Development of the high-strength ductile ferritic alloys via regulating the intragranular and grain boundary precipitation of G-phase
Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal › peer-review
Author(s)
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Detail(s)
Original language | English |
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Pages (from-to) | 180-199 |
Journal / Publication | Journal of Materials Science and Technology |
Volume | 136 |
Online published | 28 Aug 2022 |
Publication status | Published - 10 Feb 2023 |
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Abstract
A typical G-phase strengthened ferritic model alloy (1Ti:Fe-20Cr-3Ni-1Ti-3Si, wt.%) has been carefully studied using both advanced experimental (EBSD, TEM and APT) and theoretical (DFT) techniques. During the classic “solid solution and aging” process, the superfine (Fe, Ni)2TiSi-L21 particles densely precipitate within the ferritic grain and subsequently transform into the (Ni, Fe)16Ti6Si7-G phase. In the meanwhile, the elemental segregation at grain boundaries and the resulting precipitation of a large amount of the (Ni, Fe)16Ti6Si7-G phase are also observed. These nanoscale microstructural evolutions result in a remarkable increase in hardness (100–300 HV) and severe embrittlement. When the “cold rolling and aging” process is used, the brittle fracture is effectively suppressed without loss of nano-precipitation strengthening effect. Superhigh yield strength of 1700 MPa with 4% elongation at break is achieved. This key improvement in mechanical properties is mainly attributed to the pre-cold rolling process which effectively avoids the dense precipitation of the G-phase at the grain boundary. These findings could shed light on the further exploration of the precipitation site via optimal processing strategies.
Research Area(s)
- G-phase, Grain boundary segregation, Nano-precipitates, Precipitation strengthening
Citation Format(s)
Development of the high-strength ductile ferritic alloys via regulating the intragranular and grain boundary precipitation of G-phase. / Yang, Mujin; Huang, Chao; Han, Jiajia et al.
In: Journal of Materials Science and Technology, Vol. 136, 10.02.2023, p. 180-199.
In: Journal of Materials Science and Technology, Vol. 136, 10.02.2023, p. 180-199.
Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal › peer-review