Experimental and computational investigation of drilling parameters and cooling conditions on super-duplex stainless steel 2507

Abstract

This manuscript studies various process parameters like cutting velocity, feed rate, and cooling condition (dry, cryogenic, and emulsion) during drilling experiments performed on super-duplex stainless steel (SDSS) 2507 with coated and uncoated drill bits. The thrust force ranged from a minimum of 878.8 N (uncoated tool and emulsion cooling) to a maximum of 2500.1 N (uncoated tool and dry cooling), while torque values ranged from 19.87 to 2249.6 Nm under varying conditions. It was observed that thrust force and torque increased with higher feed rates and reduced with higher cutting velocities. Emulsion cooling consistently produced the lowest reactions, with an average reduction of 43% in thrust force compared to dry cooling, while dry drilling resulted in the highest forces and torques due to increased friction and heat. The use of a coated tool reduced the thrust force by up to 12% on average compared to uncoated tools under the same conditions. All three parameters studied (cutting velocity, feed rate and cooling condition) had statistically significant effects on thrust force (p ≤ 0.05), while torque was mainly influenced by feed rate and cooling condition, with a lesser effect from cutting velocity (p ≈ 0.06). The manuscript also presents the use of various computer-based modelling methods, including linear regression (R² = 0.9357 for thrust force), exponent-law relations (R² = 0.9854 for thrust force, 0.9375 for torque), artificial neural networks (mean error of 0.11% for thrust force, 0.3% for torque), and fuzzy-logic inference systems (R² = 0.9927 for thrust force, 0.9935 for torque), to model the outputs’ behaviour in relation to the input with remarkable precision.