Investigation of the electrical conductivity of solid oxide fuel cell interconnects at presence of manganese spinels

Chromium containing alloys are among the best candidates for solid oxide fuel cell interconnects. However, the problem of reduction of electrical conductivity during high temperature oxidation should be solved. The aim of this research was to investigate the electrical behavior of AISI 430 ferritic stainless steel which was coated in a Mn-base pack mixture by pack cementation method. Electrical conductivity was tested as a function of oxidation time at 750 ºC and as a function of temperature by annealing the samples from 400 to 900 ºC. Results showed that the coating layer was converted to Mn3O4 and MnFe2O4 spinels during oxidation. These spinels caused to the improvement of the electrical conductivity of coated substrates compared to uncoated substrates.