Study on Fracture Failures of the Super Heater Water Pipe Boiler

Abstract

The purpose of this study was to analyse the failure of the super heater pipe of the Heat Recovery Steam Boiler Generator (HRSG), which had broken. Investigations are carried out in several stages. First of all, the microstructure of the pipe was observed using an Optic Olympus GX71 Microscope and a Scanning Electron Microscope (SEM) was used to observe the fracture surface to find the initial crack. Thereafter, chemical composition testing, to determine the type of material used in the super heater pipe. The presence of deformation by creep was due to overheating seen on the super heater pipes. Moreover, It was due to operating at elevated temperatures and pressures with long operating times. This condition caused the thickness of the pipe to thin so that it would break due to crack propagation which penetrated the wall of the pipe until breaking as the material was no longer able to withstand the steam pressure inside the pipe. Obviously that this condition indicates that the crack propagation occurred until final failure.