Preparation and Property of Anti-Corrosion Aluminum Containing Phosphate Coating

Using tetraethyl orthosilicate modified aluminum dihydrogen phosphate as binder, magnesium dichromate as passivator and aluminum powder as filler, the water-borne aluminum containing phosphate coating solution was prepared. Then the anti-corrosion aluminum containing phosphate coating was obtained by spraying the coating solution on 300M high-strength steel. The corrosion resistance in neutral salt spray and the high temperature oxidation resistance of the coating were investigated. The results show that the coating surface was dense and flat. After corrosion in the neutral salt spray for 1 000 h, no corrosion products were formed on the coating surface. After oxidation at 600 ℃ for 100 h, the coating surface remained integrity and the oxidation mass increase per unit area was 8.051 7 g·m-2, which was much lower than that of 300M high-strength steel (23.811 1 g·m-2); the oxidation rate of the coating was also lower than that of the high-strength steel, indicating the excellent high-temperature oxidation resistance of the coating.