Application of the Taguchi Method to Improve the Machining Roughness in Hard Turning of Alloy Steel SKD61: A Case Study

Surface roughness is a crucial parameter for evaluating the quality of metal cutting processes. In this research, the Taguchi method was applied to optimize cutting parameters in order to minimize surface roughness during the hard turning process of SKD61 alloy steel under minimal quantity lubrication (MQL) cooling conditions. The selected cutting parameters included cutting speed, cutting depth, feed rate, and material hardness, each with three levels: high, low, and medium. The experimental setup was designed using Taguchi’s L27 array. The study revealed that the feed rate had the most significant impact on surface roughness, followed by the cutting depth. Optimal surface roughness was achieved using the following cutting conditions: cutting speed of 80m/min, feed rate of 0.1mm/rev, cutting depth of 0.2mm, and material hardness of 45HRC. Additionally, a regression model was developed to predict surface roughness with an impressive determination coefficient of 86.65%.