INFLUENCE OF THE BEAM DEFLECTION ON PROPERTIES OF THE ELECTRON BEAM HARDENED LAYER
- 1 Faculty of Mechanical Engineering, Brno University of Technology, the Czech Republic
The usage of the high-energetic source of the electron beam enables a repeated surface quenching of the chosen areas of an engineering part surface. Different techniques of the electron beam deflections allow the creation of hardened layers of different shapes and above all the thicknesses. The deflection was tested at one point, six points, a line and a field on the material 42CrMo4 (1.7225). The effect of the process speed and defocusing of the electron beam was studied. The electron beam surface quenching resulted in a very fine martensitic microstructure with the hardness over 700 HV0.5. The thickness of the hardened layers depends on the type of deflection and depends directly on the process speed. The maximum observed depth was 1.49 mm. The electron beam defocusing affects the width of the hardened track and can cause an extension of the trace up to 40%. The hardness values continuously decrease from the surface to the material volume.