METHOD FOR MEASURING THICKNESS OF SOLIDIFIED SHELL IN CONTINUOUS CASTING BILLET

摘要

PURPOSE:To prevent breakout and to improve the quality of a billet by providing ultrasonic probes in the wall of a casting mold, transmitting ultrasonic waves therefrom and determining the thickness of the solidified shell of the billet in the casting mold in accordance with the reflected waves thereof. CONSTITUTION:The molten metal 2 in a tundish 1 is poured through an immersion nozzle 8 into a casting mold 7, and a solidified shell 5 is formed and is drawn downward. The inside wall of the mold 7 is constituted of copper plates 71, and the plates 71 are enclosed with iron plates 81 for reinforcement. Plural ultrasonic probes 8a, 8b, 8c, 8d are attached in the walls and are connected by means of lead wires to an ultrasonic thickness gage 6. Ultrasonic waves are emitted from the probes 8a-8d, then the oscillated waves, the waves reflected from the interface between the plates 71 and the shell 5, the waves reflected from the interface between the shell 5 and the unsolidified metal 2, etc. are inputted to the gage 6, by which the thickness of the shell 5 is continuously measured.