Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler

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GUPTA, Gagan Kumar;CHATTOPADHYAYA, Somnath .
Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler. 
Strojniški vestnik - Journal of Mechanical Engineering, [S.l.], v. 63, n.5, p. 287-299, june 2018. 
ISSN 0039-2480.
Available at: <https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/>. Date accessed: 11 apr. 2021. 
doi:http://dx.doi.org/10.5545/sv-jme.2016.4188.
Gupta, G., & Chattopadhyaya, S.
(2017).
Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler.
Strojniški vestnik - Journal of Mechanical Engineering, 63(5), 287-299.
doi:http://dx.doi.org/10.5545/sv-jme.2016.4188
@article{sv-jmesv-jme.2016.4188,
	author = {Gagan Kumar Gupta and Somnath  Chattopadhyaya},
	title = {Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler},
	journal = {Strojniški vestnik - Journal of Mechanical Engineering},
	volume = {63},
	number = {5},
	year = {2017},
	keywords = {coal based boiler; corrosion; creep; fractographic analysis; SEM; superheater tube},
	abstract = {This paper highlights a methodology for failure investigation of superheater tubes made of the material T-22 of a coal-based boiler. The process includes visual observation, the identification of sampling locations, the determination of the bulk chemical composition of the base alloy, microstructural investigation using optical microscopy, the exploration of finer structural details using a scanning electron microscope (SEM), the evaluation of hardness over samples obtained from different locations, the fractographic analysis of different failed locations, the X-ray diffraction (XRD) study of corrosion products adhered to inner surfaces, and the determination of the nature of the failure. Within a span of four months, three successive failures of superheater tubes were reported. The tubes were observed to have undergone significant wall thinning. Microscopic examinations using SEM on the failed region and a region some distance away on the as-received tubes were conducted in order to determine the failure mechanism. Layer-wise oxidation corrosion (exfoliation) in the inner surface was observed. Apart from major cracking, a number of nearly straight line crackings were observed in the longitudinal direction of both tubes. Close to cracking/bulging, void formation/de-cohesion of grain boundary indicated creep deformation under service exploitation. The failure mechanism was identified to be a result of excessive oxidation corrosion along the inside wall to reduce thickness, the spheroidization of alloy carbides and the coarsening of precipitate as well as creep void formation along grain boundary leading to inter-granular cracking with material flow near regions covered with thick scales. Moreover, there was a drastic reduction in bulk hardness of alloy and finally ‘thin lip fish mouth’ fractures.},
	issn = {0039-2480},	pages = {287-299},	doi = {10.5545/sv-jme.2016.4188},
	url = {https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/}
}
Gupta, G.,Chattopadhyaya, S.
2017 June 63. Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler. Strojniški vestnik - Journal of Mechanical Engineering. [Online] 63:5
%A Gupta, Gagan Kumar
%A Chattopadhyaya, Somnath 
%D 2017
%T Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler
%B 2017
%9 coal based boiler; corrosion; creep; fractographic analysis; SEM; superheater tube
%! Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler
%K coal based boiler; corrosion; creep; fractographic analysis; SEM; superheater tube
%X This paper highlights a methodology for failure investigation of superheater tubes made of the material T-22 of a coal-based boiler. The process includes visual observation, the identification of sampling locations, the determination of the bulk chemical composition of the base alloy, microstructural investigation using optical microscopy, the exploration of finer structural details using a scanning electron microscope (SEM), the evaluation of hardness over samples obtained from different locations, the fractographic analysis of different failed locations, the X-ray diffraction (XRD) study of corrosion products adhered to inner surfaces, and the determination of the nature of the failure. Within a span of four months, three successive failures of superheater tubes were reported. The tubes were observed to have undergone significant wall thinning. Microscopic examinations using SEM on the failed region and a region some distance away on the as-received tubes were conducted in order to determine the failure mechanism. Layer-wise oxidation corrosion (exfoliation) in the inner surface was observed. Apart from major cracking, a number of nearly straight line crackings were observed in the longitudinal direction of both tubes. Close to cracking/bulging, void formation/de-cohesion of grain boundary indicated creep deformation under service exploitation. The failure mechanism was identified to be a result of excessive oxidation corrosion along the inside wall to reduce thickness, the spheroidization of alloy carbides and the coarsening of precipitate as well as creep void formation along grain boundary leading to inter-granular cracking with material flow near regions covered with thick scales. Moreover, there was a drastic reduction in bulk hardness of alloy and finally ‘thin lip fish mouth’ fractures.
%U https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/
%0 Journal Article
%R 10.5545/sv-jme.2016.4188
%& 287
%P 13
%J Strojniški vestnik - Journal of Mechanical Engineering
%V 63
%N 5
%@ 0039-2480
%8 2018-06-27
%7 2018-06-27
Gupta, Gagan, & Somnath  Chattopadhyaya.
"Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler." Strojniški vestnik - Journal of Mechanical Engineering [Online], 63.5 (2017): 287-299. Web.  11 Apr. 2021
TY  - JOUR
AU  - Gupta, Gagan Kumar
AU  - Chattopadhyaya, Somnath 
PY  - 2017
TI  - Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler
JF  - Strojniški vestnik - Journal of Mechanical Engineering
DO  - 10.5545/sv-jme.2016.4188
KW  - coal based boiler; corrosion; creep; fractographic analysis; SEM; superheater tube
N2  - This paper highlights a methodology for failure investigation of superheater tubes made of the material T-22 of a coal-based boiler. The process includes visual observation, the identification of sampling locations, the determination of the bulk chemical composition of the base alloy, microstructural investigation using optical microscopy, the exploration of finer structural details using a scanning electron microscope (SEM), the evaluation of hardness over samples obtained from different locations, the fractographic analysis of different failed locations, the X-ray diffraction (XRD) study of corrosion products adhered to inner surfaces, and the determination of the nature of the failure. Within a span of four months, three successive failures of superheater tubes were reported. The tubes were observed to have undergone significant wall thinning. Microscopic examinations using SEM on the failed region and a region some distance away on the as-received tubes were conducted in order to determine the failure mechanism. Layer-wise oxidation corrosion (exfoliation) in the inner surface was observed. Apart from major cracking, a number of nearly straight line crackings were observed in the longitudinal direction of both tubes. Close to cracking/bulging, void formation/de-cohesion of grain boundary indicated creep deformation under service exploitation. The failure mechanism was identified to be a result of excessive oxidation corrosion along the inside wall to reduce thickness, the spheroidization of alloy carbides and the coarsening of precipitate as well as creep void formation along grain boundary leading to inter-granular cracking with material flow near regions covered with thick scales. Moreover, there was a drastic reduction in bulk hardness of alloy and finally ‘thin lip fish mouth’ fractures.
UR  - https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/
@article{{sv-jme}{sv-jme.2016.4188},
	author = {Gupta, G., Chattopadhyaya, S.},
	title = {Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler},
	journal = {Strojniški vestnik - Journal of Mechanical Engineering},
	volume = {63},
	number = {5},
	year = {2017},
	doi = {10.5545/sv-jme.2016.4188},
	url = {https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/}
}
TY  - JOUR
AU  - Gupta, Gagan Kumar
AU  - Chattopadhyaya, Somnath 
PY  - 2018/06/27
TI  - Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler
JF  - Strojniški vestnik - Journal of Mechanical Engineering; Vol 63, No 5 (2017): Strojniški vestnik - Journal of Mechanical Engineering
DO  - 10.5545/sv-jme.2016.4188
KW  - coal based boiler, corrosion, creep, fractographic analysis, SEM, superheater tube
N2  - This paper highlights a methodology for failure investigation of superheater tubes made of the material T-22 of a coal-based boiler. The process includes visual observation, the identification of sampling locations, the determination of the bulk chemical composition of the base alloy, microstructural investigation using optical microscopy, the exploration of finer structural details using a scanning electron microscope (SEM), the evaluation of hardness over samples obtained from different locations, the fractographic analysis of different failed locations, the X-ray diffraction (XRD) study of corrosion products adhered to inner surfaces, and the determination of the nature of the failure. Within a span of four months, three successive failures of superheater tubes were reported. The tubes were observed to have undergone significant wall thinning. Microscopic examinations using SEM on the failed region and a region some distance away on the as-received tubes were conducted in order to determine the failure mechanism. Layer-wise oxidation corrosion (exfoliation) in the inner surface was observed. Apart from major cracking, a number of nearly straight line crackings were observed in the longitudinal direction of both tubes. Close to cracking/bulging, void formation/de-cohesion of grain boundary indicated creep deformation under service exploitation. The failure mechanism was identified to be a result of excessive oxidation corrosion along the inside wall to reduce thickness, the spheroidization of alloy carbides and the coarsening of precipitate as well as creep void formation along grain boundary leading to inter-granular cracking with material flow near regions covered with thick scales. Moreover, there was a drastic reduction in bulk hardness of alloy and finally ‘thin lip fish mouth’ fractures.
UR  - https://www.sv-jme.eu/article/critical-failure-analysis-of-superheater-tubes-of-coal-based-boiler/
Gupta, Gagan, AND Chattopadhyaya, Somnath.
"Critical Failure Analysis of Superheater Tubes of Coal-Based Boiler" Strojniški vestnik - Journal of Mechanical Engineering [Online], Volume 63 Number 5 (27 June 2018)

