1#常压炉出口短节腐蚀分析与预防对策

对独山子炼油厂三蒸馏装置的1^#常压炉出口短节的腐蚀原因进行了分析，包括炉管材料化学成分分析，拔头原油硫含量，酸值分析和宏观检验。结合对短节选材，短节结构设计，短节焊接方式等的分析，认为由于短节选材不当，结构，焊接方式不合理，导致了此部位高温环烷酸腐蚀的发生与加剧。并结合分析结果，提出了控制环烷酸腐蚀的主要应选择耐环烷酸腐蚀的材料等措施。

CORROSION ANALYSIS AND PREVENT MEASURE OF THE SHORT-ARMED TUBE AT THE EXIT OF A FURNACE IN A DISTILLATION UNIT

The course of corrosion failure of the short armed pipe at the exit of a furnace in a distillation unit was analyzed. Emphasis was put on the chemical composition, sulphur content and acid value of crude oil, optical inspect of the furnace tube, combined with analysis on selecting materials, structure design, welding etc. It was found that the inappropriate selection of materials as well as the inadvisable structure design and the inapposite welding caused the naphthenic acid corrosion at high temperature spots in the short armed pipe of exit of the furnace. The effect of stress led to final bursting. According to experiment results, measures to prevent such corrosion failure have been suggested. The main measure to control the naphthenic acid corrosion at high temperature spots is the selection of appropriate corrosion resistant materials.