Effect of Cold Deformation on the Machinability of a Free Cutting Steel

Abstract

The effect of cold deformation on the machinability of a free cutting steel has been investigated through characterization of the variation in size and morphology of the sulfide inclusions. The machinability has been indexed in terms of cutting force, surface roughness, and chip characteristics. The possible interrelations between inclusion characterizing parameters and machinability indices have been examined. Increased cold deformation was found to increase interinclusion spacing as well as aspect ratio of the inclusions. These variations in inclusion characteristics, in turn, were found to reduce the cutting forces and the chip length up to a critical amount of deformation. The results highlight the influence of inclusion characterizing parameters on machinability characteristics of free cutting steels.

Keywords:

• Axial cutting force
• Chip morphology
• Chip thickness
• Cold deformation
• Free cutting steel
• Fuzzy logic
• Inclusion aspect ratio
• Inclusion parameters
• Inclusion volume fraction
• Interinclusion spacing
• Machinability
• Simulated deformation
• Structure property correlation
• Surface roughness
• Tangential cutting force

ACKNOWLEDGMENTS

The financial support received from M/s Usha Martin Ltd, Kolkata, India for this investigation is gratefully acknowledged. The authors are grateful to Prof. A. B. Chattopadhyay of Mechanical Engineering Department of IIT, Kharagpur for providing the experimental facility for cutting force measurement.

Notes

∗Maximum value for a particular evaluation factor.