Machining characteristics investigations of duplex stainless steel by considering dual effect of chip breaker and cooling conditions

Duplex stainless steels (DSSs) use in many applications because of their superior properties like high corrosion, good strength, and low cost. On the other hand, machinability of DSSs is very low due to its superior ductility. This study investigates optimization of cutting parameters, cutting environments (dry and cold air), and chip breaker forms by Taguchi–Grey relational analysis in turning of 2205 grade DSS. The turning tests were conducted using Taguchi’s L16 mixed design by measuring and evaluating the cutting force components and surface roughness criteria (Ra and Rz). When turning of DSS2205 material in medium cutting condition, it is suitable to use low feed rate and high cutting speed for reducing of cutting force and surface roughness. In addition, it was shown that the chip breaker form is as important as the cooling medium in terms of minimizing Built-Up-Edge (BUE), which negatively affects the machinability outputs. Grey relational grade (GRG) indicated that the optimum results for all cutting conditions were the cutting speed of 160 m/min, the feed rate of 0.15 mm/rev, GM chip breaker, and cold air cutting environment. Experimental and ANOVA results indicated that the feed rate is the most important parameter on turning of DSS2205, followed by chip breaker, and cutting environment.