Corrosion cracking of a mild steel in orange juice

Stress corrosion cracking (SCC) results from the combined action of three factors: The tensile stresses in the material, a corrosive medium and elevated temperature. In this study, the stress corrosion cracking and microstructural analysis of a mild steel immersed in orange juice medium was investigated using weight loss technique and SEM analysis. The mild steel coupons were heat treated to various austenitic temperatures, cooled in water and immersed in orange juice. The weight losses of the mild steel samples were measured at a two days interval and the corrosion rate was the determined. The results obtained show that SCC relative to mild steel is mainly a function of the acidity of the medium under study, and the corrosion rate increases with increase in exposure time throughout the exposure time. Also, the higher the austenitic temperature the more the resistance to corrosion attack due to higher hardness obtained at higher temperatures. The SEM analysis revealed that the transgranular and intergranular attacks were visibly responsible for the corrosion of this material in this medium. The evolution of hydrogen at low pH of the medium due to the presence of acidic citric acid eliminated the possibility of protective formation on the throughout the exposure period.