Acid Failure of Mild Steel in 2 M Sulphuric Acid in the Presence of Vernonia amygdalina

The degradation of mild steel in 2 M sulphuric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Mild steel coupons of dimension 4 cm by 1.5 cm were immersed in test solutions of uninhibited acid and also those containing extract concentrations of 60,100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the reaction were recorded and examined. The results showed that while extract concentration was increasing, H2 evolution and % I.E increased, with a reduction in corrosion rate. The reduction in corrosion rate was observed to follow in order of increasing extract concentration. Also, phytoconstituent-metal interaction mechanism was best explained by Freundlich isotherm, with the 4 minutes curve becoming the best contact time for the extract phytochemicals to properly adsorb to metal surface across all concentrations used. Furthermore, an expression suitable for estimating corrosion rate values once concentration is known was also obtained. The microstructural studies however, revealed that increasing the extract concentration led to considerable reduction in the dominant coarsening of the oxide of iron phase, while the pearlite and ferrite phases were highly dispersed

Environment Induced Failure of Mild Steel in 2 M Sulphuric Acid Using Chromolaena odorata

Failure investigation of mild steel sample in 2 M sulphuric acid solution in the presence of Chromolaena odorata extract was conducted using the gasometric method. Mild steel coupons, each measuring 4 cm by 1.5 cm were completely immersed in test solutions of free acid and also those containing extract quantities of 60, 100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the experiment were recorded and analyzed. The result showed that maximum inhibitor efficiency which has a relationship with lowest corrosion rate was obtained at the highest inhibitor concentration of 140 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volume. Temkin isotherm best described the metal surface interaction adsorption mechanism. Once concentration of the acid is known, an expression for estimating corrosion rate values in the presence of the extract was obtained. Also, the photomicrograph study showed a direct relationship between the extract quantity and the extent of corrosion. Sample immersed in the 140 cm3 extract quantity showed no trace of the third phase but rather the presence of a finely distributed pearlite phase indicating that increased inhibitor concentration led to a reduction in the deterioration of the metal

Assessing the deterioration behaviour of mild steel in 2 M sulphuric acid using Bambusa glauscescens

The study investigated the deterioration of mild steel in 2 M sulphuric acid solution in the presence of Bambusa glauscescens extract using gasometric technique. Steel coupons measuring 4 cm by 1.5 cm were immersed in test solutions of uninhibited acid and also those containing extract concentrations of 60,100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the reaction were documented and analyzed. The analysis showed that while extract concentration was increasing, H2 evolution and % I.E increased. There was also a corresponding reduction in corrosion rate as extract concentration increased. The decrease in corrosion rate was observed to follow in order of increasing extract concentration. Phytochemical-metal interaction mechanism was best described by Freundlich isotherm, with the 4 and 12 minutes curve becoming the best and worst contact time for the extract phytochemicals to suitably adsorb to metal surface for all concentrations used. An expression suitable for calculating corrosion rate values once concentration is known was also deduced. Furthermore, the microstructural studies revealed that increasing the extract concentration resulted in significant reduction in the dominant coarsening of the oxide of iron phase, while the pearlite and ferrite phases became finely disperse