Evaluation of Phase Transition of Austenitic Stainless Steel due in Hydrogen Embrittlement by Eddy Current Magnetic Signature Method
武田 翔 内一 哲哉 高木 敏行 山本 宏樹 （東北大） 榎 浩利 飯島 高志 （産総研）
austenitic stainless steeleddy current testinghydrogen embrittlementmartensitic transformationnondestructive evaluation
In this study, we focus on the eddy current testing (ECT) as a method to investigate the hydrogen embrittlement mechanism of austenitic stainless steels which are widely used in hydrogen components. ECT is applied to hydrogen-charged austenitic stainless steel AISI 304 specimens with different amounts of residual strain. Permeability values of the specimens are estimated by comparing the signals obtained by the ECT experiment and the results of the electromagnetic field analysis, and the phase transformation is evaluated from the change of the permeability. As a result, it is confirmed that the relative permeability increase with increasing the applied strain, and the relative permeability also increase only by charging hydrogen. From these results, it is indicated that α’ phase increases by both charging hydrogen and applying strain. Therefore, the possibility of ECT as an in-situ evaluation method of the phase transformation of austenitic stainless steel by hydrogen charge is suggested.