CN106269904A - Calibration method for roll gap of rolling mill - Google Patents

Abstract

A rolling mill roll gap calibration method, the rolling force deviation of the last piece of steel strip rolled before the roll change is used as the zero clearing standard after the roll change to calibrate; the roll gap calibration of the rolling mill is divided into the following two situations: 1) changing the work roll The final roll gap calibration process is as follows: after the roll is changed, after the roll gap pressure is 1500 tons, the deviation rolling force of the last piece of strip steel is rolled as the standard adjustment level, and the calibration is cleared; 2) The roll gap after changing the backup roll The calibration process is as follows: the calculation is based on the deviation rolling force when the last piece of strip is rolled during four consecutive back-up roll replacement cycles, and the average value of the four times is taken. After the roll change, the roll gap pressure is 1500 tons. This average value is used as the standard adjustment level for calibration and zeroing. The invention can realize reliable and accurate calibration of the roll gap, and can ensure the precision of the calibration of the roll gap of the rolling mill in the state where the accuracy of the current equipment is greatly reduced due to long-term use, ensure the smooth progress of the rolling process, and ensure safe production.

Description

A Calibration Method for Roll Gap of Rolling Mill

technical field

The invention relates to automatic control of steel rolling, in particular to a method for calibrating the roll gap of a rolling mill.

Background technique

The hot-rolled strip finishing mill must control the roll gap value with high precision during the rolling process, and the roll gap must be calibrated every time the work roll or backup roll is changed, which is also called zero adjustment of the rolling mill.

Whether the roll gap calibration is accurate is of great significance to the normal rolling of the finishing mill, because factors such as rolling stability, roll gap setting, and AGC thickness automatic control during the rolling process are all based on the original roll gap after roll gap calibration. If the calibration is inaccurate, it will inevitably have adverse effects on rolling and cause accidents.

Due to the long-term heavy load operation of the finishing mill unit of the hot rolling line, the overall equipment accuracy has declined, resulting in some problems during calibration, such as excessive deviation of rolling force, inaccurate copper bar values, little reference value, human measurement errors and other factors But it is impossible to determine a unified roll gap calibration standard. In addition, there have been many production accidents recently, such as steel jamming and flat folding in the finishing mill when rolling the first piece of steel after roll gap calibration. This all shows that the current roll gap calibration method can no longer adapt to our safe production.

Contents of the invention

The purpose of the present invention is to provide a rolling mill roll gap calibration method, which can ensure the accuracy of the rolling mill roll gap calibration, ensure the smooth progress of the rolling process, and ensure safety under the condition that the accuracy of the current equipment has been greatly reduced due to long-term use. Production.

To achieve the above object, the present invention adopts the following technical solutions:

A rolling mill roll gap calibration method, the rolling force deviation of the last piece of steel strip rolled before the roll change is used as the zero-clearing standard after the roll change for calibration; the roll gap calibration of the rolling mill is divided into the following two situations:

1) The roll gap calibration process after changing the work roll is: after changing the roll, after the roll gap pressure is 1500 tons, the deviation rolling force of the last piece of strip steel rolled is used as the standard adjustment level, and the calibration is cleared;

2) The roll gap calibration process after changing the back-up roll is as follows: the calculation is based on the deviation rolling force when the last piece of strip is rolled during the four-time back-up roll change cycle, and the average value of the four times is taken, and the roll is changed. Finally, after the roll gap pressure is 1500 tons, the average value is used as the standard adjustment level, and the calibration is cleared.

Compared with prior art, the beneficial effect of the present invention is:

A rolling mill roll gap calibration method, the rolling force deviation of the last strip rolled before the roll change is used as the zero-clearing standard after the roll change, which can realize reliable and accurate calibration of the roll gap, and can be used in the current equipment due to long-term use In the state where the accuracy is greatly reduced, the accuracy of the roll gap calibration of the rolling mill is guaranteed, the smooth progress of the rolling process is ensured, and safe production is ensured.

detailed description

The present invention will be described in detail below, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

In order to scientifically evaluate whether the calibration process is accurate and to achieve reliable and accurate calibration of the roll gap, it is first necessary to determine the deviation rolling force on both sides of the work roll during stable production, the deviation rolling force when the rolling mill is stationary, and when the rolling force is 1500 tons Factors such as the floating range of rolling force and deviation rolling force.

The original operator can only observe the deviation of the rolling force instantaneously from the OPS screen, and the deviation of the rolling force is fluctuating at any time due to the influence of factors such as the gap between the parts such as the roll and the frame, the thickness of the oil film, and the eccentricity of the roll. , it is difficult to fix at a constant value, which is not conducive to operator observation.

Through long-term observation and analysis of various data during calibration, the roll gap level after rolling the last piece of strip steel in the rolling mill has reached the most stable strip threading position, and the oil column deviation and rolling force deviation at this time are A best clearing state, clearing in this state is the most conducive to the rolling of the next strip steel, so the present invention is to use the rolling force deviation of the last piece of strip before changing the rolls as the value after changing the rolls. The zero clearing standard is calibrated.

Adopt rolling mill roll gap calibration of the present invention to be divided into following two situations:

1) The roll gap calibration process after changing the work roll is: after changing the roll, after the roll gap pressure is 1500 tons, the deviation rolling force of the last piece of strip steel rolled is used as the standard adjustment level, and the calibration is cleared;

2) The roll gap calibration process after changing the back-up roll is as follows: take the deviation rolling force when rolling the last strip during the four-time back-up roll change cycle as the basis for calculation, take the average value of the four times, and after changing the roll , after the roll gap pressure is 1500 tons, the average value is used as the standard adjustment level, and the calibration is cleared.

Since there may be a large change in the oil column and deviation rolling force after changing the back-up roll, the influence of other factors must be taken into consideration. The calculation is based on the deviation rolling force of a piece of steel strip, and the average value of four times is taken, and the deviation rolling force at this time is used for calibration and clearing. This is the calibration process after changing the back-up roll.

The invention not only avoids personal habits of human operation through automatic program control, but also greatly reduces the calibration risk caused by the occasional fluctuation of the force measuring system of the rolling mill.

Embodiment 1: In order to verify the implementation effect of the present invention, we compare the data before and after the implementation of the project. See Table 1 for the level difference between roll gap calibration and reasonable roll gap before the project is implemented. Table 2 is the difference between roll gap calibration and reasonable roll gap after project implementation Reasonable level difference of roll gap.

Table 1: Unit: mm

Table 2: Unit: mm

Through the comparison of the data in Table 1 and Table 2, it can be clearly seen that after the implementation of the project, the calibration accuracy of the roll gap has made a big leap compared with the previous period, which has greatly improved the stability.

Claims (1)

1. a mill roll-gap scaling method, it is characterised in that the rolling force deviation rolling last block strip steel before roll change is made Demarcate for the clearing standard after roll change；Mill roll-gap is demarcated and is divided into following two situation:

1) the roll gap calibration process after roller that changes jobs is: after roll change, after roll gap presses 1500 tons, to roll last block band Steel deviation roll-force adjusts level as standard, carries out demarcating clearing；

2) change the roll gap calibration process after roller that supports for for: use to take continuously four times and change last block band of rolling in the backing roll cycle Deviation roll-force during steel is for according to calculating, taking the meansigma methods of four times, after roll change, puts down with this after roll gap presses 1500 tons Average adjusts level as standard, carries out demarcating clearing.