Modified Rate Approach Method to Evaluate Fatigue Life of Carbon Steel Under Simulated Synchronously Changing BWR Conditions

The fatigue life of carbon steel is influenced by Boiling Water Reactor (BWR) conditions such as water temperature, dissolved oxygen concentration, water flow rate and so on. These parameters changes constantly during the operation of BWR plants and strain rate changes in the structural components occur because of temperature changes. In general, fatigue life evaluation equations have been formulated based on fatigue data obtained under constant conditions. Before using these equations to evaluate the fatigue life of actual components, a study is necessary to make sure they are applicable to changing conditions. In this study, fatigue tests were performed under changing strain amplitude, strain rate, temperature, dissolved oxygen content, and water flow rate conditions. It was confirmed that the proposed fatigue life equation could predict the fatigue life under practical changing conditions.Copyright © 2006 by ASME