In this study, we investigate the effect of the duration of mechanical alloying on the microstructures and mechanical properties of ODS ferritic/martensitic steel. The Fe(bal.)-10Cr-1Mo pre-alloyed powder and Y2O3 powder are mechanically alloyed for the different mechanical alloying duration (0 to 40 h) and then constantly fabricated using a uniaxial hot pressing process. Upon increasing the mechanical alloying time, the average powder diameter and crystallite size increased dramatically. In the initial stages within 5 h of mechanical alloying, inhomogeneous grain morphology is observed along with coarsened carbide and oxide distributions; thus, precipitate phases are temporarily observed between the two powders because of insufficient collision energy to get fragmented. After 40 h of the MA process, however, fine martensitic grains and uniformly distributed oxide particles are observed. This led to a favorable tensile strength and elongation at room temperature and 650oC.

Abstract
1. Introduction
2. Experimental
3. Results and discussion
    3.1 Evolution of powder properties and microstructureswith different length of mechanical alloying times
    3.2 Evolution of tensile properties with differentlength of mechanical alloying times
4. Conclusions
References

• 노상훈(부경대학교 재료공학과) | Sanghoon Noh (Department of Materials Science and Engineering, Pukyong National University) Corresponding Author
• 김태규(한국원자력연구원 재료안전기술개발부) | Tae Kyu Kim (Nuclear Materials Division, Korea Atomic Energy Research Institute)