In this study, the effect of the microstructure, hardness, and cutting speed on main cutting force and surface roughness in medium carbon microalloyed steel cooled in different mediums after hot forging, was investigated. As-received sample, which was not hot forged, and the samples cooled in the sand, air, oil, and polymerized water after hot forging were used for the experimental studies. The machinability tests were performed via turning method by using coated carbide and coated ceramic cutting tools with five cutting speed (120, 150, 180, 210, and 240 m/min), constant feed rate (0.04 mm/rev), and constant depth of cut (0.6 mm). The microstructure examinations of the samples were carried out and their hardness values were determined. Also, the wear of cutting tools were examined with scanning electron microscope. In the experimental study, it was revealed that the microstructure, hardness and cutting speed had a significant effect on the surface roughness values of the samples cooled in dissimilar environments following forging. Moreover, the samples cooled in air and polymerized water, whose hardness increased depending on the increase in the cooling rate, had the highest cutting force after machining by using the coated carbide and ceramic tool.

本研究研究了热锻后在不同介质中冷却的中碳微合金钢的组织，硬度和切削速度对主切削力和表面粗糙度的影响。未经热锻的按样接收的样品，以及在热锻后在沙子，空气，油和聚合水中冷却的样品用于实验研究。通过使用涂层硬质合金和涂层陶瓷切削工具通过车削方法进行切削性测试，切削速度为五种切削速度（120、150、180、210和240 m / min），恒定进给速度（0.04 mm / rev）和恒定深度切割（0.6毫米）。进行了样品的微观结构检查，并确定了它们的硬度值。另外，用扫描电子显微镜检查切削工具的磨损。在实验研究中 结果表明，显微组织，硬度和切削速度对锻造后在不同环境中冷却的样品的表面粗糙度值有显着影响。此外，在空气和聚合水中冷却后的样品，其硬度随冷却速率的增加而增加，在使用涂层的硬质合金和陶瓷工具进行机械加工后，其切削力最高。