Experimental Investigation of Delta Phase Precipitation in Inconel 625 Superalloy Aged at 550, 625 and 725 °C

Abstract The δ is an important stable phase that replaces the metastable γ'' in the microstructure of Inconel 625 superalloy. The present work aims to investigate the kinetic of δ-phase precipitation in the microstructure of Inconel 625 nickel-based superalloy aged at 550, 625 and 725 °C u...

Full description

Saved in:
Bibliographic Details
Published inMaterials research (São Carlos, São Paulo, Brazil) Vol. 23; no. 1
Main Authors Baldan, Renato, Silva, Antonio Augusto Araujo Pinto da, Tanno, Tiemi Manfio, Costa, Eliara Torres da, Brentegani, João Victor Negri, Couto, Antonio Augusto
Format Journal Article
LanguageEnglish
Portuguese
Published ABM, ABC, ABPol 01.01.2020
Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
Subjects
aging
delta phase
ENGINEERING, CHEMICAL
Inconel 625
MATERIALS SCIENCE, MULTIDISCIPLINARY
METALLURGY & METALLURGICAL ENGINEERING
microstructure
superalloy
Inconel 625
delta phase
microstructure
aging
superalloy
Online AccessGet full text

Cover

More Information
Summary:Abstract The δ is an important stable phase that replaces the metastable γ'' in the microstructure of Inconel 625 superalloy. The present work aims to investigate the kinetic of δ-phase precipitation in the microstructure of Inconel 625 nickel-based superalloy aged at 550, 625 and 725 °C up to 1000 h. Aging temperatures were chosen based on the thermodynamic simulation using JMatPro software which indicated that this phase is stable at temperatures below 905 °C. Microstructure of the heat-treated samples was analyzed via SEM/EDS and microhardness evolution was performed by Vickers microhardness tests. The results have shown that the samples aged at 550 °C (all times), 625 °C (all times) and 725 °C up to 200 h did not presented microstructural evidences of δ precipitation. However, samples aged at 725 °C for 500 and 1000 h clearly presented an acicular δ-phase precipitated mainly at the grain boundaries. It was noted changes in the microhardness at different aging time and temperatures probably due to the presence of γ'' and/or δ phases. The sample aged at 625 °C for 1000 h presented the highest microhardness value (333 ± 10 HV).
ISSN:1516-1439
1980-5373
1980-5373
DOI:10.1590/1980-5373-mr-2019-0546