OXIDATION OF 304L STAINLESS STEEL BY STEAM AND BY AIR.

Abstract The oxidation of 304L stainless steel has been measured in steam and in air in the temperature range from 1000 to 1375 C (1832 to 2507 F) using a thermogravimetric technique. This temperature range is of interest in the analysis of a reactor loss-of-coolant accident. Experiments in steam showed initial linear weight gain with time for the first 6 to 28 minutes, followed by parabolic rate behavior. The linear reaction rate constant W/t was found to be 1.1 × 105 exp (−44,350/RT) while the parabolic constant W2/t was found to be 2.4 × 101 2 exp (−84,300/RT), where T is in °K and W is in mg/cm2 and t is in sec. The parabolic rate controlling process is diffusion through an Fe-Ni-Cr spinel layer observed in the inner layer of the scale. The oxidation of 304L stainless steel by air from 1100 to 1360 C (2012 to 2480 F) was slow compared to the oxidation by steam in this same temperature range, parabolic rates being lower than those in steam by a factor of ~ 103. Although X-ray diffraction observed Fe3O4...