Abstract
A manufacturing and single-cell fuel cell performance study of stamped, laser welded, and
gas nitrided ferritic stainless steel foils in an advanced automotive bipolar plate assembly
design was performed. Two developmental foil compositions were studied: Fee20Cre4V
and Fee23Cre4V wt.%. Foils 0.1 mm thick were stamped and then laser welded together to
create single bipolar plate assemblies with cooling channels. The plates were then surface
treated by pre-oxidation and nitridation in N2e4H2 based gas mixtures using either
a conventional furnace or a short-cycle quartz lamp infrared heating system. Single-cell
fuel cell testing was performed at 80 C for 500 h at 0.3 A/cm2 using 100% humidification
and a 100%/40% humidification cycle that stresses the membrane and enhances release of
the fluoride ion and promotes a more corrosive environment for the bipolar plates. Periodic
high frequency resistance potential-current scans during the 500 h fuel cell test and posttest
analysis of the membrane indicated no resistance increase of the plates and only trace
levels of metal ion contamination.
