Chromate formation at the interface between a solid oxide fuel cell sealing glass and interconnect alloy

High-temperature interactions between glass–ceramic sealants and Cr-containing ferritic interconnects used in solid oxide fuel cells (SOFC) lead to the formation of detrimental chromate interfacial phases, such as BaCrO4 or SrCrO4, which can cause mechanical failure of the SOFC. In this work, these interactions are characterized by reacting Cr2O3 powders with a SrO-containing sealing glass and by characterizing representative reaction couples between the glass and 430 stainless steel. The extent of chromate formation depends on the reaction time and temperature, and the effect of the partial pressure of oxygen is modeled by thermochemical calculations.

► The formation of SrCrO4 was observed in mixtures of SrO-containing sealing glass and Cr2O3 powders.
► Cr2O3 transports from the 430SS to the glass interface, or surface and reacts with O2 to form SrCrO4.
► The effect of the partial pressure of oxygen is modeled by thermochemical calculations.
► The calculations are consistent with the formation of SrCrO4 at interfaces with access to air.