Method for producing silicon steel based on preparation unit

Abstract

The invention belongs to the technical field of silicon steel smelting, and particularly relates to a method for producing silicon steel based on a preparation unit, which comprises the following steps of: (1) centering an outlet section, pressing a front coil of strip tail, positioning the strip tail in a double-cut shear, centering an inlet section, pressing a rear coil of strip head, positioning the strip head in the double-cut shear, shearing by the double-cut shear, moving a welding machine pressing plate, and splicing, performing hybrid welding; and (2) after the previous coil is unloaded, the belt wrapper runs to a working position, the leading tape is wound on the coiling machine, and two programs, namely an automatic mode and a manual mode, are additionally arranged in EPC (Electronic Program Control) input. The default EPC function of each roll of tape head adopts an automatic input mode, the EPC is automatically input, the manual input function needs to be started after a manual mode is manually clicked in an operation picture, and the EPC is manually input; and (3) the width specification of the base material is 1000-1300mm, and a leading tape with the width of 1000mm is adopted. The welding process is optimized, the condition for inputting the EPC centering function of the coiling machine is designed, and the production efficiency of a unit and the yield of a rolling mill are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon steel smelting, and in particular relates to a method for producing silicon steel based on a preparation unit. Background Art

[0002] Ultra-high grade non-oriented silicon steel and high magnetic induction oriented silicon steel are mainly produced by single-stand rolling mills. These two varieties have high silicon content, high brittleness, high rolling difficulty, and many broken strips. In addition, due to the reversible rolling characteristics of single-stand rolling mills, the head and tail lead strips (unrolled sections) are long and the yield rate is low. Therefore, when the domestic 20-high rolling mill is used to roll silicon steel with a silicon content of more than 3.0%, a preparation unit process is added before rolling. The preparation unit is mainly used to weld the lead strip material (generally Q235 after pickling) at the head and tail of the steel coil after (normalization) pickling and preheat the steel coil to improve the rolling stability and rolling yield rate of the cold rolling process. The preparation unit consists of a double uncoiler (one for silicon steel coil uncoiler and one for lead strip uncoiler), a pinch straightener, slitting shears (three sets, one set for each uncoiler and one set in front of the coiler), side guide rollers (two sets, one set of side guides behind each uncoiler), a laser-arc hybrid welder, a tension roller, an electromagnetic induction heating device, a tension coiler, and a centering device (one set of CPC device behind each uncoiler, and EPC at the coiling location). Its main function is to heat the steel coil to 100-150°C, weld the lead strip at the head and tail, and roll the steel coil at the same time. (Note: Due to its own characteristics, the twenty-roll single-stand rolling mill cannot be rolled at the head and tail for 8m-12m, which has a great impact on the yield rate.) The welding machine process is: front coil tail, rear coil head, shearing, centering, welding, and digging the weld. The current design of the preparation unit has certain defects, which are mainly reflected in the following aspects: (1) After welding the lead strip, the crescent shears dig out the edges of the weld, but the strip is not heated before digging. Due to the high silicon content and high brittleness, invisible cracks or even cracks are easily formed on the edges during digging, causing the parent material to break brittlely when coiling on the rolling mill; (2) The width of the base material is any width between 960mm and 1280mm, while the guide strip has only three widths: 1000mm, 1100mm and 1200mm. The welding machine is for center welding (the center of the base material and the guide strip are aligned). The width of the guide strip is different from that of the base material, and the two sides of the weld are not aligned. The EPC alignment is unilateral alignment, which causes the strip head to be unevenly coiled after passing the weld, and the rolling mill cannot roll at the uneven coiling part. (3) The preparation unit supplies the raw materials required for the production of 3-4 single-frame units. The width specifications are different, and the lead coils of different widths are frequently replaced. The unit production efficiency is low. The base material with uneven head and tail coils cannot be rolled normally, and the cold rolling yield is low. Summary of the invention

