Novel HRB500E steel billet electromagnetic heating direct rolling method

Abstract

The invention relates to the technical field of metallurgical direct rolling, and particularly discloses a novel HRB500E steel billet electromagnetic heating direct rolling method which comprises the following system components: an induction heating system, a mechanical pneumatic system, an electromagnetic heating coil, a thyristor frequency converter, a console and a PLC (Programmable Logic Controller) system, performing direct rolling logic control: designing four waiting bits, namely a C9 waiting bit, a C8 waiting bit, a C7 waiting bit and a C1 waiting bit, by electromagnetic heat compensation; in the direct rolling process, when the pulling speed is lower than 3.8 m / min during direct rolling of the bar, a rolling line is informed of temperature measurement to verify the electromagnetic heat compensation effect, and steel billets with the head rolling temperature not meeting the standard are removed after electromagnetic heat compensation; according to the detected different billet temperatures, different heating standards and parameter calling are designed; the direct rolling electromagnetic heat compensation control logic is adopted, and real-time tracking of steel billets is achieved through steel billet detection; and according to the detected different billet temperatures, different heating standards and parameter calling are executed, stable direct rolling is achieved, and the direct rolling efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical direct rolling, and in particular to a novel electromagnetic heating direct rolling method for HRB500E steel billets. Background Art

[0002] At present, my country's steel production capacity is seriously oversupplied, and competition in the steel market is becoming increasingly fierce. If steel companies want to survive and develop in the fierce market competition, they must either have their own variety advantages or their own cost advantages. In the field of bars and wires, especially building materials, many steel companies are pursuing the goal of reducing production costs by all means. The heating furnace in hot rolling is a device with relatively high energy consumption and pollutant emissions in steel production. Although the unit energy consumption is decreasing year by year, the goal of substantial energy savings cannot be achieved by using traditional processes. For this reason, billet direct rolling technology came into being. Many domestic steel companies, especially private companies, have tried to directly roll continuous casting billets without heating furnaces and hot rolling continuous casting billets, and have achieved success. At present, many companies have formed large-scale production.

[0003] With the development of direct rolling technology, there are many problems: in the direct rolling technology without heating, the temperature of the continuous casting billet is about 1050℃, the continuous casting speed is calculated according to 4 meters / second, and the temperature drops by 0.7℃ per second. The casting process takes about 4 minutes, the temperature of the head drops by 168℃, and the temperature of the billet head drops to 882℃. After passing through the 174-meter direct rolling roller, the temperature drops by 60℃. Before the billet enters the No. 1 rolling mill, the temperature of the billet head drops to 820℃, and the temperature difference between the head and the tail is greater than 100℃. The billet temperature below 900℃ causes the steel biting current to exceed the rated current, which has a great impact on the motor and reducer. Comparing the currents of each batch, the current of some rolling mills exceeds the standard significantly.

[0004] In addition, too low head temperature will lead to uneven deformation of the head of the rolled piece, which may easily cause cracks in the head billet and lead to steel piling accidents.

[0005] The utilization rate of direct rolled steel billets is low. Single-machine single-stream is adopted, and the capacity of the continuous casting machine is much larger than the capacity of a single steel rolling line. Single-line direct rolling will cause a large number of hot billets to turn over to the cooling bed during steelmaking, increasing gas consumption and secondary heating time.

[0006] During the direct rolling of steel billets, the flexible connection of steel billets is poor, the gap between steel billets fluctuates greatly, and the gap time is long, most of which reaches more than 7 seconds, resulting in low direct rolling efficiency. Therefore, the research on HRB500E electromagnetic heating head-to-tail rolling, controlled rolling and controlled cooling is of great significance to reducing energy consumption and increasing direct rolling output, so as to solve the problem of large gap fluctuation and low direct rolling efficiency caused by poor temperature control in existing direct rolling technology. Summary of the invention

[0007] In view of the problems existing in the prior art, the object of the present invention is to provide a novel electromagnetic heating direct rolling method for HRB500E steel billet.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a new type of HRB500E steel billet electromagnetic heating direct rolling method, comprising the following steps:

