Banca de DEFESA: LUAN MAYK TÔRRES COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : LUAN MAYK TÔRRES COSTA
DATA : 12/03/2019
HORA: 09:00
LOCAL: Sala G2 - Setor de Aulas IV
TÍTULO:

INFLUENCE OF ADDING COATINGS BASED ON PVC AND ALUMINUM IN THE DEPOSITED METAL BY COATED ELECTRODES E-7018

PALAVRAS-CHAVES:

microstructure, molten zone, PVC films, aluminum ink, E-7018

PÁGINAS: 149
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
ESPECIALIDADE: Soldagem
RESUMO:

The shielded metal arc welding (SMAW) presents competitive advantages that this union process as one of most important in industrial scale. However, the humidity absorption is a problem that requires special cares to stock the electrodes, to avoid the mechanical properties degradation. Trying to control the H, PVC films and aluminum ink coatings were applied in E-7018 electrodes to weld ASTM SA36 steel. In this paper was realized a comparative study among different welded samples: E-7018, pure and with coating, and using BRH4-R electrode. The molten zone characterization of these samples is a sequential continuation of the works developed by RAMOS (2015) and SOUZA (2017). Through the optical and scanning electron microscopies, it was observed that the molten zone microstructure, in all samples, is composed by acicular, polygonal and Widmanstatten ferrite, upper bainite, ferrite-carbine aggregates and, in some regions, MA micro-constituent. The EBSD technique, in addition to the others methods, confirmed that the welding using BRH4-R electrode formed coarser grains than the others samples, less amount of acicular ferrite and also AF with lower aspect ratio. Among the E-7018 electrodes, it could be observed the coating was responsible to refine the monten zone microstructure, comparing with the pure condition, to form AF grains in greater quantity and smaller. In all cases, the acicular ferrite aspect ratio variated between 2 and 10. Though the EBSD, it was possible to note the coating provided higher MA microconstituent formation and this condition could reduce the steel toughness. The BRH4-R presented the lowest formation of MA.

MEMBROS DA BANCA:
Externo à Instituição - ALEXANDRE QUEIROZ BRACARENSE - UFMG
Presidente - 2156996 - AUGUSTO JOSE DE ALMEIDA BUSCHINELLI
Externo ao Programa - 1938946 - NICOLAU APOENA CASTRO
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO