Improving the Corrosion Resistance of Carbon Steel Via Aluminum-Based Coating from Ionic Liquid Electrolytes at Room Temperature

Abstract

Improving the corrosion resistance of carbon steel is of great importance to realize widely use in various industries. The anti-corrosion coating is a significant protective strategy. Therefore, uniform aluminum coatings (AlO_x-CS), electrodepositing in ionic liquid electrolyte at room temperature, was developed to enhance corrosion resistance of carbon steel. The lower part of the electrode has a better distribution uniformity than the upper part of the electrode, and the distribution of a line has the lowest variance. The uniform AlO_x-CS coating is the most corrosion resistant due to sealed Al₂O₃ layers. The corrosion rate of the AlO_x-CS coating is 0.4 mm a⁻¹. The self-corrosion current density of AlO_x-CS coating is 34.4 μA cm⁻², nearly 2 times compared with pristine carbon steel. The impedance value with AlO_x-CS coating is increased by nearly 300 times compared with pristine carbon steel. The morphology and composition of aluminum-based reinforced coatings had no significant changes in atmospheric exposure, 3.5 pct NaCl salt spray and 3.5 pct NaCl immersion environments. The aluminum-based reinforced coatings can enhance the lifespan of carbon steel materials, while also reducing economic losses and safety hazards.