An Experimental Study on Corrosion Behavior of En8 and En24 Grade Steels. (2015)

• Record Type: Journal Article
• Authors: I, Aparna devi.; Sudhakar, I.; Ramana, V.S.N. Venkata
• Is Part Of: Materials today. Volume 2:Number 4/5(2015)
• Page Start: 1251
• Page End: 1256
• Publication Date: 2015
• Subjects: Heat treatment -- austenitization -- hardening -- pitting corrosionIntroduction; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2015.07.039
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Corrosion is one of the detrimental phenomena that restricts the service period of components. It can be confined locally to form a pit and leads to intergranular cracks and progresses by anodic loss. Naval applications such as ships, submarines and automobile sectors are always prone to failure because of corrosion. Even though aluminium alloys possess excellent corrosion resistance, their applications are restricted from economical considerations and acceptance of steels cannot be forbidden in the global market. EN8 and EN24 grades of steel are widely used in automobile sector in the form of shafts, studs, bolts, connecting rods, screws and rollers but they possess low corrosion resistance. Above considered steels can be easily heat treated to change the morphology. Most of the investigations on the steels are confined in the domain of enhancing the mechanical properties using heat treatment. But, scanty of open literature is available in the area of enhancing corrosion resistance of above cited steels by adopting heat treatment. The present investigation deals with an objective to implement different heat treatments such as annealing, normalizing and hardening with different quenchants (water and oil) to witness its effect on corrosion behavior of selected EN8 and EN24 grades of steels.Potentiodynamic polarization and electrochemical impedance tests were carried out to compare corrosion behavior of heat treated samples. Normalizing, oil quenching and water quenching exhibit lesser degree of corrosion resistance compared to that of annealed specimen. Annealing is found to be effective because of coarse grain structure obtained which facilitates in dissolution of alloy carbides and cementite which reduces the number of sites available for galvanic coupling and hence increase the corrosion resistance. Among chosen grades of steels, EN24 grade of steel exhibited better corrosion resistance than EN8.