Abstract
The burst of an Incoloy 800HT superheater tube, operating at 160–690 °C steam was investigated using metallographic inspection and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). It was observed that the analyzed fracture surface has an intergranular cracks morphology. Corrosion product deposits were also found on the inner wall of the failure tube. The microstructure analysis of the tube samples showed that the inner wall of the tube was covered by a layer of loose oxide and intergranular cracks propagated from the inner surface towards the outer wall of the tube. The elemental EDS results of the corroded tube samples showed a sulfur-rich layer between the matrix and oxide layer, and the sulfur was also found in the white corrosion depositions. The performed test results revealed that the tube burst was caused by a local overheat-induced sulfidation-oxidation process. Finally, the failure mechanism was discussed and suggestions were made to prevent occurrence of similar failures.
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.