The Role of Friction in Metal Cutting

Abstract

Metal-cutting studies were made with free-cutting steel SAE 1112 and alloy steel SAE 4135 in the as-received condition with artificially controlled tool-chip contact areas and flank contact areas (artificial wear lands). The experimental results for steel SAE 1112 at a speed range of 0.083 to 1010 fpm, reveal that friction under metal-cutting conditions on the rake face can be explained satisfactorily by a junction model with possible superimposed general plastic flow above the junctions in accordance with the general rules of plastic deformation (von Mises instantaneous yield criterion). The experimental results also reveal that the friction mechanism at the controlled flank-wear contact area is essentially the same as that occurring at the tool face. The difference in behavior of the two steels was attributed to the role that manganese sulfide appears to play in free-cutting steels.