Bio-Inhibitor on Corrosion Rate of ASTM A53 Steel in Marine Environment

¹ Department of Ocean Engineering, Faculty of Marine Technology, Institut Teknologi Sepuluh Nopember, Keputih, Sukolilo, 60111 Surabaya, Indonesia
² Department of Environmental Engineering, Faculty of Civil, Environmental and Geo Engineering, Institut Teknologi Sepuluh Nopember, Keputih, Sukolilo, 60111 Surabaya, Indonesia

^* Corresponding author : hermankelautan@gmail.com

Abstract

There are many methods to prevent the corrosion process. One of them is corrosion inhibitors usage. Inhibitor divided into two types, there are organic inhibitor and non-organic inhibitor. Organic inhibitor could be obtained by extracting some materials which exist in nature. In this research, bio-inhibitors were made from rambutan (Nephelium lappaceum) peel, banana (Musa acuminata Colla) peel, mango (Mangifera indica L.) leaves and papaya (Carica papaya)leaves. The determination of corrosion rate used weight loss method. The material of carbon steel ASTM A53 was used in the research. The salinity of artificial seawater was 35 ‰. The results showed that corrosion rate on carbon steel ASTM A53 was 0.2172 mpy at mango leaves and the efficiency of those inhibitor was 44.5%. The corrosion rate carbon steel ASTM A53 was 0.2436 mpy for corrosion rate and 37.8% of inhibitor efficiency when it used papaya leaves as bioinhibitor. Meanwhile, it reached 0.2739 mpy and 0.2812 mpy of corrosion rate for banana peel and rambutan peel, respectively. The efficiency of inhibitor were 30% and 28.2% for banana peel and rambutan peel, respectively. The corrosion rate on carbon steel ASTM A53 without inhibitor was 0.3914 mpy. Based on the microstructure results, all specimens in all variation of treatments showed pitting corrosion and uniform corrosion on specimen. In conclusion, mango leaves, papaya leaves, banana peel and rambutan peel have potentially to be used as bio-inhibitor to decrease the corrosion rate in marine environment.