Depok, July 5th 2023. Corrosion that damages metal structures continues to occur and cause losses. From an economic point of view, many losses are experienced per year due to corrosion. Rini Riastuti, Permanent Professor in the Field of Corrosion, Faculty of Engineering, Universitas Indonesia (FTUI), who was inaugurated by the Rector of the Universitas Indonesia (UI) on Wednesday (05/07/2023) this morning, mentioned the losses suffered due to the corrosion incident. This was conveyed in his inaugural speech which took place at Makara Art Center UI, Depok Campus, West Java.
Corrosion is commonly known as the term rust. Metal corrosion occurs due to a decrease in the quality or destruction of the metal surface in an aggressive environment in the form of liquids, gasses or soil. According to Rini, corrosion causes the visual appearance of objects to deteriorate and the industry experiences plant downtime because it has to replace the corroded equipment. Corrosion also causes a loss of product due to leaks in containers, tanks or piping, as well as a loss of efficiency because the industry has to incur high costs.
In addition to economic losses, metal corrosion can also cause contamination that is detrimental to health. For example, if a can of food packaging is dented, the food inside will be contaminated with the white tin layer in the can that has peeled off. Therefore, it is necessary to make efforts to control and inhibit the corrosion reaction.
Several attempts can be made to control and inhibit the corrosion reaction. First, through the use of safe inhibitors. Inhibitors are chemical substances (organic and inorganic) which are added to the system in small amounts, and form a passive layer on the surface of the metal that will be protected. Usually, inhibitors are in the form of liquids or vapors which are used in water and oil or gas transportation pipes.
“Currently, students of the Department of Metallurgy and Materials FTUI are conducting a lot of research on the use of plants, whether it is the leaves, fruit, or bark, to be used as inhibitors. Examples that have been studied are betel leaves, green tea leaves, white tea leaves, soursop leaves, red spinach leaves, jamblang fruit, secang wood, mangosteen rind, and many more. All of these ingredients contain polyphenolic and anthocyanin substances as high antioxidants which are expected to become environmentally friendly inhibitors,” said Rini.
Efforts to prevent metal corrosion can also be done by coating methods, such as electroplating, galvanization, and organic coating (paint). Coating basically provides a barrier to prevent water and oxygen from coming into direct contact with the iron surface. In addition, metal protection with cathodic protection methods can be an option for large industries. This method can be carried out using a sacrificial anode or impressed current .
Rini assesses that the corrosion process never stops. For this reason, there is a need for socialization related to corrosion, starting from the level of education, the functions of the personnel needed, as well as courses and training on corrosion cases. There are four categories identified by the European Federation of Corrosion (EFC) for personnel dealing with corrosion cases. Category A: Corrosion Scientists and Engineers, namely those involved in the development of techniques and methods regarding the mechanism of corrosion-personnel, such as chemists, metallurgists, physicists, researchers and practitioners. Categories B and C: Corrosion Technologists and Technicians, namely those who collaborate directly with scientists, have an understanding of basic scientific principles and are able to apply them. Finally, category D: Operatives, namely personnel carrying out tasks in the field under the supervision of corrosion engineers .
“In addition, it is very important to practice virtually all risk-based corrosion control. Usually, it is initiated by identifying the main mechanisms of corrosion attack, then making reasonable interventions. This could include changing materials, selecting corrosion inhibitors, or changing component designs or expected physical conditions. The critical stage varies to analyze corrosion, often with a modeling approach,” said Rini concluding her presentation.
