Pitting corrosion is one of the common problems of steel pipes, especially in the oil and gas industry. According to the studies, the inner surface of the pipes is in the vicinity of different fluids, which can cause pitting corrosion in the pipes and its destruction. In this research, the simultaneous presence of pitting corrosion and hydrogen in oil and gas pipelines has been investigated using laboratory data and finite element simulation. In this regard, data was extracted using various laboratory tests on pipeline steel, and the effect of important parameters such as the number of holes, the presence of hydrogen, and the dimensions of the holes were simulated and eva‎luated.Also, the validation of the simulation results was done based on the results of various numerical and laboratory studies, as well as the eva‎luation of industrial samples, and the matching of the data obtained from the simulation and the data extracted from the industrial sample was confirmed. Based on the obtained results, the change in the depth of the pits caused by pitting corrosion has resulted in an increase in stress concentration and the presence of hydrogen causes weakness in the bonds, and the presence of these two factors at the same time can take the pipeline out of service in a shorter period of time. and reduce its life by 18%, also in the continuation of this research, fitness for service of a gas transmission pipeline with pitting corrosion was investigated. Although the results obtained from the fitness for service confirm the previous results; But in industries such as oil, gas and petrochemicals, the effect of the presence of hydrogen is ignored; Therefore, in this research, the presence of hydrogen is important and it changes the results of service qualification.

عبدالمجيد اسلامي , محمد علي گلعذار

نويد سعيدي

علي اشرفي , ابوذر طاهري زاده