The painted steel mesh guardrails are coated using the galvanized electrostatic powder coating process (after rust removal, phosphatization, and passivation, the phosphatized film not only prevents rust but also enhances the adhesion of the powder coating layer. The surface of hot-dip galvanized steel is smooth, and without the necessary pre-coating treatment, the powder coating can easily peel off and fall off. Therefore, the required surface treatment is still indispensable).