热轧双相钢的发展

1 前言热轧双相钢是由一定成分的低碳或低合金钢经控轧和控冷而得到具有铁素体和马氏体双相组织的钢。这种钢有75％～85％的铁索体及15％～25％的弥散于铁素体基体的岛状马氏体。同时,保留少量的残余奥氏体。

The Techniques to Reduce Variations within One Plate

Conventional techniques to control variations within one plate have been based on preset models and constant automatic position control (APC or pressure feedback automatic gauge control(PAGC).However.because of the rolling force prediction error in the preset models and of the inadequate response speed of dynamic system and of the eccentricity, etc.,the conventional method has not given satisfactory results, the statistics'variations within one plate are in range of 0.25-0.60 mm The authors have developed the techniques to control the variations, which are dynamic intelligent control of hydraulic screwdown system. synchronism control of hydraulic screwdown, eccentricity control method by rotary encoder and the curve of modulus of mill measured automatically, etc., The techniques were fully and successfully industrialized in The Plate Mill of Maanshan Iron and Steel Company and good results that variations are in range of 0.08-0.15min hare been obtained in that mill.

Adaptive Modification of the Rolling Force Prediction

In rolling process, the rolling force is an important parameter. The precision of the predicted rolling force will directly affect the precision of the finished product. By using adaptive control theory and fusing the measured and predicted data, the precision of the predicted rolling force is gradually improved. This system has been used in plant for more than one year, and the result of the application shows that the system has steady and reliable performance, and high precision.

Dynamic characteristics of cold rolling mill and strip based on flatness and thickness control in rolling process

The dynamic model of cold rolling mill based on strip flatness and thickness integrated control was proposed,containing the following sub-models:the rolling process model,the dynamic model of rolls along axial direction,and the compensation model.Based on the rule of volume flow rate,the dynamic rolling process model was built.The work roll and backup roll were taken as elastic continuous bodies,the effect of shear and moment of inertia were taken into consideration,and then the dynamic model of rolls was built.The two models were coupled together,and the dynamic model of rolling mill was built.In the dynamic model,the thermal expansion of the rolls,the wear of the rolls and other related parameters can not be considered.In order to compensate the dynamic model,the coupled static model of rolls and strip was applied.Then,according to the inner relationship of these models,the dynamic model and the compensation model were coupled,and the dynamic model of rolling mill based on the strip flatness and thickness integrated control was built.The dynamic simulation of the rolling process was made,and the dynamic thickness and the dynamic flatness information were obtained.This model not only provides a theory basis for the virtual rolling,but also provides a platform for the application of advanced control theory.

An Expert System in Automatic Gauge Control for Rolling Process

Beacuse the practical mathematic model of rolling process can't be built accurately,this paper established an expert system to control the rolling steels' gauge by adjusting the setup roll open, which combined the experience of theoreticians and operators. The system applied the expression method of rule-skeleton+rule-body', and selected an appropriate non-exact reference model and self-study algorithm. The whole system, including auxiliary routes, is designed in Borland C++. Some experiments on this system have been done, and a good result has been achieved.

Compound control for speed and tension multivariable coupling system of reversible cold strip mill

To weaken the nonlinear coupling influence among the variables in the speed and tension system of reversible cold strip mill, a compound control(CC) strategy based on invariance principle was proposed. Firstly, invariance principle was used to realize static decoupling between the speed and tension of reversible cold strip mill. Then, considering the influence caused by the time variation of steel coil radius and rotational inertia of the left and right coilers, as well as the uncertainties, a CC strategy that is composed of extended state observer(ESO) and global sliding mode control(GSMC) with backstepping adaptive was proposed,which further realized dynamic decoupling and coordination control for the speed and tension system. Theoretical analysis shows that the resulting closed-loop system is global bounded stable. Finally, the simulation was carried out on the speed and tension system of a 1422 mm reversible cold strip mill by using the actual data, and through the comparison of the other control strategies, validity of the proposed CC strategy was shown by the results.

Study on Rotational Stabilization in a Laser Tracking System

The high rolling speed of a missile heavily affects the stabilizing capability of the inertial platform in the laser tracking system （LTS） of the missile. In this paper, a rotational stabilizing platform （RSP） and a fuzzy-PID controller is designed to stabilize the inertial platform. This controller integrates the advantages of both fuzzy controller and classic PID controller. A comparison study is carried out to illustrate the advantages of the proposed fuzzy-PID controller over the classic PID controller. Numerical results indicate that the fuzzy-PID controller outperforms the classic one in effectively handling nonlinear disturbances and quickly stabilizing the inertial platform at the sudden change of missile roiling speed.