Microstructure and Mechanical Properties of 9Cr-ODS Ferritic/Martensitic Steels by Mechanically Alloyed and Spark Plasma Sintering

Abstract:

9Cr-0.35wt.%Y₂O₃ oxide dispersion strengthened (ODS) ferritic/martensitic steels were prepared by mechanically alloying (MA) and spark plasma sintering (SPS). FE-SEM and TEM with X-ray energy spectrum (EDX) were employed to characterize the microstructural evolution and chemical composition before and after heat treatment. The tensile properties at room temperature were also investigated by electronic tensile test. The result shows that it is mainly of equiaxed ferrite microstructure by SPS with mean grain size of about 500nm. Dispersoids about 5-20nm which are enriched in Y, Ti and O uniformly distribute in the matrix. It exhibits a high relative density, ultimate tensile strength and yield strength of 99.5%, 1554MPa and 1430MPa, respectively. The microstructures are of slender lath martensitic after 10%NaCl water solution quenching, while after tempering at 750 which change into mainly equiaxed ferritic and a little residual ferrite. The ODS steel exhibits ultimate tensile strength, yield strength and total elongation of 1198MPa, 1006MPa and 12.8% after tempering, respectively.

• Periodical: Materials Science Forum (Volumes 747-748)
• Pages: 636-640
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.747-748.636
• Online since: February 2013
• Authors: Jian Yang, Zhi Meng Guo, Wei Wei Yang, Ji Luo, Cun Guang Chen
• Keywords: Ferritic/Martensitic, Heat Treatment, ODS Steels, SPS

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