[0009] S1. System components: induction heating system, mechanical pneumatic system, electromagnetic heating coil, thyristor inverter, control console and PLC system;

[0010] S2, direct rolling logic control: electromagnetic heating design 4 waiting positions: C9 waiting position, C8 waiting position, C7 waiting position, C1 waiting position;

[0011] S3, direct rolling process: when the pulling speed is lower than 3.8m / min during direct rolling of bars, the rolling line is notified to measure the temperature to verify the effect of electromagnetic heating. After electromagnetic heating, the billet whose head rolling temperature does not meet the standard is removed;

[0012] S4. Design different heating standards and parameter calls according to the different billet temperatures detected.

[0013] Specifically, the induction heating system in step S1 includes a slotted inductor, a cabinet, a capacitor, a water pump motor and a water tank, and a stainless steel waterway;

[0014] Mechanical and pneumatic system: The mechanical part is divided into automatic feeding control mechanism, pneumatic pushing device, variable frequency speed regulating motor, and pneumatic control mechanism;

[0015] Console and PLC system: Console control is divided into automatic control and manual control to operate the entire set of equipment.

[0016] Specifically, the C9 waiting position in step S2 includes 2 sections of furnace rollers, 7 sections of direct rolling rollers, 6 sections of direct rolling rollers, and an electromagnetic heating roller. The designed operation mode is continuous operation. The C9 waiting position also includes 5 thermal detectors and pyrometers including C05 detector, C9 detector, C8 detector, C7 detector, and C6 detector.

[0017] Specifically, the C8 waiting position in the step S2 includes 5 sections of direct rolling rollers, and 4 sections of direct rolling rollers are designed for start-stop control, which are divided into two modes: entering and exiting. When the C04 detector and the C03 detector have no steel, the roller will keep running until the C04 detector detects that there is steel, completing the roller entry. When the C04 detector has steel, the previous steel leaves the C7 detector and the operation is delayed. The delay value is adjusted according to different specifications of the screen. The detectors include C03 detector, C04 detector, and H5 detector.

[0018] Specifically, the C7 waiting position in the step S2 includes 2 sections of direct rolling rollers and 1 section of direct rolling rollers, which are designed for start-stop control and are divided into two modes: vehicle entry and vehicle exit. Vehicle entry means that the C01 detector, C02 detector, and H7 detector are empty of steel, and the rollers will continue to run until H7 detects steel, completing the vehicle entry condition. Vehicle exit means that the H7 detector has steel, but the C03 detector and C04 detector are empty of steel, and then the vehicle exit condition is met. The detectors include C01 detector, C02 detector, and H7 detector.

[0019] Specifically, the C1 waiting position in step S2 includes continuous casting output roller section 1 and continuous casting output roller section 2, which are designed for start-stop control and are divided into two modes: vehicle entry and vehicle exit. Vehicle entry means that there is no steel at the C1 virtual billet position, and the roller will continue to run. The C1 virtual billet is set at the falling edge of the 8-stream detector, and reset at the falling edge of the R1 detector.

[0020] Specifically, the specific steps of the direct rolling process in step S3 are:

[0021] (1) Before the start of direct rolling, the billet in the furnace must be confirmed. The billet must be produced in a complete furnace to ensure normal delivery. The furnace is empty during direct rolling;

[0022] (2) Before the start of direct rolling in the heating furnace, the information of unrolled billets must be withdrawn, and the furnace number of the direct rolling start station 2 must be notified. The direct rolling furnace number information must be transmitted to the finishing station in a timely manner to ensure timely rolling;

[0023] (3) When the rolling line lights up yellow, a single steel is required, and the heating and continuous casting are manually fed into a single stream; when the rolling line lights up green, the heating and continuous casting are automatically fed into the direct rolling of the corresponding stream according to the hourly output of the rolling line specifications, and the steel demand rhythm is matched;

