Ro, I. -Jun Lee, Chang-Gi Aota, Leonardo Shoji Choi, Woonam Won, Sungbin Ahn, Jae-Pyoung Kim, Hae-Ryoung Choi, Gwanghyo Gault, Baptiste Kim, Se-Ho 2025-04-25T02:00:08Z 2025-04-25T02:00:08Z 2025-04-25 2025-05 2238-7854 https://pubs.kist.re.kr/handle/201004/152291 Reinforcing steels play a crucial role in ensuring structural safety, particularly in seismic areas where fatigue failure can have catastrophic consequences. In this work, we examine how microstructural and compositional characteristics influence the fatigue performance of core-shell hybrid reinforcing steels (B500B). Following fatigue testing up to five million cycles, we observed a pronounced increase in both pore size and density, most notably in the shell region, attributable to a high concentration of inclusions. High-resolution microscopy revealed the presence of voids adjacent to MnS particles, alongside nanoscale cementite precipitates and Cu clusters at the interfaces of the cementite and surrounding martensite. Furthermore, elemental partitioning of Mn, Cu, Si, Ni, and Cr led to an enrichment of carbon in the tempered martensite, rendering the shell more brittle and prone to fatigue-induced cracking. These findings highlight the necessity of precise control over alloying elements to minimize the formation of detrimental phases, thereby improving the fatigue resistance and overall durability of reinforcing steels in seismic applications. English Elsevier Editora Ltda Influence of chemical composition and microstructure on fatigue performance of reinforcing steel Article 10.1016/j.jmrt.2025.03.260 1 Journal of Materials Research and Technology, v.36, pp.2589 - 2599 Journal of Materials Research and Technology 36 2589 2599 N scie scopus 001464628900001 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article MECHANICAL-PROPERTIES TEMPERED MARTENSITE SULFIDE INCLUSIONS GIGACYCLE FATIGUE VOID NUCLEATION CARBON CEMENTITE GROWTH PRECIPITATION EMBRITTLEMENT