Microstructure and mechanical properties of high-Mn-ODS steels

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:825

Article

Seils, S.^1,2  Kauffmann, A.¹  Delis, W.¹  Boll, T.^1,2  Heilmaier, M.¹ 

[1] Karlsruhe Inst Technol KIT, Inst Appl Mat IAM WK, Engelbert Arnold Str 4, D-76131 Karlsruhe, Germany

[2] Karlsruhe Inst Technol KIT, Karlsruhe Nano Micro Facil KNMF, Hermann von Helmholtz Pl 1, D-76344 Eggenstein, Leopoldshafen, Germany

关键词: ODS steel;    High-Mn steel;    Mechanical alloying;    Microstructure characterization;    Strengthening mehanisms;   

DOI  :  10.1016/j.msea.2021.141859

来源: Elsevier

【 摘 要 】

The contribution of dislocation density to strength of Cr-Ni containing austenitic ODS steels is assumed to be limited by dynamic recovery during consolidation of mechanically alloyed powder [Seils et al. Materials Science and Engineering A 786 (2020) 139452]. In order to prevent the reduction in dislocation density by dislocation annihilation subsequent to thermally activated cross slip during recovery, Cr and Ni were replaced by 24 and 34 wt% of Mn in the present study. The comparably lower stacking fault energy leads to larger stacking fault widths and, hence, lower probability of cross slip. The Mn-ODS steels were successfully manufactured by mechanical alloying and subsequent field assisted sintering. X-ray diffraction analysis revealed increased dislocation densities for both Mn-ODS alloys compared to a previously reported Cr-Ni-ODS steel. Formation of additional epsilon-phase was observed in the lower Mn alloy. Compression and hardness tests confirmed an improved strength and hardness of the Mn-ODS steels. Less thermal stability was found compared to the Cr-Ni-ODS steels due to pronounced ripening of oxide particles as well as grain coarsening in both investigated alloys.

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