It's immanent to steel processing to introduce impurities into surface of detail. Grease, residuals of grinding and polishing compositions, oxidation, inclusions of pure iron or other metals efficiently prevent natural built-up of protecting passivation layer what opens door to corrosion. Mechanical cleaning is usually unsuccessful and in case of complex shapes is difficult or expensive or risky due to possible damage of detail. In practice, electrochemical etching was proven to be the most efficient and cost effective way of cleaning surface of steel details from corrosion promoting impurities. Moreover, electrochemical etching improves the look of the surface, smoothes sharp edges, removes colour stains from welds or cuts and appropriately prepares the surface for next steps of the processing chain like passivation or electropolishing.
In practice, it turns out that chemical or electrochemical etching is the most effective and economically justified process of cleaning surfaces from the remains of corrosion promoting contaminants. In addition, etching improves the appearance of the surface: it smoothes scratches and sharp edges, removes discoloration in places of welding, cutting or welding, ensures the proper degree of surface preparation for more advanced final product processing processes, such as passivation or electropolishing.