Performance Evaluation Of Uncoated Carbide Cutting Tools In Turning Nst

ABSTRACT

In metal cl.Itting operations, performance of the cutting tool is the major determinant

of the productivity, functionality and production cost of the machined component. In this

work, the performance of uncoated cemented carbide tools with International Standard

Organisation (ISO) designation SNMA 120406 was evaluated for tumitu; of NST 37.2 steel.

Turning operations were conducted on M300 /-Iarrison type lathe driven by 3.0 hp Kapak

induction motor. The cutting conditions used were: cutting speed, 20.42, 29.06 and 42.42

m/min; feed rate, 1.0, 1.8 and 2.2 mmlrev; and depth of cut, 0.2, 0.4 and 0.6 mm under dry

machining. Results showed that both flank and nose wear increased with increase in

number of pass, cutting speed, depth of cut and feed rate. The optical surface roughness of

the machined workpiece varied from 0.658 - 0.924 and case hardening of the machined

surface was observed. Segmented chips with smaller coil radii, which were less voluminous

and more manageable were produced at all cutting conditions investigated. Chip breakabi/ity

tends to increase with increase in cutting speed. The use of uncoated carbide tools has

proved to enhance the productivity and surface quality in turning of NST 37-2 steel