Aluminum chloride is corrosive to stainless steel. Stainless steel is an alloy of iron that includes a minimum of 10.5% chromium. This chromium prevents the iron from rusting and gives stainless steel its corrosion-resistant properties. However, aluminum chloride is a strong acid that can dissolve the chromium oxide layer that protects stainless steel from corrosion. This can lead to the pitting and rusting of stainless steel.

The corrosiveness of aluminum chloride to stainless steel is also influenced by the concentration of the aluminum chloride solution, the temperature of the solution, and the duration of exposure. Higher concentrations of aluminum chloride, higher temperatures, and longer exposure times all increase the risk of corrosion.

To protect stainless steel from corrosion by aluminum chloride, it is important to avoid contact between the two materials. If contact is unavoidable, it is important to minimize the concentration of aluminum chloride, the temperature of the solution, and the duration of exposure. It is also important to rinse stainless steel surfaces with water after exposure to aluminum chloride to remove any residual acid.