Connection between hardness and stresses in the plastic region

Abstract

In studying plastic deformation by measurement of hardness [1] it is necessary to use a hardness-stress calibrating graph plotted from the results of tests under the simplest stress conditions. For the use of these graphs in plastic deformation in general to be well-founded, it is essential to have experimental data confirming that the hardnessstress curve is common to various states of stress. However, [1–3] give this data from tensile, compressional and torsional tests only. Clarification of this problem is particularly important, because all the stress and deformation components for a number of cases of practical importance can be determined by reference to the stress intensities at various points in a body [4].

The present work gives the results of experimental work on the connection between stresses and hardness under conditions of two- and three-dimensional stress.