The oxygen dissolution in metallic zirconium has been investigated by
electrochemical and X-ray techniques, The mechanism of the zirconium o
xidation process is proposed. It is shown that during the first stage
of the process, oxygen dissolves in the metal matrix acting as an elec
tron donor. The region of oxygen solid solutions in zirconium reaches
25 at. % oxygen. After oxygen saturation of the metal surface the seco
nd stage starts; zirconium oxides form.