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Indexed by:期刊论文

Date of Publication:2016-02-01

Journal:JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE

Included Journals:SCIE、EI、Scopus

Volume:25

Issue:2

Page Number:545-552

ISSN No.:1059-9495

Key Words:Hastelloy C-276; hot compression; kinetic equation; metadynamic recrystallization; Ni-Cr-Mo-based superalloy

Abstract:The metadynamic recrystallization (MDRX) behavior of a typical Ni-Cr-Mo-based superalloy Hastelloy C-276 was investigated using two-stage isothermal compression tests on a Gleeble thermal-mechanical simulator in the temperature range of 1050-1200 degrees C, the strain rate range of 0.1-5.0 s(-1), the strains of 0.32, 0.45, and 0.6 at the first stage of compression, and the interval times of 0.5-30 s. The results show that the microstructure and the stress-strain relation of the studied superalloy vary during the interruption period due to the occurrence of MDRX. The MDRX softening fraction and recrystallized grain size increase rapidly with the increasing of interval time, deformation temperature, and strain rate. The effect of strain at the first stage of compression on MDRX is less pronounced. The kinetics of MDRX softening was established based on the flow stress curves, and the apparent activation energy of MDRX of Hastelloy C-276 is evaluated as 241 kJ/mol.