Remaining life estimation of a service exposed economiser tube

A service exposed (80,000 hr) economiser tube of a 60 MW boiler of a therma l power plant was investigated for the detailed metallurgical assessment ne cessary for remaining life estimation. The investigation included hot tensi le tests, hardness measurement, microscopy and thickness measurement. Analy sis revealed that there was no degradation of mechanical properties and mic rostructural features. The reduction in tube thickness was primarily due to oxidation and corrosion/erosion processes. Taking into account all the exp erimental data and mechanics aspects of the tube an estimated remaining lif e of 20,000 hrs was calculated and thus recommended for further use. (C) 19 99 Elsevier Science Ltd. All rights reserved.