The surface modification of gear steel(40Cr) by high current pulsed electron beam(HCPEB).The surface morphology and properties were characterized with optical microscopy,scanning electron microscopy(SEM) and micro-Vikers hardness testing machine.The results show that the grain refinement of 40Cr steel near the surface and distributes the acicular constituent.The thickness of melted layer attained 2~3 μm.Elevation of hardness in the range of several hundreds micrometers near the treated surface was found for...