High-strength steel has high strength and low thermal conductivity, and its thin-walled parts are very susceptible to residual stress and deformation caused by cutting heat during the drilling process, which affects the machining accuracy and quality. High-strength steel thin-walled components are widely used in aerospace and other high-end sectors; however, systematic investigations into their temperature fields during drilling remain scarce, particularly regarding the evolution characteristics of the temperature field in thin-wall drilling and the quantitative relationship between drilling parameters and these temperature variations. This paper takes the thin-walled parts of AF1410 high-strength steel as the research object, designs a special fixture, and applies infrared thermography to measure the bottom surface temperature in the thin-walled drilling process in real time; this is carried out in order to study the characteristics of the temperature field during the thin-walled drilling process of high-strength steel, as well as the influence of the drilling dosage on the temperature field of the bottom surface. The experimental findings are as follows: in the process of thin-wall drilling of high-strength steel, the temperature field of the bottom surface of the workpiece shows an obvious temperature gradient distribution; before the formation of the drill cap, the highest temperature of the bottom surface of the workpiece is distributed in the central circular area corresponding to the extrusion of the transverse edge during the drilling process, and the highest temperature of the bottom surface can be approximated as the temperature of the extrusion friction zone between the top edge of the drill and the workpiece when the top edge of the drill bit drills to a position close to the bottom surface of the workpiece and increases with the increase in the drilling speed and the feed volume; during the process of drilling, the highest temperature of the bottom surface of the workpiece is approximated as the temperature of the top edge of the drill bit and the workpiece. The maximum temperature of the bottom surface of the workpiece in the drilling process increases nearly linearly with the drilling of the drill, and the slope of the maximum temperature increases nearly linearly with the increase in the drilling speed and feed, in which the influence of the feed on the slope of the maximum temperature increases is larger than that of the drilling speed.

This investigation uses polycrystalline cubic boron nitride (PCBN) tools for precision turning of D6AC (45CrNiMoVA) hardened steel, thereby enabling the manufacturing of components that meet the requirements of intelligent manufacturing lines. A Taguchi’s L16 (4³) orthogonal design was employed to systematically investigate the effects of cutting speed, depth of cut, and feed rate on cutting force, cutting temperature, surface roughness, and tool wear. Analysis of variance (ANOVA) was then conducted to quantify the contribution of each cutting parameter, and high-accuracy predictive models (R² > 0.86) were established for the key response variables, namely cutting force components (F_x, F_y, F_z), cutting temperature (T), and flank wear width (VB_max). The results show that excellent surface quality can be achieved within the investigated range, namely at cutting speeds of 100–250 m·min⁻¹, depths of cut of 0.05–0.2 mm, and feed rates of 0.05–0.125 mm·rev⁻¹, with surface roughness (Ra) below 0.8 μm and mostly around 0.4 µm. At a feed rate of 0.05 mm·rev⁻¹, the measured Ra was greater than the theoretical value (Ra*), whereas at a feed rate of 0.075 mm·rev⁻¹, Ra was lower than Ra*, with the difference increasing as feed rate increased. The ANOVA results showed that cutting forces were dominated by depth of cut, cutting temperatures by feed rate, and tool wear by depth of cut. The optimal process strategy was derived as follows: first, prioritize a lower feed rate; second, select an appropriate depth of cut based on tool failure or deformation control objectives; and third, choose a suitable cutting speed according to tool-life requirements or machining efficiency. This study provides process guidance and predictive tools for PCBN finishing of D6AC steel, thus promoting green, precise, and efficient machining of high-strength, high-hardness, and low-thermal-conductivity materials.