The Research Of Thickness Control Optimization In Baosteel1580mm HSM

With the increasing of the steel grade and steel gauge categories, the rolling pacing and the equipment degradation, the percentage of the sub-quality steel because of thickness has became a big problem for Baosteel, and steps must be taken to solve the problem. The main evaluating indicator of thickness control ability includes:thickness precision and the out-of-tolerance degree of thickness. And the conventional evaluating indicator in the steel production process is the lockup of the steel thickness which is out of the thickness tolerance, and that depends on the setup precision of the mathematical model in the strip head end, which leads to the higher expectation for the thickness setup model precision.The research of the steel strip thickness control technology is introduced in this paper, such as the computer control system of the hot strip mill, the finishing rolling rules’ calculation, the factors that affects the strip thickness, the development of the thickness control technology, the thickness automatic control theory and the thickness compensation strategy.The mathematical model of the finishing mill for1580mm HSM is analyzed, such as the temperature calculation model, roll force calculation model, speed model and roll gap calculation model; the data preparation, the reduction regulation calculation, exit temperature calculation and the model self-learning, which is the basis of the improvement of the thickness setup model and the reduction of the lockup of the strip thickness.Based on the practical conditions, the roll gap compensation is applied in the first rolling material of one schedule by means of statistical analysis; the roll force learning coefficient upper limit of the micro alloyed steel is determined; the tail end thickness deficiency is reduced greatly by means of tail end compensation; the CEQ of IF steel conjoining slab calculation model is set up by means of deformation resistance values analysis with the clustering tool and the IF steel conjoining slab lot is optimized.The roll setup roll gap precision is improved greatly and the thickness lockup ratio is reduced from0.5%to0.35%with the application of the above optimization considering the1580mm HSM condition.