Effects of molybdenum on precipitation behaviours in aged cast stainless steels. Issue 24 (22nd August 2016)

• Record Type: Journal Article
• Authors: Hamaoka, Takumi; Konno, Toyohiko J.; Sawabe, Takashi; Nishida, Kenji; Dohi, Kenji
• Is Part Of: Philosophical magazine. Volume 96:Issue 24(2016)
• Page Start: 2518
• Page End: 2536
• Publication Date: 2016-08-22
• Subjects: Duplex stainless steel -- ageing -- precipitation -- G-phase -- χ-phase -- transmission electron microscopy; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2016.1205231
• Languages: English
• ISSNs: 1478-6435

Abstract

Abstract: The effects of Mo on precipitation behaviours in aged cast stainless steels have been investigated. Mo-free CF3 steel and Mo-bearing CF3M steel, both of which consisted of a duplex structure of ferrite and austenite phases, were prepared. Microstructural evolution in the ferrite phase during ageing at 723 K has been observed by transmission electron microscopy (TEM). Precipitates in CF3 steel were identified to belong to the G-phase and possess lattice coherency with the ferrite phase at interphase boundaries. On the other hand, precipitates in CF3M steel were found to be nanodomains of not only to the G-phase but also to another phase enriched in Mo. Some of the nanodomains containing Mo exhibited diffraction patterns having pseudo five-fold symmetry, but others exhibited regular periodicity in high-resolution TEM images. The atomic structure of the Mo-related nanodomains is proposed to be a distorted χ -phase that retains coherency with the matrix.