Control of deformation and annealing process to produce incoherent Σ3 boundaries in Hastelloy C-276 alloy. (June 2021)

• Record Type: Journal Article
• Authors: Zhang, Xiao-yu; Zhong, Jun; Guo, Sheng-li; Zhao, Jun
• Is Part Of: Nuclear materials and energy. Volume 27(2021)
• Publication Date: 2021-06
• Subjects: Hastelloy C-276 -- Annealing treatment -- Incoherent Σ3 grain boundary -- Grain boundary character distribution -- EBSD; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2021.100944
• Languages: English
• ISSNs: 2352-1791

Abstract

Graphical abstract: Highlights: Low and moderate strain treatments were used for optimizing the GBCD in C-276 alloy. Convoluted Σ3 (incoherent Σ3) boundaries were observed in different annealing time. Evolution of coherent & incoherent Σ3 boundaries was studied in annealing treatment. Through activating SIBM without the SRX, the GBCD of C-276 alloy could be optimized. Control of deformation and annealing may produce more incoherent Σ3 boundaries. Abstract: Hastelloy C-276 samples were cold-rolled with their thickness reduction of 7.5% and 15%, and then annealed at 1100 °C for 5–60 min in solid solution. The grain boundary character distributions (GBCDs) were characterized by a technique of electron back scatter diffraction (EBSD). Results indicated that, more convoluted Σ3 boundaries (i.e. incoherent Ʃ3 boundaries) are generated by reasonable annealing time in low strain (7.5%) sample during strain-induced boundary migration (SIBM) processing. They can induce higher Ʃ3 n fraction and activate more interactions between special boundaries for GBE. Instead, more coherent Ʃ3 boundaries were produced by moderate strain (15%) and annealing treatment with the occurrence of static recrystallization (SRX). The recrystallized fine grains possess fewer incoherent Ʃ3 boundaries cannot promote to get more multiple twinning for optimization of GBCD. Therefore, reasonable deformation and annealing treatment parameters lead to more incoherent Ʃ3 boundaries would play an important role in the optimization of GBE.