ALLOYING OF THE SURFACE LAYERS USING ELECTRON BEAM ON PRECOATED SURFACES
The surface of the sample is being covered in whatever way with a material layer with specified properties. Then, the surface is treated by a pulsed electron beam. As a result of rapid melting, mixing and recrystallization of the surface layer it is formed the compound of the coated and the base materials. Corrosion resistance and wear resistance of the formed alloy is significantly higher than the base material. The thickness of the modified layer can greatly exceed the thickness of the coating.
Due to the high cooling rate of the fused layer, it is possible the formation of compounds that under normal (equilibrium) conditions are not formed, such as Cu / Au, Fe / Si, Mo / Cu, Fe / Pb.
Base on this principle it is being developed technology in order to improve the corrosion resistance of constructional materials in liquid-metal coolants.
The proposed technology is highly efficient, characterized by large thickness of the modified layer, parameters controllability and ease of the units’ construction.
Enhancement of constructional steel corrosion resistance in liquid-metal coolants.
External view of steel EP823 after corrosion tests in a stream of lead at a speed of 1.5 m / s, at a temperature of 6500c, and the oxygen content of C [O] ~ 5x10-5 %.
|The modified sample (3000 hours) and the unmodified sample (1000 hours).|