Evaluation of Hydrogen Embrittlement Risk of Long-Term Operated Gas Pipelines Made of 10G2BT Steel

It was established that the metal of long-term operated gas pipelines made of 10G2BT steel contains relatively little hydrogen, which does not create prerequisites for the pipes hydrogen embrittlement. However, for the considered cases, it was established that the microstructure of steel is characterized by increased defectiveness, which increases with the extension of the pipeline operation time. Such a defective microstructure has an increased ability of absorbing hydrogen, and therefore there is a risk of hydrogen embrittlement of the material. It was concluded that the use of long-term operated pipelines for transportation mixtures of natural gas and hydrogen without additional verification is problematic.