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The paper deals with the corrosion behavior of steels with reduced effective chromium content in the matrix, with the intent to estimate their long-term behavior in low aggressive environments, typical for the secondary and primary circuits of nuclear power plants. Materials for this research were steels with varying characteristics of influence of effective chromium content precipitation of chromium carbides or spinodal breakdown of chromium / martensitic steels, creating other types of chromium-rich phases, e.g. borides in austenitic steels. In addition, materials used as additional welding material or high alloy steel bolts were used. In these mentioned materials is chromium released by various mechanisms and the content of effective chromium in the solid solution is reduced (up to several units of wt. %), which may cause the overall passivity of the steel, to sensitivity to intergranular corrosion.Based on the basic techniques of material identification, the causes of different behavior of both types of steels after sensitization or tempering were estimated. They are described as being risky in terms of heterogeneity in the chromium content, which manifest themselves as active ways of corrosion.
Keywords: Corrosion behavior, steels with reduced chromium content, low aggressiveness environment, reduced corrosion resistance, intergranular corrosion, heterogeneity of chromium content© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.