| Substituting waterborne paint for traditional solvent paint is one of the development trends in coating industry. Waterborne coating is widely used to protecting metals due to its advantages such as low pollution and low cost, however, its anti-corrosion performance is farther inferior to solvent coating. Machinery components often undergo wear during installing, dismantling and using, which may lead to lifetime reducing. Therefore, it is needful that the protective coating for machinery components should have the performance of both anticorrosion and lubricantion. In this thesis, some research work has been done taking the fastener protection coating as engineering background. The fastener coating with anticorrosion performance and lubricantion was prepared by adding different kinds of pigments into the waterborne epoxy resin. Water transport in the coating and the corrosion electrochemical behavior of the coating/steel systems were investigated using EIS and various physical testing techniques such as SEM and Raman spectroscopy. The kind, the dosage of pigments and the compatibility between the pigment and the waterborne epoxy binder were studied. In this paper, the corrosion electrochemical behavior of various coating system with artificial defect on steel was also analysed using SVET connecting with EIS, which deepened the understanding of the behavior of coating cathodic delamination. The main results are listed as follows:Firstly, water transport behavior in waterborne epoxy coating without pigment was investigated. The result showed that the penetrability-resistance of the waterborne epoxy coating without pigment is not as good as solvent one due to a mass of nano size micro-defect in the waterborne coating. The delamination behavior of the water-borne epoxy coating with an artificial defect on carbon steel was investigated. The result showed that the delamination mechanism of the waterborne epoxy coating is the cathodic delamination, with the exposed steel in the defect as the anode and the delamination front as the cathode.Farther, it was experimented to enhance the film anticorrosive performance by adding PTFE,aluminum flakes and nano Al powder into the matrixes, respectively. The result showed that the stratified structure with PTFE enriched on the surface of the coating can be obtained by control the cure process, which can provid lubricantion. The flaw due to the poor compatibility between PTFE and the waterborne epoxy resin is the main reason resulting in the poor anticorrosion performance.Moreover, the anticorrosive performance of the waterborne epoxy resin modified by lamellar aluminum was investigated. The results showed that protective properties of aluminum flakes modified coating decreased with PVC increasing. The aluminum flakes had feeble cathodic protection effect in high PVC coating, and the corrosion product of aluminum powder repaired holes in short time. However, after enough time, the barrier effect of the lamellar aluminum-rich coating was less notable. The aluminum flakes can not increase the anticorrosion performance of the coating due to the high porosity of the coating.The addition of nano Al powder can enhance the compactness of the waterborne epoxy resin. The best permeability-resistance of the coating was obtained when the pigment concentration is 1%. The corrosion electrochemical behavior of the nano Al composite coating/steel system with artificial defect was investigated and the results showed that nano Al powder can provide cathodic protection effect, which decreased the coating delamination rate.Finally, Nano Al and PTFE composite pigment was experimented to modify the waterborne epoxy resin. The result showed that Nano Al and PTFE particles had synergetic effect, thus the permeability-resistant of the composite coating was increased. Moreover, the coating delamination rate decreased comparing with the waterborne epoxy varnish.
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