On-line acquisition method for plasticity coefficient of rolled piece during rolling of medium plate

Abstract

The invention relates to an on-line acquisition method for plasticity coefficient of a rolled piece during rolling of a medium plate, and belongs to the technical field of rolling. The method comprises the following steps: (1) determining the inlet thickness of the rolled piece; (2) acquiring the actual outlet thickness of the rolled piece; (3) solving key points on a plastic curve; (4) fitting the plastic curve; (5) calculating the tangent slope at the actual pressing measurement point to obtain the plasticity coefficient; (6) applying the solved plasticity coefficient to an AGC control model on line; and (7) triggering next period, turning to step (1) and reacquiring the plasticity coefficient according to the acquired data. The method has the advantages that the method does not depend on the investment of process computers and is not influenced by complex factors in a production field; the result has no jump phenomenon; and the acquisition process is stable, can be directly embedded into basic automation to be applied, and continuously correct the plasticity coefficient along with the rolling process according to the change of a roll force and the change of a roll gap so as to improve the thickness compensation precision of an AGC system and apply to high-precision AGC control.

Description

Technical field: [0001] The invention belongs to the technical field of rolling, and in particular relates to an online acquisition method for the plasticity coefficient of a rolled piece during the rolling process of a medium-thick plate. Background technique: [0002] At present, the thickness automatic control system, referred to as AGC, is generally used in the rolling process of medium and heavy plate mills. The commonly used AGC control models are the thickness gauge AGC control model and the dynamic setting AGC model. The model forms are as (1) and (2) shown. [0003] Thickness gauge AGC model: Δ S k = - M + Q M · Δ h k - - - ( 1 ) [0004] Dynamically set the AGC model: ...

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Problems solved by technology

[0009] 1. The acquisition error is large, that is, the difference between the slope of the tangent line at the actual depression point and the average slope is large;

[0010] 2. The operation of the basic automation AGC function depends on the process computer. When the process computer is shut down, the basic automation can only use the default value;

[0011] 3. During the rolling process, the rolled piece is affected by the temperature difference between the head and the tail and external factors of the watermark. The fluctuation of the thickness of the steel plate directly affects the actual value of the plastic coefficient of the rolled piece. Using a fixed average plastic coefficient to obtain the AGC model will cause the thickness control of the system to be inaccurate. precise

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