Influence of minor alloying elements on the initial stages of oxidation of austenitic stainless steel materials

Abstract

Surface oxidation of Fe-19Cr-17Ni, Fe-19Cr-18Ni-1Al and TiC-enriched Fe-19Cr-18Ni-1Al alloys was investigated by photoelectron spectroscopy (PES). The experiments were conducted at 323 K in pure O 2 (2.7 × 10 −6 mbar). Composition and morphology of the nanoscale surface oxides were determined quantitatively by inelastic electron background analysis. Moreover, use of synchrotron radiation facilities were necessary to obtain improved sensitivity for studying minor alloying elements such as Al and Si. The results indicate oxygen-induced segregation of Al, which significantly hinders the oxidation of the major alloying elements Fe and Cr. Ti remains in its inert carbide form. The relative concentration of Fe within the oxide layer was found to increase with the oxide-layer thickness, indicating greater mobility of Fe relative to other alloying elements.

New insight on early oxidation stages of austenitic stainless steel from in situ XPS analysis on single-crystalline Fe–18Cr–13Ni

“…However, the increase observed in the oxygen uptake at saturation with temperature increasing to 150 and 250 • C (Fig. 4) is not reproduced by the calculated thickness which According to previous studies [22,24] Fig. 5 (b)).…”

“…• C at different oxygen pressures on the sample surface pre-annealed at 700 were carried out at P O 2 > 10 −6 mbar [20,21,24,39,49]. At these pressures, the detailed information on oxide film growth in the very first stages is lost.…”

“…Studies reported in the literature were carried out at 10 −6 mbar or higher pressure for exposures larger than 1 000 L [20,21,24], overlooking the initial stages of oxidation.…”

“…Although previous studies [16,19,20,22,24] have shown that no abrupt interface is formed between oxide and metal, layered models have been widely applied to describe the stratification of oxidized surfaces and quantify their composition. In this work, we have performed comparative analysis of the XPS intensities measured at 45…”

AES of thin oxide layers on a duplex stainless steel surface

“…Recent publications have also presented investigations of the low-temperature oxidation of austenitic stainless steel and duplex stainless steels. [11,12] These studies concluded that the oxide films, formed at low temperature and at low oxygen pressure, consist of mixed Fe-Cr oxides, and are duplex in nature, with an outer, Fe-rich spinel covering an inner, rhombohedral Cr 2 O 3 layer. [13,14] This study is one of a group of studies aiming to investigate the initial phases of the oxide growth on duplex stainless steel.…”