ANALYSIS OF SURFACE ROUGHNESS IN TURNING OF MILD STEEL

Abstract

In metal cutting and manufacturing industries, surface finish of a product is very crucial in determining the quality. Good surface finish not only assures quality, but also reduces manufacturing cost. Surface finish is important in terms of tolerances, it reduces assembly time and avoids the need for secondary operation, thus reduces operation time and leads to overall cost reduction. Besides, good-quality turned surface is significant in improving fatigue strength, corrosion resistance, and creep life. In this research, the main objective is to study the effect of cutting speed, feed and depth of cut on surface roughness of mild steel in turning operation. Different cutting parameters have different influential on the surface finish. In the experiment conducted in this research, 3 cutting speed, 3 feed and 3 depth of cut were used. Design of experiment, the total set of experiments carried out is 27 sets. At first, the mild steel was undergone chemical composition test using Arc Spectrometer, and was decide that it is be of grade IS: 2062-2006 Grade: E-250 (Fe410W) B . The cutting speed, feed and depth of cut were decide using the suitable range recommended; which were 62.17m/min, 98.09m/min. and 154.74m/min. for cutting speed, 0.2mm, 0.3mm and 0.4mm for depth of cut 0.2mm , 0.25mm and 0.3mm. The specimen was turned under different level of parameters and was measured the surface roughness using a Taylor Hobson’s Surtronic 3+. From the result, it is concluded that higher cutting speed or lower depth of cut produce better surface finish. The optimum cutting speed, feed and depth of cut in this case were 154.74 m/min , 0.2mm/rev and 0.2mm. Which produced average surface roughness 3.21μm. Cutting speed, feed and depth of cut are a significant parameter in influencing the surface roughness.