Method for controlling a six-stand rolling mill and control circuit therefor

Abstract

The application relates to the field of cold rolling technology and discloses a control method and a control circuit for six-stand rolling. The multi-stand rolling mill comprises a first stand, a second stand, a third stand, a fourth stand, a fifth stand and a sixth stand, a loop is arranged in front of the first stand, and an uncoiler is arranged in front of the loop. The continuous rolling method comprises the following steps: obtaining a first strip steel, normalizing and pickling the first strip steel; unwinding the first strip steel on the uncoiler; heating the first strip steel, when the first strip steel is heated to 81-99 DEG C, the first strip steel is sent to the loop; before the first strip steel passes through the loop and reaches the first stand, the first strip steel is heated, when the first strip steel is heated to 121-200 DEG C, the first strip steel is sent to the first stand to start rolling. The application realizes the continuous rolling of high-grade oriented silicon steel and high-grade non-oriented silicon steel, improves the production efficiency, improves the product quality and reduces the production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cold rolling, in particular, to a control method of six-stand rolling and a control circuit thereof. BACKGROUND

[0002] Green manufacturing is attracting more and more attention in the steel industry. How to improve the rolling efficiency of the cold rolling mill and reduce the energy consumption of the rolling process is the focus of the industry. Using a single-stand reversible rolling mill to produce cold-rolled sheets has low rolling efficiency and high production cost, which is not conducive to improving the yield, efficiency and quality of cold-rolled products. Six-stand continuous rolling has great advantages in production efficiency, energy saving and cost reduction. SUMMARY

[0003] The purpose of the present application is to provide a control method of six-stand rolling and a control circuit thereof, which realizes the rolling of high-grade non-oriented silicon steel and high-grade oriented silicon steel, improves production efficiency, improves product quality, and reduces production cost.

[0004] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0005] According to an aspect of an embodiment of the present application, a continuous rolling method of a multi-stand rolling mill is provided, the multi-stand rolling mill comprising a first stand, a second stand, a third stand, a fourth stand, a fifth stand and a sixth stand, a loop is arranged in front of the first stand, a plate shape gauge roller is arranged at the outlet of the first stand, an uncoiler is arranged in front of the loop, the continuous rolling method comprising: obtaining a first strip, normalizing and pickling the first strip; unwinding the first strip on the uncoiler; heating the first strip, when the first strip is heated to 81-99℃, the first strip is sent to the loop; before the first strip reaches the first stand through the loop, the first strip is heated, when the first strip is heated to 121-200℃, the first strip is sent to the first stand to start rolling; obtaining real-time plate shape data of the first strip at the outlet of the first stand through the plate shape gauge roller; obtaining ideal plate shape data of the first strip; comparing the real-time plate shape data with the ideal plate shape data, if the real-time plate shape data exceeds the ideal plate shape data, controlling the first stand to perform micro-camber rolling compensation; controlling the second stand, the third stand, the fourth stand, the fifth stand and the sixth stand to perform medium-camber rolling on the first strip.

[0006] In some embodiments, temperature sensors are arranged at the outlets of the first, second, third, fourth, fifth and sixth stands, and the multi-stand further comprises an emulsion system, the first strip steel is heated before it passes through the loop to the first stand, when the first strip steel is heated to 121-200℃, the first strip steel is sent to the first stand to start rolling, the method further comprises: obtaining first real-time temperature data of the first strip steel at the outlets of the first, second, third and fourth stands; obtaining first ideal temperature data of the first strip steel; comparing the first real-time temperature data with the first ideal temperature data, if the first real-time temperature data is out of the range of the first ideal temperature data, then controlling the emulsion system to spray the first flow of emulsion, and reducing the first real-time temperature data of the first strip steel to the range of the first ideal temperature data by the emulsion.

[0007] In some embodiments, after comparing the first real-time temperature data with the first ideal temperature data, if the first real-time temperature data is out of the range of the first ideal temperature data, then controlling the emulsion system to spray the first flow of emulsion, and reducing the first real-time temperature data of the first strip steel to the range of the first ideal temperature data by the emulsion, the method further comprises: obtaining second real-time temperature data of the first strip steel at the outlets of the fifth and sixth stands; obtaining second ideal temperature data of the first strip steel; comparing the second real-time temperature data with the second ideal temperature data, if the second real-time temperature data is out of the range of the second ideal temperature data, then controlling the emulsion system to spray the second flow of emulsion, and reducing the second real-time temperature data of the first strip steel to the range of the second ideal temperature data by the emulsion.

[0008] In some embodiments, after comparing the second real-time temperature data with the second ideal temperature data, if the second real-time temperature data is out of the range of the second ideal temperature data, then controlling the emulsion system to spray the second flow of emulsion, and reducing the second real-time temperature data of the first strip steel to the range of the second ideal temperature data by the emulsion, the method further comprises: when the first strip steel is rolled to the outlet of the sixth stand, the first strip steel is coiled.

