Pulsed Electron Beam Processing of Boride Layer on L6 Steel

Abstract

The concentrated energy sources, such as intense pulsed electron beams (IPEB), to modify the surface properties of machine parts and tools allows flexible regulation of the structural-phase state of materials in a wide range. The current research aims to create a functional layer on the surface of L6 steel by subsequent electron beam processing (EBP) of a diffusion boride layers by the IPEB of a megawatt power level. The EBP of a diffusion layer based on boron and aluminum on L6 steel leads to the transformation of the layer by remelting and crystallization of the upper zone of the diffusion layer up to 220 µm deep. Meanwhile the thickness of the whole diffusion layer is 580-620 µm. The microstructure of the layer has become more compact (pores have disappeared) and the roughness has decreased. The maximum microhardness on the surface of the diffusion layer reaches 870 HV. The hardness distribution is uneven, which indicates alternation of hard and soft components in the layer, and lower hardness on the surface indicates predominantly aluminized zone. Microhardness of the modified layer after EBP has increased to 1400 HV.