The Formation of Carbide Coatings at the Microarc Thermodiffusion Tungstenizing of Steel

Abstract

When steel is tungstenized under the conditions of microarc heating, a diffusion layer with a thickness of 200–210 μm and a microhardness of 12.5–13.5 GPa is formed. The base of the layer is a solid solution of tungsten in iron, which contains WC, Fe₂W₂C, and Fe₇W₆ inclusions of various degrees of dispersity, including nanosized inclusions. The diffusion coefficient of tungsten in this case is 36 times higher than that in the case of furnace heating, which is explained by the influence of “electronic wind” on the atoms and ions of the diffusant.