Abstract: This paper takes the intensification of corrosion during the blending of Iraqi heavy crude oil in an atmospheric and vacuum distillation unit in a petrochemical refinery as the research object. Through analyzing the processing of Iraqi heavy crude oil by this unit and such units in other refining and chemical enterprises, and analyzing the components by laboratory methods, the reasons for the increase in corrosion rate during the processing of Iraqi heavy crude oil are found in the end. According to the reasons, the paper proposes the adjustment and corrosion protection measures for long-term processing of Iraqi heavy crude oil. And through taking these measures, the paper obtains a reverse verification of the correctness of the cause analysis.

Key words: Iraqi heavy crude oil, atmospheric and vacuum distillation unit, corrosion prevention, blending