Pickling is a cleaning process used to remove rust, mill scale, and oxide layers from steel before galvanizing or further processing. It usually involves immersing the steel in a controlled acid solution that dissolves unwanted surface contaminants.
A clean surface is necessary because zinc does not bond properly to heavy oxides or scale. If cleaning is incomplete, coating defects such as bare spots or poor adhesion may occur. After pickling, the steel is rinsed and prepared for the next stage of production.
Although highly effective, pickling must be carefully managed for safety, waste treatment, and acid concentration control. In industrial operations, proper pickling improves coating quality, process consistency, and final product appearance. It is a key preparation step in many galvanizing plants.