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In contrast to the Armco iron the kansite formation on the surface of 0.8%C

steel with different structures reduces the rate of corrosion. Hydrogenation of this

steel is reduced by 30 ... 35% due to pyrite, troilite and kansite formation on troostite,

and pyrite and kansite on the martensitic structure of steel. This confirms the

necessity to take into account the influence of sulphides on electrode reactions and

the hydrogen absorption. The 0.45%C steel structure has a less influence on the

corrosion rate in a chloride-acetate solution, versus 0.8%C steel. The pyrite and

troilite formation leads to a significant increasing in the efficiency of anode processes

and corrosion rate is determined by hydrogen depolarization. In the presence of a

kansite, 0.45%C steel in sorbite and troostite structures is corroded for anode control

at a lower rate versus kansite absence. It is concluded that the influence of different

sulphide composition on the corrosion rate depends on the structure of steels. Thus,

on Armco iron and 0.8%C steel surfaces sulphides reduce the corrosion rate, and in

case of 0.45%C steel they increase it.

By electrochemical hydrogenation of 0.45%C steel in chloride-acetate

solutions, the ferrito-perlite is the most hydrogenated, and troostite and martensite

have a less ability to hydrogenation. Iron sulphides mainly reduce the overvoltage of
cathode processes on steels in a different structures, with the exception of the troilite

on ferrite-perlite and sorbite, and pyrite on martensite. Their formation leads to an
increasing of hydrogen volume, but practically does not lead to an increasing of steel

hydrogenation in troostite and martensite structures.
It has been shown for the first time that iron sulphides reduce the overvoltage

of hydrogen allocation on Armco iron and carbon steels after different heat

treatments and increase the hydrogen volume allocated for cathode polarization,

while hydrogenation of carbon steels is determined not only by the structure, but also

by the type of corrosion products on the surface.

For practical estimation of steels workability in hydrogen sulphide media, the

correlation between the corrosion rate, hydrogenation and corrosion cracking

resistance in the solution of NACE was established. The corrosion of 0.8%C steel and

0.45%C steel in the solution of NACE has an pit-like type. The maximum depth of