Effect of Tool Thermal Characteristics on Hardened Steel Turning Performance

Abstract

The white layer formed in hard cutting is widespread due to the intensive property of hardened steels and it also has important effects on machined surface integrity and service performance. In order to study the issue about the formation of white layer and concluding the relationship between the characteristics of white layer, tool flank temperature and the thermal conductivity, we used SCM415 (carburizing and quenching) as the object to carry out a series of high-speed dry cutting tests and observing the white layer by using optical microscope Axio Scope A1 in this paper. By analyzed these results we found that the temperature of tools is lower when the thermal conductivity of tool is higher and the greater the thermal conductivity of tool is, the more obvious the influence of the temperature change on the flank face is. When the flank temperature increased, the thickness of white layer increased. However, the white layer thickness is reduced, when the flank temperature are more than a certain range. Flank wear in a certain range can reduce the thickness of white layer and improve the surface quality.