[0024] (4) If the head rolling temperature after electromagnetic heating does not meet the standard, the rolling temperature is less than 910°C or the rolling temperature is greater than 970°C, and the billet is rejected;

[0025] (5) Continuously optimize the electromagnetic heating program to ensure that the temperature difference of the 2# shear rod is within 20°C, the 2# shear temperature of the billet specifications of 20*2mm and 22*2mm is 930±15°C, and the 2# shear temperature of the billet specifications of 25*2mm, 28mm and 32mm is 900±15°C. Fine-tune the power of the electromagnetic heating temperature according to the 2# shear temperature;

[0026] (6) During direct rolling, if the heating furnace is empty and on standby, the overall furnace temperature is controlled at 700-800℃;

[0027] (7) To ensure the safety of the equipment, the temperature in front of the straightening machine should be lower than 800℃, and it is strictly forbidden to bite into the straightening machine; if the straightening effect is not ideal, there is warping or deflection, or even scratching the furnace wall, an emergency stop operation should be performed.

[0028] Specifically, in step S4, 9 gears are designed according to different detected billet temperatures.

[0029] The present invention has the following beneficial effects:

[0030] The novel HRB500E steel billet electromagnetic heating supplement direct rolling method designed by the present invention adopts direct rolling electromagnetic heating supplement control logic, realizes real-time tracking of steel billets through steel billet detection; realizes head-to-tail rolling of direct rolling steel billets through waiting position design; designs direct rolling electromagnetic heating supplement process to realize smooth direct rolling of steel billets; designs electromagnetic heating supplement direct rolling temperature control standard, executes different heating standards and parameter calls according to different detected steel billet temperatures, realizes stable direct rolling, and improves direct rolling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is the system distribution diagram of the direct rolling logic control of the new HRB500E steel billet electromagnetic heating direct rolling method. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely further describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, a novel electromagnetic heating direct rolling method for HRB500E steel billet comprises the following steps:

[0034] 1. System components: induction heating system, mechanical pneumatic system, electromagnetic heating coil, thyristor inverter, control console and PLC system; the induction heating system includes slot inductor, cabinet, capacitor, water pump motor and water tank, and stainless steel water circuit; mechanical pneumatic system: the mechanical part is divided into automatic feeding control mechanism, pneumatic pushing device, variable frequency speed regulating motor, pneumatic control mechanism; control console and PLC system: the control console is divided into automatic control and manual control to operate the whole set of equipment.

[0035] 2. Direct rolling logic control: Electromagnetic heating is designed with 4 waiting positions: C9 waiting position, C8 waiting position, C7 waiting position, and C1 waiting position.

[0036] The C9 waiting position includes 2 sections of furnace rollers, 7 sections of direct rolling rollers, 6 sections of direct rolling rollers, and electromagnetic heating rollers. The designed operation mode is continuous operation. The C9 waiting position also includes 5 thermal inspection and pyrometers including C05 detector, C9 detector, C8 detector, C7 detector, and C6 detector.

[0037] The C8 waiting position includes 5 sections of direct rolling rollers and 4 sections of direct rolling rollers designed for start-stop control. It is divided into two modes: entering and exiting. When there is no steel in the C04 detector and the C03 detector, the roller will keep running until the C04 detector detects that there is steel, completing the roller entry. When there is steel in the C04 detector, the previous steel will leave the C7 detector and the operation will be delayed. The delay value is adjusted according to different specifications on the screen. The detectors include C03 detector, C04 detector and H5 detector.

[0038] The C7 waiting position includes 2 sections of direct rolling roller table and 1 section of direct rolling roller table, which are designed for start-stop control and are divided into two modes: vehicle entry and vehicle exit. Vehicle entry means that there is no steel in the C01 detector, C02 detector and H7 detector, and the roller table will keep running until H7 detects steel, completing the vehicle entry condition. Vehicle exit means that there is steel in the H7 detector, but there is no steel in the C03 detector and C04 detector, then the vehicle exit condition is met. The detectors include C01 detector, C02 detector and H7 detector.

