Article ID: ISIJINT-2019-104
Ultra-fast cooling technology as an effective method for control microstructure and property, is widely used in hot rolled strips. For precise control of strip temperature in cooling process, a mathematical model based on UFC is established to calculate UFC-T and CT in high pressure mode, or only CT in low pressure mode. Temperature calculation compensation strategy is obtained to solve the situation that re-reddening after UFC process affects CT calculation. Furthermore, for existing self-learning strategy care less about evolution of strip temperature and has no ability to eliminate errors quickly, a multi-dimensional self-learning control strategy is proposed including dynamic self-learning gain, distributed temperature self-learning strategy and velocity coefficient for heat transfer self-learning. With help of proposed control strategies, strip temperature in cooling process is precise calculated and controlled. The model and strategies have been applied successfully in a 2050 HSM for development of low cost and feature strip products.