Banca de QUALIFICAÇÃO: ALISSON DENIS CARROS NIZES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALISSON DENIS CARROS NIZES
DATE: 02/05/2023
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/mohammad
TITLE:

STUDY OF THE EFFECT OF CARBON PARTITIONING ON THE MECHANICAL AND ELECTROCHEMICAL PROPERTIES OF THE SAE 9254 STEEL

PAGES: 75
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia Física
SPECIALTY: Corrosão
SUMMARY:

In the present work, of effect of a quenching and partitioning cycle on the mechanical and electrochemical properties of the SAE 9254 steel was studied. Initially, the critical phase transformation temperatures were assessed by dilatometry. The samples were treated following four quenching and partitioning routes using quenching interruption temperatures of 200 °C and 250 °C and reheating temperatures of 300 °C and 400 °C. Quantitative assessment of the ferrite and austenite phases was undertaken by X-ray diffractometry. Qualitative analysis was carried out by optical microscopy (OM) and scanning electron microscopy (FEG-SEM) coupled to EDS detector for evaluating the presence of segregations. Mechanical properties were evaluated by Vickers microhardness and nanoindentation tests. Electrochemical properties were assessed by electrochemical impedance spectroscopy and potentiodynamic polarization using a 0.1 M NaCl solution as the electrolyte. X-ray diffraction revealed the presence of retained austenite for the samples subject to all treatment routes with similar contents. Microstructural characterization by OM showed the presence of martensite and retained austenite, with segregation regions. EDS analysis of these regions revealed the presence of manganese, silicon, chromium and carbon. Dilatometric curves showed volumetric expansion during the reheating step, evidencing secondary martensite formation (fresh martensite).  

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 3068039 - MOHAMMAD MASOUMI
Membro Titular - Examinador(a) Externo à Instituição - EDISON MARCELO SERBINO - FSA
Membro Titular - Examinador(a) Externo à Instituição - CARLOS ALBERTO DELLA ROVERE - UFSCAR
Membro Suplente - Examinador(a) Interno ao Programa - 1893637 - ALEJANDRO ANDRES ZUNIGA PAEZ
Membro Suplente - Examinador(a) Interno ao Programa - 1646041 - CARLOS TRIVENO RIOS