An experimental study of the efficiency of new cutting fluids during turning hardened 35NiCrMo 16.6 steel

The present paper deals with the application of new water-based semi-synthetic cutting fluids when machining hardened steels and more generally high strength alloys. A qualification test is defined on the basis of a longitudinal turning operation, and as a part of a study absolutely necessary to be engaged in view to choose an alternative new cutting fluid in accordance to the current French legislation and statutory regulations concerning the environment. The effectiveness of ten commercially available cutting fluids is studied, in relation with the technical objectives to be achieved in terms of quality: dimensional accuracy, surface finish, tool damage and tool life, chip breaking and disposal.Measured and calculated values of cutting force, tool wear, surface roughness, apparent coefficient of friction on the tool face, are compared to those obtained when machining is performed without application of cutting fluid (dry cutting), with application of a 6-bar compressed air jet (air cutting), and with application of two “reference cutting fluids”: a well known cutting fluid of the previous generation, and a water solution containing 3% triethanolamine by volume