ON LINE MEASURING METHOD FOR MOLD 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 a ble to adapt to the hostile environment of the mould owing to the loca tion of the transducer far away from the operating site. Theoretical a nalysis and simulation tests in the laboratory have proved that the po wer signal is periodic with the same frequency as the oscillation cycl e, and the maximum power in a cycle has a linear relationship with the mould friction. A continuous billet easter was employed in the indust rial trials to investigate the effects of a variety of casting conditi ons including the steel carbon content, quantity of mould cooling wate r, mould wear, different feeding mechanisms of oil lubrication, and so me abnormal conditions. The results have shown that the method has a s ufficient sensitivity to variation, especially to the instantaneous va riation of the power, i.e. the mould friction, and it has been identif ied that the power can be used as an effective parameter with regard t o determining mould wear and taper, detecting surface defects, optimis ing the casting parameters, and predicting and thus preventing breakou ts for on line monitoring during continuous casting. Application of th e method will still closely depend on the establishment of a dynamic m athematical model which describes the mould oscillation and lubricatio n behaviour, and the employment of computers for process control.