The global climate changes -produced by greenhouse gases emissions such as CO 2 , NO x and SO x - pose a progressively higher demand for replacing today’s fossil fuel based energy production by less pollutant technologies. Among the alternative energies available proton exchange membrane (PEM) fuel cells have been considered to power traortation vehicles such as automobiles and buses due to their high power density, relatively quick start-up, low operating temperatures and low greenhouse gas emissions. Fuel cells are expected to play a major role in the economy of this century and future. It is predicted that the future aga is hydrogen age. One important component in a PEMFC stack is the bipolar plate. This multi-functional component provides the electrical connectivity from cell to cell. Its functions also include distributing reactant gases and removing heat and produced water. Therefore, the bipolar plate material must be chemically stable, highly electrical and thermal conductive; have low contact resistance with the backing (carbon paper or carbon cloth), good mechanical strength, low gas permeability and inexpensive massive production. The earlier traditional option was the use of non-porous graphite plates due to their intrinsic high electrical conductivity and chemical stability in the PEM fuel cell aggressive environment. Although the performance of graphite plates are suitable related to these properties they are brittle and lack mechanical resistance. Another drawback is the need for machining the flow field channels which raises the manufacturing cost making it prohibitive for mass production. Considering especially traortation applications metal bipolar plates are more resistant to mechanical shocks and vibrations that could lead to cracking and leaking of reactant gases. Metallic bipolar plates are coated with protective coating layers to avoid corrosion. Coatings should be conductive and adhere to the base metal without exposing the substrate to corrosive media. Stainless steels, Ni-based alloys, Ti-based alloys and aluminium-based alloys have been investigated widely and considered candidates for PEMFC bipolar plate materials. Coating on stainless steels surfaces has been used for the improvement of corrosion resistance and contact resistance. Coatings are normally divided into two types: carbon-based and metal-based. The former includes graphite, conductive polymers and diamond-like carbon. The latter includes noble metals, metal nitrides and metal carbides (such as titanium, chromium and zirconium nitrides and carbides). In this work two coats, Cr 2 N and Cr 23 C 6 , were created on 316L stainless steel by chromium electroplating-plasma nitriding and chromium electroplating-solid carburizing, respectively. Then, the coats were subjected to sandblasting and heat treating in 400, 500 and 800 ° c. All the corrosion tests were done in sulfuric acid solution (with pH=2.0 and added 5 ppm HF) in 70±5 ° c with air purging. The results of potentiostatic corrosion test in PEM simulated cathodic condition (constant potential 600mV(SCE)) indicated that sandblast-heat treatment significantly decrease the corrosion current density. The lower corrosion current densities for Cr 2 N and Cr 23 C 6 obtained in 500 ° c_40 minutes and 500 ° c_25 minutes, respectively. Good behavior of coats is related to low dissolution rate of passive films. Potentiodynamic polarization corrosion test and electrochemical impedance spectroscopy (EIS) test couldn‘t predict the coats corrosion behavior in potentiostatic test. The behavior of all coats were passive in potentiodynamic polarization test, that indicates formation of a passive layer in oxidizing media. The traassive potential for all coats were above 600 mV(SCE). So in potentiostatic test (at 600 mV(SCE)), passive films were stable. According to EIS results the corroding solution couldn’t penetrate in coats even after immersing the samples for 500 hours. This resistance is related to blocking the pores (due to passive film formation) and low defects in coats and in passive film. Keywords: PEM fuel cell, bipolar plates, corrosion, sandblasting, plasma nitriding, solid carburizing