Effects of Temperature and Sulfate on the Pitting Corrosion of Titanium in High-Temperature Chloride Solutions

Abstract

The effects of temperature (100-230 • C) and sulfate concentration (0-0.5 mol L −1 ) on the pitting corrosion of titanium were studied in de-aerated 1 mol L −1 NaCl solution using cyclic potentiodynamic polarization (CPP) and linear-sweep thermammetry measurements. With increasing temperature, the breakdown potential E b of titanium decreased, while the repassivation potential E rp of titanium remained constant in 1 mol L −1 NaCl solution. The presence of sulfate ions shifted both the E b and E rp to higher values, implying that the pitting of titanium was inhibited. In 1 mol L −1 NaCl solution with 0.5 mol L −1 sulfate addition, titanium did not undergo passivity breakdown at 200 • C, even up to 9 V vs. SHE. X-ray photoelectron spectroscopy results showed that the inhibition effect of sulfate on the pitting could be attributed to the competition for adsorption sites on the oxide surface. A metastable pitting temperature threshold (MPTT) was defined for titanium as a function of sulfate to chloride mole ratio using linear-sweep thermammetry measurements. The MPTT results were consistent with those obtained in CPP measurements. The results confirmed that the MPTT of titanium was elevated by the addition of sulfate ions.

Pitting corrosion on anodized titanium: Effect of halides

“…In this solution, titanium has the lowest anodic current densities, that is, the highest corrosion resistance. As reported in literature, in the presence of chlorides ions, breakdown potential several volts more positive than the free corrosion potential is necessary to initiate corrosion on titanium. Localized corrosion is caused by the migration of the ions across the passive film.…”

Influence of Temperature on Corrosion Behavior of 2A02 Al Alloy in Marine Atmospheric Environments

“…High temperatures hinder the formation of water films [34,36], in which case the electrochemical reaction is unlikely to initiate and progress. At the same time, temperature also influences the rates and mechanisms of electrochemical reactions [37,38,39]. Han and Li [35] observed that the weight gain and maximum pitting depth of LY12 Al in 1 mg/100 cm 2 Cl − increased with rising temperature.…”

Insights into Galvanic Corrosion Behavior of Ti-Cu Dissimilar Joint: Effect of Microstructure and Volta Potential

“…Controlling the localized corrosion of copper in severe environments such as desalination facilities, heat exchangers, plumbing, transformers or bearings in the oil industry, and copper corrosion due to electrolyte formation on electronic components or local chloride accumulation in building materials (or atmospheric corrosion) has attracted a lot of attention [ 5 , 6 , 7 , 8 , 9 ]. Titanium, because of its higher corrosion resistance and better mechanical properties in comparison with copper, has proven to be a good candidate to be joined with copper for better corrosion performance [ 10 ]. The superior corrosion resistance of Ti compared to Cu is related to the chemically unreactive, condensed and adherent oxide films formed on its surface [ 10 , 11 ].…”

“…Titanium, because of its higher corrosion resistance and better mechanical properties in comparison with copper, has proven to be a good candidate to be joined with copper for better corrosion performance [ 10 ]. The superior corrosion resistance of Ti compared to Cu is related to the chemically unreactive, condensed and adherent oxide films formed on its surface [ 10 , 11 ]. In fact, Ti-Cu bimetals, which combine the properties of both Ti and Cu, meet multiple necessities in terms of high thermal strength, good corrosion resistance, and high thermal and electrical conductivities for specific applications [ 12 , 13 , 14 , 15 ].…”