In the framework of the EU project HyStories, the possibility of hydrogen storage in old depleted gas reservoirs and natural gas underground storage facilities is examined throughout Europe. In the course of this project, the task of work package materials and corrosion, is to test the resistance of selected tubing materials to hydrogen embrittlement under relevant conditions by using autoclaves. Furthermore, the effective diffusion coefficients are determined by electrochemical permeation measurements and hydrogen uptake, is measured as well.Two carbon steel grades have been investigated; steel L80 with a tempered
martensitic microstructure and ferritic - perlitic steel K55. In autoclave testing, a tensile specimen stressed at 90 % of specified minimum yield strength via a spring and a sample to determine hydrogen uptake is investigated. After the experiment, hydrogen uptake is analyzed by thermal desorption spectroscopy. Autoclave tests are performed with four gases composition, 120 bar H2, 120 bar H2 + 15 bar CO2, 120 bar H2 + 1 bar H2S and 120 bar H2 + 15 bar CO2 + 1 bar H2S with and without addition of electrolytes containing 1 and 200 g/l sodium chloride. Experiments were carried out at room temperature and 120°C for 720 hours. All these conditions were selected to be representative of the European porous media likely to store hydrogen. Based on the obtained results, an evaluation of steels (L80 and K55) resistance to hydrogen storage conditions is given.