Optimum design and performance evaluation of layer face milling cutter for cutting 508III steel

摘要

Water chamber head is an important component of the steam generator in the nuclear power plant AP1000. It is made of 508III, a type of steel with high strength, low hardness, high toughness, and poor machinability. Traditional cutters are not efficient in cutting process, while the layer face milling cutter is able to reduce the cutting force at cutter teeth and, therefore, can prolong the tool life and improve the cutting efficiency thanks to the use of the layered milling technique. In this work, structural parameters of the layer face milling cutter for processing 508III are determined from aspects of the cutter structure, the cutter head diameter, and the cutter tooth density, with regard to characteristics of the heavy-duty cutting process. Next, geometrical parameters of the cutter, including the axial rake angle, the radial rake angle, the cutting edge angle, and the step structure, are optimized by means of single-factor experiment and static analysis. Finally, the performance of the optimized cutter is verified by two-level fuzzy comprehensive evaluation with using the indexes determined in the above experiment. The optimization of the layer face milling cutter can not only raise the cutting efficiency but provide some support, both theoretically and technically, for heavy-duty cutting applications.