[0009] In some embodiments, the first ideal temperature data is 100-300℃, the first flow is 1000-4000L / min, the second ideal temperature data is 50-100℃, and the second flow is 2000-8000L / min.

[0010] In some embodiments, after the first strip steel is rolled to the outlet of the sixth stand, the method further comprises: obtaining a second strip steel after normalizing and pickling when the tail of the first strip steel reaches the uncoiler; uncoiling the second strip steel on the uncoiler, welding the tail of the first strip steel and the head of the second strip steel by a laser welding machine, and rolling the second strip steel according to the rolling method of the first strip steel after the welding is completed.

[0011] In some embodiments, the work roll diameter of each stand in the multi-stand is at least 230 mm and at most 340 mm; the last stand of the multi-stand is rolled with a tension of 8-20 kg / mm 2 .

[0012] In some embodiments, the continuous rolling method is used to roll high-grade silicon steel, including high-grade non-oriented silicon steel and high-grade oriented silicon steel; the chemical composition of the high-grade silicon steel includes C: 0.001-0.004%, Si: 2.0-4.5%, Mn: 0.1-1.5%, Al: 0.01-3.0%, P: ≤0.04%, S: ≤0.004%, the balance being Fe and impurities; the raw material thickness of the high-grade silicon steel is 1.0-3.5 mm, the finished product thickness is 0.1-1.0 mm, and the total reduction is 66%-93%.

[0013] According to an aspect of the embodiments of the present application, there is provided a control circuit applied to the tandem rolling method of the multi-stand rolling mill as described above, the control circuit comprising: six temperature sensors for detecting the temperatures of the outlets of the first, second, third, fourth, fifth and sixth stands, respectively; a master control chip for receiving the temperature data of the outlets of the first, second, third, fourth, fifth and sixth stands, respectively; an emulsion pump driving circuit comprising a first optocoupler, a relay, a first transistor, a second transistor, a first diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and an emulsion pump, wherein the input end of the control end of the first optocoupler is connected to a first power supply through the first resistor, the output end of the control end of the first optocoupler is connected to the collector of the first transistor, the base of the first transistor is connected to the master control chip through the second resistor, the base of the first transistor is grounded through the third resistor, the emitter of the first transistor is grounded, the input end of the control end of the first optocoupler is connected to a second power supply through the fourth resistor, the output end of the control end of the first optocoupler is connected to one end of the base of the second transistor and one end of the sixth resistor through the fifth resistor, the other end of the sixth resistor and the emitter of the second transistor are grounded, the collector of the second transistor is connected to the positive pole of the first diode and one end of the control end of the relay, the other end of the control end of the relay is connected to the negative pole of the first diode, the other end of the control end of the relay is connected to the second power supply through the fourth resistor, one end of the control end of the relay is connected to a live wire, the other end of the control end of the relay is connected to a zero wire through the emulsion pump, the first resistor, the second resistor, the fourth resistor and the fifth resistor are used for current limiting, and the third resistor and the sixth resistor are used for discharge loop.

[0014] In some embodiments, the control circuit further comprises a solenoid valve driving circuit, the solenoid valve driving circuit comprises a second optocoupler, a MOS tube, a second diode, a third triode, a capacitor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a solenoid valve, the emulsion pump draws emulsion through the solenoid valve to the strip steel, the input end of the control end of the second optocoupler is connected with the first power supply through the seventh resistor, the output end of the control end of the second optocoupler is connected with the collector of the third triode, the base of the third triode is connected with the main control chip through the eighth resistor, the base of the third triode is grounded through the ninth resistor, the emitter of the third triode is grounded, the input end of the control end of the second optocoupler is connected with one end of the eleventh resistor, the negative electrode of the second diode and the positive electrode of the solenoid valve through the tenth resistor, the other end of the eleventh resistor is connected with the third power supply, the positive electrode of the second diode is connected with the negative electrode of the solenoid valve and the drain of the MOS tube, the output end of the control end of the second optocoupler is connected with one end of the capacitor, one end of the twelfth resistor and the gate of the MOS tube, the other end of the capacitor, the other end of the twelfth resistor and the source of the MOS tube are grounded, the seventh resistor, the eighth resistor, the tenth resistor and the eleventh resistor are used for current limiting, and the ninth resistor and the twelfth resistor are used for discharge loop.

[0015] Compared with the prior art, the technical scheme of the present application has the following remarkable advantages: the strip steel is heated to 81-99 DEG C before being sent to the loop, so that the strip steel is prevented from being broken due to bending stress in the loop, the strip steel is heated to 121-200 DEG C before being cold-rolled, so that the brittleness of the strip steel is reduced, the six-roller six-stand continuous rolling mill is used to realize continuous rolling, the total reduction rate of the strip steel is 66%-93%, the rolling stability is good, the speed of the outlet strip steel can reach 1500 m / min at most, the production efficiency is improved by 6 times, the production cost is reduced by 50%, and the rolled finished strip steel has good transverse thickness precision and flatness precision.

