Influence Degree and Scheme of Hot Reduction on Properties of the Carbon Steel

Authors : Igor Alex Vakulenko, Serhii Plitchenko, Ahmet Fatih Yılmaz

Pages : 150-156

Doi:10.52795/mateca.1634663

View : 67 | Download : 55

Publication Date : 2025-04-30

Article Type : Research Paper

Abstract :This study examines the impact of hot plastic deformation at 1250°C on austenite grain refinement and mechanical properties in carbon steel for railway wheels. The deformation strategies—single-step versus two-step compression with equivalent total strain—were compared to assess their effects on austenitic microstructure and material performance. Austenite grain size was quantified via light microscopy and quantitative structural analysis, while mechanical properties were evaluated using a universal tensile testing machine, following the ASTM E8 standard, at room temperature. (strain rate: 10⁻³ s⁻¹) Results reveal that austenite grain refinement occurs proportionally with increasing deformation, irrespective of the compression scheme. However, the deformation strategy significantly influences strength and ductility at lower strain levels. Specifically, two-stage compression at smaller strains (e.g., below 60% total deformation) enhances ultimate tensile strength by up to 10% and ductility by 30–40% compared to single-step compression. This improvement is attributed to partial retention of austenite substructure during interrupted deformation, which alters dynamic recrystallization kinetics and promotes dislocation redistribution. The differential effect diminishes progressively with higher strain levels, and beyond 60% deformation, both schemes yield equivalent grain sizes and mechanical properties due to complete recrystallization and microstructural homogenization. These findings underscore the critical role of deformation sequencing in optimizing mechanical performance during thermomechanical processing, particularly for applications requiring tailored strength-ductility balances in high-temperature-formed carbon steels.
Keywords : Austenit, Tane boyutu, Sıcak plastik deformasyon, Karbon çeliği, Mukavemet

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