Search

CN-122007168-A - Control method for uniform head and tail temperature in high-strength steel plate rolling process

CN122007168ACN 122007168 ACN122007168 ACN 122007168ACN-122007168-A

Abstract

The invention discloses a control method for uniform head and tail temperatures in a high-strength steel plate rolling process, which is realized based on a rolling mill guide cooling water pipe device consisting of a guide base frame, a cooling water pipe, an electric regulating valve, a position sensor and a PLC control system, wherein the cooling water pipe is integrated on a guide Wei Jijia, the electric regulating valve is connected with the cooling water pipe, the position sensor is in signal connection with the PLC control system, the PLC control system is electrically connected with the electric regulating valve, and the specific control method comprises the following steps of 1) device installation and debugging, 2) basic parameter setting, 3) position and speed detection, 4) dynamic avoidance and time node calculation, 5) gradient cooling control and 6) closed loop feedback regulation. According to the invention, the cooling water pipe assembly is integrated in the rear guide system of the rolling mill, and the precise space-time control of the cooling water flow is realized by combining the linkage control of the electric regulating valve and the position detecting mechanism, so that a closed-loop temperature control system is formed, the problem of uneven temperature of the head and the tail of the rolling of the steel plate is effectively solved, and the quality and the production yield of the steel plate product are improved.

Inventors

  • XU SHAOPU
  • LIU KELONG
  • TANG ZHENGLEI
  • SUN BINGHONG
  • KANG WENJU

Assignees

  • 南阳汉冶特钢有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (7)

  1. 1. A control method for uniform head and tail temperature in the rolling process of a high-strength steel plate is characterized by being realized based on a rolling mill guide cooling water pipe device consisting of a guide base frame, a cooling water pipe, an electric regulating valve, a position sensor and a PLC control system, wherein the device is integrated in a rolling mill rear guide system to form a closed-loop temperature control system, and the specific control method comprises the following steps of: 1) The device is installed and debugged, namely a guide Wei Jijia is fixed at the outlet side of a rolling mill, the deviation between the center line of a cooling water pipe and the center line of the rolling mill is less than or equal to 1mm, the height of the cooling water pipe group from the surface of a steel plate is about 150mm, the angle error is less than or equal to 0.5 DEG, a position sensor signal wire adopts a shielding twisted pair, the grounding resistance is less than or equal to 4 omega, and a UPS uninterrupted power supply is configured; 2) Setting basic parameters, namely setting rolling speed in a PLC control system to be 0.5-3.8m/s, steel plate thickness to be 8-60mm, cooling temperature to be 850-950 ℃, cooling intensity to be 150m < 3 >/h for strong cooling, 100m < 3 >/h for middle cooling and 20m < 3 >/h for weak cooling, setting a steel plate head-tail basic avoidance area to be 500mm from the head to the tail, setting response time of an electric regulating valve to be less than or equal to 0.3 seconds, control precision to be +/-1%, and setting the PLC sampling period to be 50ms; 3) Detecting the position and speed, namely detecting the rolling position of the steel plate in real time through a position sensor, collecting the main transmission speed of the rolling mill through an encoder, and transmitting signals to a PLC control system in real time; 4) The PLC control system accurately calculates the time node of the steel plate reaching the cooling area from the head to the tail according to the length and rolling speed of the steel plate, when the edge of the steel plate enters a preset avoiding area, the PLC outputs a control signal, and the electric regulating valve completes opening degree regulation within 0.3 seconds; 5) Gradient cooling control, namely adopting a strong cooling mode when the middle part of the steel plate passes through a cooling zone, carrying out linear gradual cooling from strong cooling to weak cooling in a transition zone outside a head and tail avoidance zone, adopting a weak cooling mode in the head and tail avoidance zone, increasing the cooling water quantity by 15% when the thickness of the steel plate is increased by 5mm, and increasing the rolling speed by 0.5m/s and prolonging the avoidance zone by 100mm; 6) And closed loop feedback regulation, namely acquiring data in real time by the position sensor and the temperature detection element, transmitting the data to the PLC, and dynamically adjusting the opening of the electric regulating valve by the PLC according to the actual temperature difference to ensure that the temperature difference of the head, the middle and the tail of the steel plate is controlled within 10 ℃.
  2. 2. The method for controlling the head and tail temperature uniformity in the high-strength steel plate rolling process according to claim 1, wherein the cooling water pipes in the step 1) are stainless steel water pipes distributed in an annular mode, the pipe diameter phi is 200mm, the wall thickness is 8mm, the surface is provided with water outlets which are arranged in a spiral mode phi and 10mm, the water nozzles arranged at the water outlets are provided with stop valves, independent control of single water nozzles can be achieved, and the water pipes are connected with a main water supply system through connectors, so that maintenance and replacement are facilitated.
  3. 3. The method for controlling the head and tail temperature uniformity in the high-strength steel plate rolling process according to claim 1, wherein the electric regulating valve in the step 1) is a DN200 electric ball valve, is provided with a position feedback sensor, can realize stepless adjustment of 0-100% opening degree, and can be automatically put into use within 0.5 seconds when a main valve fails.
  4. 4. The method for controlling the temperature uniformity of the head and the tail of a high-strength steel plate rolling process according to claim 1, wherein in the step 1), a guide Wei Jijia is fixed on the outlet side of a rolling mill through bolts, a water supply system is provided with a bypass pipeline, and the guide Wei Runhua is maintained during maintenance.
  5. 5. The method for controlling the head and tail temperature uniformity in the rolling process of the high-strength steel plate according to claim 1, wherein in the step 4), the real-time detection of the position of the steel plate is realized through the high-temperature detection before the rolling mill, and the head and tail position states of the steel plate are accurately judged by combining rolling pass length data.
  6. 6. The method for controlling the head and tail temperature uniformity in the high-strength steel plate rolling process according to claim 1, wherein the rolling mill guide cooling water pipe device is composed of a guide base frame, a cooling water pipe, an electric regulating valve, a position sensor and a PLC control system, wherein the cooling water pipe is integrated on a guide Wei Jijia, the electric regulating valve is connected with the cooling water pipe, the position sensor is in signal connection with the PLC control system, the PLC control system is electrically connected with the electric regulating valve, and the whole device is integrated on a rolling mill rear guide system to form a closed-loop temperature control system.
  7. 7. The method for controlling the head and tail temperature uniformity in the high-strength steel plate rolling process of claim 1, wherein a PLC control system selects Siemens S7-1500 PLC, and forms linkage control with an electric regulating valve and a position sensor to realize accurate time-space control of cooling water flow.

