Drilling Process Improvements in EN31 Steel Under Different Environments

Abstract

Drilling is an important manufacturing process. This process is difficult and becomes complex in drilling of the high strength materials like EN31 steel, which finds wide industrial applications due to its favourable mechanical properties. The present work is the experimental investigations in drilling of EN31 steel under different drilling environments. The number of experimental runs has been decided using the Box-Behnken design methodology. The experiments have been performed under dry and wet conditions using soluble oil as drilling medium. Initially, the work is focused on the improvement in drilling characteristics under wet drilling as compared to the dry drilling. Later on, the effect of drilling input parameters while drilling of EN31 steel on output responses for has been studied using analysis of variance (ANOVA). The finding has been studied based on the main effect and interaction plots. Regression models in actual form for the output responses have been presented using ANOVA analysis for dry and wet drilling conditions separately. Mean surface roughness values under dry and wet drilling are also shown. From this work, it can be concluded that the wet drilling is better suited for drilling of high strength materials like EN31 steel owing to its better cooling the lubricating nature of the drilling medium used.