The effects of cryogenic cooling on chips and cutting forces in turning AISI 1040 and AISI 4320 steels

Application of conventional cutting fluids often cannot control the high cutting temperatures, especially in high production machining. In addition, they are a major source of pollution in machining industries. Cryogenic cooling is a potential environmentally friendly clean technology for desirable control of the cutting temperature. The present work deals with experimental investigations on the role of cryogenic cooling by liquid nitrogen jets on chip formation and cutting forces in turning AISI 1040 steel and AISI 4320 steel at industrial speed-feed combinations by two types of carbide inserts of different geometrical configurations. The experimental results indicate the possibility of a substantial reduction in cutting forces by cryogenic cooling, which enabled a reduction in cutting forces by favourable chip formation, chip-tool interaction and also retention of tool sharpness due to reduced cutting temperature. Thus cryogenic cooling, if properly employed, is not only environmentally friendly but can also improve machinability characteristics.