Corrosion of pre-oxidized nickel alloy X-750 in simulated BWR environment
Artikel i vetenskaplig tidskrift, 2017

Samples of pre-oxidized Alloy X-750 were exposed to a simulated boiling water reactor environment in an autoclave at a temperature of 286 °C and a pressure of 80 bar for four weeks. The effect of alloy iron content on corrosion was investigated by comparing samples with 5 and 8 wt% Fe, respectively. In addition, the effect of two different surface pre-treatments was investigated. The microstructure of the formed oxide scales was studied using mainly electron microscopy. The results showed positive effects of an increased Fe content and of removing the deformed surface layer by pickling. After four weeks of exposure the oxide scale consists of oxides formed in three different ways. The oxide formed during pre-oxidization at 700 °C, mainly consisting of chromia, is partly still present. There is also an outer oxide consisting of NiFe2O4 crystals, reaching a maximum size of 3 ?m, which has formed by precipitation of dissolved metal ions. Finally, there is an inner nanocrystalline and porous oxide, with a metallic content reflecting the alloy composition, which has formed by corrosion. © 2017 Elsevier B.V.

TEM

STEM

Oxidation

SEM

Superalloys

Nickel

Författare

Silvia Tuzi

Chalmers, Fysik, Biologisk fysik

Haiping Lai

Chalmers, Fysik, Biologisk fysik

Kenneth Göransson

Westinghouse Electric Sweden AB

Mattias Thuvander

Chalmers, Fysik, Biologisk fysik

Krystyna Marta Stiller

Chalmers, Fysik, Biologisk fysik

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 486 350-360

Drivkrafter

Hållbar utveckling

Fundament

Grundläggande vetenskaper

Ämneskategorier

Metallurgi och metalliska material

Styrkeområden

Materialvetenskap

DOI

10.1016/j.jnucmat.2017.01.051