Temperature Effect on the Austenitic Stainless Steel UNS N08031 Used in the Wet Method Phosphoric Acid Production

Abstract

The influence of temperature (between 20 and 80 degrees C) on the electrochemical behaviour of UNS N08031 (Alloy 31) was evaluated in a contaminated phosphoric acid solution, which simulates the typical concentrations used in the industrial wet process (40 wt.% H3PO4, 2 wt.% H2SO4 and 0.42 wt.% KCl). Alloy 31 electrochemical behaviour was studied by means of polarisation curves and electrochemical impedance spectroscopy. Results demonstrated that temperature decreases the corrosion resistance of Alloy 31.