The effect of dissolved oxygen on fatigue behavior of Alloy 690 steam generator tubes in borated and lithiated high temperature water

摘要

Corrosion fatigue behavior of Alloy 690 tubes used for actual steam generator was investigated in borated and lithiated high temperature water containing ＜5 ppb(by weight)and 5500 ppb dissolved oxygen(DO)using boat-shaped specimens.It was found that the fatigue life at 5500 ppb DO was longer than at ＜5 ppb DO.The surface cracks and fracture characteristics of the specimens after fatigue tests were carefully examined.The effects of DO concentration on fatigue crack initiation and propagation of Alloy 690 tubes in high temperature water are discussed.