The influence of iron sulfides created on 0.45%C steel and microstructure of this steel
on hydrogen overvoltage was investigated. It was shown, that iron sulfides on the surface of
0.45%C steel, usually, decrease hydrogen overvoltage of hydrogen depolarization. The
greatest effect was created by the cansite films. Corrosion of ferrite-perlite microstructure
passes under anode control. Corrosion of troostite microstructure passes under mixed
cathode-anode control, and for sorbite and martensite microstructures it passes under cathode
control. The presence on the surface of steel FeS corrosion passes under cathode control and
Fe9S8 under anode control. In the presence of FeS2 it passes under cathode control, and on
troostite microstructure passes under anode control.