Abstract
The effect of Nb and Cu addition on the creep properties of a high Mn-N austenitic stainless steel was investigated at 600 and 650 C. In the original high Mn-N steel, which was initially precipitate-free, the precipitation of M23C6 (M = Cr, Fe) and Cr2N took place mostly on grain boudaries during creep deformation. On the other hand, the minor addition of Nb resulted in high number density of Z-phases (CrNbN) and MX (M = Nb; X = C, N) carbonitrides inside grains by combining with a high content of N, while suppressing the formation of Cr2N. The addition of Cu gave rise to the independent precipitation of nanometer-sized metallic Cu particles. The combination of the different precipitate-forming mechanisms associated with Z-phase, MX and Cu-rich precipitates turned out to improve the creep-resistance significantly. The thermodynamics and kinetics of the precipitation were discussed using thermo-kinetic simulations.
Original language | English |
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Pages (from-to) | 49-57 |
Number of pages | 9 |
Journal | Materials Characterization |
Volume | 83 |
DOIs | |
Publication status | Published - 2013 |
Bibliographical note
Funding Information:The authors gratefully acknowledge the financial support provided by the Korea Government Ministry of Knowledge Economy (Grant No. 2011101010004A ), Korea Institute of Science and Technology (Grant No. 2E24022 ) and POSCO .
Keywords
- Coarsening
- Creep strength
- Cu particle
- High Mn-N austenitic steel
- Precipitates
- Z-phase
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering