Abstract
The cutting efficiency of a high speed steel tool does not only depend upon the raw material, its constituent and heat treatment, but also on the form of cutting edge. In studying the cutting efficiency of tools, the measurement of cutting force on the edge is highly desirable. High speed steels used in this experiment were three kinds containing various amount of Co as follows : (i) C 0.72, Cr 4.23, W 17.76, V 0.94, (ii) C 0.75, Cr 4.20, W 19.47, V 1.68, Co 5.70. (iii) C 0.83, Cr 4.22, W 20.49, V 2.24, Co 11.60.
Steels cut were three kinds, (i) annealed Cr-steel, (ii) Ni-Cr-steel tempered after quenched in oil and (iii) austenitic stainless-steel. In the experiment, the cutting forces on the tool were measured by the testing apparatus of “Schiess Defries”, and the following terms were investigated: (1) the effect of the size of bite on the cutting efficiency, (2) the relations between the cutting force and the material to be cut, cutting speed, depth of cut and feed of the bite and (3) the effects of depth of cut and feed of bite on the cutting efficiency.
The results of this experiments were as follows:-
(1) Cutting efficiency becomes higher as the tool size increases when it is properly hardened, (2) Cutting speed has almost no effect on cutting force, (3) Cutting force is nearly in direct proportion to the increase of cutting depth, (4) as the cutting area increases, the cutting efficiency decreases rapidly, (5) as far as the present experiments are concerned, the less the feed for the same cutting area, the thinner the shavings, and the higher the cutting efficiency.
