Estimation of Remaining Life of ASTM A106 Grade B Steel Pipes Used in Refinery Industries

This research focuses on the investigation and estimation of the remaining life of ASTM A106 Grade B steel pipes. The examined pipes have been in service for 7 years at a temperature of 280 degrees Celsius and a working pressure of 61 bar, conveying mostly methane as the fluid. Various tests including thickness measurement, chemical composition analysis, examination of microstructure using optical microscopy and scanning electron microscopyenergy dispersive X-ray spectroscopy, tensile testing at ambient and elevated temperatures, and macrohardness testing were conducted to estimate the remaining life. According to the obtained results, all samples exhibited a ferrite-pearlite microstructure, and no significant reduction in the thickness of the examined specimens was observed. Moreover, considering the current operational conditions, it is concluded that the pipes are in good condition for service for an additional 7 years with a confidence level of 4.99%.