347H不锈钢在NaCl-KCl-MgCl熔盐中的腐蚀行为：气相、液相及界面比较

Corrosion Behavior of 347H Stainless Steel in NaCl-KCl-MgCl Molten Salt: Vapor, Liquid, and Interface Comparison.

作者信息

Liu Zhiwen, Li Huigai, Wang Yang, Peng Yanjie, Sun Luyan, Liang Jianping

机构信息

College of Materials Science and Engineering, Shanghai University, Shanghai 200072, China.

Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.

出版信息

Materials (Basel). 2025 Jul 21;18(14):3412. doi: 10.3390/ma18143412.

DOI:10.3390/ma18143412

PMID:40731622

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12300096/

Abstract

The suitability of 347H stainless steel (SS347H) for chloride salt environments is critical in selecting materials for next-generation concentrated solar power (CSP) systems. This study investigated the corrosion behavior of SS347H in a ton-scale purification system with continuously flowing chloride salt under three conditions: exposure to NaCl-KCl-MgCl molten salt vapor, immersion in molten salt, and at the molten salt surface interface. Results revealed that corrosion was most severe in the molten salt vapor, where HCl steam facilitated Cl reactions with Fe and Cr in the metal, causing dissolution and forming deep corrosion pits. At the interface, liquid Mg triggered displacement reactions with Fe/Cr ions in the salt, depositing Fe and Cr onto the surface, which reduced corrosion intensity. Within the molten salt, Mg's purification effect minimized impurity-induced corrosion, resulting in the least damage. In all cases, the primary corrosion mechanism involves the dissolution of Fe and Cr, with the formation of minor MgO. These insights provide valuable guidance for applying 347H stainless steel in chloride salt environments.

摘要

对于下一代聚光太阳能发电（CSP）系统而言，347H不锈钢（SS347H）在氯化物盐环境中的适用性对于材料选择至关重要。本研究调查了SS347H在吨级净化系统中的腐蚀行为，该系统在三种条件下有连续流动的氯化物盐：暴露于NaCl-KCl-MgCl熔盐蒸汽中、浸入熔盐中以及处于熔盐表面界面处。结果表明，在熔盐蒸汽中腐蚀最为严重，其中HCl蒸汽促进了Cl与金属中的Fe和Cr发生反应，导致溶解并形成深腐蚀坑。在界面处，液态Mg引发了与盐中Fe/Cr离子的置换反应，将Fe和Cr沉积到表面，从而降低了腐蚀强度。在熔盐内部，Mg的净化作用使杂质引起的腐蚀最小化，造成的损害最小。在所有情况下，主要腐蚀机制都涉及Fe和Cr的溶解，并形成少量MgO。这些见解为在氯化物盐环境中应用347H不锈钢提供了有价值的指导。