Abstract
A heat resistant cast steel tube from an ammonia plant made of modified HP40 steel that failed after seven years of service was investigated for damage mechanism. The assessment of material degradation was carried out using optical microscopy, scanning electron microscopy (SEM) in combination with energy dispersive spectroscopy (EDS) analysis and mechanical tests. The main cause of failure appears to be overheating and localized corrosion along the network of intergranular carbides. Failed portion of the tube showed that the interdendritic eutectic carbides had coarsened, secondary carbides were precipitate and strongly coaresned within the austenitic regions. Witch decrease the mechanical strength and ductility of the service exposed tube compared with the as cast tube. Presence of unacceptable impurities like chlorine in the internal working gas destroy the protective oxide layer leading to penetration of corroding elements and degradation of service life of the tube.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Engineering Research in Africa
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.
