Electrochemical Impedance Spectroscopy Research Of Waterborne Silicate Anticorrosion Coatings For Ships

Corrosion does much harm to service performance and service life of ships.It will reduce the strength of the ship's structure and will make the equipment can't work normally.When the corrosion is the serious,the ship will be out of control in the ocean,and then the disaster will happen.Although the corrosion of ships in the ocean is inevitable,the corrosion rate of ships can be controlled.At present,the most effective anticorrosive method for the protection of ships is the use of anticorrosive coatings.In recent years,the research of anticorrosive coatings tends to the direction of environmental protection and waterborne inorganic anticorrosive coatings with excellent environmental characteristics become the current research focus.Aiming at the disadvantage of the existing waterborne inorganic anticorrosive coatings,the new waterborne inorganic anticorrosive coatings were designed and prepared,namely that Selecting 400 mesh spherical zinc powder or 500 mesh spherical zinc powder collocated with E777-2 to prepare waterborne silicate zinc-rich antirust paint and Selecting glass flake or micaceous iron collocated with E777-2 to prepare waterborne silicate anticorrosive paint.The performances of coatings were characterized by coating-thickness gauge,CLSM,measuring instrument of contact angle measuring,instrument of pencil hardness,adhesion tester,measuring instrument of impact strength and electrochemical workstation.The results showed that:the film forming effect of antirust paint became worse with the increase of film thickness;two kinds of antirust paint could be wetted by water;when the film thickness was the same,the particle size of zinc powder had no effect on the hydrophilicity and hydrophobicity of antirust coatings;when the particle size of zinc powder was constant,hydrophilicity and corrosion resistance of antirust coatings increased with the increase of film thickness;when the film thickness was constant,the smaller the particle size of zinc powder became,the better anticorrosion performance of antirust coatings would be;the adhesion of anticorrosive coatings of which impact strength was 50kg cm was 1 grade;pencil hardness of glass flake anticorrosive coatings could reach up to 3H but pencil hardness of micaceous iron anticorrosive coatings could reach up to 4H;the anticorrosion performance of anticorrosive paint was enhanced with the increase of flake anticorrosive pigment in the coating;the corrosion resistance of composite coatings decreased with the increase of contact time with the corrosion medium;the anticorrosion performance of composite coatings was enhanced with the increase of flake anticorrosive pigment in the coating;the corrosion resistance of glass flake composite coatings was higher than that of micaceous iron composite coatings;the composite coatings exposed in the ambient had the best anticorrosion effect and the anticorrosive ability of composite coatings after deionized water short-time permeation was higher than that of composite coatings after seawater short-time permeation;the anticorrosive effect of glass flake composite coatings immersed in seawater was better than that of glass flake composite coatings immersed in 3.5%NaCl solution but the anticorrosive effect of micaceous iron composite coatings immersed in seawater was less than that of micaceous iron composite coatings immersed in 3.5%NaCl solution.