Study of machinability of case hardening steel in production environment

The investigation is based on field studies in full scale production and machinability is evaluated in terms of tool wear of cemented carbide inserts. The aim of this study was to investigate how rather small variations in chemical composition between different batches of a case hardening steel affect machinability. Continuous wear is observed to be low for all of the investigated inserts. However, some of the tools show discontinuous wear, like spalling of coating. The discontinuous wear is believed to be caused by unevenness of the forged scale of the machined component and not by variations in the material workpiece bulk properties. Since this wear mechanism may cause a premature tool breakage, it is very important to investigate this finding in more detail. To be able to evaluate the effect of chemical composition on machinability further experiments are necessary, in a more controlled environment with a material having a larger variation in composition