International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Steel components often operate in hydrogen-rich environments, where hydrogen dissolves in the steel. This leads to a degradation of mechanical properties, shifting the material behavior under load from plastic to brittle. To investigate these changes in mechanical properties of various pure metals and engineering alloys in the presence of hydrogen, it is crucial to maintain a stable hydrogen concentration in the sample throughout the tensile test. This paper presents the possibilities of the in-situ electrochemical charging technique as an alternative. In this method, the test specimen is placed in a specially designed tensile/hydrogenation electrochemical cell filled with electrolyte, where the specimen acts as the cathode during the mechanical tests. In those conditions, hydrogen forms on the surface of the specimen, and some of it diffuses into its internal structure. This method offers a reliable and practical approach for studying hydrogen embrittlement and its impact on material performance.

The fatigue strength of 40X steel at 25 oC was determined following ASTM E606M standard for strain-controlled tests. The studied experimental dependence was modelled with a power function as well as with the functions and coefficients described in the standard. The material expresses plastic properties for cyclic loadings above 0.2% strain amplitude.