Hot Corrosion Behaviour by Electrochemical Techniques of Inconel 718 in Aeronautical Applications

Aeronautical industry needs materials that possess the ability to maintain their properties at high temperatures, that materials are high-temperature materials, superalloys, used on components of turbines. Aeroengines depends of nickel-based superalloys for hottest sections due to the resistance to fatigue and creep in operative conditions. Considering the operative temperatures of aeroengines, hot corrosion must be investigated to determinate the behaviour of the superalloy, in this case Inconel 718 in presence of Na₂SO₄, NaVO₃ and 80V₂O₅-20Na₂SO₄. The results showed that the salts aggressivity increased with temperature, leading the material to corrosion. 80V₂O₅-20Na₂SO₄ was most aggressive salt. Na₂SO₄ and NaVO₃ increase corrosion rate while temperature increases. The electrochemical results coincide with SEM analysis.