The metal will rust three days after sandblasting.

Chemical corrosion, also known as "dry corrosion", refers to the corrosion caused by the chemical reaction between the metal surface and the medium.

Attention shall be paid to sand blasting:

The best is within 1 hour. The sooner the better. After sandblasting, there is no oxide skin on the surface. The carbon steel with rough surface will be oxidized after being placed for a long time. Grinding and derusting: use a grinder to install soft steel wire ring for polishing and derusting. Disadvantages: large dust, trouble to clean, trouble to connect, and need to brush primer or passivate immediately after use.

Sand blasting is suitable only if it requires a large amount of dust, and it is not recommended to use it because of its cumbersome use. Generally, the effect of rust remover on the market is good, but the disadvantage is that it will rust quickly after use, which may take a few minutes, maybe dozens of minutes, which is of little significance, unless rust prevention treatment, passivation fluid, water-based rust inhibitor, etc. are immediately carried out after rust removal.

One more step, but it is also a stopgap. My recommendation is to use the rust remover that can remove rust and prevent rust as a whole. It will not rust for half a year to a year, and the adhesion of the surface to the electroplating parts and paint will increase several times.