気が付けば8月も半ば、未だ新型コロナウィルス収束の気配無く、という状況ではありますが、ちょっといいニュースが参りました。IEEEからの学術論文誌であるIEEE Transactions on Instrumentation & Measurement誌にInspection of pitting corrosions on weld overlay cladding using uniform and rotating eddy current testing（一様渦電流及び回転渦電流プローブを用いた溶接クラッド孔食の検出）と題した論文が受理されました。
Authors: Jiuhao Ge, Fanwei Yu, Takuma Tomizawa, Haicheng Song, Noritaka Yusa
Title: Inspection of pitting corrosions on weld overlay cladding using uniform and rotating eddy current testing
Abstract: This study investigated the applicability of detecting pitting corrosions on stainless steel weld overlay cladding using uniform eddy current testing, which is insensitive to surface undulation, and rotating eddy current testing, which can be considered a superposition of uniform eddy current testing in orthogonal directions. The performance of the two techniques in detecting artificial pitting corrosions on and next to weld beads was compared. The signal distributions revealed that only rotating eddy current testing was capable of describing the surface profiles of pitting corrosions. The results of uniform eddy current testing could not distinguish between pitting corrosions and cracks. The probability of detection curves drawn to quantitatively indicate the detection capabilities of the two techniques revealed that uniform eddy current testing with induced eddy currents parallel and perpendicular to weld beads was better than rotating eddy current testing in detecting pitting corrosions on and next to weld beads, respectively. Scanning twice by uniform eddy current testing at orthogonal orientations may be a better process for detecting pitting corrosion on weld overlay cladding compared with using rotating eddy current testing. The measured signals of the two techniques in normal direction were located around the edges of the pitting corrosions, which only indicated the depth around edges. The results suggest that uniform and rotating eddy current testing with normal direction magnetic field signals may be inadequate for evaluating the maximum depth of pitting corrosions or large corrosions.