JMES The International Journal of Mechanical Engineering and Sciences
Vol 9, No 1 (2025)

Oxide Dispersion Strengthened Steels: Precipitation Kinetics and Matrix Phase Transformation

Unegbu, Hyginus Chidiebere Onyekachi (Department of Mechnical Engineering Ahmadu Bello University Nigeria)
Yawas, Danjuma S. (Department of Mechnical Engineering Ahmadu Bello University Nigeria)
Asabe, B Dan (Department of Mechnical Engineering Ahmadu Bello University Nigeria)
Alabi, A A (Department of Mechnical Engineering Ahmadu Bello University Nigeria)



Article Info

Publish Date
30 Mar 2025

Abstract

This study presents a comprehensive investigation of the microstructural features, precipitation kinetics, phase transformations, and mechanical properties of Oxide Dispersion Strengthened (ODS) steels, with a focus on the impact of Y₂O₃ particle dispersion. Detailed microstructural analysis using Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) revealed a fine and uniform distribution of Y₂O₃ particles, averaging 10-15 nm in size, which contributed to significant grain refinement to 5-7 µm. The precipitation kinetics, examined through Differential Scanning Calorimetry (DSC) and dilatometry, showed a diffusion-controlled mechanism with an activation energy of 230 kJ/mol. The dispersed oxide particles delayed the austenite-to-martensite transformation, stabilizing the austenitic phase at higher temperatures, as confirmed by in-situ High-Temperature X-ray Diffraction (HT-XRD). Mechanical tests demonstrated a hardness of 320 HV and a tensile strength of 600 MPa, with a total elongation of 12%. These results highlight the effectiveness of oxide dispersion in enhancing the mechanical strength and thermal stability of ODS steels. The findings suggest that ODS steels are highly suitable for high-performance applications, particularly in environments such as nuclear reactors and aerospace, where high temperature, radiation resistance, and mechanical durability are critical. Future work should explore the long-term stability of these materials under operational conditions to further optimize their performance.

Copyrights © 2025






Journal Info

Abbrev

jmes

Publisher

Subject

Energy Materials Science & Nanotechnology Mechanical Engineering

Description

Topics covered by JMES include most topics related to mechanical sciences including energy conversion (wind, turbine, and power plant), mechanical structure and design (solid mechanics, machine design), manufacturing (welding, industrial robotics, metal forming), advanced materials (composites, ...