METHOD FOR MEASURING MAGNETIC TRANSFORMATION RATE OF STEEL PLATE IN ANNEALING FURNACE, DEVICE FOR MEASURING MAGNETIC TRANSFORMATION RATE OF SAME, CONTINUOUS ANNEALING PROCESS, AND CONTINUOUS HOT-DIP GALVANIZING PROCESS

摘要

Provided are a method for measuring the magnetic transformation rate of a steel sheet in an annealing furnace and an apparatus for measuring the magnetic transformation rate of a steel sheet in an annealing furnace, and a continuous annealing process and a continuous galvanizing process which utilize the method for measuring the magnetic transformation rate and the apparatus for measuring the magnetic transformation rate. A method for measuring a magnetic transformation rate of a steel sheet in an annealing furnace before the steel sheet is subjected to a heating treatment in the annealing furnace, by using a driving coil and receiving coils arranged on one surface side of the steel sheet so that the receiving coils are arranged on both sides of the driving coil and parallel to a surface of the steel sheet, the method including delivering an alternating-current driving signal to the surface of the steel sheet by using an air-core driving coil having a size larger than a width of the steel sheet, measuring the driving signal reflected by the steel sheet by using air-core receiving coils having a size larger than the width of the steel sheet, and determining the magnetic transformation rate of the steel sheet by using a measurement processing unit based on a distance between the steel sheet and the driving coil which has been corrected by using the measured values of the driving signal obtained by using the receiving coils.