Cutting speed influence on surface integrity of hard turned bainite steel

The purpose of this paper is to examine how the surface integrity of bainite steels is affected by hard turning. Tests were conducted on a lathe using different cutting speeds. The surface was evaluated in terms of residual stress, surface roughness and microstructure analysis. Tests showed that hard turning provides good surface integrity. Effect of cutting speed on residual stress was investigated in order to find how the residual stress could be altered. It was found that there is a cutting speed where maximum compressive residual stress is generated. The surface roughness of the hard turned test samples followed the same pattern; an certain cutting speed gives the lowest surface roughness values. The surface of the test samples showed no or little alteration to the microstructure. Based on the results it can be concluded that hard turning of bainite steel is a suitable manufacturing process.