Failure investigation of Reheat Cross Section and Rear Screen Wall Tubes of 600 MW coal power plant

Abstract

Tube material that is operated at high temperatures has a higher possibility of failure, due to the addition of temperature and also influenced by the corrosive environment, pressure, and static-dynamic stress. The rupture occurred in the Rear Screen Wall and Reheat Cross Section Tubes that disruptive the performance of the overall Boiler. It was urgently needed to analyze the cause of the rupture. The material tube needs to be prepared to test in the laboratory. The analysis methods were through mechanical tests which are visual observation, fractography, hardness test, metallography or microstructure examination, and deposit analysis. The results showed that the Reheater Cross Section tube leakage caused by the formation of macro cracks that have been spread along the tube, compounded by flue gas erosion on the outer of the tube. On the other hand, Rear Screen Wall tube leakage caused by thinning from the outside of the tube, it occurred as a result of erosion of the flue gas and bursts from the Reheater Cross Section tube that leaked.