MICROSTRUCTURAL IMPRINTS IN FAILURE OF POWER PLANT BOILER TUBES | ||||
| The International Conference on Applied Mechanics and Mechanical Engineering | ||||
| Article 32, Volume 15, 15th International Conference on Applied Mechanics and Mechanical Engineering., May 2012, Page 1-12 PDF (6.28 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/amme.2012.36935 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| U. K. Chatterjee | ||||
| Metallurgical Consultant & Professor (Retired), Indian Institute of Technology, Kharagpur 721302, India. | ||||
| Abstract | ||||
| ABSTRACT Power plant boiler tubes fail in service due to a number of reasons and through various mechanisms. Overheating is a prime cause, and creep, corrosion, erosion and hydrogen damage constitute major mechanisms of failure. Long-term overheating brings about microstructural changes like grain growth, disintegration of pearlite, spheroidization of carbides, graphitization and decarburization leading to loss of strength of the tube material, eventually resulting in stress rupturing or creep rupture through grain boundary void formation. A tube burst resulting from short-term overheating also often bears the imprint of microstructural changes occurring due to transformation of the high temperature phase. Overheating also accelerates the process of hydrogen damage, where the presence of grain boundary fissures bears the evidence of such type of failure. The paper deals with the theoretical aspects of microstructural changes as encountered in boiler tube failures and presents a few case histories to highlight the metallographic features in failures due to overheating and hydrogen damage. | ||||
| Keywords | ||||
| Failure analysis; Power Plant; Boiler Tubes; Microstructures | ||||
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