Basic study on numerical simulation of ultrasonic wave propagation behavior in statically cast stainless steel

Nagai, Masaki; Central Reseach Institute of Electric Power Industry; Japan

Nagai, M.; Central Research Institute of Electric Power Industry; Japan
Lin, S.; Central Research Institute of Electric Power Industry; Japan
Nakahata, K.; Ehime University; Japan

ID: ECNDT-0410-2018
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Session: Microstructural Scattering - UT 1
Room: J2
Date: 2018-06-13
Time: 10:00 - 10:20

Cast stainless steel (CASS) is widely used in primary coolant piping of nuclear power plants because of its high corrosion resistance and high strength. An in-service inspection based on ultrasonic testing (UT) has to be conducted for weld joints of primary coolant piping on the basis of JSME Rules on Fitness-for-Service for Nuclear Power Plants. However, it is difficult to detect and size flaws in CASS components with high accuracy because of the following reasons: Ultrasonic waves are scattered and attenuated due to coarse grains, and anisotropic and heterogeneous properties in CASS lead to ultrasonic beam splitting and skewing. In order to solve such problems, it is important to deeply understand wave propagation behavior in CASS based on numerical simulation. In this study, we prepared a statically cast stainless steel specimen, and observed its cross-sectional macrographs and wave propagation behavior experimentally. Then, we applied the cellular automaton coupled finite element model to predict the microstructures of CASS, and carried out three-dimensional wave propagation simulation based on FEM with the consideration of predicted microstructures.