Process and material development for the production of bainitic steels

  bainitic ferrite IEHK Figure 1: SEM picture of a bainitic micro-structure consisting of bainitic ferrite (dark) and a second phase (bright)

Bainitic steels serve the applications where high strength and high toughness is needed and increasingly substitute micro-alloyed steels.

Their microstructure is composed of slightly carbon enriched bainitic ferrite and a carbon enriched second phase e.g. carbides ( Fig. 1 ). The bainite transformation is rather complicated as it is partially diffusion controlled and the transformation mechanism changes with temperature.

 

In current research projects, various process routines are investigated and the material concepts are optimized for a bainitic microstructure according to the respective application.

Research topics are the control and modeling of the phase transformation in the hot rolling process and the forging of gear components.

The group materials processing deals with the alloy design, the optimization of the cooling strategy, the microstructural characterization, the impact on the mechanical properties and the modeling and understanding of the basic mechanisms and phenomena related to the bainitic transformation.