Stainless separator for fuel cell and method of manufacturing the same

A method of manufacturing a stainless steel separator for fuel cells, comprising:

• preparing a stainless steel sheet as a matrix;
• performing surface modification on a surface of the stainless steel sheet to form a Cr-rich passive film having a comparatively increased amount of Cr in a superficial layer of the stainless steel sheet by decreasing an amount of Fe in the superficial layer of the stainless steel sheet;
• and
• heat-treating the surface-modified stainless steel sheet at 100˜300° C. under vacuum, in air or in an inert gas atmosphere.

A stainless steel separator for fuel cells, comprising:

• a stainless steel sheet as a matrix;
• a Cr-rich passive film formed on a surface of the stainless steel sheet and containing 20˜75 wt % chromium;
• and
• a coating layer formed on the Cr-rich passive film and having a thickness of 30˜300 nm, the coating layer being one selected from a metal nitride layer (MNx), a metal/metal nitride layer (M/MNx), a metal carbide layer (MCy), and a metal boride layer (MBz) (0.5≦x≦1, 0.42≦y≦1, 0.5≦z≦2).

A stainless steel separator for fuel cells, comprising:

• a stainless steel sheet as a matrix;
• and
• a Cr-rich passive film formed on a surface of the stainless steel sheet and containing 20˜75 wt % chromium,
• wherein the stainless steel separator is heat treated at 100˜300° C. under vacuum, in air or in an inert gas atmosphere.