Banca de QUALIFICAÇÃO: EMANOELA PEREIRA DE MATTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : EMANOELA PEREIRA DE MATTOS
DATA : 22/12/2016
HORA: 08:30
LOCAL: Sala de Aula PPGCEM
TÍTULO:

High Temperature Brazing of the lean duplex stainless steels UNS S32101 e UNS S2304 and of the duplex UNS S2205 using diferent Ni-base amorphous foils.

PALAVRAS-CHAVES:

 High temperature brazing, Ni-based amorphous foils, Duplex stainless steel, Lean duplex stainless steel, Intermetallics.

PÁGINAS: 50
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Duplex stainless steels have been extensively used, replying different classes of ferritic or austenitic stainless steels in important fields as the chemical, petrochemical and food industries. These steels are characterized by a biphasic microstructure containing approximately equal fractions of ferrite and austenite, with an excellent combination of mechanical properties and corrosion resistance. For the fabrication of components with a complex geometry with this kind of steels, solid state diffusion welding or high temperature brazing are advantageous as compared to other conventional fusion metal joining methods. In this context this work reports results of preliminary brazing tests, with the purpose to qualify the brazing process for the investigated stainless steels:  lean duplex UNS S32101 and UNS S32304 and duplex UNS S32205. As brazing alloys were used Ni-based amorphous foils with different amounts of alloying elements Cr, Fe and specially of the metalloids Si, B, P e C. The brazing was performed under high vacuum (10^-4 mbar) at temperatures of 1020, 1100 and 1160°C for 30’ and 1 hour.The characterization of the brazed joints in relation to the microstructural integrity of the steels, the occurrence of intermetallic phases in the fusion zone and in the transition base metal / brazing alloy was executed by optical and scanning electronic microscopy, energy-dispersive X-ray spectroscopy, X-rays diffraction and Vickers microhardness. On base of the obtained results it was possible to indicate the more adequate brazing alloy for the investigated classes of duplex steels, as well as the better choice of process parameters.

MEMBROS DA BANCA:
Presidente - 2156996 - AUGUSTO JOSE DE ALMEIDA BUSCHINELLI
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo à Instituição - WANDERSON SANTANA DA SILVA - UFSC