Abstract: As the price of Russian crude oil on the international market has fallen, some refining companies have increased the processing amount of Russian crude oil in atmospheric and vacuum distillation units in order to achieve their efficiency goals, resulting in the blending ratio of Russian crude oil exceeding the design conditions, and the corrosion problem of equipment in the units needs to be solved urgently. The potential corrosion of sulfur, chlorine, salt and other harmful substances in crude oil to atmospheric and vacuum distillation units was analyzed by comparing the change data of harmful components in crude oil before and after adjusting the blending ratio of Russian crude oil in an atmospheric and vacuum distillation unit. Combined with the equipment corrosion problems occurred in the plant in recent years, the anti-corrosion control measures for increasing the amount of Russian crude oil blending under super-design conditions were established from the aspects of technology, equipment and management, and the corrosion problem of atmospheric and vacuum distillation equipment caused by corrosive substances in Russian crude oil was solved. At the same time, corrosion analysis methods and control measures for atmospheric and vacuum distillation units with low blending ratio of Russian crude oil were provided.

Key words: Russian oil, blending ratio, atmospheric and vacuum distillation units, corrosion prevention