Effects of temperature and dissolved oxygen on cyclic crack growth rate of carbon and low alloy steels in high temperature water

摘要

Fatigue crack growth rate of carbon and low alloy steels in high temperature water has been extensively studied, while little attention has been directed to the effects of temperature and dissolved oxygen on this parameter for simulated BWR waterenvironments. The authors reported that low cycle fatigue life of such materials decreased considerably with increasing temperature and dissolved oxygen in water. Based on these observations, fatigue crack growth rate should be considered to be affectedby these factors.Cyclic crack growth rate for carbon and low alloy steels has been studied in high temperature water using compact tension type specimens, as determined by cyclic frequency, temperature and dissolved oxygen. The acceleration of this growth rate was foundto be maximum at 100°C and minimum at 200°C, the former not being influenced by frequency or oxygen content. The effect of oxygen on growth rate could be detected only at 288°C for carbon steel and the effect of frequency was evident at higher temperature and oxygen content.