In situ surface analysis of annealed Fe-1.5%Mn and Fe-0.6%Mn low alloy steels

The oxidation of two binary alloys, Fe-1.5%Mn and Fe-0.6%Mn, was studied in terms of the annealing conditions and paying special attention to the selective oxidation of manganese. The crystallographic structure of the surfaces and their compositions were determined by RHEED and XPS by using in situ analytical devices attached to the annealing reactor to avoid surface contamination after the treatments. Additionally, ex situ investigations on the morphology and composition of the surfaces were performed by FEG-SEM, WDX, and GIXRD. The annealing processes were performed at 800 degrees C under N(2)-5%H(2) protective atmospheres at water vapor dew points between -10 and -30 degrees C. The oxides formed were identified and the resulting surface structures resolved.