Aluminium nitride films have been deposited on steel substrates (304L and mild steel), in the: aim of realising anti-corrosion coatings. The adhesion of the films can be notably improved, by the presence of thin AIN(x) underlayer, (unfortunately the galvanic coupling between aluminium and steel leads to a fast degradation of the coatings) or by increasing the substrate temperature. Stress measurements showed that the role of temperature in the improvement of the coatings adhesion can not be explained by a decrease of the stress in the film. Electrochemical tests pointed to the fact that the protection of the 304L stainless-steel and mild-steel substrates by AIN coatings is due to its insulating nature. However, this protection is, to a great extent affected by the open porosity of the films that remains quite high.