Effect of Titanium and Molybdenum Addition on the Oxidation Resistance and Mechanical Properties of Fe-Al-Cr Alloys

Abstract

The oxidation resistance of Fe-Al-Cr alloys containing 0.5% titanium and 0∼2% molybdenum in carbon dioxide at the temperature of 600°∼900°C under a pressure of 10 kg/cm² were studied together with their mechanical properties.
The results were summarized as follows.
(1) The oxidation of Fe-Al-Cr alloys increased with increasing molybdenum contents and also with decreasing oxidation temperature.
(2) Remarkable oxidation was noted at the testing temperature of 600°C for the alloys containing 2% of molybdenum. This oxidation phenomenon is attributed to the formation of MoO₃ in the oxide film and also to the occurence of internal oxidation of aluminum in the alloy.
(3) The room temperature tensile strength increased and elongation decreased as the molybdenum contents increased, but the lowing of tensile strength was observed when the molybdenum content exceed 1.5%.
(4) The creep rupture strength and high temperature strength of Fe-Al-Cr alloy was proved to be improved by the addition of 0.5% of molybdenum and 0.5% of titanium without sacrificing superior oxidation resistance which is the noticeable merit of the alloy.