Affiliations: [a] Department of Electrical System Engineering,
Polytechnic University, Kodaira-shi, Tokyo, Japan | [b] Center for Nondestructive Evaluation, Iowa State
University, Ames, IA, America | [c] Organization of Advanced Science and Technology, Kobe
University, Nada-ku Kobe, Japan | Université Laval, Canada | Tohoku University, Japan
Correspondence:
[*]
Corresponding author: Daigo Kosaka, Polytecnic University
2-32-1, Ogawanishimachi, Kodaira-shi, Tokyo 187-0035, Japan. E-mail:
dkosaka@iastate.edu
Abstract: This paper discusses material aging diagnosis what uses a
non-destructiveness evaluation system. The diagnosis is based on magnetic
characteristics of material. It is well known that the magnetism of strong
magnetic materials is extremely sensitive with respect to the change of
microstructure and to residual-stress variation. For example, coercive force
and minor-loop coefficients have shown a linear relationship with rolling
reduction. We have proposed a method what is an impedance measurement of a
sensor. The method needs a magnetizer with one coil and an impedance meter. The
method is simpler than a method what use coercive force. We have compared the
method with a method what is a measurement of coercive force. Relationship
between strain of carbon steels and experimental results of using coercive
force or impedance measurements has measured. Carbon steel sample specimens
with some strain loading in the experiment have been used. The experimental
results have shown that the method can detect strain of steel just like a
method of using a coercive force measurement.
Keywords: Residual strain, ferromagnetic materials, magnetic properties, iron loss, impedance, eddy current testing
