Analysis of the Anti-corrosion Performance of Dodecyl Benzene Sulfonic Acid Sodium Salt on Various Heat-Treated Dual-Phase EN8 Steel in an Acidic Environment

Abstract

This work focuses on the investigation of the corrosion inhibition of heat-treated EN8 steel in the presence of sodium salt of dodecyl benzene sulfonic acid in 0.5 M H2SO4 using the Gravimetric and Electrochemical methods. Austenitizing is performed at 700, 750, 790, and 900 °C for 2 h followed by quenching in water. When the heat-treated metal is exposed to 0.5 M H2SO4 at the temperature of 30, 40, 50, and 60 °C in the presence of dodecyl benzene sulfonic acid sodium salt inhibitor, the corrosion inhibition increased with different heat treatment conditions depending on the phase change. This work investigates the activation and adsorption isotherm parameters. The adsorption isotherms were used to estimate Gibb's free energy change. The inhibition efficiency increased with inhibitor concentration and decreased with temperatures. Out of all the isotherms examined, the Langmuir adsorption isotherm produced the best-fit results, according to the adsorption study. Corrosion and inhibition on the metal's surface were confirmed by surface characterization.