This paper presents four case studies of ethylene cracking tube premature failures that took place in
a local petrochemical industry. 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, and thermal shock