Electropolishing removes microscopic surface protrusions through anodic dissolution and forms a chromium-rich passive film, significantly improving corrosion resistance and cleanliness.

Applications: hygienic-grade scenarios such as food, pharmaceutical, semiconductor, and medical devices; also used for decorative mirror finishes.

Process key points: - The electrolyte is mostly a phosphoric acid-sulfuric acid system, and temperature and current density must be matched. - Mechanical pretreatment is required before polishing; otherwise, deep scratches cannot be eliminated. - Thorough cleaning is required after polishing to prevent residual liquid from causing pitting.

Common issues: over-polishing leading to dimensional changes, surface fogging, and preferential corrosion at weld seams.