Patent ID: 8828258

Claim:
A method for surface treatment of a stainless steel separator for a fuel cell, comprising: preparing a stainless steel sheet containing nickel, chrome and iron, and having a passive film on a surface of the stainless steel sheet; and dipping the stainless steel sheet into an etching solution formed by mixing one of oxalic acid (C 2 H 2 O 4 ) and hydrogen peroxide (H 2 O 2 ) with a solution of nitric acid (HNO 3 ) and sulfuric acid (H 2 SO 4 ) prepared as a basic solution at a temperature of 50˜70° C. for 30 seconds to 30 minutes to selectively lower the amount of Fe in the passive film formed on the surface of the stainless steel sheet, wherein the stainless steel separator has a contact resistance of 20 mΩ·cm 2 or less and corrosion current of 1 μA/cm 2 or less wherein the etching solution comprises 5˜20 wt % pure nitric acid, 2˜15 wt % pure sulfuric acid, 0.5˜10 wt % pure oxalic acid or pure hydrogen peroxide, and a balance of water.