Design and implementation of an automated secondary cooling system for the continuous casting of billets

This paper describes a heat transfer model based automatic secondary cooling system for a billet caster. The model aims to minimize the variation in surface temperature and excessive reheating of the billet strands. It is also used to avoid the low ductility trough of the solidifying steel, which aggravates the tendency of steel to crack. The system has been designed and implemented in an integrated steel plant. A Programmable Logic Controller (PLC) based automation system has been developed to control the water flow in the secondary cooling zones of the strand. The results obtained through field trials have shown complete elimination of internal and off-corner cracks for the fifty billet samples that were monitored.