A contribution to the strain-hardening process analysis of hardened steel during high-speed machining

摘要

High-speed machining of hard materials, which is nowadays widely applied in the tool manufacturing industry, has several advantages over conventional machining. However, in practical machining one of the important tasks is still to define the values of the cutting speed limit where we enter into the high-speed region. In the paper some of the results of the investigation of the strain hardening process of hardened steel (52 HRC) in milling with a speed range from 50 to 1500 m/min are presented. The influence of the cutting speed into the strain-hardening rate is identified by micrographs and measurement of micro hardness, and the chip shape is also discussed. On basis of the results obtained it is possible to predict the searched speed limit when the cutting process enters into the high-speed region.