Revisiting Graphite Electrodes for Electric Arc Furnaces: Three‐Dimensional Microstructural Heterogeneity as a Design Parameter for Fracture Resistance

ABSTRACT Graphite electrodes are widely used in electric arc furnaces due to their high mechanical stability, electrical conductivity, and thermal resistance. Early detection and understanding of fracture mechanisms are therefore essential to mitigating catastrophic failures, saving money and time. In this work, we investigate the mechanical response and post‐fracture microstructure of a series of graphite electrode bars using tensile tests combined with X‐ray micro‐computed tomography (micro‐CT), X‐ray diffraction (XRD), Raman spectroscopy, and image‐based quantitative analysis. Six industrial graphite bars, with differences in fracture peak load and energy, were analyzed by the micro‐CT technique, and volumetric and surface‐based descriptors for each phase were quantified and correlated with the tensile response. A strong relationship was found between fracture energy and both graphite and particle‐related metrics, indicating that microstructural connectivity and interfacial complexity govern the energy absorption during crack propagation. Surface roughness and fractal dimension analyses of post‐fracture surfaces further reveal differences in crack‐path tortuosity among the samples. XRD and Raman spectroscopy provide complementary information. Overall, this study establishes a quantitative, three‐dimensional microstructural design framework for fracture‐resistant graphite electrodes, offering insights for the microstructural design of more durable graphite electrodes.