Samples of a Mn steel after cathodic polarization (0.1 N H2SO4, current d. 10 mA/cm(2), time 2-24 h) as well as the untreated steel samples were analyzed for H content. Then, both types of samples were subjected to tensile and corrosion tests in NaCl soln. (3% by mass). The samples after cathodic polarization showed higher content of H and exhibited deterioration of their mech. and corrosive properties in comparison with the untreated samples.