EFFECTS OF VARYING INHIBITORS OF CARICA PAPAYA (PAWPAW), AZADIRACHTA INDICA (DOGOYARO), AND SOLANUM LYCOPERSICUM (TOMATO) LEAVES EXTRACT AS INHIBITOR ON THE CORROSION BEHAVIOUR OF (316,2101,2205) STAINLESS STEEL IN 0.5M SULPHURIC ACID

摘要

The electrochemical behavior of austenitic stainless steel 316 Type, Duplex stainless steel 2205 and 2101 Duplex Stainless steel, in 0.5M sulphuric acid withg varying inhibitors concentration were studied. The inhibitors understudy were locally available plants in Nigeria. Tomato leaves Extract (Solanum lycopersicum). Pawpaw leaves Extract (Carica papaya) and Dogoyaro leaves Extract (Azhadirachta Indica) of 0.1wt%, 0.3wt% and 0.5wt% concentrations were prepared, as corrosion inhibitors. The electrochemical behavior at different concentrations of the inhibitors in the acidic media were studied using Potentiodynamic method at room temperature with the aid of Verstat potentiostats. Dogoyaro (Azadirchta indica), Tomato (Solanum lycopersicum) and Pawpaw (Carica papaya) inhibited corrosion for all the steel understudy in 0.5M sulphuric acid. The corrosion rates were observed to decrease with increase in concentration of the Extracts. The most inhibitive extract of the three inhibitors is Dogoyaro (Azadirachta indica) followed by Pawpaw (Carica papya) and Tomato (Solanum lycopersicum) in sulphuric acid. All The extracts were effective and eco-friendly.