What is the optimum reduction needed for forging?

What is the optimum reduction needed for forging?

Forging reduction should be sufficient to consolidate the defects inherent to the casting process such as porosity and other voids while achieving a general wrought structure by breaking down the cast structure. A 3-to-1 reduction, using the open die process, is usually sufficient to achieve these results (with strict control of the process, less than 3-to-1 can be sufficient). Depending on the alloy and customer requirements, higher reduction may be necessary to achieve certain additional mechanical or physical requirements.