Effect of prestress on cutting of nickel-based superalloy GH4169

摘要

In view of the serious tensile residual stress distributed on the machined surface in cutting nickel-based superalloys GH4169, the prestressed cutting method has been adopted to actively control the surface residual stress. Numerical and experimental studies have been performed to investigate the effect of prestress on the cutting of GH4169. Based on the principle of prestressed cutting, a three-dimensional finite element model (FEM) of prestressed cutting has been established. Simulation results indicate that compared with cutting without prestress, remarkable increases of compressive residual stress and deeper distribution are observed. In addition, insignificant increments of cutting force and uniform serrated chip morphology are noted with higher prestress. Subsequently, a novel prestressed loading device for shaft parts has been prepared, and then an experimental setup has been developed. Single-factor experiments of prestressed cutting nickel-based superalloys have been carried out. It can be revealed that a significant rise of compressive residual stress is obtained as the prestress increases. Experimental and simulation results agree well in view of cutting force, chip morphology, and residual stress, which verify the effectiveness of the established FEM. A slight decrease in surface roughness and better machined surface integrity are found. Simultaneously, no additional work hardening appears on the machined surface.