Abstract: The normal operation of the convection section of cracking furnace in ethylene plant is one of the important factors affecting the long-term operation of cracking furnace. The convection section operates under complex conditions, making it prone to leaks with their locations and causes varying. A statistical analysis was conducted on corrosion-induced leaks occurring in the convection section of a cracking furnace of a petrochemical company in recent years. And the typical leak cases were analyzed in detail by means of macroscopic morphology inspection, energy spectrum and scanning electron microscope inspection, sample physical and chemical inspection and other methods. The results indicate that leaks in the convection section were primarily caused by corrosion perforation resulting from abnormalities in the dilution steam system, feedstock system, and other external factors. Based on the analysis results, the preventive measures against the abnormalities in the dilution steam system and feedstock system were proposed to prevent the corrosion of the convection section furnace tubes. This also provided guidance for the operation and preventive maintenance of the cracking furnace in the future.

Key words: cracking furnace, convection section, corrosion leakage, preventive measures