In order to provide a method by means of which the surface of substrates can be protected from corrosive attack and which, in particular, avoids the necessity for oxidative treatment to form oxide layers on surfaces or for phosphatizing or chromatizing treatment steps and is, in addition, simple to apply, it is proposed that the substrate be brought into contact with a solution of a polymer which exhibits UCST properties and which is caused to be deposited onto the surface of the substrate as a layer by decreasing the temperature of the polymer solution.