Investigation of Descaling Techniques for Naturally Oxidized Iron Based Alloy

Sammanfattning

Abstract: To meet the future demand for sustainable and environmentally friendly “green” chemical cleaning solutions for rust removal from naturally oxidized iron alloys, this study showed how an optimized DES (Deep Eutectic Solvents) can enhance descaling performance. A series of experiments were conducted using different combinations of acetic acid, malonic acid, and choline chloride in aqueous solutions. Bicycle chain components with naturally formed rust layers were used as representative samples. The samples were immersed in chemical solutions for varying durations to evaluate the influence of composition and exposure time on rust removal performance. Surface characterization was performed using optical microscopy, and quantitative analysis was carried out using a Python-based image processing method. Rust-covered areas were identified through HSV (Hue, Saturation, Value) color thresholding, allowing calculation of rust coverage percentage before and after treatment. Descaling efficiency was determined based on the reduction in rust coverage. The results demonstrate that the presence of choline chloride along with malonic acid significantly enhances the oxide dissolution capability of organic acid solutions. This study highlights a greener way to remove rust from iron-based alloys with the potential for environmentally favourable chemical systems and provides a quantitative framework for evaluating descaling performance using image-based analysis.