고경도강의 단속선삭 가공시 표면특성 연구

Abstract

This study investigates the effect of machining parameters on surface roughness during interrupted turning of SCM440 alloy steel with non-circular and asymmetrical geometries. Interrupted turning is characterized by intermittent contact between the tool and workpiece, which increases cutting forces and thermal loads, negatively impacting tool life and surface quality. SCM440 is a chromium-molybdenum alloy steel with high strength, wear resistance, and thermal stability, making it suitable for high-stress environments such as aerospace and automotive components. However, research on interrupted turning of SCM440 with non-circular and asymmetrical shapes remains limited. In this study, Taguchi’s design of experiments (DOE) methodology was applied to analyze the influence of cutting speed, feed rate, and depth of cut on surface roughness. Experiments were conducted on a CNC lathe using a coated carbide insert under various machining conditions. The optimal cutting parameters were determined based on signal-to-noise (S/N) ratio analysis, and analysis of variance (ANOVA) was used to assess the statistical significance of each parameter’s effect on surface roughness. The results showed that cutting speed and feed rate significantly affect surface roughness, while the influence of depth of cut is relatively minor. The optimal conditions for minimizing surface roughness were found to be a cutting speed of 140 m/min, a feed rate of 0.1 mm/rev, and a depth of cut of 1.0 mm. In the verification experiments, the average surface roughness was measured at 0.979 μm, confirming the reproducibility and consistency of the experiments. This study provides valuable insights for optimizing interrupted turning processes to achieve superior surface quality in non-circular and asymmetrical SCM440 components.