Factors affecting redundant work in the cold drawing of metal strip.

The redundant work in strip drawing has been investigated by the equivalent strain technique. A new procedure has been developed which is capable of consistently reproducing measurements of the redundant-work factor to within +/- 5%. The assumptions of plane-strain conditions and "ideal" material behaviour have been considered and the limitations these assumptions impose on predictions of the redundant-work factor have been assessed. Large differences in the magnitude of the redundant-work factor have been found between the materials used in this investigation, that could not be explained in terms of variation in strength or work-hardening rate. A strong positive correlation has "been found however, "between the redundant-work factor and the magnitude of the relative rate of change of work-hardening rate with strain