Abstract
The influence of different parameters (pH and aeration of the solutions, temperature and geometric features) on the electrochemical behavior of commercially pure titanium in sodium chloride solutions at intermediate temperatures was studied, with the aim of contributing to the understanding of the crevice corrosion susceptibility of this metal. The titanium ion that forms in the active dissolution region was determined bo be Ti3+. Electrochemical and gravimetric techniques were used. Pitting of titanium was found only at high anodic overpotentials (~5.3V), but crevice corrosion can occur at the free corrosion potential. The utilization of a two-compartment cell showed that a maximum ratio of cathodic area to anodic area cannot be surpassed in order to model the activation of the metallic surface in the crevice. The development of an ohmic drop through the corrosion products at the entrance of the crevice is proposed as a stabilizing factor in the corrosion process.
Highlights
An Electrochemical Study of the Crevice Corrosion of TitaniumUniversidade Federal do Rio Grande do Sul, Escola de Engenharia, Programa de Pós-graduação em Engenharia Metalúrgica e dos Materiais -PPGEMM, Av
Crevice corrosion is a localized form of corrosion which is very difficult to predict, and which can occur when metallic parts in close contact with non-metallic or other metallic materials are immersed in corrosive solutions, mainly those containing chlorides or other aggressive ions
The results of the present study confirm certain assumptions made in the literature about the crevice corrosion of titanium in chloride solutions
Summary
Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Programa de Pós-graduação em Engenharia Metalúrgica e dos Materiais -PPGEMM, Av. Estudou-se a influência de diferentes fatores na corrosão por fresta em titânio comercialmente puro, em cloreto de sódio, a temperaturas intermediárias. Pites foram encontrados no titânio apenas a altos potenciais (~5,3V) mas a corrosão por fresta pode aparecer ao potencial de corrosão. O desenvolvimento de uma queda ôhmica através dos produtos de corrosão na entrada da fresta é proposto como um fator estabilizador da corrosão. Pitting of titanium was found only at high anodic overpotentials (~5.3V), but crevice corrosion can occur at the free corrosion potential. The utilization of a two-compartment cell showed that a maximum ratio of cathodic area to anodic area cannot be surpassed in order to model the activation of the metallic surface in the crevice. The development of an ohmic drop through the corrosion products at the entrance of the crevice is proposed as a stabilizing factor in the corrosion process
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have