Influence of Process Parameters on Surface Roughness Hole Diameter Error and Burr Height in Drilling of 304L Stainless Steel

Abstract

Machining of stainless steel materials is known to be very difficult due to the formation of BUE, low heat conductivity, high ductility, high tensile strength, high fracture toughness, high work-hardening rates, and high modulus of elasticity and reactivity at high cutting speed with most tool materials. This work aims to study the influence of process parameters such as spindle speed, feed rate, point angle and cutting tool on surface roughness, hole diameter error, burr height, and chip study during dry drilling of 304L stainless steel. Dry drilling is considered to be environmentally friendly drilling process. The cutting tools considered was M2 HSS drills and these drills were subjected to deep cryogenic treated at −191 ℃ for 20 h and post-tempered at 180 ℃ for 2 h. Experiments have been conducted according to full factorial design. From analysis of variance (ANOVA), the most dominant parameters for surface roughness, burr height, and hole diameter error were found to be cutting tools. Furthermore, experiments have been conducted to evaluate tool life of untreated drill, cryogenic treated one-tempered drills, and cryogenic treated two-tempered drills at a constant speed of 650 rpm, feed rate = 15 mm/min, and point angle 118 ℃. Compared to untreated drills, the enhancement in tool life was 53.84% for DCT1T drills and 92.30% for DCT2T drills. Compared to DCT1T, enhancement in tool life was 23.8% for DCT2T drills.