1) Chemical method:
Use pickling paste or spray to assist the re-passivation of the rusted part to form a chromium oxide film to restore the corrosion resistance. After pickling, to remove all contaminants and acid residues, it is very important to rinse properly with clean water. After all treatment, re-polish with polishing equipment, and seal with polishing wax. For local slight rust spots, you can also use a 1:1 mixture of gasoline and engine oil to wipe off the rust spots with a clean rag.
2) Mechanical method:
Sandblast cleaning, blast cleaning with glass or ceramic particles, annihilation, brushing, and polishing. All kinds of contamination, especially foreign iron particles, can be a source of corrosion, especially in humid environments. Therefore, mechanically cleaned surfaces should preferably be properly cleaned in dry conditions. The use of mechanical methods can only clean the surface, and cannot change the corrosion resistance of the material itself. Therefore, it is recommended to re-polish with polishing equipment after mechanical cleaning and seal with polishing wax.