Transformation of chloride contaminated unstable rusts on weathering and plain carbon steels into stable forms by treatment with extract of fruit juice of Indian gooseberry (Amla)

Abstract

Fruit juice of Indian gooseberry (Sanskrit name : Amla) is found to transform unstable rusts formed on plain carbon steel into stable phases and improve its resistance to corrosion. The results indicate that the extract of the fruit has deteriorating effect on corrosion resistance of rust of weathering steel. Electrochemical impedance spectroscopy and cyclic polarization tests are performed to assess the resistance to corrosion. XRD studies have been conducted to identify the rust phases before and after treatment of rust. The untreated rusts generated in salt spray chamber have strong phases of akaganeite and lepidocricite which on treatment with fruit extract of Amla transformed in to stabler phases of magnetite and goethite. The untreated rusts changed from red brown to black colour after its treatment with Indian gooseberry.