저방사화 페라이트/마르텐사이트 강의 저사이클피로 특성에 관한 일렉트로 슬래그 재용해의 효과

Effect of Electro-Slag Remelting Process on Low Cycle Fatigue Property of Reduced Activation Ferritic/Martensitic Steels

Reduced activation ferritic/martensitic steels (RAFMs), such as F82H, are the primary near-term candidate for ITER test blanket modules as well as components of the fusion DEMO reactor. In this study, the effects of electro-slag remelting (ESR) on low cycle fatigue (LCF) property for F82H steel were investigated. Increased concentrations of Ta rich oxides, such as TaOx and TaOx-Al₂O₃, have been correlated with a reduction of the LCF property of F82H, as they have been detected at higher levels at crack initiation points and fracture surfaces. Their presence in the steel was observed to have a direct effect on fatigue lifetime. The higher total strain range, Δɛt -=1.0%, of ESR processed F82H was observed, and it was found that the number of cycle to failure (Nf) was about twice that of conventional F82H. It was revealed that ESR processed F82H exhibited an improved fatigue lifetime due to the removal of Ta rich oxides.