The influences of adiabatic shear evolution on tool failure in high-speed machining of railway steel

Abstract

Adiabatic shear evolution in serrated chip will lead to inevitable impacts on the tool failure with the cutting speed increasing. The high-speed machining experiment of railway steel was carried out by applying the cemented carbide insert. The chip morphology transformation with white layer during adiabatic shear evolution was observed, and its influence on the tool failure mechanism on rake face was further investigated microscopically. The experimental results were concluded that the isolated segment chip formation due to adiabatic shear fracture weakened the wear effects on the rake face under higher cutting speed. The periodical cycle from adiabatic shear banding to fracture which resulted in a thermal–mechanical coupling effect mainly influenced the rake face failure mechanisms.