ABSTRACT
Important examples of catastrophic oxidation are found during oxidation of metals and alloys in the presence Mo03 (m.p. 795°C), V20 5 (mp. 674°C), Bi20 3 (m.p. 820°C), and PbO (m.p. 888°C). Leslie and Fontana [17] investigated the special features of this type of oxidation for such systems as Fe, Ni, Cr, stainless steel, lnconel, Hastelloy, and other commercial high-temperature alloys in the presence of Mo03 and V 20 5• In all cases, increased oxidation rates were observed compared to those in dry air. Since rapid oxidation took place, the oxide scales were invariably porous, spongy, or nonadherent to the substrate alloy. Rathenau and Meijering [18] also studied the oxidation behavior of a few pure metals, binary and ternary alloys when buried in Mo03 powder. They too observed accelerated attack above certain critical temperatures depending on the metal or alloy system. However, they [18] were the first to point out the importance of a liquid oxide phase in such aggressive attack. They reported that accelerated attack occurred at the eutectic temperatures of the binary or ternary oxides involved. For Cr-containing alloys, the onset of catastrophic oxidation occurred near the temperature at which liquid Mo03 dissolves Cr20 3.
