高マンガン鋼旋削時の超硬工具の摩耗とその解析的予測(その1)

工具摩耗特性と切りくず生成模型

抄録

Wear of carbide tools in turning high manganese steels is examined in comparison with those in turning an austenitic steel and a plain carbon steel. The results obtained are as follows: (1) Although the cutting forces in turning 18% Mn steel are similar to those in turning 18% Cr-Ni steel and 0.46% C steel, the chip contact length is rather short. Large normal stress on the cutting edge and high temperature close to the major cutting edge characterize severe wear at the corner part. (2) The use of tools with large corner radii is effective to improve the tool wear. (3) The experiment proves that the wear characteristics of carbide tools in turning 18% Mn steel and 18% Cr-Ni steel are expressed by the same equation that one of the authors et al. have proposed when machining plain carbon steels. The characteristic constants involved in the wear equation have the same value for the work materials used. (4) A three-dimensional cutting model accompanying with formation of a lateral curl of chip is proposed. The chip shape predicted agrees well with that produced in actual turnings.