ANALYSIS OF MACHINING CHARACTERISTICS IN HARD TURNING

Precision hard turning, an alternative to the conventional turning-hardening-grinding process sequence is a cost-effective and high productivity process for components which are often hardened above 45 HRC.In the present work, an attempt has been made to analyse the influence of the cutting parameters such as, cutting speed and feed on the cutting force and average surface roughness obtained during hard turning of bearing steel hardened nearly to 60 HRC using uncoated polycrystalline cubic boron nitride inserts.Exprimental results indicated that cutting force and average surface roughness decreased with the increase in the cutting speed and increased with the increase in the feed rate.Therefore, higher cutting speed and a lower feed rate is recommended for better machining performances indicated by lower cutting forces and lower surface roughness.