Residual Stress Alterations via Cold Rolling and Stretching of an Aluminum Alloy
SourceA solution heart-treated, cold-water quenched experimental aluminum alloy was subjected to two sequential mechanical treatments: an 11.5% reduction by cold rolling followed by a 1.25% cold stretching. The layer-removal and hole-drilling strain-gage methods of residual stress analysis were used, independently, to quantify both the changes in residual stresses produced by cold rolling and the reduction of stress produced by cold stretching. The initial residual stress condition, surface compression with mid-plane tension, was reversed by the cold rolling mechanical treatment to a condition of tensile surface stresses with mid-plane compression. Cold stretching produced a marked reduction in the magnitudes of the cold-rolling-induced residual stress. The independent experimental results of the layer-removal and hole-drilling strain-gage methods corroborated the effectiveness of stretching as a method for reducing residual stresses.