A synergy of different corrosion failure modes pertaining to T91 steel impacted by extreme lead–bismuth eutectic flow pattern. (March 2021)

• Record Type: Journal Article
• Authors: Li, Cong; Fang, Xiaodong; Wang, Qingsheng; Shen, Mingli; Wang, Haoliang; Zeng, Xian; Liu, Yujing; Meng, Gang
• Is Part Of: Corrosion science. Volume 180(2021)
• Publication Date: 2021-03
• Subjects: T91 -- Oxygen-saturated LBE -- Oxidation -- Erosion -- Impact angle -- Cottrell atmosphere; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.109214
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Dynamic corrosion with varying lead–bismuth eutectic flow patterns was performed. Flow direction played a more important part in comparison to fluid velocity. Nanoscale Cottrell atmosphere at scale-alloy interface altered local oxidation. Erosion mechanics motivated LBE penetration into steel matrix. Role of oxidation stress enhanced by high curvature of erosion cavity was revealed. Abstract: This paper reports an attempt to speculate about corrosion resistance of T91 steel to extreme lead–bismuth eutectic (LBE) flow pattern. We build a modified dynamic corrosion apparatus permitting assemblages of oxidation, erosion or dissolution attack proceeding together within oxygen-saturated LBE. After corrosion test at 400℃ up to 1000 h, discrepancies of corrosion performance under various flow patterns were described by diffusion or mass transfer kinetics as well as erosion mechanics. In justification of dense Fe-O layer and cracks across oxide scales detected within typical erosion cavities, we put forward oxide growth stress enhanced by high surface curvature.