Machining of AISI 4140 steel under cryogenic cooling—tool wear, surface roughness and dimensional deviation

Increase in cutting velocity and feed for machining with high productivity is generally restricted by the elevated cutting temperature which causes rapid tool failure. In precision machining also, the major problem is the high cutting temperature, which impairs the dimensional and form accuracy of the product, its surface integrity by inducing tensile residual stresses and surface and subsurface cracks. Application of conventional cutting fluid often cannot control the high cutting temperature in high production machining. Besides, they are the major source of pollution from machining industries. Cryogenic cooling is an environment friendly clean technology for desirable control of cutting temperature. The present work investigates the role of cryogenic cooling by liquid nitrogen jet on average chip–tool interface temperature, tool wear, dimensional accuracy and surface finish in turning AISI 4140 steel under industrial speed–feed conditions.