Microstructure characteristic and mechanical property of transformable 9Cr-ODS steel fabricated by spark plasma sintering. (15th October 2017)

• Record Type: Journal Article
• Authors: Zhou, Xiaosheng; Liu, Yongchang; Yu, Liming; Ma, Zongqing; Guo, Qianying; Huang, Yuan; Li, Huijun
• Is Part Of: Materials & design. Volume 132(2017)
• Page Start: 158
• Page End: 169
• Publication Date: 2017-10-15
• Subjects: Nanoparticles -- Oxide dispersion strengthened steel -- Interface structure -- Spark plasma sintering -- Strengthening mechanism; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.06.063
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Transformable 9Cr oxide dispersion strengthened (ODS) steel was prepared by mechanical milling and consolidated by spark plasma sintering (SPS). Microstructural features in different fabrication stages were studied by X-ray diffraction, optical microscopy, scanning and transmission electron microscopy. In the mechanical milling stage, deformed, amorphous and fractured Y2 O3 particles are identified, and certain amount of Y2 O3 may decompose into the matrix. As a rapid densification technique, SPS will retain the high density of dislocations produced in milling. For both as-sintered and as-annealed 9Cr-ODS steels, interface structures and orientation relationships between Y2 O3 and the iron matrix have been examined, as well as the size distributions of Y2 O3 particles. The as-sintered 9Cr-ODS steel exhibits higher strength at room temperature than the as-annealed one, and contributions of various microstructural features to yield strength of 9Cr-ODS steels in both conditions have been evaluated. Graphical abstract: Microstructure characteristics of 9Cr-ODS steels in sintered and annealed conditions, as well as contributions of various microstructure features to yield strength of 9Cr-ODS steels in both conditions. Highlights: Y2 O3 nanocrystalline would grow significantly at about 660 °C. Certain orientation relationship exists between Y2 O3 and matrix with semi-coherent interface structure. Dominated strengthening mechanisms are different in sintered and annealed ODS steels.