Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

被引：11

作者：

Sen-Britain, Shohini ^{[1
]}

Cho, Seongkoo ^{[1
]}

Kang, Shinyoung ^{[1
]}

Qi, Zhen ^{[1
]}

Khairallah, Saad ^{[1
]}

Rosas, Debra ^{[1
]}

Som, Vanna ^{[1
]}

Li, Tian T. ^{[1
]}

Qiu, S. Roger ^{[1
]}

Wang, Y. Morris ^{[2
]}

Wood, Brandon C. ^{[1
]}

Voisin, Thomas ^{[1
]}

机构：

[1] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[2] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA USA

来源：

NATURE COMMUNICATIONS | 2024年 / 15卷 / 01期

关键词：

RESISTANCE; BEHAVIOR; SPATTER; 316L; FATIGUE;

D O I：

10.1038/s41467-024-45120-6

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Pitting corrosion in seawater is one of the most difficult forms of corrosion to identify and control. A workhorse material for marine applications, 316L stainless steel (316L SS) is known to balance resistance to pitting with good mechanical properties. The advent of additive manufacturing (AM), particularly laser powder bed fusion (LPBF), has prompted numerous microstructural and mechanical investigations of LPBF 316L SS; however, the origins of pitting corrosion on as-built surfaces is unknown, despite their utmost importance for certification of LPBF 316L SS prior to fielding. Here, we show that Mn-rich silicate slags are responsible for pitting of the as-built LPBF material in sodium chloride due to their introduction of deleterious defects such as cracks or surface oxide heterogeneities. In addition, we explain how slags are formed in the liquid metal and deposited at the as-built surfaces using high-fidelity melt pool simulations. Our work uncovers how LPBF changes surface oxides due to rapid solidification and high-temperature oxidation, leading to fundamentally different pitting corrosion mechanisms. Mechanisms occurring during seawater corrosion of as-built laser powder bed fusion 316L stainless steels are largely unknown. Here, the authors show that Mn, Si-rich slags found in between laser tracks are responsible for corrosion.

引用

页数：13