[0016] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and are not limiting to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0018] Figure 1 A continuous rolling method flow chart according to one embodiment of the present application is shown;

[0019] Figure 2 A emulsion pump driving circuit schematic diagram according to one embodiment of the present application is shown;

[0020] Figure 3 A schematic diagram of an electromagnetic valve driving circuit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the examples set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art.

[0022] Moreover, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the

[0023] The block diagrams in the drawings show only the functionality of the features and can not imply a physical or logical corresponding structure. These blocks can be implemented by hardware, software, or by any combination of hardware and software. In some embodiments, the functionality of the blocks can be implemented by software. In some embodiments, the functionality of the blocks can be implemented by one or more modules of the software.

[0024] The flow diagrams shown in the drawings are examples only and are not necessarily to scale. Also, the flow diagrams can not include all of the steps or options discussed. For instance, some operations / steps can be combined, some operations / steps can be performed in an order different from that shown, and some operations / steps can be performed in parallel. Moreover, some operations / steps can be omitted, or other operations / steps can be added.

[0025] The technical solutions of the embodiments of the present application are briefly described as follows:

[0026] According to some embodiments, as shown in Figure 1 A tandem rolling method of a multi-stand rolling mill, the multi-stand rolling mill comprising a first stand, a second stand, a third stand, a fourth stand, a fifth stand and a sixth stand, a loop is arranged in front of the first stand, the multi-stand rolling mill further comprises a plate shape gauge roller, the plate shape gauge roller is arranged at the outlet of the first stand, an uncoiler is arranged in front of the loop, the tandem rolling method comprises:

[0027] In step 101, a first strip steel is obtained, and the first strip steel is normalized and pickled;

[0028] In step 102, the first strip steel is uncoiled on the uncoiler.

[0029] Step 103, the first strip is heated, the first strip is heated to 81-99℃, then the first strip is sent to the loop;

[0030] Step 104, before the first strip passes through the loop to reach the first stand, the first strip is heated, when the first strip is heated to 121-200℃, then the first strip is sent to the first stand to start rolling;

[0031] Step 105, the real-time plate shape data of the first strip at the outlet of the first stand is obtained by the plate shape instrument roller;

[0032] Step 106, the ideal plate shape data of the first strip is obtained;

[0033] Step 107, the real-time plate shape data is compared with the ideal plate shape data, if the real-time plate shape data exceeds the ideal plate shape data, then the first stand is controlled to perform micro-camber rolling compensation;

[0034] Step 108, the second stand, the third stand, the fourth stand, the fifth stand and the sixth stand are controlled to perform medium-camber rolling on the first strip.

[0035] Based on the above embodiment, in step 101, the first strip is a strip coil, after the first strip is uncoiled, normalizing and pickling are performed, and after the normalizing and pickling are completed, the first strip is re-coiled into a strip coil;

[0036] In step 102, the first strip after normalizing and pickling is placed on the uncoiler, and the first strip is uncoiled again on the uncoiler;

[0037] In step 103, the first strip is heated before the loop, when the first strip is heated to 81-99℃, the first strip is sent to the loop;

[0038] In step 104, before the first strip passes through the loop to reach the inlet of the first stand, the first strip is heated, when the first strip is heated to 121-200℃, then the first strip is sent to the first stand to start rolling.

[0039] In steps 105 to 107, a plate shape instrument roller is arranged at the outlet of the first stand to facilitate the acquisition of real-time plate shape data at the outlet of the first stand. The real-time plate shape data is the actual plate shape data of the strip obtained by the plate shape instrument roller in real time. The ideal plate shape data can be set according to actual needs, and the ideal plate shape data is the plate shape data of the strip that is desired to be rolled. The plate shape at the outlet of the first stand is controlled during rolling, so that the strip obtains a good edge stress state when deformed in the first stand, which is beneficial to the rolling of the subsequent stands and greatly improves the stability of rolling.

[0040] After the first stand is controlled to perform micro-camber compensation, step 108 is entered to control the second stand, the third stand, the fourth stand, the fifth stand and the sixth stand to perform medium-camber rolling on the first strip.

[0041] The present application heats the strip before it enters the loop, thereby reducing the brittleness of the strip and preventing brittle fracture of the strip when it moves inside the loop. The strip is heated again before the first stand, which effectively reduces the occurrence of edge cracks during rolling and prevents strip breakage at the crack during subsequent rolling. The products produced by the single-stand cold rolling mill are transferred to the multi-stand cold continuous rolling mill of the present application, which not only realizes the rolling of high-grade non-oriented silicon steel and high-grade oriented silicon steel, but also improves the production efficiency, reduces the production cost and improves the product quality.

[0042] In order to better understand the present application, the following will be described in detail in combination with the drawings. Figure 1 The details of the present application will be described in detail.

