AN UPPER BOUND ANALYSIS OF THE DEFORMATION MODE OF COLD SANDWICH ROLLING

A mathematical model of cold symmetrical sandwich rolling was established by applying the upper bound method.The deformation mode was calculated for the sandwich with soft cladding during cold rolling. The relative calculating results were presented graphically. It is shown that there exist three possible deformation modes, namely proportional deformation, interface splitting, and unsteady deformation, depending on the process parameters. Larger reduction, stronger interface bonding, smaller relative base-metal strength and rolled thickness increase the proportional deformation zone and decrease the interface splitting zone. The unsteady deformation zone exists only when the relative base-metal strength and thickness are large enough.