Sodium salt of dodecyl benzene sulphonic acid as an effective corrosion inhibition for different heat-treated steel in sulphuric acid medium

The purpose of this work is to use electrochemical and gravimetric techniques to investigate the inhibition of DBSS on the corrosion of heat-treated dual-phase AISI 1040 steel in a 0.5 M sulphuric acid solution at 35 °C. The corrosion studies are performed by potentiodynamic polarization study (PDP), electrochemical impedance study (EIS), and gravimetric method. To confirm the inhibition surface characterization like x-ray diffraction technique (XRD) analysis, scanning electron microscopy (SEM), and EDS analysis are performed. Depending on the phase change of metals due to heat treatment, the corrosion inhibition of the heat-treated metal increased when it was exposed to 0.5 M H₂SO₄ at 35 °C in the presence of dodecyl benzene sulphonic acid sodium salt (DBSS) inhibitor. The highest inhibition efficiency of 63%, 82%, 87%, 43%, and 63% was obtained for AISI 1040 steel at heat treatment conditions of Normalized, Quenched at 700 °C, Quenched at 750 °C, Quenched at 790 °C and Quenched at 900 °C respectively. In the gravimetric and electrochemical study, the IE increases with the increase with the concentration of DBSS unto 75% from gravimetric analysis and 87% from PDP analysis for Quenched at 750 °C and 790 °C respectively. The metal protection is achieved by heat treatment process as well as by using DBSS as inhibitor. Corrosion inhibition on the metal’s surface was confirmed by SEM and XRD. In addition, the adsorption of DBSS on the anodic and cathodic sites of the metal surface was well explained.