Cutting parameter optimization of CNC dry milling process of AISI 410 and 420 grade MSS

Abstract Optimization of CNC dry milling parameters for martensitic stainless steel (MSS) grades AISI 410 and AISI 420 was done by using Taguchi method (S/N ratio and ANOVA). L9 orthogonal array is used for designing the experiments with 3 levels of spindle speeds and feeds with a constant depth of cut. The impact of machining parameters on surface roughness was investigated. From response table for S/N ratios, the rank obtained for spindle speed clearly indicates that spindle speed is the most significant factor for affecting the surface roughness than feed rate for both MSS grades 410 and 420. ANOVA results revealed that the contribution percentage of spindle speed for surface roughness is higher than feed. Optimum values of cutting parameters were obtained at a spindle speed of 1500 rpm and a feed of 30 mm/min. The experimental values at optimum cutting condition were compared with predicted values and it shows good conformity with the experimental results with a low error percentage. Even though both the MSS grades have wide range of applications the major drawback is with poor machinability. So this experiment aims to improve the productivity and quality of CNC milling operations for both the MSS grades. Moreover less number of studies for cutting parameter optimization were done for MSS grades 410 and 420 yet. Hence more works are needed for optimizing the cutting parameters of these grades for various machining operations especially on CNC machines.