A Study of the Machinability of Metals : Effect of microstructure on cutting mechanism, tool life, and surface finish

Abstract

The effect of microstructure of materials on machinability of carbon steels (S15C, S40C and SK4) was investigated from the viewpoint of cutting mechanism, tool life, and surface finish. The experimental results on cutting mechanism are studied in the first half of this paper. It was found that inclination angle of the starting boundary line of the flow region was almost constant, and inclination angle of the end boundary line and the size of the flow region showed a maximum value at the lamellar portion of pearlite of 20-30%. The results obtained from the experiments on tool life and surface finish are studied in detail in the later half of this paper. The effect of spheroidized pearlite structure in high carbon steels on machinability was compared with the lamellar pearlite structure.