The above-mentioned surface treatments were simultaneously subjected to a 100-hour salt spray test. The test comparison results showed that electrophoresis had the strongest corrosion resistance, followed by electroplating oxidation. Oxidation had the most serious acid regurgitation problem, followed by electrophoresis and electroplating.

If the casting is only for aesthetics and corrosion protection, the surface treatment methods with the best cost and effect are electrophoresis and spraying. For electrophoresis and spraying processes, the use of sandblasting pretreatment process can avoid acid regurgitation.

If the casting has mechanical performance requirements, hard oxidation or chrome plating can be used to achieve high hardness and high wear resistance.