Study of Corrosion Fatigue Phenomena and Lifetime Improvement of Steam Turbine Blades Used for Mechanical Drives (1st Report: Relation of Corrosive Chemicals Enrichment Zone and Corrosion Fatigue)

摘要

Corrosion fatigue phenomena of low-pressure blade on chemical enrichment zone for mechanical-drive steam turbines were studied by FEA vibration response and fracture surface analysis. Effects of Main factors as corrosive chemicals, corrosion pit size and enrichment concentration are quantitatively analyzed according to useful data and actual samples of blades and operation experience. Based on these detailed studies, blades have been improved to have sufficient integrity under practical chemical enrichment zone.