What is the difference between alkaline treatment of aluminum parts and degreasing of steel parts?

[China Aluminum Network] Alkali corrosion of aluminum parts is very different from that of steel parts. The first is that aluminum itself is not resistant to alkali. For this reason, it is necessary to perform degreasing in a solution of a weakly basic salt or in an organic solution before alkali etching. After the oil on the surface of the workpiece is basically removed, it is carried out in a strong alkali. Flash, otherwise the surface of aluminum will be over-etched.

The alkali etching of aluminum parts is mainly to remove the oxide film on the surface of the article. At the same time when the oxide film is removed, the oil contamination is also brought together, but the alkali etching time needs to be completed within several seconds to several tens of seconds. The degreasing of the steel parts is the direct effect of the degreasing solution on the surface of the steel parts, but it does not react with the oxide layer on the surface of the steel parts, ie, the degreasing solution does not corrode the steel parts and can be soaked in the lye Always check.