Corrosion of austenitic stainless steels and nickel-based alloys in concentrated phosphoric acid at elevated temperatures

The corrosion sensitivity of several austenitic stainless steels (316L, 316Ti, Sanicro28, Sanicro35) and nickel-based alloys (Hastelloy G30 Hastelloy G35) was determined at elevated temperatures in food grade phosphoric acid (FGPA). materials were submerged a harsh environment >85 wt% FGPA ranging from 80 to 160°C. main aim understand the phenomena occurring such define temperature range for which is within acceptable limits these materials. Moreover, role material's chemical composition on resistance experimentally elucidated. by weight loss measurements, scanning electron microscopy energy dispersive X-ray spectroscopy. high concentrations alloying elements selected metals allow them form protective passive surface film, inhibits further oxidation. Depending stability will be resistant up higher temperatures. Alloys with an increased molybdenum content showed general pitting 140°C. copper resulted improved