Failure Experiences of Ethylene Cracking Tubes

This paper presents several case studies of ethylene cracking tube premature failures that took place in a local petrochemical company. State of the art analytical techniques, macro etching of carburization depth, optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray fluorescence (XRF) were utilized in analyzing and troubleshooting these failures. These tube failures represent typical failures that occur in ethylene cracking furnace tubes, and were caused by different damage mechanisms, i.e. creep/carburization, thermal fatigue/carburization, and thermal shock. Appropriate preventive solutions are suggested to overcome these failures in the future.

Key words: ethylene cracking tube, carburization, creep, thermal fatigue, thermal shock