329 低K値側のSCC進展速度線図の見直し(OS10-1 応力腐食割れ,減肉配管,OS10 エネルギー機器の経年変化に関する健全性評価手法の開発とその適用(1))

抄録

The purpose of this study is to clarify the effect to SCC growth evaluation, when deleting the lower shelf of the SCC growth rate curves used for FFS. Numerical calculation was conducted for 600A piping, and found that this deleting is less effected to the growth evaluation. Moreover, for such piping, cracks are considered to be stopped in the middle of thickness regardless of initial crack size or crack growth rate curves. Therefore, when the residual stress becomes negative before required wall thickness, it is thought that SCC growth evaluation should not necessary.