Analyzing Cutting Temperature in Hard-Turning Technique with Standard Inserts Through Both Simulation and Experimental Investigations  
[PERSON]  
1 Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education,  
Ho Chi Minh City 700000, Vietnam; [EMAIL_ADDRESS] (L.H.G. ); [EMAIL_ADDRESS] (V.T.N. mainly generated in three distinct zones: the primary zone, where the workpiece material suffers plastic deformation; the secondary zone, arising from friction between the tool and the chip; and the tertiary zone, caused by friction between the tool and the workpiece [5; 6; 7], as shown in Figure 1. Unfortunately, the elevated temperatures in the cutting zones, ranging from 800 to 1200 \({}^{\circ}\)C, reduce the tool's strength, hardness, and wear resistance [8]. Moreover, the damage to the cutting tool due to the thermal issue also reduces the ability to control dimensional accuracy and maintain desired surface integrity, which leads to high machining costs and a reduction in product quality [9]. Therefore, many researchers have investigated the mechanism of heat generation and heat conduction to control its effects. Numerous researchers have employed actual cutting experiments or combined them with FEA simulations to evaluate the influence of input parameters on machining characteristics. The finite element method has been demonstrated as an effective approach for analyzing the chip-formation process and forecasting essential machining performance metrics, such as cutting temperatures, forces, and stresses. Hard turning differs significantly from conventional turning [10]. Hard turning is a finishing operation that involves high-speed cutting with a low feed rate and a shallow depth of cut not exceeding 0.2 mm [11; 12; 13; 14]. [PERSON] et al. [15] and [PERSON] et al. [16] predicted cutting force and temperature distribution based on the FEA simulation models. They indicated that the tool should not be used near or over the diffusion and bonding limits of the materials employed in that particular tool grade. [PERSON] et al. [17] employed FEA simulations to examine the heat generated in the machining zones. Results from the FEA model were as accurate as those from experiments. The influence of workpiece hardness and cutting conditions on thermal generation during the hard turning of AISI H13-tool steel was investigated by [PERSON] et al. [18]. According to the findings, workpiece hardness represented 63.77% of the cutting temperature, with cutting speed and feed rate following in at 16% and 4.78%, respectively. The depth of the cut factor has the least impact. Furthermore, [PERSON] et al. [19] discovered that while hard-turning AISI 52100 steel, cutting temperature rises with the increasing depth of cut, feed rate, cutting speed, and flank wear. [PERSON] et al. [20] used the response surface methodology (RSM) to create a model to forecast workpiece temperature during the machining process of Al 6351. The results also showed that increasing the cutting speed causes higher cutting temperatures. [PERSON] et al. [21] studied the cutting process of Inconel 718 by changing the rake angle. The cutting temperature when employing a tool with a negative rake angle is approximately 900 \({}^{\circ}\)C, whereas it is 750 \({}^{\circ}\)C for a neutral rake angle and 700 \({}^{\circ}\)C for a positive rake angle. Also, [PERSON] et al. [22] used carbide inserts to hard turn AISI 1040 steel (40 HRC) and examined the effects of rake and cutting-edge angles on cutting temperature. They discovered that a negative rake angle is typically used in hard turning to increase tool  
Figure 1: Mechanisms of heat generation and conduction in hard machining. strength and withstand high compressive pressures. [PERSON] et al. [23] and [PERSON] et al. [24] investigated the impact of nose radii on the machining process of Ti- and Mg-based alloys. They both observed that larger nose radii lead to higher cutting temperatures, which can adversely affect tool life and surface integrity.