Title:
METHOD FOR MEASURING SILICON CONCENTRATION OF STEEL PRODUCT AND METHOD FOR MANUFACTURING FLAT ROLLED MAGNETIC STEEL SHEETS AND STRIPS
Document Type and Number:
Japanese Patent JP3707547
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method for accurately measuring Si concentration in the vicinity of the surface layer of a steel product without performing high-frequency AC excitation.
SOLUTION: The magnetization level of the steel product 1 is controlled by adjusting a current to be passed through a magnetizer 3. An eddy current sensor 4 and an eddy current sensor electronic circuit 5 are used to perform eddy current measurement. On the basis of the result of the measurement, the Si concentration of the steel product is measured. A magnetizing current of the DC magnetizer 3 is controlled by a magnetization level controller 2 so that the magnetization level is brought sufficiently close to a saturation level in a previously measured B-H curve of each steel sheet at the measurement of average concentration, and to a level in which variations of differential permeability due to samples do not substantially affect the eddy current measurement. At the measurement of surface layer concentration, the magnetizing current is set at one-tenth of a magnetizing current at the measurement of average concentration.
Inventors:
Hiroharu Kato
Akio Nagato
Toshihiko Iida
Akio Nagato
Toshihiko Iida
Application Number:
JP2002040883A
Publication Date:
October 19, 2005
Filing Date:
February 19, 2002
Export Citation:
Assignee:
jfe Steel Corporation
International Classes:
G01N27/72; (IPC1-7): G01N27/72
Domestic Patent References:
| JP2001228120A | ||||
| JP8136509A | ||||
| JP2000065801A |
Attorney, Agent or Firm:
Toshiaki Hosoe