Oxide evolution on Alloy X-750 in simulated BWR environment
Artikel i vetenskaplig tidskrift, 2016

In order to simulate the environment experienced by spacer grids in a boiling water reactor (BWR), specimens of the Ni-based Alloy X-750 were exposed to a water jet in an autoclave at a temperature of 286 degrees C and a pressure of 80 bar. The oxide microstructure of specimens exposed for 2 h, 24 h, 168 h and 840 h has been investigated mainly using electron microscopy. The specimens suffer mass loss due to dissolution during exposure. At the same time a complex layered oxide develops. After the longest exposure the oxide consists of two outer spinel layers consisting of blocky crystals, one intermediate layer of nickel oxide interspersed with Ti-rich oxide needles, and an inner layer of oxidized base metal. The evolution of the oxide leading up to this structure is discussed and a model is presented.


Alloy X-750

Nickel based alloys

High temperature water


Oxide formation



Silvia Tuzi

Chalmers, Fysik, Biologisk fysik

Kenneth Göransson

Westinghouse Electric Sweden AB

Seikh Mohammad Habibur Rahman

Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Sten Eriksson

Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Fang Liu

Chalmers, Fysik, Biologisk fysik

Mattias Thuvander

Chalmers, Fysik, Biologisk fysik

Krystyna Marta Stiller

Chalmers, Fysik, Biologisk fysik

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 482 19-27