Non-vacuum electron-beam surfacing of coatings with the ultrafine structure

Abstract

The paper employs an ELV-6 accelerator to surface low-carbon steel with a tungsten carbide powder thus obtaining steel coatings with high hardness but low wear resistance. The abrasive wear resistance is considerably increased by changing the composition of the surfacing mixture due to the introduction of nickel as an austenite stabilizer and titanium carbide as a modifier. Besides, the paper deals with surfacing with a powder mixture of chromium carbide, chromium, and titanium carbide to produce bifunctional coatings with both high wear and corrosion resistance, which is explained by the presence of chromium in the layer. The methods of physical metallurgy are used to study mechanisms responsible for property changes. A substantial increase in wear resistance is shown to be related to the ductile austenitic structure formed in the deposited layer matrix when nickel is introduced and to rapid structure refinement in the presence of multiple centers of crystallization represented by dispersed precipitates of TiC.