Corrosion behavior of 650 MPa high strength low alloy steel in industrial polluted environment containing different concentration of Cl-

This study investigates the mechanism by which chloride ions (Cl-) influence the corrosion behavior of 650 MPa high-strength low-alloy (HSLA) steel in industrially polluted environments, utilizing wet/dry cyclic corrosion testing combined with Corrosion Big Data Technology. The research reveals that the corrosion process of 650 MPa HSLA steel occurs in two distinct stages: an initial corrosion stage and a stable corrosion stage. During the initial phase, the weight loss rate increases rapidly due to the instability of the rust layer. Notably, the study demonstrates that 650 MPa HSLA steel exhibits superior corrosion resistance in Cl-containing environments. Over time, the formation of a corrosion product film reduces the weight loss rate. However, the intrusion of chloride ions at increasing concentrations gradually destabilizes the α/γ* phases of the rust layer, leading to a looser structure and a lower polarization resistance (Rp). The application of Corrosion Big Data Technology in this study provides robust validation and analysis of the experimental results, offering new insights into the corrosion mechanisms of HSLA steel in chloride-rich environments.