MIZAN TEPI UNIVERSITY
College of Engineering and Technology
Department of Mechanical Engineering
Optimization of Surface Roughness for Turning Medium Carbon Steel
AISI1030
Prepared By
Kassahun Girma (M.sc)
Lecturer in Mechanical Engineering Department
Email: kasahungirma72@gmail.com
July, 2022
Tepi, Ethiopia
ABSTRACT
In this Research entitled by “Optimization of Surface Roughness for Turning Medium
Carbon Steel AISI1030” was investigated by considering Spindle speed, Feed rate & Depth of
cut as chief Machining Parameters. Medium carbon steel AISI1030 is mostly used in high
strength and toughness application such as Gear, Gear Shaft, Rear axle shaft, Spring valve,
Levers, cams, crank shaft, Spline shaft etc. For minimum Surface Roughness Turning process
has to be optimized on the basis of Cutting Parameter and trend. Surface Roughness response on
the basis of parameter and Material Hardness has to be established. Samples of AISI1030 were
examined under two states; normal samples and samples subjected to Hardening heat treatment.
Experiment determined optimum surface roughness by controlling cutting parameters. Turning
operation was conducted with spindle speed; 56rpm, 450rpm, 1120rpm feed rate; 0.17m/rev,
0.35mm/rev& 0.6mm/rev and depth of cut; 0.5mm, 1.0mm&1.5mm. The experiment was carried
out based on Taguchi design of experiment. Optimum results were determined with the help of
MINITAB software: S/N ratio, main effect, interaction effect & Analysis of Variance (ANOVA).
In turning normal AISI1030 samples minimum surface roughness of 4.046µm was obtained at 4th
combination of cutting parameters at 450rpm spindle speed. 0.17mm/rev feed and 1.0mm DOC.
From ANOVA spindle speed plays significant role with contribution of 35.64% to minimize
surface roughness followed by DOC (31.62%) & last feed rate with contribution of 28.6%. In
order to minimize surface roughness it is recommended to increase spindle speed and decrease
feed rate. For AISI1030 samples subjected to hardening heat treatment minimum surface
roughness of 5.206µm (28.67% higher than that of normal AISI1030) is obtained. It was found
that further increase in spindle speed worsen surface finish. From ANOVA in turning hardened
AISI1030 feed rate contributes total of 56.64% followed by spindle speed 39.26% and DOC with
2.89% contribution. To minimize surface roughness both feed rate and spindle speed has to be
reduced. The study was successful in achieving optimization of turning process in reducing
Surface Roughness using a Taguchi Design of Experiment.
Key words: Optimization; Surface Roughness; Taguchi; Turning; ANOVA