An Investigation on Machining of Hard AISI 4340 Steel Under Varying Environmental Conditions

Cutting fluids play a significant part of metal working industries. They are broadly utilized due to their capacity to diminish tool wearing, cutting force, temperature, etc. to improve workpiece surface quality. The present work focuses on the machinability study of hard AISI 4340 steel using eco-friendly cutting fluids. Turning experiments are carried out using coated carbide inserts through Small Quantity Lubrication (SQL) under different cutting velocities and feed. Dry, rice bran oil-based solution and alkaline solution are chosen to be the environmental conditions. Under different machining conditions, types of chips, cutting force, surface roughness, etc. are noted. Full factorial type response surface methodology is used to decide on experimental runs. Tool wear tests are also performed under wet conditions. Cutting force is observed to be significantly reduced in a chosen wet environment under some cutting conditions. Rice bran oil-based emulsifier is found to perform better than alkaline solution to increase tool life.