| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlled cooling of a hot rolled steel which can secure uniformity in both shape characteristics and material characteristics in the transverse direction, through enhancement of accuracy of cooling control by estimating an internal temperature distribution (temperature distribution through the thickness) of a heavy steel plate highly accurately, when the controlled cooling is performed by jetting a coolant on the hot rolled steel, and apparatus therefor. SOLUTION: In the controlled cooling apparatus for the steel which comprises a group of nozzles to jet the coolant, a supply control means of the coolant jetted from the group of nozzles, and a conveying speed control means, ultrasonic waves are transmitted and propagated by an ultrasonic sensor into the steel being cooled. Based on a relationship between a propagation speed of the ultrasonic wave and the temperature of steel, the internal temperature distribution (temperature distribution through the thickness) of the steel is estimated highly accurately. Based on the estimation result, the internal temperature of the steel (average temperature) is obtained and the jetting coolant quantity from the group of nozzles or both of the jetting coolant quantity and the conveying speed are controlled so as to match a target average temperature or cooling speed. COPYRIGHT: (C)2005,JPO&NCIPI
|
