The development of ignition and subsequent combustion from quasi-stable temperatures was studied for several iron, nickel, and cobalt-based alloys. The quasi-stable temperature was produced by heating a specimen with a continuous wave carbon dioxide laser. Endothermic and exothermic transitions appear to play an important role in the development of thermal runaway, ignition, and combustion. The apparent effect of the endothermic transitions was to accelerate the rate of oxidation of the alloy, which produced abrupt changes in surface temperature as well as increasing the rate of increase in surface temperature. In the final stages of the thermal runaway phase, endothermic and exothermic events forced the alloy surface rapidly into combustion. Total destruction of the specimen followed immediately. The results for the iron-based alloy UNS S66286, which represent the phenomena observed, are presented. A spontaneous ignition temperature, enhanced oxidation temperature and ignition temperature for the solid alloy have been defined. Data are presented for the oxygen pressure range of 1.7 to 13.8 MPa.