Effect of hydrogen chloride on the corrosion of an FeCrAlY alloy in simulated coal gasifier atmospheres

An iron chromium aluminium yttrium steel was exposed to a simulated coal gasifier atmosphere containing 1000 ppm and 2200 ppm hydrogen chloride at 450°C. Increasing hydrogen chloride content was found to accelerate reaction rates, and significantly alter the microstructure and composition of the corrosion product. Tentative explanations for these results, involving vapour phase transport of metal chlorides are proposed.