Stamp-Forming of Heads of Railway Tank Cars

In order to ensure the cold stamping quality of railway tank car heads, die surfaces with three different types of draw bead structures at the die entrance, including round draw bead, rectangular draw bead and no draw bead, were designed for the head stamping process. Then, the head stamping processes for the three types of die entrances were simulated using the finite element method. The simulation results were analyzed and compared in terms of wrinkles, spring-back, and thickness variation. On this basis, a reasonable die structure was selected and manufactured for stamping experiments. The result shows that the die entrance with rectangular draw bead could effectively avoid wrinkles and blowups, and has a smaller spring back. The stamping experiment results with the rectangular draw bead indicate that the stamped heads has no defects; the minimum thickness is 9.6 mm, and the maximum thickness is 10.5 mm, which consist with the computational results. Therefore, adopting the die with rectangular draw bead for cold stamping of railway tank car heads is effective.