On-line Measurement of Work Roll Profile in a Hot Strip Finishing Mill

Abstract

An on-line roll profile meter has been developed to measure the surface contour of the work roll in a hot strip finishing mill. The system consists of a sensor head with twenty ultrasonic distance meters, a sensor head scanner, a signal processing unit and a computer. The ultrasonic distance meter uses a water column as sound propagation medium. Ten distance meters measure the distribution of distance between the roll surface and the reference surface of the sensor head. Other ten distance meters monitor the straightness of the reference surface. A tensioned wire is used as the reference of the straightness. Each distance meter can measure the sound velocity directly in the water column to compensate for the error due to the sound velocity variation. The off-line and on-line measurements were carried out at the No. 2 hot strip mill in Chiba Works of Kawasaki Steel. The results showed that the measuring accuracy was less than ±10μm.