EFFECT OF Mn ON CORROSION OF Fe-Cr AND Fe-Cr-Ni ALLOYS IN DRY CO2 AT 650 °C

摘要

Model alloys Fe-9Cr, Fe-20Cr and Fe-20Cr-20Ni with and without 2 wt.% Mn were exposed to Ar-20CO2 gas at 650 °C. All undoped alloys underwent breakaway oxidation, resulting in thick iron-rich oxide scales. The additions of Mn dramatically suppressed the formation of iron oxides on Fe-20Cr and Fe-20Cr-20Ni, but not Fe-9Cr. Carburisation occurred beneath scales of all alloys except Fe-20Cr-20Ni-2Mn.