Evaluation of the influence of crack branching structure and oxide fillings of stress corrosion cracking for depth sizing based on eddy current testing
大瀧 啓太郎 Keitaro OHTAKI 内一 哲哉 Tetsuya UCHIMOTO 高木 敏行 Toshiyuki TAKAGI 遊佐 訓孝 Noritaka YUSA 竹田 陽一 Yoichi TAKEDA
Depth sizing Eddy current testing Electromagnetic nondestructive evaluation Oxidation Stress corrosion cracking
This study discusses the stress corrosion cracking (SCC) model which improves accuracy of depth sizing of SCCs with eddy current testing (ECT). For this purpose, the factors that influence ECT for SCCs are evaluated. In this study, the crack morpholog y and oxide fillings in SCCs are evaluated. As a first step, SCCs introduced at room temperature and fatigue cracks with oxide fillings are evaluated. To discuss the EC signals of SCCs, SCCs are artificially introduced and their ECT signals are obtain ed. The EC signals of SCCs are much smaller than that of fatigue cracks. To discuss the influence of oxides in fatigue cracks on EC signals before SCC, oxides are systematically filled in fatigue cracks by thermal treatment, and their EC signals are obtained. The EC signals are changed before and after filling oxides and different from the type of oxide fillings. and their EC signals are obtained. The EC signals are changed before and after filling oxides and different from the ty oxide fillings.