[0043] According to some embodiments, a temperature sensor is arranged at the outlet of each of the first stand, the second stand, the third stand, the fourth stand, the fifth stand and the sixth stand, and the multi-stand further comprises an emulsion system. In step 104, the first strip is heated before it passes through the loop to the first stand, and when the first strip is heated to 121-200℃, the first strip is sent to the first stand to start rolling. The continuous rolling method further comprises:

[0044] Obtaining first real-time temperature data of the first strip at the outlet of the first stand, the second stand, the third stand and the fourth stand;

[0045] Obtaining first ideal temperature data of the first strip;

[0046] Comparing the first real-time temperature data with the first ideal temperature data, if the first real-time temperature data exceeds the range of the first ideal temperature data, then controlling the emulsion system to spray the first strip with an emulsion at a first flow rate, so as to reduce the first real-time temperature data of the first strip to within the range of the first ideal temperature data by the emulsion.

[0047] Based on the above embodiments, the first flow rate and the first ideal temperature data can be set according to actual needs. In some embodiments, the first ideal temperature data is set to 100-300℃, and the first flow rate is set to 1000-4000 L / min.

[0048] If the first real-time temperature data exceeds the range of 100-300℃, the emulsion system is controlled to spray emulsion with a flow rate of 1000-4000 L / min to reduce the first real-time temperature data of the first strip steel to within the range of 100-300℃. The concentration of the emulsion is 3%-5%.

[0049] According to some embodiments, after comparing the first real-time temperature data with the first ideal temperature data, if the first real-time temperature data exceeds the range of the first ideal temperature data, the continuous rolling method further comprises:

[0050] Obtaining second real-time temperature data of the first strip steel at the exit of the fifth stand and the sixth stand;

[0051] Obtaining second ideal temperature data of the first strip steel;

[0052] If the second real-time temperature data exceeds the range of the second ideal temperature data, the emulsion system is controlled to spray emulsion with a second flow rate to reduce the second real-time temperature data of the first strip steel to within the range of the second ideal temperature data.

[0053] Based on the above embodiments, the second ideal temperature data and the second flow rate can be set according to actual needs. In some embodiments, the second ideal temperature data is set to 50-100℃, and the second flow rate is set to 2000-8000 L / min.

[0054] If the second real-time temperature data exceeds the range of 50-100℃, the emulsion system is controlled to spray emulsion with a flow rate of 2000-8000 L / min to reduce the second real-time temperature data of the first strip steel to within the range of 50-100℃. The concentration of the emulsion is 3%-5%.

[0055] By controlling the rolling temperature of the strip steel to be within the range of the first ideal temperature data and the second ideal temperature data, the brittleness of the strip steel can be reduced, brittle fracture of the strip steel can be prevented, and the stability of the strip steel rolling can be improved. By reducing the temperature of the strip steel at the exit of the fifth stand and the sixth stand to within 100℃, rusting of the strip steel at high temperature can be prevented, and good surface quality can be obtained.

[0056] In the rolling process, the first stand, the second stand, the third stand and the fourth stand are lubricated by the emulsion with a concentration of 3% to 5% and a flow rate of 1000 to 4000 L / min, and the fifth stand and the sixth stand are lubricated by the emulsion with a concentration of 3% to 5% and a flow rate of 2000 to 8000 L / min.

[0057] Among them, the first stand, the second stand, the third stand and the fourth stand reduce the friction coefficient during rolling through the emulsion, reduce the rolling load, and on the other hand, the strip temperature will not be too low through the smaller emulsion flow; the fifth stand and the sixth stand reduce the friction coefficient during rolling through the emulsion, avoid vibration during rolling, and on the other hand, the strip surface temperature is reduced a little lower through the larger emulsion flow.

[0058] According to some embodiments, when the second real-time temperature data is compared with the second ideal temperature data, if the second real-time temperature data exceeds the range of the second ideal temperature data, the emulsion system is controlled to spray the second flow of emulsion, and after the second real-time temperature data of the first strip is reduced to the range of the second ideal temperature data by the emulsion, the continuous rolling method further comprises:

[0059] When the first strip is rolled to the outlet of the sixth stand, the first strip is coiled.

[0060] Based on the above embodiments, after the first strip is rolled from the first stand to the sixth stand, the first strip is coiled again into a strip coil, and the strip coil is convenient to take and place after coiling.

[0061] Further, after the first strip is coiled when the first strip is rolled to the outlet of the sixth stand, the continuous rolling method further comprises:

[0062] When the tail of the first strip reaches the uncoiler, the second strip after normalizing and pickling is obtained;

[0063] The second strip is uncoiled on the uncoiler, the tail of the first strip and the head of the second strip are welded by a laser welding machine, and after welding, the second strip is rolled according to the rolling method of the first strip.

