Carbon steel behavior towards Cucumeropsis mannii shell extract as an ecofriendly green corrosion inhibitor in chloride medium

This study advanced on previous studies by investigating the hardness and tensile strength of carbon steel under different loads after determining the corrosion rate at different temperature, immersion time and corrosion inhibitor concentration in a chloride medium using Cucumeropsis mannii shell extract (CMSE) as an eco-friendly green corrosion inhibitor. The inhibition efficiency was evaluated by weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization techniques. Adsorption behavior and material characterization were investigated. The result revealed maximum inhibition efficiency of 92.2% and 91.2% could be attained by EIS and PDP techniques respectively. The corrosion rate decreases as the inhibitor's concentration increases and vice versa for temperature and immersion time. The Young modulus and hardness of carbon steel decreased at higher load under corrosion attack in the absence of CMSE. The green corrosion inhibitor exhibited a mixed-type with a spontaneous physisorption behavior on carbon steel surface. Material characterization revealed presence of active functional groups in the extract with formation of uniform and pitting corrosion on carbon steel surface. In conclusion, Cucumeropsis mannii shell extract behaved excellently as corrosion inhibitor for carbon steel in chloride solution