Effect of Corrosion of Mild Steel in Tomato and Pepper Environment Using Factorial Experiment Design

Abstract

Investigation on the effect of corrosion of mild steel immersed in tomatoes and pepper fluid has been successfully carried out. The study employed the traditional weight loss method to determine the weight loss in the metals during the exposure period. The experimental corrosion rate of the mild steel were determined from data from the weight loss. The exposure period lasted for 35 days taking 7 days interval to determine the weight loss in the coupons.  pH and microbial test were also examined. pH examination was carried out to measure the hydrogen ion concentration and to define the alkalinity or acidity of the solution. The research employed the design of experiment module of a Minitab software to analyze the corrosion effect of mild steel in tomatoes and pepper environment. The result show that the pH of the tomato was acidic at 4.20 within the first 7 days of exposure but moved to neutrality and finally alkalinity at 9.31 at the end of the experiment, while the pH of the pepper fluctuated between 5.29 and 5.45 which is also shows acidic. Both media moved to alkalinity after 35 days of exposure. The results revealed that the highest corrosion rate was found in mild steel immersed in tomato (0.3078mm/y). It was evident that more bacteria were discovered in the pepper than in the tomato during the exposure period. The experimental modelling used was done on a 95% confidence level and the result explained approximately 73.96% of the variability in the response variable corrosion Rate for mild steel.