On line measuring method for mould friction in continuous casting

A method of mould friction measurement based on the electric power of the motor driving the oscillation table has been developed, which is able to adapt to the hostile environment of the mould owing to the location of the transducer far away from the operating site. Theoretical analysis and simulation tests in the laboratory have proved that the power signal is periodic with the same frequency as the oscillation cycle, and the maximum power in a cycle has a linear relationship with the mould friction. A continuous billet easter was employed in the industrial trials to investigate the effects of a variety of casting conditions including the steel carbon content, quantity of mould cooling water, mould wear, different feeding mechanisms of oil lubrication, and some abnormal conditions. The results have shown that the method has a sufficient sensitivity to variation, especially to the instantaneous variation of the power, i.e. the mould friction, and it has been identified that the power can be used as an effective parameter with regard to determining mould wear and taper, detecting surface defects, optimising the casting parameters, and predicting and thus preventing breakouts for on line monitoring during continuous casting. Application of the method will still closely depend on the establishment of a dynamic mathematical model which describes the mould oscillation and lubrication behaviour, and the employment of computers for process control.