1. Surface pretreatment: Use acid washing, electrolytic polishing and other methods to remove harmful substances such as surface rust and oxide layer, making the surface clean and smooth.

2. Grinding: Mechanical or manual grinding is used to remove surface burrs, unevenness, and other defects.

3. Polishing: Using mechanical polishing or chemical polishing methods to improve the surface smoothness to a certain level.

4. Sandblasting treatment: Spray abrasive on the surface to remove dirt and defects.

5. Cleaning: Clean with water or solution to remove sandblasting abrasives and polishing agent residues, ensuring a clean and smooth surface.

6. Surface treatment: According to different requirements and applications, the surface is treated with electroplating, anodizing, etc. to improve its corrosion resistance and decorative properties.