Effects of temperature and water vapour on Cr-species volatilisation, oxidation and scale adhesion of a Type 409L stainless steel for application as interconnect of low temperature solid oxide fuel cells.

Though the classical transport theory does not mathematically express the Arrhenius-like relation between Cr-loss flux due to volatilisation and absolute temperature, such relation was experimentally observed for 409L stainless steel exposed at 600–750 °C. Volatilisation calculation in the present cases can be estimated giving such relation because of the nearly linear relation between mass transfer coefficient and temperature. Cr-loss fluxes in O 2 with 20 and 40 % H 2 O are close to or coincided with the fluxes calculated from MnCr 2 O 4 evaporation. Increasing water vapour could enhance volatilisation contributed from the raised CrO 2 (OH) 2 pressure, reduce oxidation rate, and worsen scale adhesion. • 409L stainless steel was assessed at 600–750 °C for SOFC interconnect application. • Flux of Cr loss by volatility related to temperature in the Arrhenius-like form. • Cr-loss flux equation can be simplified resulting in the Arrhenius-like relation. • Water vapour could help reduce oxidation rate with enhanced scale volatilisation. • Water vapour could worsen the scale adhesion. [ABSTRACT FROM AUTHOR]