Yang, Dae Cheol Song, Sang Yoon Kim, Han-Jin Lee, Sang-In Dutta, Biswanath Kim, Young Kyun Shim, Jae-Hyeok Suh, Jin-Yoo Na, Young Sang Sohn, Seok Su 2024-01-19T09:32:28Z 2024-01-19T09:32:28Z 2023-08-02 2023-05 0921-5093 https://pubs.kist.re.kr/handle/201004/113728 The issue of hydrogen embrittlement (HE) in face-centered (FCC) structured alloys is significant for H storage and transportation application due to unanticipated damage beyond its predicted service life. This unpredictable situation may harm human life and limit hydrogen to a reliable source of renewable energy in industrial fields. Recent research has suggested that multi-principal element alloys possess high resistance to HE. However, there has been limited exploration of how their unique properties affect the HE mechanisms. In this study, using simple model VCrCoNi alloys with analogous grain sizes, the reduction rate of ductility by hydrogen uptake was measured through a slow strain rate tensile test following electro-chemical H charging. Further, the origin of HE resistance was investigated by analyzing various factors such as hydrogen contents, fracture and deformation behaviors, and grain boundary properties using thermal desorption spectroscopy, scanning electron microscope, and electron backscatter diffraction. Despite the consistent trends of the H content, stacking fault energy, and stress with increasing V content, the resistance to HE is the highest for the alloy with an intermediate ratio of V and Cr, namely, for the V0.7Cr0.3CoNi alloy. Through the analysis of grain boundary characteristics, the high resistance is attributed to large fractions of special boundaries and special triple junctions and large twin-related domain size, which suppresses crack growth and interlinkage. The favorable grain boundary characteristics result from mechanical dynamic recovery, achieved by the competitive effects of solid-solution strengthening and stacking fault energy. Thus, the present study provides novel insights into enhancing HE resistance in FCC-structured alloys. English Elsevier BV Roles of the grain-boundary characteristics and distributions on hydrogen embrittlement in face-centered cubic medium-entropy VxCr1-xCoNi alloys Article 10.1016/j.msea.2023.145028 1 Materials Science and Engineering: A, v.873 Materials Science and Engineering: A 873 N scie scopus 001029592600001 2-s2.0-85152230735 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Science & Technology - Other Topics Materials Science Metallurgy & Metallurgical Engineering Article AUSTENITIC STAINLESS-STEELS INTERGRANULAR CORROSION MICROSTRUCTURES TEMPERATURE PRINCIPLES BEHAVIOR Hydrogen embrittlement Medium-entropy alloy Solid -solution strengthening Stacking fault energy Grain boundary characteristics