Engenharia de Materiais
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/17
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Resultados da Pesquisa
- Electrochemical characterization of 13Cr low-carbon martensitic stainless steel - Corrosion study with a mini-cell setup(2022-10-27) CALDERON- HERNANDEZ, J. W.; GONZALEZ-RAMIREZ, M. F.; SEPULVEDA-CASTANO, J. M.; SANTOS-MARTINEZ, J. D.; QUISPE-AVILES, J. M.; Rodrigo Magnabosco; Goldenstein H.© 2022 The Authors.13Cr low-carbon martensitic stainless steels also known as supermartensitic stainless steels (SMSS) have superior properties than conventional martensitic stainless steels. The SMSS have better weldability and corrosion resistance. Nevertheless, corrosion resistance depends on phases transformations which are induced generally by heat treatments. In this work, the electrochemical properties of a SMSS were evaluated as a function of the tempering temperature (400 °C-700 °C). The susceptibility to intergranular corrosion was determined throught the degree of sensitization (DOS) using the Double Loop - Electrochemical Potentiokinetic Reactivation technique (DL-EPR) in a conventional three electrodes corrosion cell. On the other hand, the pitting susceptibility was evaluated by potentiodynamic polarization using a homemade corrosion mini-cell (based on a sessile electrolyte droplet), thus avoiding crevice problems typically seen with conventional arrangements. Imaging the microstructure with SEM, XRD analysis and thermodynamic and kinetic simulations were performed to understand the microstructural transformations and their relationship with corrosion resistance. The most severe sensitization occurs at the temperature where reversed austenite transformation is highest.
- Intermetallic phases formation during short aging between 850 °c and 950 °c of a superduplex stainless steel(2012) Magnabosco R.; Dos Santos D.C.This paper is based on the study of intermetallic phase formation during aging between 850 C and 950 C, for periods up to 5 min; those treatments were conducted in liquid aluminum bath, allowing fast heating of the small sized specimens. It was found that backscattered electron images could be used in the automatized routines of quantitative stereology of intermetallic phases and nitrides found in duplex and superduplex stainless steels. A measurable intermetallic phase fraction was observed just after 1 min aging in the studied temperatures, but it was not possible to distinguish sigma and chi phases from the observed intermetallic phases. Nitrides were also observed, but they were probably formed in steel manufacturing, since there was no significant influence of aging on its volume fraction. © 2012 Elsevier Editora Ltda. and Brazilian Metallurgical, Materials and Mining Association.