[0039] The C1 waiting position includes the 1st section of the continuous casting output roller table and the 2nd section of the continuous casting output roller table. It is designed for start-stop control and is divided into two modes: car entry and car exit. When the car is entering, there is no steel at the C1 virtual billet position, and the roller table will continue to run. The C1 virtual billet is set by the falling edge of the 8-stream detector and reset by the falling edge of the R1 detector.

[0040] 3. Direct rolling process:

[0041] (1) Before the start of direct rolling, the billet in the furnace must be confirmed. The billet must be produced in a complete furnace to ensure normal delivery. The furnace is empty during direct rolling;

[0042] (2) Before the start of direct rolling in the heating furnace, the information of unrolled billets must be withdrawn, and the furnace number of the direct rolling start station 2 must be notified. The direct rolling furnace number information must be transmitted to the finishing station in a timely manner to ensure timely rolling;

[0043] (3) When the rolling line lights up yellow, a single steel is required, and the heating and continuous casting are manually fed into a single stream; when the rolling line lights up green, the heating and continuous casting are automatically fed into the direct rolling of the corresponding stream according to the hourly output of the rolling line specifications, and the steel demand rhythm is matched;

[0044] (4) When the pulling speed is lower than 3.8m / min during bar direct rolling, the rolling line is notified to measure the temperature to verify the electromagnetic heating effect. The billet whose head rolling temperature does not meet the standard after electromagnetic heating is removed. The range of the head rolling temperature not meeting the standard after electromagnetic heating is that the rolling temperature is less than 910℃ or the rolling temperature is greater than 970℃.

[0045] (5) Continuously optimize the electromagnetic heating program to ensure that the temperature difference of the 2# shear rod is within 20°C, the 2# shear temperature of the billet specifications of 20*2mm and 22*2mm is 930±15°C, and the 2# shear temperature of the billet specifications of 25*2mm, 28mm and 32mm is 900±15°C. Fine-tune the power of the electromagnetic heating temperature according to the 2# shear temperature;

[0046] (6) During direct rolling, if the heating furnace is empty and on standby, the overall furnace temperature is controlled at 700-800℃;

[0047] (7) To ensure the safety of the equipment, the temperature in front of the straightening machine should be lower than 800℃, and it is strictly forbidden to bite into the straightening machine; if the straightening effect is not ideal, there is warping or deflection or even scratching the furnace wall, emergency stop operation should be performed to avoid damage to the equipment.

[0048] 4. Design different heating standards and parameter calls according to the different billet temperatures detected.

[0049] Nine gears are designed according to the different billet temperatures detected. The given parameters and speed control of the thyristor inverter in each gear are different. The heating power is large when the temperature is low, and the heating power is small when the temperature is high. In addition, the number of heating sections opened at different temperatures is different to achieve precise heating.

[0050] The present invention realizes stable direct rolling through electromagnetic heat supplement direct rolling control technology, with a rolling gap of less than 4 seconds, a temperature difference between the head and tail of the rolled steel billet of less than 20 degrees Celsius, and a start rolling temperature of greater than 910°C.

[0051] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0052] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A novel HRB500E steel billet electromagnetic heating direct rolling method, characterized in that: The following steps are involved: S1. System components: induction heating system, mechanical pneumatic system, electromagnetic heating coil, thyristor inverter, control console and PLC system; S2, direct rolling logic control: electromagnetic heating design 4 waiting positions: C9 waiting position, C8 waiting position, C7 waiting position, C1 waiting position; S3, direct rolling process: when the pulling speed is lower than 3.8m / min during direct rolling of bars, the rolling line is notified to measure the temperature to verify the effect of electromagnetic heating. After electromagnetic heating, the billet whose head rolling temperature does not meet the standard is removed; S4. Design different heating standards and parameter calls according to the different billet temperatures detected.

2. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The induction heating system in step S1 includes a slotted inductor, a cabinet, a capacitor, a water pump motor and a water tank, and a stainless steel waterway; Mechanical and pneumatic system: The mechanical part is divided into automatic feeding control mechanism, pneumatic pushing device, variable frequency speed regulating motor, and pneumatic control mechanism; Console and PLC system: Console control is divided into automatic control and manual control to operate the entire set of equipment.

3. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The C9 waiting position in step S2 includes 2 sections of furnace rollers, 7 sections of direct rolling rollers, 6 sections of direct rolling rollers, and an electromagnetic heating roller. The designed operation mode is continuous operation. The C9 waiting position also includes 5 thermal detectors and pyrometers including C05 detectors, C9 detectors, C8 detectors, C7 detectors, and C6 detectors.

4. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The C8 waiting position in the step S2 includes 5 sections of direct rolling rollers, and 4 sections of direct rolling rollers are designed for start-stop control, which are divided into two modes: vehicle entry and vehicle exit. Vehicle entry is when there is no steel in the C04 detector and the C03 detector, and the roller will continue to run until the C04 detector detects that there is steel, completing the vehicle entry into the roller. Vehicle exit is when there is steel in the C04 detector, and the previous steel leaves the C7 detector, and the operation is delayed. The delay value is adjusted according to different specifications of the screen. The detectors include C03 detector, C04 detector, and H5 detector.

5. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The C7 waiting position in the step S2 includes 2 sections of direct rolling rollers and 1 section of direct rolling rollers, which are designed for start-stop control and are divided into two modes: vehicle entry and vehicle exit. Vehicle entry means that the C01 detector, C02 detector, and H7 detector are empty of steel, and the rollers will continue to operate until H7 detects steel, completing the vehicle entry condition. Vehicle exit means that the H7 detector has steel, but the C03 detector and C04 detector are empty of steel, and then the vehicle exit condition is met. The detectors include C01 detector, C02 detector, and H7 detector.

6. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The C1 waiting position in step S2 includes continuous casting output roller section 1 and continuous casting output roller section 2, which are designed for start-stop control and are divided into two modes: vehicle entry and vehicle exit. Vehicle entry means that there is no steel at the C1 virtual billet position, and the roller will continue to run. The C1 virtual billet is set at the falling edge of the 8-stream detector, and reset at the falling edge of the R1 detector.

7. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: The specific steps of the direct rolling process in step S3 are: (1) Before the start of direct rolling, the billet in the furnace must be confirmed. The billet must be produced in a complete furnace to ensure normal delivery. The furnace is empty during direct rolling; (2) Before the start of direct rolling in the heating furnace, the information of unrolled billets must be withdrawn, and the furnace number of the direct rolling start station 2 must be notified. The direct rolling furnace number information must be transmitted to the finishing station in a timely manner to ensure timely rolling; (3) When the rolling line lights up yellow, a single steel is required, and the heating and continuous casting are manually fed into a single stream; when the rolling line lights up green, the heating and continuous casting are automatically fed into the direct rolling of the corresponding stream according to the hourly output of the rolling line specifications, and the steel demand rhythm is matched; (4) If the head rolling temperature after electromagnetic heating does not meet the standard, the rolling temperature is less than 910°C or the rolling temperature is greater than 970°C, and the billet is rejected; (5) Continuously optimize the electromagnetic heating program to ensure that the temperature difference of the 2# shear rod is within 20°C, the 2# shear temperature of the billet specifications of 20*2mm and 22*2mm is 930±15°C, and the 2# shear temperature of the billet specifications of 25*2mm, 28mm and 32mm is 900±15°C. Fine-tune the power of the electromagnetic heating temperature according to the 2# shear temperature; (6) During direct rolling, if the heating furnace is empty and on standby, the overall furnace temperature is controlled at 700-800℃; (7) To ensure the safety of the equipment, the temperature in front of the straightening machine should be lower than 800℃, and it is strictly forbidden to bite into the straightening machine; if the straightening effect is not ideal, there is warping or deflection, or even scratching the furnace wall, an emergency stop operation should be performed.

8. The new HRB500E steel billet electromagnetic heating direct rolling method according to claim 1 is characterized in that: In step S4, nine gears are designed according to different detected billet temperatures.

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