The influence of cryogenic cooling on tool wear, dimensional accuracy and surface finish in turning AISI 1040 and E4340C steels

In all machining operations, tool wear is a natural phenomenon and it eventually leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality particularly when the work piece is quite strong, hard and heat resistant. Conventional cooling methods are not only ineffective but also deteriorate the working environment by producing harmful gasses and smokes. Attempts have already been initiated to control the pollution problem by cryogenic cooling which also enables get rid of recycling and disposal of conventional fluids and possible damage of the machine parts by corrosion, etc. This paper deals with experimental investigation on the role of cryogenic cooling by liquid nitrogen jet on tool wear and product quality in plain turning of AISI 1040 and E4340C steel at industrial speed-feed combinations by two types of carbide inserts of different geometry. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by cryogenic cooling application mainly through reduction in the cutting zone temperature and favourable change in the chip-tool and work-tool interaction. (C) 2001, Elsevier Science BN. All rights reserved.