The unusual scaling behaviour of iron-22·9% chromium in air at 1100°C☆

摘要: Abstract The oxidation of an iron-22·9% chromium alloy in air at 1100 and 1400°C has been studied using thermogravimetric measurements, metallography electron-probe microanalysis. scales formed 1100°C are four types: (i) oxide, containing very small quantities iron which grows a declining rate manner characteristic on alloys higher content, (ii) oxide forming “roof” over stratified inner layer chromium-rich oxides beneath rich iron, (iii) multi-layer scale consisting alternate regions iron-rich (iv) scale, similar to that lower showing virtually pure outer complex oxides. Type is also readily 1400°C. Scales types have not reported previously the literature. importance partial or complete lifting, cracking removal initial Cr2O3 determining mode extent scaling emphasized. nature proposed mechanism growth largely agreement with kinetic measurements.