High-temperature oxidation studies of low-nickel austenitic stainless steel. Part I: Isothermal oxidation

The oxidation behavior of low-nickel austenitic stainless steel (LNiSS) in air at 873 and 973 K was investigated for 500 hr. The oxide scales formed d uring the process were examined by a wide range of experimental techniques including SEM/EDS, XRD, and EPMA, in order to determine their influence on kinetics behavior. Kinetics laws were close to parabolic at both temperatur es, but the morphology of scales showed important differences with temperat ure. At 873 K the oxide scale was thinner, with irregular growth, intrusion s, and without spallation. It was concluded that slower kinetics and advant ageous scale morphology suggest that LNiSS is a suitable material for isoth ermal oxidation in air at 873 K At higher temperatures, uniformly thick sca les plus iron-rich nodules were observed with different composition regions . The most destructive features was the formation of Fe-rich nodules, which were vulnerable to spalling during cooling.