Analysis of The Chip Formation of Bainitic Steel in Drilling Processes

Continuously cooled bainitic steels have the potential to replace conventional quenched and tempered steels in automotive applications. Whereas the machining performance often decides about the cost effectiveness of a particular part, little general knowledge exists about the machinability of such novel steels. First practical experiences with drilling operations confirm the good machinability of bainitic steels as well as the potential for further optimization. Also from a scientific point of view a better understanding of chip formation in the drilling process is desirable. This includes the variation of forces over the drilling edge and the determination of corresponding shear angles. For generating real chip roots a quick stop device was developed. In addition to conventional metallographic micro sections, a non-destructive method namely computer tomography was used for characterization of chip formation based on chip roots.