Failure Investigation of Condensate Pump Shaft

摘要

The premature failure of condensate pump shaft was investigated in this paper. The shaft was attached with feed water condensate pump system in thermal power plant boiler. The shaft was fabricated from martensitic stainless steel. A detailed study was carried out to determine the root cause of the shaft failures. Visual examination, macroanalysis, chemical analysis, micro-structural characterization, and fractography examinations were also carried out to ascertain the probable cause of shaft failure. Finally, it was concluded that the failure of the shaft was due to the torsional fatigue initiated by the cracks at the thread roots.