Patent ID: 7971630

Claim:
A method for detecting a crater end of a continuously cast product, the method comprising the steps of installing an ultrasonic shear wave sensor for transmitting an ultrasonic shear wave to the continuously cast product and receiving the transmitted ultrasonic shear wave in a continuous casting machine, detecting based on variations of an ultrasonic signal received by the ultrasonic shear wave sensor that the crater end of the cast product is matched with the installed position of the ultrasonic shear wave sensor, calibrating a physical property value of the cast product used in a calculation based on a heat condition equation in solidifying the cast product, the physical property value being at least one of density, enthalpy, thermal conductivity, solidus temperature, heat removed in the mold, heat transfer coefficient in a secondary cooling zone, and temperature of molten steel, such that the crater end computed based on the heat condition equation using casting conditions at that time is matched with the installed position of the ultrasonic shear wave sensor, and after the calibration, determining the crater end by the calculation based on the heat condition equation under respective casting conditions by using the calibrated physical property value.