Cyclic oxidation resistance of rare earth oxide gel coated Fe-20Cr alloys

AUTOR(ES)

Fernandes, Stela Maria de Carvalho, Ramanathan, Lalgudi Venkataraman

FONTE

Materials Research

DATA DE PUBLICAÇÃO

2007-09

RESUMO

Rare earths (RE) have been used to increase high temperature oxidation resistance of chromium dioxide and alumina forming alloys. The RE can be added as elements (or oxides) to the alloys or applied as an oxide coating to the alloy surface. RE oxide gels, obtained by the sol-gel technique, were used to coat Fe-20Cr specimens prior to cyclic oxidation tests in the temperature range RT-900 °C. The cyclic oxidation resistance of the alloy increased with time required to reach a specific chromium dioxide layer thickness, and this was influenced by RE ion radius, the coating morphology and coverage. Extended cyclic oxidation tests from peak temperatures of 900, 1000 and 1100 °C at cooling rates of 330 and 1000 °C/s revealed the marked influence of La2O3 coatings. The role of RE in increasing overall oxidation resistance of chromium dioxide forming alloys is discussed.

Documentos Relacionados

• High temperature oxidation resistance of rare earth chromite coated Fe-20Cr and Fe-20Cr-4Al alloys
• Effect of surface deposited rare earth oxide gel characteristics on cyclic oxidation behavior of Fe20-Cr alloys
• High Temperature Oxidation Behavior of Yttrium Dioxide Coated Fe-20Cr Alloy
• Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint
• Effect of pre-oxidation on high temperature sulfidation behavior of FeCr and FeCrAl alloys