Calculation and enhancement of fatigue life by ε-N approach and corrosion fatigue in steam turbine rotor

Abstract

Power plants production’s growth capacity has led to increased concerns about efficiency and reliability of steam turbines. Its components are prone to cracking and failure caused by creep and fatigue. The present work used Ansys® and nCode GlyphWorks® package to predict tensions and deformations. The methodology used allows calculate the level of structural damage caused to each work cycle. Analysis of the application of a chemical process on the rotor to improve failure resistance influenced the component life, avoiding corrosion fatigue. To create residual stresses on the surface of material was used Shot peening process. Thermal analysis results show that the rotor supports approximately 3.18 × 104 cycles, obtaining a maximum error of 12.5% compared to experimental reference. The shot peening process increased the rotor life by about 3000 h (10.5%) and changes in the heat treatment microstructure increased by 9.6% in number of cycles.