Characterization of oxide layers grown on D9 austenitic stainless steel in lead bismuth eutectic

Nanoscale characterization of HT-9 exposed to lead bismuth eutectic at 550°C for 3000h

“…It is not likely that the excess of Cr originates from the oxide layer since no increase in electrical conductivity was found. It appears that the oxide layers grown in the LBE environment follow a similar mechanism as proposed in [13]. Only the fact that the Cr content is lower in HT-9 than in the D9 steel studied there and that HT-9 has more interfaces due to its martensitic structure can account for the different appearance and growth rate of the oxide layers formed.…”

“…It is not entirely clear what causes this interface. But since the interface between layer 3 and layer 2 is the original steel interface and was in contact with the LBE at an earlier stage as it was described elsewhere [13], this change might be caused by the direct contact between Fe-Cr spinel and LBE. Because the inner layer 3 reflects the grain structure of the steel it is assumed here that the inner layer 3 adopts the steel grains by O diffusion inwards.…”

Evaluation of the Mechanical Properties of Naturally Grown Multilayered Oxides Formed on HCM12A Using Small Scale Mechanical Testing

“…It is believed that, due to the fact that the author did not distinguish the two layers, only the average value was reported. Hosemann et al [30] had observed similar behavior in oxidation layers from D9 steel after 2000-3000 h in LBE, where the biggest values of hardness are found in the inner layer together with a small decrease in E-modulus.…”

“…In both nuclear and non-nuclear applications, liquid metal coolants are under consideration as the primary heat transfer media [23][24][25][26]. High temperature oxidation of HCM12A in such extreme environments leads to the formation of a multilayered oxide structure, which have been studied previously on a range of different alloys [6][7][8][27][28][29][30]. Oxide layers formed on HCM12A have been previously studied by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), micro-X-ray diffraction (XRD), electron backscattered diffraction (EBSD), electron energy-loss spectroscopy (EELS), energy filtered transmission electron microscopy (EFTEM) and transmission electron microscopy (TEM) [19][20][21][22] and during exposure to LBE by SEM/EDX, EBSD, 3D atom probe tomography (APT) and scanning probe microscopy (SPM) [21,[31][32][33].…”

“…The oxide layers grown in a high temperature LBE environment are on the order of 10-30 lm thick; few conventional techniques for measuring mechanical properties have been developed for testing features on this scale. Nanoindentation in selected areas has been one of the main techniques in order to measure the hardness and reduced modulus [30,31]. Micro-cantilever testing, developed by [14], was used to evaluate the elastic modulus and fracture strength of the oxide and steel/oxide interface grown on HCM12A in this work; few other technique offer the level of resolution and discrimination necessary to measure the mechanical properties of micro-scale features.…”