Oxide formation on titanium alloys in primary water of nuclear pressurised water reactor. (15th April 2019)

• Record Type: Journal Article
• Authors: Bignon, Quentin; Martin, Frantz; Auzoux, Quentin; Miserque, Frédéric; Tabarant, Michel; Latu-Romain, Laurence; Wouters, Yves
• Is Part Of: Corrosion science. Volume 150(2019)
• Page Start: 32
• Page End: 41
• Publication Date: 2019-04-15
• Subjects: Titanium -- Corrosion -- Dissolution -- Anatase -- Rutile; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.01.020
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The oxide layer formed is made of a dense oxide layer covered by crystallites. The continuous dense TiO2 scale is made of rutile for Ti CP and anatase for α/β alloys. All alloys are covered by small TiO2 anatase and large FeTiO3 ilmenite crystallites. The dissolution of TiO2 dense scale plays a key role in the corrosion mechanisms. Oxygen vacancy is the main point defect responsible for the growth of the dense TiO2 layer. Abstract: Three titanium alloys were exposed to primary water at 300 °C. Oxides of the three alloys consisted of a dense layer and surface crystallites. The dense oxide layer of Ti CP was made of TiO2 rutile whereas it was made of TiO2 anatase for both Ti 64 and Ti10-2-3. Surface crystallites of the three alloys were composed of TiO2 anatase and FeTiO3 ilmenite. Oxide dissolution and precipitation phenomenon were found to play a key role in the corrosion mechanisms. Oxygen vacancies were identified as the main point defect responsible for the growth of the dense oxide layer.