Beyond breakaway corrosion – Influence of chromium, nickel and aluminum on corrosion of iron-based alloys at 600 ° C

Breakaway corrosion remains a challenge for many high temperature applications. The oxide formed after breakaway is commonly considered non-protective. This study investigates the protective properties after breakaway on a wide set of (Fe,Cr,Al/Ni)-model alloys by thermogravimertric analysis, ion/electron microscopy and X-ray spectroscopy. The results show that the oxide scales formed after breakaway exhibit similar microstructural features on all FeCr(Ni/Al)-alloys, and that the growth rate is greatly influenced by alloy composition for some alloys while is has little influence on others. This observation may be of great help in the selection and development of materials for use in harshly corrosive environments.