Material Analysis of Degraded Steam Turbine Rotor

Abstract

This article deals with structural, fractographic and non-destructive analysis of a defective rotor made of 26NiCrMoV14-5 steel and assessment of possible technological failures resulting in the occurrence of cracking and subsequent defects. Metallographic analysis of the microstructure and evaluation of the steel metallographic purity were executed, including analysis of inclusions present and ultrasonic testing. Attention was paid to fractographic analysis of fracture areas. Degradation possibilities were monitored in relation to technological failures. The aim was to elucidate the cause of the rotor defect hindering its operational use.