Analysis of Surface Roughness in Hard Turning Using Wiper Insert Geometry

Hard turning process is currently replacing the conventional grinding operations in many industries. If properly designed, hard turning can give equivalent results to grinding process in terms of accuracy and machined surface quality. Wiper inserts are being used in machining operations because of their competence to generate superior machined surface. Surface roughness is major requirement for many industrial components and is one of the important parameter considered to describe machinability of metals and metal alloys. This paper investigates performance of wiper inserts in hard turning of oil hardening non-shrinking steel. The oil hardening non-shrinking steel is commonly used material for making measuring instruments and gauges wherein surface roughness is very important aspect. The major emphasis here is given to study and compare performance of wiper insert in terms of surface finish with conventional inserts. Influence of process parameters such as speed, feed, depth of cut and nose radius (for wiper and conventional inserts) on surface roughness is analyzed using analysis of variance (ANOVA) and analysis of means (AOM) plots. From the analysis, it can be clearly seen that wiper inserts produce a very good machined surface compared to conventional inserts.