[0064] Specifically, in order to make the skilled person more easily understand the present application, in some embodiments, the continuous rolling method of the present application is used for rolling high-grade silicon steel, which includes high-grade non-oriented silicon steel and high-grade oriented silicon steel;

[0065] Further, the high-grade silicon steel has a chemical composition including C: 0.001-0.004%, Si: 2.0-4.5%, Mn: 0.1-1.5%, Al: 0.01-3.0%, P: ≤0.04%, S: ≤0.004%, and the balance of Fe and impurities;

[0066] The high-grade silicon steel has a raw material thickness of 1.0-3.5 mm, a finished product thickness of 0.1-1.0 mm, and a total reduction of 66%-93%.

[0067] The above is only for clearer description, and does not limit the steel grade and specification rolled by the present application.

[0068] Further, the work roll diameter of each rack in the multi-rack is at least 230 mm and at most 340 mm;

[0069] The last rack of the multi-rack is rolled with a tension of 8-20 kg / mm 2 .

[0070] Based on the above embodiment, the conventional high-grade oriented silicon steel or high-grade non-oriented silicon steel is rolled by using a 20-roll rolling mill with a work roll diameter of 60-100 mm. The small roll diameter can reduce the rolling force and is beneficial to the rolling of a large deformation resistance steel grade, but the frequency of replacing the roll is high, and the production auxiliary time is long. In the present application, the work roll diameter of the rolling mill is increased to 230-340 mm, which can effectively improve the rolling tonnage of the roll and reduce the roll replacement frequency.

[0071] According to some embodiments, as shown in Figure 2 , the present application provides a control circuit applied to the continuous rolling method of the multi-rack rolling mill as described above, and the control circuit includes:

[0072] Six temperature sensors for detecting the temperatures at the outlets of the first rack, the second rack, the third rack, the fourth rack, the fifth rack and the sixth rack, respectively;

[0073] A master control chip for receiving the temperature data at the outlets of the first rack, the second rack, the third rack, the fourth rack, the fifth rack and the sixth rack, respectively;

[0074] The emulsion pump driving circuit 200 comprises a first optocoupler U1, a relay K, a first triode Q1, a second triode Q2, a first diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and an emulsion pump M, an input end of a control end of the first optocoupler U1 is connected with a first power supply through the first resistor R1, an output end of the control end of the first optocoupler U1 is connected with a collector of the first triode Q1, a base of the first triode Q1 is connected with a main control chip through the second resistor R2, the base of the first triode Q1 is grounded through the third resistor R3, an emitter of the first triode Q1 is grounded, an input end of a controlled end of the first optocoupler U1 is connected with a second power supply through the fourth resistor R4, an output end of the controlled end of the first optocoupler U1 is connected with a base of the second triode Q2 and one end of the sixth resistor R6 through the fifth resistor R5, the other end of the sixth resistor R6 and an emitter of the second triode Q2 are grounded, a collector of the second triode Q2 is connected with a positive pole of the first diode D1 and one end of a control end of the relay K, the other end of the control end of the relay K is connected with a negative pole of the first diode D1, the other end of the control end of the relay K is connected with the second power supply through the fourth resistor R4, one end of a controlled end of the relay K is connected with a live wire, the other end of the controlled end of the relay K is connected with a zero wire through the emulsion pump M, the first resistor R1, the second resistor R2, the fourth resistor R4 and the fifth resistor R5 are used for current limiting, and the third resistor R3 and the sixth resistor R6 are used for a discharge loop.

[0075] Based on the above embodiment, the main control chip detects the first real-time temperature data of the first strip steel at the outlet of the first rack, the second rack, the third rack and the fourth rack through the temperature sensor, and compares the first real-time temperature data with the first ideal temperature data, if the first real-time temperature data exceeds the range of the first ideal temperature data, a high level is outputted to the base of the first triode Q1 through the second resistor R2, the first triode Q1 is turned on, the first triode Q1 controls the first optocoupler U1 to be turned on, the controlled end of the first optocoupler U1 transmits the second power supply to the base of the second triode Q2 through the fifth resistor R5, the base level of the second triode Q2 is raised, the second triode Q2 is turned on, the second triode Q2 controls the control end (coil end) of the relay K to be powered, the controlled end (contactor end) of the relay K is attracted, the emulsion pump M is powered to work, and the emulsion is sprayed to the strip steel, so as to reduce the first real-time temperature data of the strip steel to the range of the first ideal temperature data.

[0076] When the first real-time temperature data falls within the range of the first ideal temperature data, the main control chip detects the first real-time temperature data of the first strip steel at the outlets of the first, second, third and fourth racks through the temperature sensor, and compares the first real-time temperature data with the pre-set first ideal temperature data. When the value of the first real-time temperature data that is less than the first ideal temperature data exceeds the first set value, the main control chip stops outputting a high level to the base of the first triode Q1, the base of the first triode Q1 is discharged through the third resistor R3, the base level of the first triode Q1 rapidly decreases, the first triode Q1 is turned off, the first triode Q1 controls the first optocoupler U1 to be turned off, the second power supply cannot be transmitted to the base of the second triode Q2, the base of the second triode Q2 is discharged through the sixth resistor R6, the base level of the second triode Q2 rapidly decreases, the second triode Q2 is turned off, the second triode Q2 controls the control end (coil end) of the relay K to lose power, the controlled end (contactor end) of the relay K is disconnected, the emulsion pump M loses power and stops working, and the spraying of the emulsion is stopped.

