The structure type of porthole die has a crucial impact on metal flow balance in die cavities, strength of seam weld, and die strength. At present, there was little industrial case for the application of protection-type porthole die. In this study, a novel combined porthole die which includes protection, upper, and lower dies was designed to manufacture a multi-cavity and thin-walled profile. The plastic deformation behavior and flow velocity distribution of metal in die cavities were examined by numerical simulation. Seam weld strength and por...
