TY - JOUR
T1 - Pre-Oxidized and Nitrided Stainless Steel Alloy Foil for Proton Exchange Membrane Fuel Cell Bipolar Plates: Part 1. Corrosion, Interfacial Contact Resistance, and Surface Structure
AU - Brady, M. P.
AU - Wang, H.
AU - Turner, J. A.
AU - Meyer, H. M.
AU - More, K. L.
AU - Tortorelli, P. F.
AU - McCarthy, B. D.
PY - 2010
Y1 - 2010
N2 - Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2× the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but near continuous chromia for treated 2205 stainless steel, which was linked to the variation in ICR values. Promising corrosion resistance was observed under simulated aggressive PEMFC anode- and cathode-side bipolar plate conditions for both materials, although ICR values were observed to increase. The implications of these findings for stamped bipolar plate foils are discussed.
AB - Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2× the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but near continuous chromia for treated 2205 stainless steel, which was linked to the variation in ICR values. Promising corrosion resistance was observed under simulated aggressive PEMFC anode- and cathode-side bipolar plate conditions for both materials, although ICR values were observed to increase. The implications of these findings for stamped bipolar plate foils are discussed.
KW - Corrosion resistance
KW - Durability
KW - Metallic bipolar plates
KW - Nitride
KW - Polymer electrolyte/proton exchange membrane (PEM) fuel cells
UR - http://www.scopus.com/inward/record.url?scp=77953128017&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2010.03.055
DO - 10.1016/j.jpowsour.2010.03.055
M3 - Article
AN - SCOPUS:77953128017
SN - 0378-7753
VL - 195
SP - 5610
EP - 5618
JO - Journal of Power Sources
JF - Journal of Power Sources
IS - 17
ER -