INVESTIGATIONONEFFECTOFCUTTINGPARAMETERSON SURFACEROUGHNESSANDMACHININGTIMEINTURNINGEN31 UNDER FLOODED MACHINING AND MQLSET-UP)

Hard turning is a turning process done on materials with a Rockwell C hardness greater than 45. It is typically performed after the work piece is heat treated. The process is intended to replace or limit traditional grinding operations. Hard turning can be applied for purely stock removal purpose or finishing purpose. Hard turning when applied for surface finish purpose can competes favorably with rough grinding (Ra = 0.5-0.8 µm). In Hard turning cutting velocity (Vc) is high i.e. machining time (Tm) is low due to which high amount of heat is generated at the chip-tool interface which not only increase the tool wear but also deteriorates the job quality in terms of surface finish. Therefore large amount of cutting fluid is used to increase the performance of hard turning operation due to which it becomes easier to keep tight tolerances but on the other hand use of cutting fluid has become more problematic in terms of cost, disposal, wastage and environmental pollution. Minimum quantity lubrication (MQL) is a good alternative to this flooded lubrication. This study investigates the performance of MQL with flooded lubrication in turning EN-31 by using Response Surface Methodology (RSM). ANOVA was used to find out the significant parameters. The results indicated that when range of cutting parameters (cutting velocity, feed & D.O.C) was low to medium turning with MQL provides some favorable results in terms of surface finish but with increase in the level of cutting parameters specially Vc and feed the surface finish obtained under MQL was less as compared to flooded lubrication, it means that MQL fails to reduce friction at the work–tool interface there by restricting the use of MQL to low range of cutting parameter only.