TRANSITION METAL NITRIDE, SEPARATOR FOR FUEL CELL, FUEL CELL STACK, FUEL CELL VEHICLE, METHOD OF MANUFACTURING TRANSITION METAL NITRIDE, AND METHOD OF MANUFACTURING SEPARATOR FOR FUEL CELL

摘要

PROBLEM TO BE SOLVED: To provide a transition metal nitride which is low in the contact resistance generated between separators and electrodes, is excellent in corrosion resistance, and is low in cost, and to provide a separator for fuel cell, a fuel cell stack, and a fuel cell vehicle.

SOLUTION: The transition metal nitride obtained by nitriding a base material including an austenitic stainless steel having a Cr concentration of 25% or more includes: a first layer (first nitrided layer) formed continuously on a base layer formed by the base material, having a stacked crystal structure of a nano-level including a nitride having a cubic crystal structure of M4N type, and a nitride having a hexagonal crystal structure of M2-3N type; and a second layer (second nitrided layer) formed continuously on the first layer, including a nitride having at least one kind of crystal structure out of hexagonal crystal structures of Cr2N, CrN, and M2-3N type, and a cubic crystal structure of M4N type, and being formed as a surface-nitriding-processed portion of the base material continuously in a depth direction from a surface of the base material.

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