Effect of triethanolamine borate on corrosion resistance of hot-rolled mild steels in industrial laminar cooling processes

The high chloride ion concentration in laminar cooling water used during hot rolling production can cause pitting corrosion on steel surface. This study investigates triethanolamine borate (TEA-B), an eco-friendly and thermally stable organic inhibitor, for the first time as a corrosion control additive in this process. Mild steel samples were immersed in an industrial water environment containing 0.06 wt% sodium chloride content and different TEA-B concentrations (0–5 wt%) for 30 days. Electrochemical tests, surface characterisation, and immersion experiments were conducted to evaluate the inhibition performance and mechanism. The results revealed that the corrosion rate decreased significantly with increasing TEA-B concentration, reaching a maximum inhibition efficiency of 88 % at TEA-B concentration of 5 wt%. XPS and KPFM analyses confirmed that the corrosion inhibition mechanism is associated with the chemical adsorption of BO3 functional groups onto surface Fe atoms, which suppresses chloride ion-induced metal dissolution and the formation of Fe^2 + /Fe³⁺ oxides and Fe³⁺ hydroxides. These findings provide a promising strategy for mitigating chloride ion-induced corrosion in hot-rolled steel during industrial laminar cooling processes.