The use of pipelines made of steel resistant to hydrogen embrittlement (HE) is of great importance in the energy industry. Hydrogen penetration into the inner surface of a steel pipe during H2 transportation reduces the ductility of the steel material and increases its brittleness. This leads to a noticeable increase in the brittleness of the metal, cracking and a decrease in the efficiency of gas transportation. Thus, as a result of the interaction of hydrogen dissolved in the metal with metal defects in certain places, the mechanical properties of the gas pipeline material change. The mechanisms of the processes occurring during hydrogen embrittlement in the metal-hydrogen system are diverse. These mechanisms include hydrogen capture in lattice defects on the metal surface, the formation of new phases in the microstructure of the metal, hydrogen penetration into the metal lattice, the formation of various deposits, etc. The article analyzes some of the results of studies of the process of hydrogen capture in metal lattice defects and the mechanisms of HE occurring on the surfaces of steel materials.