How Do I Simulate Dead Cycle Time?


  • Understand heat transfer characteristics during billet loading and upsetting stages.


  • Perform thermal analysis during dead cycle time.
  • Compute heat transfer between billet and container/liner.
  • Calculate billet temperature at the start of extrusion.


  • Help design better container heating system to maintain optimum billet temperature.
  • Minimize dead cycle time.
  • Increase productivity.

What is Dead Cycle Time?

  • This is the time between the end of one extrusion cycle and the start of the next cycle.
  • Dead cycle time is typically between 15 to 20 seconds.
    • The first half is spent removing the back end of the previous billet.
    • The remaining time is for loading and upsetting the new billet.
  • This is an important factor to consider when designing the container heating system.
    • During the upsetting process, the bottom half of the billet loses heat to the container.
    • This creates a temperature gradient in the lateral direction.
    • Material flows faster in the top half than in the bottom half.
    • This produces a non-uniform flow at the die exit.