Mechanical Properties and Microstructural Characterization of Aged Nickel-based Alloy 625 Weld Metal

• Tipo: Artigo em Revista Científica Internacional
• Data: 2018-05

Autores

Cleiton Carvalho Silva (Autor) Outra; Victor Hugo C. de Albuquerque (Autor) Outra; Emerson Mendonça Miná (Autor) Outra; Elineudo P. Moura (Autor) Outra; João Manuel R. S. Tavares (Autor) FEUP

Revista

Título: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Vol. 49 Nº 5

Páginas: 1653-1673

ISSN: 1073-5623

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 4 Citações

ISI Web of Science

Scopus - 18 Citações

INSPEC

Classificação Científica

CORDIS: Ciências Tecnológicas

FOS: Ciências da engenharia e tecnologias

Outras Informações

ID Authenticus: P-00N-QCR

DOI: 10.1007/s11661-018-4526-2

Abstract (EN): The aim of this work was to evaluate the different phases formed during solidification and after thermal aging of the as-welded 625 nickel-based alloy, as well as the influence of microstructural changes on the mechanical properties. The experiments addressed aging temperatures of 650 and 950 A degrees C for 10, 100, and 200 hours. The samples were analyzed by electron microscopy, microanalysis, and X-ray diffraction in order to identify the secondary phases. Mechanical tests such as hardness, microhardness, and Charpy-V impact test were performed. Nondestructive ultrasonic inspection was also conducted to correlate the acquired signals with mechanical and microstructural properties. The results show that the alloy under study experienced microstructural changes when aged at 650 A degrees C. The aging was responsible by the dissolution of the Laves phase formed during the solidification and the appearance of gamma aEuro(3) phase within interdendritic region and fine carbides along the solidification grain boundaries. However, when it was aged at 950 A degrees C, the Laves phase was continuously dissolved and the excess Nb caused the precipitation of the delta-phase (Ni3Nb), which was intensified at 10 hours of aging, with subsequent dissolution for longer periods such as 200 hours. Even when subjected to significant microstructural changes, the mechanical properties, especially toughness, were not sensitive to the dissolution and/or precipitation of the secondary phases.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 21