Effects of N addition and annealing treatment on microstructures and mechanical properties of ODS steels
| Autor: | Gaoyong Xu, Yin Zhang, Hui Lu, Juexin Xu, Cheng Zhang, Jinping Suo |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Nuclear and High Energy Physics
Toughness Materials science Annealing (metallurgy) Spark plasma sintering 02 engineering and technology 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Grain size 010305 fluids & plasmas Nuclear Energy and Engineering Transmission electron microscopy 0103 physical sciences Ultimate tensile strength General Materials Science Composite material 0210 nano-technology Electron backscatter diffraction |
| Zdroj: | Journal of Nuclear Materials. 527:151796 |
| ISSN: | 0022-3115 |
| DOI: | 10.1016/j.jnucmat.2019.151796 |
| Popis: | In this paper, the effects of nitrogen (N) addition and annealing treatment on the microstructures and mechanical properties of ODS steels were investigated. The ODS steels with 0 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt% nitrogen were fabricated by mechanical alloying (MA) and spark plasma sintering(SPS) method. The microstructure evolution duo to N addition and annealing treatment were characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Results showed that 0.5N-ODS steel had smaller grain size and more precipitates than 0N-ODS steel. Tensile tests showed that both ultimate tensile strength and total elongation of the annealed 0.5N-ODS steel were higher with 1387 MPa and 7.6% respectively than 0N-ODS steel. It was considered that the concurrently improvement of strength and toughness were related with the microstructure feature that there are the bimodal grain size distribution, with micrometer-sized grains and nano-sized grains uniformly and a large number of precipitates in the N-ODS steel duo to N addition. Among the precipitates, there were some “core/shell” structural particles, in which the “core” is rich in Y, Ti and O and the “shell” is rich in Cr, V, N. These feature lead to a better toughness. Using a linear model to evaluate the yield strength and obtained a good agreement with the experimental results. |
| Databáze: | OpenAIRE |
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