Optimization of machining parameters using response surface methodology with desirability function in turning duplex stainless steel UNS S32760

The turning process of the duplex stainless steel (DSS) has received special attention in recent years due to its attractive combination of mechanical and corrosion properties, which are suitable for many marine and petrochemical applications, particularly where chlorides are present. Thus, a better understanding of the machining parameters is critical in attaining high quality in the turning process of the DSS. This paper presents a predictive and optimization model based on integrated response surface methodology (RSM) and desirability function to predict the surface roughness, the material removal rate, and the corresponding machining parameters during the turning of the UNS S32760 with a chemical vapor deposition (CVD) tool. The experimental design was a central composite design (CCD) with three center points and an axial distance of 1.68 from the center. The statistical significance of the developed model has been tested by the analysis of variance and the influence of the factors analyzed. The optimization results are presented considering three aims: (1) minimizing surface roughness; (2) maximizing the material removal rate; and (3) minimizing the surface roughness and maximizing the material removal rate.