Galvanization is the process of applying a protective zinc coating on iron or steel to prevent it from rusting.
Electrolysis:
Electrolysis is the process in which ionic compounds are decomposed into their elemental form by passing a direct current through the solution of salts of ions to be obtained.
Now, as the galvanized steel also have zinc on it so during electrolysis it can also be obtained as a product and can create unwanted products.
Hence, galvanized steel cannot be used in electrolysis.