Corrosion characteristics and prediction model of aluminum alloys in saturated Na2SO4 solution

Based on the actual working conditions of waste salt refining and recycling equipment, five common aluminum alloy material models, namely 2024, 3003, 5052, 6061, and 7075, were selected for short-term and long-term corrosion experiments in saturated Na2SO4 solution at temperatures of 70 °C, 80 °C, 90 °C, 100 °C, and 110 °C. The corrosion morphology and products were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy spectrometer (EDS), and other methods. The results showed that 2024 and 7075 were severely corroded, while the other three aluminum alloys were relatively light but also showed damage to local structures. The corrosion products of aluminum alloys are mainly Al2O3 and Al(OH)3, and the corrosion type is mainly localized corrosion. It was found that the accuracy of predicting the corrosion weight loss data of aluminum alloys using empirical formulas, regression analysis, and GM(1,1) model met the requirements, and the specific model used needs to be determined based on the relative error. The predicted corrosion data can be used to obtain the degree of corrosion severity at different times, achieving the effect of risk prediction. •The article studied the corrosion behavior of five common aluminum alloys in a salt solution at different temperatures.•The corrosion type was mainly localized, and the corrosion products were mainly Al2O3 and Al(OH)3.•Corrosion prediction was carried out by using empirical formulas, regression analysis, and GM(1,1) model.