Impact of sulfate to chloride ratio on titanium aluminide coating's high temperature corrosion performance in settings mimicking waste incineration

Abstract

One major problem with waste incineration is the corrosion of superheater tubes at high temperatures. The presence of sulfate and chloride in this setting poses a severe risk to the boiler's service life. In this work, pack aluminizing was used to prepare titanium aluminide coatings, which was then subjected to five distinct NaCl+Na₂SO₄ salt combination proportions for 168 h at 600 °C. The outcomes demonstrated that in the presence of solid Na₂SO₄ deposits, titanium aluminide coatings displayed remarkably low corrosion rates. Adding 1/6 NaCl significantly accelerated the rate of corrosion. The electrochemical corrosion resulting from eutectization between NaCl and Na₂SO₄ was again considerably amplified when the NaCl level was raised to 1/4.