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

Materials Research

Stela Maria De Carvalho Fernandes¹  Lalgudi Venkataraman Ramanathan¹ 

[1] ,Instituto de Pesquisas Energéticas e NuclearesSão Paulo SP ,Brazil

关键词: Rare earth;    rare earth oxide;    sol-gel;    coating;    iron-chromium alloy;    cyclic oxidation;    chromium dioxide;    morphology;    coverage;    ion radius;    protection;    scale adhesion;    oxide spalling;   

DOI  :  10.1590/S1516-14392007000300020

来源: SciELO

【 摘 要 】

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.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License