Description

Control method for uniform head and tail temperature in high-strength steel plate rolling process Technical Field The invention belongs to the technical field of metal processing, and particularly relates to a control method for uniform temperature at the head and tail of a high-strength steel plate rolling process, which is suitable for a rolling production line of high-strength steel products such as medium plates, wire rods and the like, and is particularly suitable for high-strength steel production scenes with severe requirements on temperature uniformity such as military industry and energy equipment. Background In the rolling production process of the high-strength steel plate, the uneven temperature of the head and the tail is a long-standing technical problem in the industry, and the quality and the production benefit of the steel plate product are directly affected. The traditional laminar cooling system has the defects that the cooling area is long, the final cooling temperature control error reaches +/-15 ℃, the distance between a temperature sensor and control equipment exceeds 10 meters, the timeliness of data transmission is poor, the temperature control response is obviously delayed, and the cooling water sputtering also can interfere the reading of the temperature sensor, so that the measurement error is caused. The temperature difference between the head and the tail of a rolled piece is influenced by multiple factors, the temperature difference between the head, the middle and the tail in the rolling process of a 20mm thick steel plate can reach 50 ℃, the temperature difference between the head and the tail of a 220mm steel billet produced by a continuous casting machine can reach 40-50 ℃, and the standard deviation of the yield strength of the rolled steel plate is directly caused to exceed the standard. The existing improvement measures in the industry have obvious defects that although the induction heating technology can balance the temperature of casting blanks, the power consumption per ton of steel is up to 15-30KWh, the edge shielding device can only improve the temperature difference in the width direction and can not solve the temperature difference problem in the length direction, and the traditional water cooling system has high steel cutting rate up to 1% due to the heat length and the transition length, so that serious metal resource waste is caused. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a control method for uniform head and tail temperatures in the rolling process of a high-strength steel plate, which integrates a cooling water pipe assembly in a rear guide system of a rolling mill, combines linkage control of an electric regulating valve and a position detection mechanism to realize precise space-time control of cooling water flow, forms a closed-loop temperature control system, effectively solves the problem of nonuniform head and tail temperatures in the rolling process of the steel plate, and improves the quality and the production yield of the steel plate product. In order to achieve the aim, the technical scheme adopted by the invention is that the control method for the uniform head and tail temperature in the high-strength steel plate rolling process is realized based on a rolling mill guide cooling water pipe device consisting of a guide base frame, a cooling water pipe, an electric regulating valve, a position sensor and a PLC control system, the device is integrated in a rolling mill rear guide system to form a closed-loop temperature control system, and the specific control method comprises the following steps: 1) The device is installed and debugged, namely a guide Wei Jijia is fixed at the outlet side of a rolling mill, the deviation between the center line of a cooling water pipe and the center line of the rolling mill is less than or equal to 1mm, the height of the cooling water pipe group from the surface of a steel plate is about 150mm, the angle error is less than or equal to 0.5 DEG, a position sensor signal wire adopts a shielding twisted pair, the grounding resistance is less than or equal to 4 omega, and a UPS uninterrupted power supply is configured; 2) Setting basic parameters, namely setting rolling speed in a PLC control system to be 0.5-3.8m/s, steel plate thickness to be 8-60mm, cooling temperature to be 850-950 ℃, cooling intensity to be 150m < 3 >/h for strong cooling, 100m < 3 >/h for middle cooling and 20m < 3 >/h for weak cooling, setting a steel plate head-tail basic avoidance area to be 500mm from the head to the tail, setting response time of an electric regulating valve to be less than or equal to 0.3 seconds, control precision to be +/-1%, and setting the PLC sampling period to be 50ms; 3) Detecting the position and speed, namely detecting the rolling position of the steel plate in real time through a position sensor, collecting the main transmission speed of the rolling mill th