Banca de QUALIFICAÇÃO: CICERO LEONARDO PEREIRA DE SOUZA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : CICERO LEONARDO PEREIRA DE SOUZA
DATA : 24/11/2016
HORA: 14:00
LOCAL: Sala de reuniões DEMAT
TÍTULO:

An investigation of the influence of Al and PVC films on the microstructure of the welded metal deposited by basic coated electrodes E7018

PALAVRAS-CHAVES:

Basic coated electrodes. Microconstituents. Acicular ferrite. Humidity. Diffusible  hydrogen. Coating films. Plastic. Aluminium.

 

PÁGINAS: 72
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
ESPECIALIDADE: Soldagem
RESUMO:

The shield metal arc welding (SMAW) is one of the oldest welding processes and the first one to be used in large industrial scale. During the XX century the SMAW was the most applied process for metal joining, remaining until nowadays as one of the most used in the Brazilian market.

In this kind of welding one of the biggest problems is to avoid the hydrogen induced cold cracking, what imposes rigid requirements in the storing of the  weld consumables. In order to avoid the humidity absorption, the consumables must be dried out in special ovens at temperatures in the order of 450 C, what implies in additional and higher manufacturing costs.

In this context a recent research suggested modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, The welds were developed with basic coated electrodes (hygroscopic)  externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films. The induced metallurgical changes in the deposited metal, associated with  the  addition of new materials to the electrode coating, were investigated, wereby the microconstituents in the fusion zone were quantified using a software for image analysis.  

In the actual work, with the use of a field emission microscope, MEV-FEG, high contrast images could be obtained, what allowed a detailed characterization  of the various microconstituents and a more precise description of their morphology. In special it was possible to evaluate the influence of the protective films in the grain size and aspect ratio of the microconstituent AF (acicular ferrite).  On base of a literature review a critical analysis is presented, that embraces  the effect of the  more relevant parameters on the final microstructure and resulting mechanical properties.

MEMBROS DA BANCA:
Presidente - 2156996 - AUGUSTO JOSE DE ALMEIDA BUSCHINELLI
Interno - 1652765 - MAURÍCIO MHIRDAUI PERES
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO