Evaluation of the Influence of the Combination of pH, Chloride, and Sulfate on the Corrosion Behavior of Pipeline Steel in Soil Using Response Surface Methodology

Abstract

External damage to buried pipelines is mainly caused by corrosive components in soil solution. The reality that numerous agents are present in the corrosive environment simultaneously makes it troublesome to study. To solve that issue, this study aims to determine the influence of the combination of pH, chloride, and sulfate by using a statistical method according to the design of experiment (DOE). Response surface methodology (RSM) using the Box–Behnken design (BBD) was selected and applied to the design matrix for those three factors. The input corrosion current density was evaluated by electrochemical tests under variable conditions given in the design matrix. The output of this method is an equation that calculates the corrosion current density as a function of pH, chloride, and sulfate concentration. The level of influence of each factor on the corrosion current density was investigated and response surface plots, contour plots of each factor were created in this study.

Machine Learning Modeling of Predictive External Corrosion Rates of Spent Nuclear Fuel Canister in Soil

“…6 and it was used with the Tafel method to nd the corrosion current density value of each experiment. All collected data are given in Table 2, experiments 1-13 were run in this study, and experiments 14-43 were collected from our previous studies [10,24].…”

“…Knowing the corrosion rate of metal and the properties of the soil in advance is very helpful for engineers to nd suitable protection methods for the pipeline. However, predicting the corrosion rate in complex environments such as soil is not easy because the soil environment has many factors that affect corrosion rate including the chemical concentration in the soil water, soil moisture, and soil structure [10]. Stefanoni et al have published a very successful study describing an equation that can predict the corrosion rate as a function of porosity in which water lls the voids in the soil [11].…”

“…However, there are not many studies that focus on predicting the corrosion rate of carbon steel canister in the soil environment. Our previous studies have involved predicting the corrosion rate of carbon steel based on the in uence of pH, chloride, and sulfate concentration of soil solution, using a response surface method (RSM) [10] and pH, chloride, temperature of soil solution with different investigated range values using RSM and an arti cial neural network (ANN) [24]. The limitation of our previous studies is that there are only three corrosive factors.…”

Special Issue: Corrosion Properties and Mechanism of Steels

“…The issue of corrosion processes in buried pipelines is covered in two papers prepared by Chung et al [ 1 , 2 ]. A number of specific corrosion tests were carried out to investigate the synthetic soil corrosion of a pre-buried pipeline in [ 1 ].…”

“…This equation can be applied to any corroded pipeline. External damage to buried pipelines caused by corrosive components in soil solution is studied in [ 2 ]. Increased attention is paid to the influence of the combination of pH, chloride and sulfate by using a statistical method according to the design of the experiment.…”