Wei Lianqi

Preparation and Properties of Anti-oxidation Inorganic Nano-coating for Low Carbon Steel at an Elevated Temperature

A new kind of anti-oxidation inorganic nano-coating for the common low carbon steel was prepared. It included magnesite mineral, metallurgic dust and silicate adhesive as the main raw materials. The nano-coating could be sprayed directly onto the low carbon steel slab even though with hot surface as far as under 1000°C. And at the same time, a compact thin nano-film was formed, and the film would inhibit the oxygen into the interface of the steel body and decrease the loss of weight because of oxidation. The loss was decreased by about 60% or more. The properties and mechanism of oxidation resistance of the coating were discussed through XRD, TG-DTA and SEM. The experimental results show that many reactions woulld happen among the components of the coating and then many microspheres with the size of 80–100 nm generated in the system. By using the heat of the steel body, the silicate adhesive would interact with the microspheres, and the other components of the coating would be soft and sintered so that when the coating was sprayed onto the surface of the steel slab, the intact and compact film could be formed and adhesive with the steel body. Besides the special properties of anti-oxidation, the coating could prevent the volatilization of microelement in the steel such as silicate and carbon at a high temperature. So it can improve the quality and output of steel with this new kind of nano-coating.