Corrosion behaviour of 316L stainless steel in PTA slurry

Abstract

The corrosion behaviour of 316L stainless steel (SS) in acetic–10% formic acid mixture containing Br⁻ and in simulated purified terephthalic acid (PTA) slurry was investigated to understand the corrosion mechanism of 316L SS in the drying process of PTA slurry. The results show that in acetic–10% formic acid mixture containing Br⁻, the corrosion rate of 316L SS increases with the increase in Br⁻ concentration and temperature. In the PTA slurry, the corrosion rate of 316L SS changes in a parabolic form with an increase in the solid/liquid ratio of the slurry. The slurry has the strongest corrosivity when the solid/liquid ratio of the slurry reaches ̃6·25. In a half dry–half wet PTA slurry, when the 316L steel surface remained at a suitable temperature to avoid continuous liquid film on the surface, the corrosion rate of the steel will be greatly reduced.