Fuel Cell Interconnect Structures, And Related Devices And Processes

摘要

A method for the formation of a diffusion barrier layer (56) on a surface (52) of at least one fuel cell interconnect structure (50) is described. The interconnect structure (50) is usually formed from ferritic stainless steel, and includes chromium. The method includes the step of coating an austenite phase-stabilizer (54) on the interconnect surface (52), and then heating the coated surface. The heat treatment transforms the microstructure of the surface region of the interconnect, from a substantially ferritic body-centered cubic (BCC) phase to a substantially austenitic face-centered cubic (FCC) phase. The diffusion rate of chromium through the FCC phase is relatively low. Thus, the formation of a thick layer of chromium oxide can be minimized, leading to better fuel cell performance. Related fuel cells and fuel cell stacks are also disclosed.