooling water branch pipe risers (3) thereto respectively, with the center line of the pipe being perpendicular to the main pipe; 5. Weld a DN40 straight connector to the cooling water branch pipe riser (3), followed by 20 DN40 manual ball valves (2); 6. Connect 20 metal hoses (5) of specification model DN40 to each of the manual ball valves (2); 7. Use a steel pipe with a specification of DN40 and an angle steel of 50×5 to make a cooling water cross pipe bracket (6) with a height of 1000 mm. Bolts are vertically welded on the horizontal surface of the roller side plate (9). The cooling water cross pipe bracket (6) is sleeved on the bolts. The cooling water cross pipe bracket (6) is a split type.

8. Use DN40 seamless pipes to make 20 cooling water branch pipe transverse pipes (7) with a length of 2000 mm. Cut 19 holes with a diameter of 12 mm at intervals of 50 mm on the cooling water branch pipe transverse pipe (7), and weld nozzles (8) with a diameter of 12 mm thereto. There are 19 nozzles (8) in total.

9. Connect the cooling water branch pipe cross pipe (7) to the metal hose (5) via a straight connector and fix it to the cooling water cross pipe bracket (6) via bolts; 10. Connect the solenoid valve of the pneumatic ball valve (4) to the finishing operation table through the PLC electronic control system.

2. A method for hot rolling laminar cooling using the hot rolling laminar cooling device according to claim 1, characterized in that: The cooling method is as follows:

1. Connect the solenoid valve electrical signal of the pneumatic ball valve 4 from the digital output module (6ES7322-1BL00-0AA0) of the finishing PLC1517 substation P302 to the coil terminals 13 and 14 of the intermediate relay KA14 (MYJ2N-G), connect the V+ and V- of the switching power supply (DRP-240-24) to the terminals 5 and 8 of KA14, and connect the terminals 9 and 12 of KA14 to the + and - plugs of the pneumatic solenoid valve; 2. Use PLC programming software (TIA Portal v18) and configuration software (Wincc Runtime V7.5 + SP1) to develop control programs; Define the cooling water valve output variable (Q5.5) and delay instructions in the PLC program, including: create a new DB data block to define intermediate variables, create a new FC program block and use ladder diagrams for programming; add button switches for control modes such as manual opening, manual closing, full cooling, no cooling at the head and tail, no cooling at the head, and no cooling at the tail on the wincc screen. Each control mode uses the corresponding control variables in the PLC to compile the program, and complete the switching and normal use of the above multiple control modes; 3. According to the required steel strip cooling mode, adopt a specific control mode, the specific options are as follows: (1) Full cooling mode for steel strip: Click the full cooling button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when any of the F5, F6, F7, F8, and F9 racks bites steel, the simple laminar cooling water automatically starts; when the F5, F6, F7, F8, and F9 racks throw steel 5s later (the control time can be adjusted according to actual needs), the simple laminar cooling water stops. (2) No cooling mode for the head and tail of the steel strip: Click the no cooling button for the head and tail of the steel strip on the wincc operation screen. When the background color of the button turns green, this mode takes effect. The control logic is: when the F2 and F3 racks bite the steel, and the head of the strip reaches the pre-coil heat inspection, the simple laminar cooling water is turned on. At this time, the head of the steel strip is not cooled for about 100m; when any of the F2 and F3 racks throws the steel, the simple laminar cooling water stops for 1s (the control time can be adjusted according to actual needs). At this time, the tail of the steel strip is not cooled for 100m. (3) Manual start-stop mode: Click the manual start button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: simple laminar cooling water starts. Click the manual close button on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: simple laminar cooling water stops. (4) No cooling mode for the steel strip head: Click the no cooling button for the steel strip head on the wincc operation screen. When the button background color turns green, this mode takes effect. The control logic is: when the F8 and F9 racks bite the steel, and the steel strip head reaches the pre-coil heat inspection, the simple laminar cooling water is turned on. At this time, the steel strip head is not cooled for 100m. When any of the F8 and F9 racks throws steel for 3S (the control time can be adjusted according to actual needs), the simple laminar cooling water stops. (5) No cooling mode for the tail of the steel strip: Click the no cooling button for the tail of the steel strip on the wincc operation screen. When the background color of the button turns green, this mode takes effect. The control logic is: when the F1 rack bites the steel, and any of the F5, F6, F7, F8, and F9 racks bites the steel, the simple laminar cooling water is turned on; when the F1 rack throws the steel (the control time can be adjusted according to actual needs), the simple laminar cooling water stops, and the tail of the steel strip is not cooled for 100m.

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