Investigation of the material combination 20MnCr5 and X45CrSi9-3 in the Tailored Forming of shafts with bearing seats

The Tailored Forming process chain is used to manufacture hybrid components and consists of a joining process or Additive Manufacturing for various materials (e.g. deposition welding), subsequent hot forming, machining and heat treatment. In this way, components can be produced with materials adapted to the load case. For this paper, hybrid shafts are produced by deposition welding of a cladding made of X45CrSi9-3 onto a workpiece made from 20MnCr5. The hybrid shafts are then formed by means of cross-wedge rolling. It is investigated, how the thickness of the cladding and the type of cooling after hot forming (in air or in water) affect the properties of the cladding. The hybrid shafts are formed without layer separation. However, slight core loosening occurres in the area of the bearing seat due to the Mannesmann effect. The microhardness of the cladding is only slightly effected by the cooling strategy, while the microhardness of the base material is significantly higher in water cooled shafts. The microstructure of the cladding after both cooling strategies consists mainly of martensite. In the base material, air cooling results in a mainly ferritic microstructure with grains of ferrite-pearlite. Quenching in water results in a microstructure containing mainly martensite.