Chromia Evaporation of Ferritic Stainless Steel AISI430 Coated by (La,Sr)CrO_3 Perovskite and Mn-Co Spinel

摘要

A ferritic stainless steel has been intensively studied for its potential in application as an interconnect for a solid oxide fuel cell (SOFC). However, at such a high operating temperature chromia in the gaseous phase can contaminate the cathode of the SOFC, and consequently the performance of the device degrades rapidly. To overcome this problem, two kind of ceramics, (La,Sr)CrO_3 perovskite and Mn-Co spinel were prepared as coatings on the stainless steel AISI 430 to investigate on chromia evaporation at 800°C. In this present work, the (La,Sr)CrO_3 and Co-Mn layers were formed by a sol-gel dip coating and an electrodeposition technique, respectively. The coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), rates of oxidation and rates of chromia evaporation. The coated specimens exhibited the protective behavior with a lower rate of oxidation, as well as a lower rate of chromium evaporation than the uncoated specimen both in the atmosphere of dry and humidified oxygen. But the reduction of the chromia evaporation rates of (La,Sr)CrO_3 coatings was insignificant due to the presence of Cr_2O_3 phase in the coatings.