[0077] In some embodiments, when the strip steel at the outlets of the first, second, third and fourth racks is sprayed, the emulsion pump M at the outlets of the first, second, third and fourth racks is controlled to work by using the first power AC power supply. When the strip steel at the outlets of the fifth and sixth racks is sprayed, the emulsion pump M at the outlets of the fifth and sixth racks is controlled to work by using the second power AC power supply. When the emulsion pump M at the outlets of the fifth and sixth racks is detected and controlled to work, the main control chip detects the second real-time temperature data of the first strip steel at the outlets of the fifth and sixth racks through the temperature sensor, and compares the second real-time temperature data with the pre-set second ideal temperature data. When the second real-time temperature data exceeds the second ideal temperature data, the emulsion pump M at the outlets of the fifth and sixth racks is controlled to work, and the emulsion is sprayed to the strip steel, so as to reduce the second real-time temperature data of the strip steel to be within the range of the second ideal temperature data. When the value of the second real-time temperature data that is less than the second ideal temperature data exceeds the second set value, the control mode is the same as when the value of the first real-time temperature data that is less than the first ideal temperature data exceeds the first set value. The emulsion pump driving circuit 200 is provided with two, one for controlling the emulsion pump M at the outlets of the first, second, third and fourth racks to work, and the other for controlling the emulsion pump M at the outlets of the fifth and sixth racks to work.

[0078] Further, as Figure 3As shown, the control circuit further comprises a solenoid valve driving circuit 300, which comprises a second optocoupler U2, a MOS tube Q10, a second diode D2, a third triode Q3, a capacitor C, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and a solenoid valve. The emulsion pump M draws emulsion and outputs the emulsion to the strip steel through the solenoid valve. The input end of the control end of the second optocoupler U2 is connected to the first power supply through the seventh resistor R7. The output end of the control end of the second optocoupler U2 is connected to the collector of the third triode Q3. The base of the third triode Q3 is connected to the main control chip through the eighth resistor R8. The base of the third triode Q3 is grounded through the ninth resistor R9. The emitter of the third triode Q3 is grounded. The input end of the control end of the second optocoupler U2 is connected to one end of the eleventh resistor R11, the negative electrode of the second diode D2 and the positive electrode of the solenoid valve through the tenth resistor R10. The other end of the eleventh resistor R11 is connected to the third power supply. The positive electrode of the second diode D2 is connected to the negative electrode of the solenoid valve and the drain of the MOS tube Q10. The output end of the control end of the second optocoupler U2 is connected to one end of the capacitor C, one end of the twelfth resistor R12 and the gate of the MOS tube Q10. The other end of the capacitor C, the other end of the twelfth resistor R12 and the source of the MOS tube Q10 are grounded. The seventh resistor R7, the eighth resistor R8, the tenth resistor R10 and the eleventh resistor R11 are used for current limiting. The ninth resistor R9 and the twelfth resistor R12 are used for discharge loop.

[0079] Based on the above embodiment, the main control chip detects the first real-time temperature data of the first strip steel at the outlet of the first rack, the second rack, the third rack and the fourth rack through the temperature sensor, and compares the first real-time temperature data with the first ideal temperature data. If the first real-time temperature data is out of the range of the first ideal temperature data, the emulsion pump M is controlled to work. At the same time, the emulsion comes to the solenoid valve through the emulsion pump M. The solenoid valve needs to be opened to spray the emulsion to the strip steel. The solenoid valve is used to control the spraying amount of the emulsion. The emulsion pump M is used to extract and output the emulsion, and provides the power for the emulsion output.

[0080] When the solenoid valve needs to be opened, the main control chip outputs a high level to the base of the third triode Q3 through the eighth resistor R8. The third triode Q3 is turned on. The third triode Q3 controls the second optocoupler U2 to be turned on. The control end of the second optocoupler U2 transmits the third power supply to the gate of the MOS tube Q10. The MOS tube Q10 is turned on. The MOS tube Q10 controls the solenoid valve to work.

[0081] When the solenoid valve needs to be closed, the main control chip stops outputting high level to the base of the third transistor Q3, the base of the third transistor Q3 is discharged through the ninth resistor R9, the base level of the third transistor Q3 decreases rapidly, the third transistor Q3 is turned off, the second optocoupler U2 is turned off under the control of the third transistor Q3, the gate of the MOS tube Q10 cannot receive the third power supply, the gate of the MOS tube Q10 is discharged through the twelfth resistor R12, and the MOS tube Q10 is turned off. The solenoid valve stops working.

