OXIDE COATING FILM ADHESION STRENGTH EVALUATION METHOD AND ITS EVALUATION DEVICE OF DIRECTIONAL ELECTROMAGNETIC STEEL PLATE

摘要

PROBLEM TO BE SOLVED: To provide a method capable of simply, shortly and continuously on-line evaluating a measure of adhesion strength between ferrite and an oxide coating for a directional electromagnetic steel plate under non-contact and non-destruction.;SOLUTION: The method, evaluating an adhesion strength of oxide coating of a directional electromagnetic steel plate having an oxide coating on ferrite surface and an insulating coating on the oxide coating, includes a step of lighting an area in a width direction of the directional electromagnetic steel plate, a step of taking a picked-up image by imaging a range containing the lighted area of the directional electromagnetic steel plate, a step of obtaining a luminance value Lm at the lighted area of the directional electromagnetic steel plate by image processing, and a step of calculating a bending peel diameter calculation value Dm from the luminance value Lm based on a relational expression between a luminance value L and a bending peel diameter D of the directional electromagnetic steel plate, thereby evaluating the adhesion strength of oxide coating of the directional electromagnetic steel plate.;COPYRIGHT: (C)2011,JPO&INPIT