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Title: Effect of the pre-existing carbides on the grain boundary network during grain boundary engineering in a nickel based alloy

Grain boundary engineering was carried out on an aging-treated nickel based Alloy 690, which has precipitated carbides at grain boundaries. Electron backscatter diffraction technique was used to investigate the grain boundary networks. Results show that, compared with the solution-annealed samples, the aging-treated samples with pre-existing carbides at grain boundaries need longer duration or higher temperature during annealing after low-strain tensile deformation for forming high proportion of low-Σ coincidence site lattice grain boundaries (more than 75%). The reason is that the primary recrystallization is inhibited or retarded owing to that the pre-existing carbides are barriers to grain boundaries migration. - Highlights: • Study of GBE as function of pre-existing GB carbides, tensile strain and annealing • Recrystallization of GBE is inhibited or retarded by the pre-existing carbides. • Retained carbides after annealing show the original GB positions. • More than 80% of special GBs were formed after the modification of GBE processing. • Multiple twinning during recrystallization is the key process of GBE.
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [2]
  1. Institute of Materials, Shanghai University, Shanghai 200072 (China)
  2. Key Laboratory for Microstructures, Shanghai University, Shanghai 200444 (China)
Publication Date:
OSTI Identifier:
22340361
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 91; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANNEALING; CARBIDES; DEFORMATION; DIFFRACTION; ELECTRONS; ENGINEERING; GRAIN BOUNDARIES; NICKEL BASE ALLOYS; RECRYSTALLIZATION; STRAINS