[0082] In some embodiments, two electromagnetic valve driving circuits 300 are provided, one for controlling the operation of the electromagnetic valves at the outlets of the first, second, third and fourth stands, and the other for controlling the operation of the electromagnetic valves at the outlets of the fifth and sixth stands. The two electromagnetic valves have different opening degrees, resulting in different amounts of sprayed emulsified liquid.

[0083] The strip steel is heated to 81-99 DEG C before being sent to the loop, so that the strip steel is not broken due to bending stress in the loop, and the strip steel is heated to 121-200 DEG C before cold rolling, so that the brittleness of the strip steel is reduced. The six-stand tandem cold rolling mill is used to realize continuous rolling, the total reduction rate of the strip steel is 66%-93%, the speed of the outlet strip steel can reach 1500 m / min, the production efficiency is improved by 6 times, the production cost is reduced by 50%, and the rolling stability is good. The rolled finished strip steel has good transverse thickness precision and flatness precision.

[0084] The machine time yield and the material yield of the tandem rolling method of the application and the traditional method are listed in the table, as shown in Table 1.

[0085] Table 1

[0086] Raw material thickness Finished product thickness Width Rolling speed Machine hour output Material yield The present application 2.6 0.35 1200 1300 140 99.2 Conventional method 2.6 0.35 1200 800 15 98.4 The present application 2.3 0.3 1170 1300 107 99.3 Conventional method 2.3 0.3 1170 800 12.7 98.2 The present application 2.3 0.25 1170 1000 96 99.1 Conventional method 2.3 0.25 1170 700 11.1 97.9

[0087] Wherein, the units of the raw material thickness, the finished product thickness and the width are mm, the unit of the rolling speed is m / min, the unit of the machine time yield is ton / h, and the unit of the material yield is %.

[0088] From Table 1, it can be clearly seen that the machine time yield and the material yield of the tandem rolling method of the application are higher than those of the traditional method, the production efficiency is improved, the product quality is improved, and the production cost is reduced.

[0089] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0090] It is to be understood that the application is not limited to the precise construction herein described and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A method of continuous rolling of a multi-stand rolling mill, characterized in that, The multi-stand rolling mill comprises a first stand, a second stand, a third stand, a fourth stand, a fifth stand and a sixth stand, a loop is arranged in front of the first stand, a plate shape gauge is arranged at the outlet of the first stand, an uncoiler is arranged in front of the loop, and the continuous rolling method comprises the following steps: A first strip steel is obtained, and the first strip steel is normalized and pickled; The first strip steel is unwound on the uncoiler; The first strip steel is heated, and when the first strip steel is heated to 81-99 DEG C, the first strip steel is sent to the loop; The first strip steel is heated before the first strip steel passes through the loop and reaches the first stand, and when the first strip steel is heated to 121-200 DEG C, the first strip steel is sent to the first stand to start rolling; Real-time plate shape data of the first strip steel at the outlet of the first stand is obtained through the plate shape gauge; Ideal plate shape data of the first strip steel is obtained; The real-time plate shape data is compared with the ideal plate shape data, and if the real-time plate shape data exceeds the ideal plate shape data, the first stand is controlled to perform micro-camber rolling compensation; The second stand, the third stand, the fourth stand, the fifth stand and the sixth stand are controlled to perform medium-camber rolling on the first strip steel; Temperature sensors are arranged at the outlets of the first stand, the second stand, the third stand, the fourth stand, the fifth stand and the sixth stand, and the multi-stand rolling mill further comprises an emulsion system, the first strip steel is heated before the first strip steel passes through the loop and reaches the first stand, and when the first strip steel is heated to 121-200 DEG C, the first strip steel is sent to the first stand to start rolling, and the continuous rolling method further comprises the following steps: First real-time temperature data of the first strip steel at the outlets of the first stand, the second stand, the third stand and the fourth stand is obtained; First ideal temperature data of the first strip steel is obtained; The first real-time temperature data is compared with the first ideal temperature data, and if the first real-time temperature data exceeds the range of the first ideal temperature data, the emulsion system is controlled to spray emulsion of a first flow rate, and the first real-time temperature data of the first strip steel is reduced to the range of the first ideal temperature data through the emulsion; After the first real-time temperature data is compared with the first ideal temperature data, and if the first real-time temperature data exceeds the range of the first ideal temperature data, the emulsion system is controlled to spray emulsion of a first flow rate, and the first real-time temperature data of the first strip steel is reduced to the range of the first ideal temperature data through the emulsion, the continuous rolling method further comprises the following steps: Second real-time temperature data of the first strip steel at the outlets of the fifth stand and the sixth stand is obtained; Second ideal temperature data of the first strip steel is obtained; The second real-time temperature data is compared with the second ideal temperature data, and if the second real-time temperature data exceeds the range of the second ideal temperature data, the emulsion system is controlled to spray emulsion of a second flow rate, and the second real-time temperature data of the first strip steel is reduced to the range of the second ideal temperature data through the emulsion; The first ideal temperature data is 100-300 DEG C, the first flow is 1000-4000 L / min, the second ideal temperature data is 50-100 DEG C, and the second flow is 2000-8000 L / min. The continuous rolling method is used for rolling high-grade silicon steel, and the high-grade silicon steel includes high-grade non-oriented silicon steel and high-grade oriented silicon steel. The chemical composition of the high-grade silicon steel includes C: 0.001-0.004%, Si: 2.0-4.5%, Mn: 0.1-1.5%, Al: 0.01-3.0%, P: ≤0.04%, S: ≤0.004%, and the balance of Fe and impurities.

