強加工まで引抜を行った黄銅丸棒材の残留応力

Abstract

Residual stresses in brass bar which were heavily cold drawn to cross-sectional reductions from 25 to 78% were measured. Specimens used were as extruded and annealed after extruding. These were cold drawn stepwise by the two kinds of cross-sectional reduction rate of about 20% per pass and heavier percentage per pass. The residual stresses of the specimens after drawing were almost tensile at the outer part and compressive at the inner part in the section, the distribution of which changes considerably with the increase of reduction under 60% total reduction but hardly over 60% total reduction. At the same time, residual shearing stresses in the section of each specimens were measured. It was shown that these correlate with residual microstrains in the deformed structures. Textures at the outer and inner parts in the section were measured, which changed with the increase of reduction respectively. The influence of the formation of texture on the generation of residual stress was discussed.