Pickling, aka chemical de-scaling is a cleaning process that involves the actual chemical de-scaling of the metal article. Ultimately, this process removes metallic and non-metallic contamination thereby improving the surface of the object.
Hot-forming, heat treating, welding and other high temperature operations can leave a tightly adherent oxide film.
These various oxides, referred to as scale, can be effectively removed through the process of pickling. Pickling is a more desirable option to more abrasive alternatives.
Pickling is often used in preparation for additional processing such as passivation or electropolishing on stainless steel surfaces.
Applying the pickling process to a surface before this additional processing can help to achieve superior results, especially if the surface has been subject to heat treating or welding.