The catalytic device column top circulation pipeline generated serious corrosion thinning phenomenon. The macroscopic examination, chemical composition analysis, metallographic examination, SEM analysis, EDS analysis and corrosion product analysis were carried out on pipeline. The results show that the corrosion mainly occurs in the inner wall of pipeline. The electrochemical corrosion is the main reason for the corrosion thinning of catalytic device column top circulation pipeline. The corrosion is uniform...