Banca de QUALIFICAÇÃO: EDGLAY DE ALMEIDA ROCHA FILHO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : EDGLAY DE ALMEIDA ROCHA FILHO
DATA : 01/03/2019
HORA: 14:00
LOCAL: Sala 414 do CTEC - UFRN
TÍTULO:
Study of the nitrate layer on external and internal surfaces of metal pipes: a comparative between the plasma nitriding and cathodic cage plasma nitriding
PALAVRAS-CHAVES:
pipe lines, plasma nitriding, corrosion and nitride films
PÁGINAS: 62
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Mecânica
SUBÁREA: Processos de Fabricação
RESUMO:
Plasma nitriding allows obtaining physical modification on the metal surface, such as hardness, wear resistance and corrosion. In metal pipes lines, the great challenge is their action in reducing the pressure on liquids and their contaminants. This sense, the present work proposes to get iron nitride thin films in a tube of carbon steel and another of stainless steel to reduction of corrosion and improvement in mechanical properties. Used as conventional plasma nitriding (PN) and cathodic cage plasma nitriding (CCPN) techniques. In the tests carried out with conventional nitriding, several of the tube diameters (40 mm and 51 mm) were evaluated for the cathode effect in the films production, besides the gas atmosphere present in the treatment. In the CCPN technique, was changed a proportion of gases, temperature, as well as the positioning of the sample in relation to a cathodic, positioned internal or external to the cage. The films were evaluated using X-ray diffraction (XRD), Optical Microscopy (OM) and microhardness analysis. The presence of iron nitride (FexN) and chromium nitride (CrxN) phases in the samples treated with PN and CCPN techniques was verified when a cage was placed outside the tube, however, with the use of the internal cage, the observed sample only the presence of iron nitride (Fe3N). In the tests made with conventional nitriding, we identified an external film to the thicker tube due to the greater confinement of electrons generated by the hollow cathode effect inside the tube that caused a greater erosion of the inner layer. As the tube diameter increased, this effect was reduced resulting in a thicker inner film.
MEMBROS DA BANCA:
Interna - 2614274 - MICHELLE CEQUEIRA FEITOR
Interno - 2550377 - THERCIO HENRIQUE DE CARVALHO COSTA
Externo à Instituição - ANTONIO MARCOS URBANO DE ARAUJO - UFRN
Externo à Instituição - IGOR OLIVEIRA NASCIMENTO - NENHUMA