As part of the Horizon 2020 project HyStories, the possibility of hydrogen storage in old, depleted gas reservoirs and natural gas storage facilities is being investigated throughout Europe. Within the scope of this project, the work package “materials and corrosion” has the objective of testing the applicability of selected pipe materials with respect to hydrogen embrittlement. For this purpose, a welded carbon steel grade J55 with a ferritic-pearlitic microstructure was investigated by using high pressure high temperature autoclave tests, permeation tests and analysis of uptaken hydrogen. For the autoclave tests, tensile samples have been examined that were loaded by a spring at 90% of yield strength, and samples were also examined to determine the hydrogen uptake. After completion of the tests, the hydrogen uptake was analyzed by thermal desorption spectroscopy. Four main gas compositions were used for the autoclave tests: 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 whereby the tests were carried out with and without the addition of electrolytes with a concentration of 1 and 200 g/l sodium chloride. Moreover, the experiments were conducted at room temperature and 120°C. Test duration was 720 hours. Prior to autoclave testing effective diffusion coefficient was determined to characterize diffusion behavior of hydrogen through the weld material. Results show a low hydrogen uptake even at most severe conditions. Additionally no stressed specimens failed during autoclave testing. Welded J55 is recommended as a suitable tube material for subsurface hydrogen storage.