Abstract
Radiant tubes of an ethane pyrolysis furnace at a petrochemical plant failed after a fraction of service life. The tubes developed longitudinal cracks that in extreme cases penetrated the entire tube thickness. The tubes were manufactured from HP 45 heat-resistant steel casting. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to characterize the microstructure and chemical composition of the tube samples. Microhardness testing was used to evaluate the mechanical strength while structural analysis was conducted in an X-ray diffractometer. The experimental results showed that the mode of tube failure was a combination of high temperature carburization attack and creep damage leading to intergranular cracking. The cause of failure was overheating likely during decoking operations. Better control of furnace temperature was recommended in order to avoid overheating. However, if the furnace temperature exceeds 900 °C during operation, alloy replacement must be considered. In this case, steel casting material more resistant to carburization and creep damage such as the HP + W grade was suggested as an alternative.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.