Degradation of a low alloy steel in sulfurous environment and high temperatures

Abstract

The present article analyzed the causes of premature failure in tube of a furnace located in the unit primary distillation. This constructive element was exposed to high temperatures and to the sulfurous fraction contained in the hydrocarbon that flowed for this inside. Results obtained using the technique of Fourier transform infrared spectroscopy and atomic absorption spectrometry of deposits found in the tube in the failure zone, showed the presence of compounds of sulphur, oxides and a high content of the elements iron and chromium, both constituents of the steel, identified by emission digital multichannel spectrometry as an alloy low steel. The metallographic study demonstrated the transformation and degradation of the steel microstructure because of the high temperatures and the environment. The aforesaid factors evidenced the fast deterioration of the furnace tube steel provoked by a corrosion of sulfidation/oxidation type to highs temperatures.

Keywords: high temperatures, sulphur, corrosion, furnace, oxides.