Machining-induced surface integrity and machining-parameter optimization for finish-turning of slender workpieces

Slender workpieces are characterized by high load-carrying capacity and light weight and are commonly used in the manufacture of drive shafts and key aerospace components. However, they generally have low stiffness, and chatter often occurs during the cutting process. Even with finish-turning, it is difficult to achieve ideal surface integrity, which affects the service property of the workpiece. Therefore, finish-turning experiments were conducted on 18CrNiMo7–6 steel slender workpieces. Cutting forces and surface integrity (roughness, hardness, residual stress, and microstructure) were researched for various turning parameters. In addition, the optimal process parameter was determined by conducting orthogonal experiments. The surface integrity of slender workpieces can be significantly improved by using the parameter-optimization strategy. The surface roughness obtained with the optimum parameters was reduced by a maximum of 20.1%, while the compressive residual stress increased by a maximum of 100.8%. These findings provide valuable guidance for machining slender workpieces.