文献类型：期刊文献

英文题名：Elucidating corrosion discrepancies between directed energy deposited 316L stainless steel and Inconel 625 via micro-droplet characterization and electrochemical analysis in hydrofluoric acid (HF) vapor environment

作者：Zhang, Shuyao[1,2];Li, Yajing[5];Zhao, Yue[3];Yu, Jingtai[1,2];Zhang, Zhe[1,2];Chen, Xu[1,2,4]

机构：[1]Tianjin Univ, Sch Chem Engn & Technol, Tianjin 300072, Peoples R China;[2]Tianjin Key Lab Chem Proc Safety & Equipment Techn, Tianjin 300350, Peoples R China;[3]Tianjin Univ, Sch Mat Sci & Engn, Tianjin 300350, Peoples R China;[4]Tianjin Univ, Zhejiang Inst, Ningbo 315201, Zhejiang, Peoples R China;[5]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai, Peoples R China

年份：2025

卷号：541

外文期刊名：ELECTROCHIMICA ACTA

收录：;EI(收录号：20253719147583);WOS:【SCI-EXPANDED(收录号:WOS:001583671400014)】；

基金：This work was supported by the National Key Research and Devel-opment Program of China (No. 2022YFC3004500) , and the Ningbo Natural Science Foundation (No. 2021J006) , the National Natural Sci-ence Foundation of China (No. 52505149) , China Postdoctoral Science Foundation (No. 2023TQ0113) , and Shanghai Pujiang Programme (No. 23PJD022) .

语种：英文

外文关键词：Hydrofluoric acid vapor; Electrochemical; Directed energy deposition; 316L SS; IN625

摘要：This study comparatively investigates the corrosion behavior and mechanisms of directed energy deposition (DED) fabricated 316 L stainless steel (316 L SS) and Inconel 625 (IN625) in a hydrofluoric (HF) vapor environment. A micro-droplet electrochemical approach, combining time-resolved electrochemical impedance spectroscopy (EIS) with quasi in situ imaging of the same surface region, is employed. Early-stage observations show that HF droplets condense, coalesce, and preferentially initiate attack along droplet edges. As exposure proceeds, the two alloys exhibit divergent impedance evolution: for IN625, the film resistance (Rf) and chargetransfer resistance (Rct) increase with time, whereas for 316 L they remain lower and exhibit a decreasing trend. This is attributed to differences in elemental composition and microstructural heterogeneity. A Fe-rich (63.78 %) porous corrosion layer formed, offering inadequate protection to the matrix on 316 L SS. Furthermore, microgalvanic selective dissolution of delta-ferrite accelerated corrosion. In contrast, IN625 formed a compact and protective corrosion product layer with a higher NiO content (25.5 %), while the Laves phase remained stable, enhancing passivation and effectively inhibiting corrosion.