• Mahmoud, Essam R. I.
• Algahtani, Ali
• Khan, Sohaib Zia
• Aljabri, A.
• Tirth, Vineet

Abstract

<jats:p>The present investigation portrays the tube failure in the superheater used in the power plants. The failure occurred after only three months of operation, by longitudinal fish-mouth rupture. The operating pressure of the object boiler is 192 bar while the temperature of its superheatersteam is 540 °C. The failed tubes were fabricated from standard Si killed carbon steel. Many longitudinal parallel fine crack-like grooves were detected at the outer surface of the rupture area. Metallurgical examinations revealed that the failed tube remained subjected to overheatingfor the short-term. According to the analysis of the failed tubes, the temperature reached over 600 °C by insufficient coolant flow or unpredicted operating conditions. The carbon steel emerged as an underperforming material for the applications in superheater tubes, and it is highly recommendedto replace the carbon steel by a high-grade Cr-Mo steel.</jats:p>

Topics

• impedance spectroscopy
• surface
• Carbon
• crack
• steel