2. The method of claim 1, wherein, When the second real-time temperature data is compared with the second ideal temperature data, if the second real-time temperature data exceeds the range of the second ideal temperature data, the emulsion system is controlled to spray the second flow of emulsion, and after the first strip steel is cooled to the range of the second ideal temperature data by the emulsion, the continuous rolling method further includes: When the first strip steel is rolled to the outlet of the sixth stand, the first strip steel is coiled.

3. The method of claim 2, wherein, After the first strip steel is coiled when the first strip steel is rolled to the outlet of the sixth stand, the continuous rolling method further includes: When the tail of the first strip steel reaches the uncoiler, the normalized and pickled second strip steel is obtained. The second strip steel is uncoiled on the uncoiler, the tail of the first strip steel and the head of the second strip steel are welded by a laser welding machine, and the second strip steel is rolled according to the rolling method of the first strip steel after welding.

4. The method of claim 1, wherein, The working roll diameter of each stand in the multi-stand is 230 mm at least and 340 mm at most. The last stand of the multi-stand adopts 8~20kg / mm 2 Tension rolling.

5. The method of claim 1, wherein, The raw material thickness of the high-grade silicon steel is 1.0-3.5 mm, the finished product thickness is 0.1-1.0 mm, and the total reduction is 66%-93%.

6. A control circuit for a process of continuous rolling of a multi-stand rolling mill as claimed in any one of claims 1 to 5, characterized in that, The control circuit includes: Six temperature sensors for detecting the temperatures of the outlets of the first, second, third, fourth, fifth and sixth stands respectively; A main control chip for receiving the temperature data of the outlets of the first, second, third, fourth, fifth and sixth stands respectively; The emulsion pump driving circuit comprises a first optocoupler, a relay, a first triode, a second triode, a first diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and an emulsion pump, the input end of the control end of the first optocoupler is connected with a first power supply through the first resistor, the output end of the control end of the first optocoupler is connected with the collector of the first triode, the base of the first triode is connected with a main control chip through the second resistor, the base of the first triode is grounded through the third resistor, the emitter of the first triode is grounded, the input end of the control end of the first optocoupler is connected with a second power supply through the fourth resistor, the output end of the control end of the first optocoupler is connected with one end of the base of the second triode and one end of the sixth resistor through the fifth resistor, the other end of the sixth resistor and the emitter of the second triode are grounded, the collector of the second triode is connected with the positive electrode of the first diode and one end of the control end of the relay, the other end of the control end of the relay is connected with the negative electrode of the first diode, the other end of the control end of the relay is connected with the second power supply through the fourth resistor, one end of the control end of the relay is connected with a live wire, the other end of the control end of the relay is connected with a zero wire through the emulsion pump, the first resistor, the second resistor, the fourth resistor and the fifth resistor are used for current limiting, and the third resistor and the sixth resistor are used for a discharge loop.

7. The control circuit of claim 6, wherein, The control circuit further comprises an electromagnetic valve driving circuit, the electromagnetic valve driving circuit comprises a second optocoupler, a MOS tube, a second diode, a third triode, a capacitor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and an electromagnetic valve, the emulsion pump extracts emulsion and outputs the emulsion to a strip steel through the electromagnetic valve, the input end of the control end of the second optocoupler is connected with a first power supply through the seventh resistor, the output end of the control end of the second optocoupler is connected with the collector of the third triode, the base of the third triode is connected with a main control chip through the eighth resistor, the base of the third triode is grounded through the ninth resistor, the emitter of the third triode is grounded, the input end of the control end of the second optocoupler is connected with one end of the eleventh resistor, the negative electrode of the second diode and the positive electrode of the electromagnetic valve through the tenth resistor, the other end of the eleventh resistor is connected with a third power supply, the positive electrode of the second diode is connected with the negative electrode of the electromagnetic valve and the drain of the MOS tube, the output end of the control end of the second optocoupler is connected with one end of the capacitor, one end of the twelfth resistor and the gate of the MOS tube, the other end of the capacitor, the other end of the twelfth resistor and the source of the MOS tube are grounded, the seventh resistor, the eighth resistor, the tenth resistor and the eleventh resistor are used for current limiting, and the ninth resistor and the twelfth resistor are used for a discharge loop.

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