Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Search
Filters
Close

Stress-Assisted Corrosion Of A Superheater Tube: The Role Of Thermal Fatigue Cracking And Crevice Corrosion In The Failure Mechanism

Product Number: 51321-16530-SG
Author: Ewa Labuda/ W.B.A. (Sandy) Sharp
Publication Date: 2021
$0.00
$20.00
$20.00

This paper discusses the results of a failure examination of superheater tubes from a boiler. The superheater tubes failed along steamside fissures associated with external surface welds attaching finger bars to adjacent tubes. The morphologies of the fissures were consistent with stress-assisted corrosion (SAC). In addition, cracks typical of thermal fatigue were present on some ID surfaces and at the tips of some fissures. The elemental compositions of corrosion products within the wide SAC fissures, determined using Scanning Electron Microscopy (SEM)/Energy Dispersive X-ray Spectroscopy (EDXS), support the possibility that crevice conditions led to accelerated corrosion during cool down periods, resulting in pit-like areas along the fissures. Failed and unfailed superheater tubes were examined using standard metallographic techniques. The results were used to develop a theory of the role of thermal fatigue cracking and crevice corrosion in SAC fissure initiation on the steamside surfaces of the superheater tubes and propagation through the tube walls.

Key words: stress-assisted corrosion, superheater tubes, crevice corrosion, thermal fatigue, welded attachments

This paper discusses the results of a failure examination of superheater tubes from a boiler. The superheater tubes failed along steamside fissures associated with external surface welds attaching finger bars to adjacent tubes. The morphologies of the fissures were consistent with stress-assisted corrosion (SAC). In addition, cracks typical of thermal fatigue were present on some ID surfaces and at the tips of some fissures. The elemental compositions of corrosion products within the wide SAC fissures, determined using Scanning Electron Microscopy (SEM)/Energy Dispersive X-ray Spectroscopy (EDXS), support the possibility that crevice conditions led to accelerated corrosion during cool down periods, resulting in pit-like areas along the fissures. Failed and unfailed superheater tubes were examined using standard metallographic techniques. The results were used to develop a theory of the role of thermal fatigue cracking and crevice corrosion in SAC fissure initiation on the steamside surfaces of the superheater tubes and propagation through the tube walls.

Key words: stress-assisted corrosion, superheater tubes, crevice corrosion, thermal fatigue, welded attachments

Also Purchased
Picture for 08458 Thermal Fatigue in a De-Superheater Induced by Thermal Loads
Available for download

08458 Thermal Fatigue in a De-Superheater Induced by Thermal Loads

Product Number: 51300-08458-SG
ISBN: 08458 2008 CP
Author: Bakheet Al-Yami
Publication Date: 2008
$20.00
Picture for 09159 Failure Experiences of Ethylene Cracking Tubes
Available for download

09159 Failure Experiences of Ethylene Cracking Tubes

Product Number: 51300-09159-SG
ISBN: 09159 2009 CP
Author: B. Y. Al-Yami, A. H. Al-Shawaf, Ruchuan C. Yin and A. A. Al-Ahmari
Publication Date: 2009
$20.00
Picture for 11151 Research for Creep Damage by Steam Oxidation
Available for download

11151 Research for Creep Damage by Steam Oxidation Scale of 9Cr Boiler Tubes after Long Time Service

Product Number: 51300-11151-SG
ISBN: 2011 11151 CP
Author: Hiroyasu Matsuda, Masahiko Takehara, Koji Kawano, Shigemitsu Kihara, Kouichi Yagi, Daisuke Horikoshi
Publication Date: 2011
$20.00