Metallic materials are still the most widely used group of materials particularly in both mechanical engineering and the transportation industry. However the usefulness of metals and alloys is constrained by one common problem known as corrosion (Buchweishaija, 2009). Corrosion is the destructive attack of a metal by chemical or electrochemical reaction with the environment (Uhlig et al., 2008). The basic cause of the corrosion of the metals is their tendency to return to their stable state. Nearly all metals are inherently unstable and it is their natural tendency to seek self-destruction by reacting with their environment to attain a state of lower energy by forming a metal compound. This is the state in which the majority of metals are found in nature (Haward, 1968). The use of inhibitors is one of the best methods of preventing metals against corrosion. Most of the corrosion inhibitors are synthetic chemicals, expensive and very hazardous to environments. Therefore, it is desirable to source for environmentally safe inhibitors. Plants represent a class of interesting source of compounds currently being exported for use in metal corrosion protection in most systems. The use of phytochemicals as corrosion inhibitors can be traced back to 1960s when tannins and their derivatives were used to protect corrosion of steel, iron and other tools (Ashassi-Sorkhabi et al., 2006).
Up till now extracts of plants leaves such as Hibiscus Subdariffa which was used by El-Hosary in 1972 (Al-Malki, 2007), Papaia (Zucchi et al., 1985), Eucalyptus which was used by Pravinar in 1993 (Buchweishaija, 2009), EmbilicaUflicianalis (Sanghvi et al., 1997), RosmarinusOfficinalis L. (Kliskic et al., 2000), LawsoniaIntermis (Al-Sehaibani et al.,2010), Tobacco (Davis et al., 2001), Opuntia (El-Etre et al., 2003), Mytruscommunis (Al-Sultan,2005), Artemisia (Bouklah et al., 2006), Eclipta alba (Shyamala et al., 2009), Fenugreek (Ehteram, 2008), Vernonia Amygdaline (Odiongenyi et al., 2009), Phaseolusaureus (Rajalakshimi et al., 2008), Piper guinensis (Ebenso et al., 2008), Combretumbracteosum (Okafor et al., 2009), CyamopsisTetragonaloba (Subhashini et al., 2010), Murrayakoenigii (Sharmila et al., 2010), Annona squamosal (Lebrini et al., 2010), Black Pepper (Dahmani et al., 2010), Moringaoleifera (Singh et al., 2010), AzadirachtaIndica (Okafor et al., 2010), Jatrophacurcas (Kumar et al., 2010), Citrulluscolocynthis (Chauhan et al., 2010), PalicoureaGuianensis (Lebrini et al., 2011), green tea (Loto, 2011), Pterocarpussoyauxi (Iloamaeke et al., 2012) (5, 6, 1) have been studied for corrosion inhibition of metals in acid and neutral medias. The present study aimed at investigating the inhibitive properties of ethanol extract of Sesbaniasesban plant leaves on the corrosion of carbon steel in 1M HCl solution.
For full text: click here
(Author: Hussein H. Al-Sahlanee, Abdul-Wahab A. Sultan, Mustafa M. Al-Faize