Derivation of Simplified Models of Plan View Pattern Control Function for Plate Mill

The plan view pattern control theoretical models were simplified. Under the condition of constant volume for the plan view pattern compensation, the relation between the thickness and the length can be simplified to the linearity in the segment for the plan view pattern control function. The compensation volume can be dispersed for easy calculation. By comparing the model calculation result with the actual result, it was concluded that the simplified model can be used for the online control process.

Width Compensation and Correction for the Plan View Pattern Control Function on Plate Mill

Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC( plan view pattern control) on width accuracy of plate mill. The thickness correction calculation formula was derived for compensation the width deviation caused by PVPC function,and the formula is unified under the thinning and thickening conditions. In order to improve the width calculation accuracy, width spread calculation process was modified with dividing one large reduction pass to several small reduction calculation steps. The thickness wedge was simplified to rectangle based on the volume constant principle,and the width spread model for PVPC was constructed. The width compensation and correction for the PVPC functions are used for the online control process,and the Product dimension accuracy is improved. With the decrease of crop losses,the product yield was increased with 0. 2%.

Calculation of Taper Rolling Time in Plan View Pattern Control Process

The forward slip model with adhesion was used to derive the formula of calculating taper rolling time. The relation between the rolling time and the taper length and the relation between the rolling time and the taper thickness can be obtained. The numerical solution for this formula was used on site. According to the simulation result, the roll gap value should be changed linearly with rolling time.

Precision Plate Plan View Pattern Predictive Model

According to the rolling features of plate mill, a 3D elastic-plastic FEM （finite element model） based on full restart method of ANSYS/LS-DYNA was established to study the inhomogeneous plastic deformation of multipass plate rolling. By analyzing the simulation results, the difference of head and tail ends predictive models was found and modified. According to the numerical simulation results of 120 different kinds of conditions, precision plate plan view pattern predictive model was established. Based on these models, the sizing MAS （mizushima automatic plan view pattern control system） method was designed and used on a 2 800 mm plate mill. Comparing the rolled plates with and without PVPP （plan view pattern predictive） model, the reduced width deviation indicates that the olate !olan view Dattern predictive model is preeise.

Broadside Compensation Rolling Model for Plan View Pattern Control in Wide and Heavy Plate Rolling Process

On the basis of a 5 m plate mill, a 3D rigid-plastic finite element （FE） model was developed to investigate changes of plate plan view patterns during hot rolling process. By analyzing the simulation results of conventional rolling processes, it was found that the plate plan view pattern was closely related to broadside rolling ratio. Then, the prediction models for plate plan view patterns were formulated by nonlinear regressive analysis of the simulation results and modified for high accuracy. Based on these models, the broadside compensation rolling method perform- ing at the last pass of broadside rolling phase was designed to decrease plate end crops. Comparing the plate plan view patterns with and without broadside compensation roiling, reduced plate end crops indicate that the broadside compensation roiling model is effective for plate plan view pattern control.

Analysis of Process Control Model of Plate MAS Rolling

Using the identification quantity to identify the long ear disfigurement was brought up, and by calculation, it can be found that identification quantity should be set as the quantity of long ear disfigurement of the position which is about 0. 2 times of plate width to the plate border. Conception of plate head tiny cell was brought up, and the long ear disfigurement was uncoupled into the product of elongation percentage and length of tiny cell. On the basis of prediction of long ear disfigurement, process control model of MAS rolling was built up, and application indicates that it can fit the on-line production and eliminate the long ear disfigurement commendably.