集中誘導型交流電位差法に関する研究 : 欠陥寸法の評価精度および周波数依存性の検討

概要

論文の詳細を見る
Aiming at nondestructive detection and size prediction of defects with high accuracy and resolution, an Induced Current Focusing Potential Drop (ICFPD) technique has been developed. This technique can be applied for determining the location and size of defects in components with not only simple shape such as plain surface but also more complex shape and geometry such as curved surface and dissimilar joint. This paper describes the basic principle of ICFPD and its probe development. In this ICFPD, current was induced in a conductive material by a straigth induction wire, which is electrically isolated, placed on it. The benefits of this new technique compared with the conventional ACPD are : (1) Current is induced and focused only at an explorating region. (2) Applicable to defect detection by scanning the sensor probe in an explorating region. (3) Applicable to defect detection in a weld joint of austenitic stainless steel. As the results of the innovation in instrumentation and the improvement in evaluation procedure by use of suitable parameters, the existence of defects is clearly observed as the variation of potential drops, and the nondimensional parameter (V_<c, max.>/V_<avg.>) has a direct correlation with crack depth. Especially, for the depth less than 5 mm, the ICFPD shows higher sensitivity than the conventional ACPD at the frequencies of 3, 10 and 30 kHz.
社団法人日本材料学会の論文
1994-11-15