Authors

Affiliations

  • Indian Institute of Technology (Indian School of Mines), Department of Mechanical Engineering, India 1

Paper's information

Strojniški vestnik - Journal of Mechanical Engineering 63(2017)5, 287-299

https://doi.org/10.5545/sv-jme.2016.4188

This paper highlights a methodology for failure investigation of superheater tubes made of the material T-22 of a coal-based boiler. The process includes visual observation, the identification of sampling locations, the determination of the bulk chemical composition of the base alloy, microstructural investigation using optical microscopy, the exploration of finer structural details using a scanning electron microscope (SEM), the evaluation of hardness over samples obtained from different locations, the fractographic analysis of different failed locations, the X-ray diffraction (XRD) study of corrosion products adhered to inner surfaces, and the determination of the nature of the failure. Within a span of four months, three successive failures of superheater tubes were reported. The tubes were observed to have undergone significant wall thinning. Microscopic examinations using SEM on the failed region and a region some distance away on the as-received tubes were conducted in order to determine the failure mechanism. Layer-wise oxidation corrosion (exfoliation) in the inner surface was observed. Apart from major cracking, a number of nearly straight line crackings were observed in the longitudinal direction of both tubes. Close to cracking/bulging, void formation/de-cohesion of grain boundary indicated creep deformation under service exploitation. The failure mechanism was identified to be a result of excessive oxidation corrosion along the inside wall to reduce thickness, the spheroidization of alloy carbides and the coarsening of precipitate as well as creep void formation along grain boundary leading to inter-granular cracking with material flow near regions covered with thick scales. Moreover, there was a drastic reduction in bulk hardness of alloy and finally ‘thin lip fish mouth’ fractures.

coal based boiler; corrosion; creep; fractographic analysis; SEM; superheater tube