Effects of TGO Thickness and Interface Morphology on Stress Distribution of 700 C Novel Coated Dual Pipe System

This research studied the stress distribution of a 700 degrees C novel coated steam dual pipe system under thermal- mechanical loading. By running the sequentially coupled simulation, it is shown that Mises stress distribution is strongly correlated with the TGO thickness and morphology, particularly that at the peaks of TGO/BC interface is more sensitive to the roughness. In addition, under the constant amplitude and wavelength of TGO, the maximum value of Mises stress at the peak of TGO/BC interface is directly determined by the local curvature of the interface rather than the arrangement of various waveforms. It is revealed that amplitude and wavelength of TGO are the crucial parameters controlling the stress distributed at the TGO/BC interface in the coated dual pipe system.