Title :
Effects of Magnetic Phase on the ECT Signal in the SG Tubes
Author :
Park, Duck-Gun ; Ryu, Kwon Sang ; Son, Derac ; Cheong, Yong Moo
Author_Institution :
Korea Atomic Energy Res. Inst., Daejeon, South Korea
Abstract :
The magnetic phase created in the Inconel alloy which is called permeability variation cluster (PVC) results in the distortion of an eddy current test (ECT) signal during the inspection of steam generator (SG) of a nuclear power plant (NPP). The effects of magnetic phase on ECT signals were analyzed using the inspection data of NPP. The hysteresis loops were measured for the PVC which is extracted from retired SG tubes of Kori-1 NPP. The tensile tests were performed to identify the mechanism of PVC creation. The coercivity of PVC is larger than 200 Oe, and hysteresis loop appeared in the tensile tested specimen at 600°C.
Keywords :
chromium alloys; coercive force; eddy current testing; iron alloys; magnetic hysteresis; magnetic permeability; nickel alloys; nuclear reactor steam generators; tensile testing; ECT signal; Inconel alloy; coercivity; eddy current test; hysteresis loops; magnetic phase; nuclear power plant; permeability variation cluster; steam generator inspection; temperature 600 degC; tensile tests; Eddy current testing; Eddy currents; Electrical capacitance tomography; Inspection; Magnetic hysteresis; Nuclear power generation; Permeability; Phase distortion; Power generation; Signal generators; Hysteresis loop; magnetic phase; permeability variation cluster (PVC); steam generator (SG) tube;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2009.2034537