[0003] The purpose of the present invention is to provide a method for producing silicon steel based on a preparation unit, so as to solve the problems of invisible cracks or even cracks easily formed on the edges during digging, uneven edges of the welds, frequent replacement of lead rolls of different widths, and low production efficiency of the unit.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for producing silicon steel based on a preparation unit, comprising the following contents: (1) The outlet section is centered and pressed against the tail of the previous roll, and the tail of the roll is positioned in the double shear. The inlet section is centered and pressed against the head of the next roll, and the head of the roll is positioned in the double shear. The double shear is sheared, and the welding machine pressure plate moves and seams, and then composite welding is performed. (2) After the previous roll is unloaded, the belt winder runs to the working position, and the lead belt is wound on the winder. Two additional programs are added for EPC input, one is automatic mode and the other is manual mode. A selection key for the EPC function input mode is added to the HMI screen, that is, the selection between manual mode and automatic mode; the default EPC function for each roll head adopts the automatic input mode, the unit runs, automatically records the length, and automatically inputs EPC. The manual input function needs to be manually started by clicking "manual mode" in the operation screen, and manually input EPC; (3) The width of the base material is between 1000 and 1300 mm, and a guide tape with a width of 1000 mm is used.

[0005] Preferably, the welding machine used in (1) is a laser-arc hybrid welding machine.

[0006] Preferably, in (1), the composite welding speed is 1.6-2.3 m / min, the laser power is 4.0-5.0 kW, the welding head pressure is 30%-50%, the pressure plate gap is 0.07-0.12 mm, and the induction power supply power is 10-15 kW.

[0007] Preferably, the two program modes in (2) are applied: the manual mode is applied when the length of the lead strip is not 7.5m, and the HMI screen is manually operated to start the EPC function according to the actual position of the weld; the first is when the length of the tail of the lead strip is less than a normal lead strip length, all manual winding is required; the second is when the length of the lead strip is different from the length in the automatic operation program due to equipment failure, etc.; the automatic mode is applied: under normal circumstances, after welding, the unit runs at the threading speed, when the lead strip is 7.5m (the center position of the lead strip of the previous roll tail and the next roll head) is located at the 3# slitting shear (the slitting shear in front of the coiler), the unit stops, the pinch roller in front of the 3# slitting shear is tightened, the 3# slitting shear cuts the strip, and the previous roll of strip is coiled and unloaded. The next roll head continues to thread the strip and is wound onto the coiler using a belt winding device to build a sheet. After that, when the running length of the unit reaches 8m (the length starts from the time when the 3# slitting shear is cut off), the weld has just passed the EPC photoelectric tube. The PLC issues an instruction to activate the EPC function after the two conditions of coiling tension and length > 8m are met.

[0008] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention eliminates the edge digging of the crescent shears and does not dig at the weld. Although this brings the risk of weld breakage, the problem of weld breakage is solved by optimizing the process flow and changing the welding parameters. This avoids the problem of invisible cracks or even cracks easily forming at the edges during edge digging, which causes the brittle fracture of the parent material during coiling on the rolling mill. At the same time, the consumption of the crescent shears and the maintenance cost of the equipment are saved. (2) The present invention optimizes the strip length, the center distance between the tail of the previous roll and the head of the next roll, the running length, the coiling tension and length, designs the conditions for the EPC input function, and programs the control program into the PLC, thus solving the problem of uneven coiling after welding due to the different widths of the lead strip and the base material; (3) The present invention adopts narrow strips as guide strip materials, which solves the problem of frequent replacement of guide strip materials of different widths due to changes in the width of the base material, improves the operation rate of the preparation unit, and saves the amount of guide strip materials used. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of a machine set in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0010] The technical solution of the present invention is clearly and completely described below in conjunction with the embodiments. Example 1

[0011] This embodiment takes the ultra-high grade non-oriented silicon steel with a width of 1100mm and a thickness of 2.3mm and the Q235A lead strip with a width of 1000mm and a thickness of 2.3mm as examples. Figure 1 The preparation unit production shown.

