Technical Note: Frequency Dependence of Fatigue Crack Growth Rate of Alloy 690TT in High-Temperature Boron-Lithium Water.

Alloy 690TT is a widely used material for steam generator tubes in pressurized water reactors, where it is susceptible to corrosion fatigue. In this study, the effect of loading frequency on the corrosion fatigue behavior of Alloy 690TT in boron-lithium water was investigated under small-scale yielding conditions. Along with stress ratio, the loading frequency had a significant influence on the crack path and fatigue crack growth rate. Both the corrosion fatigue crack growth rate and the environment enhancement factor were quantitatively correlated with the loading frequency in the form of exponential functions. [ABSTRACT FROM AUTHOR]