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 journalpeer-review

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Author(s)

  • Mujin Yang
  • Chao Huang
  • Jiajia Han
  • Haichen Wu
  • Shenbao Jin
  • Chenglei Wang
  • Zhou Li
  • Ruiying Shu
  • Cuiping Wang
  • Huanming Lu
  • Gang Sha
  • Xingjun Liu

Detail(s)

Original languageEnglish
Pages (from-to)180-199
Journal / PublicationJournal of Materials Science and Technology
Volume136
Online published28 Aug 2022
Publication statusPublished - 10 Feb 2023

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.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review