[0012] A method for producing silicon steel based on a preparation unit, comprising the following contents: (1) Unwinding and threading of the leader tape: The leader tape head is unwound by the leader tape unwinder and sent to the No.1 clamping and straightening machine. After the leader tape is straightened, it is aligned by the No.1 side guide roller, and then passes through the No.1 slitting shear and the No.2 clamping and straightening machine to reach the No.2 slitting shear. The leader tape after cutting is sent to the welding machine, and the leader tape head automatically stops at the center of the welding machine. At this time, the length of the leader tape to the No.1 slitting shear is about 15 m; (2) The specific steps and parameters of the lead strip welding are as follows: the outlet section is centered and pressed against the tail of the previous roll, the tail of the roll is positioned in the double shear, the inlet section is centered and pressed against the head of the next roll, the head of the roll is positioned in the double shear, the double shear is sheared, the welding machine pressure plate moves and seams, and the composite welding is performed. The welding parameters are: welding speed 2m / min, laser power 4.5kW, welding head pressure 33%, pressure plate gap 0.1mm, induction power supply power 12kW; (3) After the weld inspection is qualified, the EPC function of each roll head adopts the automatic input mode by default, the lead tape is cut at the No.1 slitting shear, the unit runs, the length is automatically recorded, and the EPC is automatically started. The unit runs at the threading speed; the tail of the lead tape is stopped at the center of the welding machine, and then the next normal roll begins to unwind and thread; (4) The head of the last normal roll is sent to the No. 2 clamping straightener by the normal roll unwinder. After the straightening, the head is centered at the No. 2 side guide roller and sent to the No. 2 slitting shear for head cutting. After head cutting, the head is automatically positioned to the welding machine and welded together with the leader tail. The specific welding steps and parameters are the same as those in step (2). (5) After welding, the unit runs at the threading speed. Before the weld reaches the EPC detection device, the EPC function is automatically turned off. When the lead strip is 7.5 m away from the No. 3 slitting shear, the unit stops, the pinch roller in front of the No. 3 slitting shear is tightened, and the tension roller outputs torque to maintain the strip tension in the electromagnetic induction heating zone. The No. 3 slitting shear cuts the strip. (6) After the previous coil is unloaded, the next coil is coiled by a belt coiler. After the tension is established, when the running length of the unit reaches 8m (starting from the time when the 3# slitting shear is cut), the weld just passes the EPC photoelectric tube. After the two conditions of coiling tension and length > 8m are met, the PLC issues an EPC function activation command, and the unit speeds up to the normal speed. The electromagnetic induction heater automatically works to heat the strip throughout the process; (7) When the strip reaches the tail-swinging length, the unit slows down to the threading speed, and the pinch roller of the No. 2 pinch straightening machine is pressed down to assist in completing the tail-swinging. After the strip tail is sheared by the No. 2 slitting shear, the unit runs at a low speed to the center of the welding machine and stops, waiting for the next section of the strip. Example 2

[0013] In this embodiment, the base material is high magnetic induction oriented silicon steel with a width of 1030 mm and a thickness of 2.5 mm, and the lead strip material is Q235A with a width of 1000 mm and a thickness of 2.5 mm. Figure 1 The preparation unit production shown.

