JOSE ANTONIO BATISTA DE SOUZA
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Artigo IPEN-doc 22350 Susceptibility of M5sup(TM) (ZrNbO) alloy to pitting corrosion at different temperatures2014 - CORREA, OLANDIR V.; OLIVEIRA, MARA C.L. de; PESSINE, ELISABETE J.; SOUZA, JOSE A.B. de; ANTUNES, RENATO A.Corrosion of fuel cladding is a major concern in the nuclear industry. Zirconium alloys are the standard materials for nuclear fuel tubing due to its notable low neutron absorption crosssection. The M5sup(TM) alloy is currently employed for the production of nuclear fuel cladding in Brazil. Pitting corrosion has been associated with the intergranular stress corrosion cracking of these materials. In this regard, the study of pitting corrosion behavior of M5sup(TM) alloy is of great technological interest in order to allow the development of safer nuclear fuel claddings. The aim of this work was to evaluate the pitting corrosion behavior of M5sup(TM) alloy at different temperatures. Electrochemical measurements comprised potentiodynamic polarization and electrochemical impedance spectroscopy analyses. The tests were conducted in 5.0 wt.% NaCl solution at room temperature, 40 ºC and 60 ºC. The corrosion resistance was shown to be dependent on the testing temperature. The M5sup(TM) alloy showed good corrosion resistance with only a slight decay as the temperature increased.Artigo IPEN-doc 22346 Influence of aging time on the corrosion behavior of 6061 Al alloy in alkaline solution2014 - CORREA, OLANDIR V.; SOUZA, JOSE A.B. de; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.Al alloys of the 6XXX series (Al-Mg-Si) are employed as structural materials in a variety of industrial applications due to a combination of high mechanical strength and good corrosion resistance. The final mechanical properties are achieved after specific precipitation hardening heat treatments. The aging time during precipitation hardening is known to affect these properties and can also influence the corrosion resistance of the alloy. The susceptibility of Al alloys to corrosion in alkaline media is well-known. In this work the effect of aging time on the corrosion behavior of 6061 Al alloy was evaluated in NaOH and NaCl solutions. The material was aged at 200 ºC for times ranging from 1 to 36 h. The corrosion behavior of the aged alloy was studied using potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that the corrosion resistance was progressively lower for increasing aging times up to 8 h in NaCl and up to 24 h in NaOH. Longer aging times led to a decrease of the corrosion current density.