[0014] A method for producing silicon steel based on a preparation unit comprises the following steps: (1) Unwinding and threading of the leader tape: The leader tape head is unwound by the leader tape unwinder and sent to the No.1 clamping and straightening machine. After the leader tape is straightened, it is aligned by the No.1 side guide roller, and then passes through the No.1 slitting shear and the No.2 clamping and straightening machine to reach the No.2 slitting shear. The leader tape after cutting is sent to the welding machine, and the leader tape head automatically stops at the center of the welding machine. At this time, the length of the leader tape to the No.1 slitting shear is about 15 m; (2) The specific steps and parameters of the lead strip welding are as follows: the outlet section is centered and pressed against the tail of the previous roll, the tail of the roll is positioned in the double shear, the inlet section is centered and pressed against the head of the next roll, the head of the roll is positioned in the double shear, the double shear is sheared, the welding machine pressure plate moves and seams, and composite welding is performed; the welding parameters are: welding speed 1.8m / min, laser power 4.7kW, welding head pressure 35%, pressure plate gap 0.1mm, induction power supply power 14kW; (3) After the weld inspection is qualified, the lead tape length requirement is not 7.5m, but 6m. Click "Manual Mode" on the operation screen. After the unit runs a certain distance at the threading speed, stop the unit, and cut the lead tape with No.1 slitting shear, or the lead tape roll is used up and does not need to be cut; stop the tail of the lead tape at the center of the welding machine, and then start unwinding and threading the next normal roll; (4) The head of the last normal roll is sent to the No. 2 clamping straightener by the normal roll unwinder. After the straightening, the head is centered at the No. 2 side guide roller and sent to the No. 2 slitting shear for head cutting. After the head cutting, the head is automatically positioned to the welding machine and welded together with the leader tail. The specific welding steps and parameters are the same as step (2); (5) After welding, the unit runs at the threading speed. Before the weld reaches the EPC detection device, the EPC function is automatically turned off. The length of the lead strip is manually adjusted. When the lead strip is 6 m away from the No. 3 slitting shear, the unit stops, the pinch roller in front of the No. 3 slitting shear is tightened, and the tension roller outputs torque to maintain the strip tension in the electromagnetic induction heating zone. The No. 3 slitting shear cuts the strip. (6) After the previous roll of strip is coiled and unloaded, the next roll of strip is coiled by a belt coiler. The EPC function is selected in manual mode. After the strip is built, the unit is running. Before the weld reaches the EPC photoelectric detection device, the HMI screen is operated to manually start the EPC function. The unit speed is increased to the normal speed of the unit, and the electromagnetic induction heater automatically works to heat the strip throughout the process; (7) When the strip reaches the tail-swinging length, the unit slows down to the threading speed, and the pinch roller of the No. 2 pinch straightening machine is pressed down to assist in completing the tail-swinging. After the strip tail is sheared by the No. 2 slitting shear, the unit runs at a low speed to the center of the welding machine and stops, waiting for the next section of the strip.

Claims

1. A method for producing silicon steel based on a preparation unit, characterized in that: It includes the following: (1) The outlet section is centered and pressed against the tail of the previous roll, and the tail of the roll is positioned in the double shear. The inlet section is centered and pressed against the head of the next roll, and the head of the roll is positioned in the double shear. The double shear is sheared, and the welding machine pressure plate moves and seams, and then composite welding is performed. (2) After the previous roll is unloaded, the belt winder runs to the working position, the lead belt is wound on the winder, and two additional programs are added for EPC input, one is automatic mode and the other is manual mode. A selection key for the EPC function input mode is added to the HMI screen, that is, the selection between manual mode and automatic mode; the default EPC function for each roll head adopts the automatic input mode, the unit runs, the length is automatically recorded, and the EPC is automatically input. The manual input function needs to be manually started by clicking "manual mode" in the operation screen, and the EPC is manually input; (3) The width of the base material is between 1000 and 1300 mm, and a guide tape with a width of 1000 mm is used.

2. A method for producing silicon steel based on a preparation unit according to claim 1, characterized in that: The welding machine used in (1) is a laser-arc hybrid welding machine.

3. A method for producing silicon steel based on a preparation unit according to claim 2, characterized in that: The composite welding speed in (1) is 1.6-2.3 m / min, the laser power is 4.0-5.0 kW, the welding head pressure is 30%-50%, the pressure plate gap is 0.07-0.12 mm, and the induction power supply power is 10-15 kW.

4. A method for producing silicon steel based on a preparation unit according to claim 3, characterized in that: The two program modes mentioned in (2) are applied: the manual mode is mainly used when the length of the lead strip is not 7.5m. The HMI screen is manually operated to activate the EPC function according to the actual position of the weld; the first is when the length of the tail of the lead strip is less than a normal lead strip length, all winding must be completed manually; the second is when the equipment failure causes the lead strip length to be different from the length in the automatic operation program; the automatic mode is applied: after welding, the unit runs at the threading speed. When the lead strip is located at the center of the previous roll tail and the next roll head lead strip, 7.5m away from the slitting shear in front of the coiler, the unit stops, the pinch rollers in front of the slitting shear are tightened, the slitting shear cuts the strip, the previous roll of strip is coiled and unloaded; the next roll head continues to thread the strip and is wound onto the coiler using a belt winding aid to build a web. After that, when the running length of the unit reaches 8m, the length is measured from the time when the slitting shear is cut off. The weld has just passed the EPC photoelectric tube. The PLC issues an instruction to activate the EPC function after the two conditions of winding tension and length > 8m are met.

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