CGC Kymon presents an open die forging technique that involves the shaping of heated metal parts between a top die attached to a ram and a bottom die attached to a hammer anvil or press bed.
Although the open die forging process is often associated with larger, simpler‐shaped parts such as bars, discs, rings, hollows or stepped bars, CGC Kymon’s open die forging technique is extremely suitable for custom‐designed metal components.
CGC Kymon’s open die forging process involves working metal parts above their recrystallization temperature and gradually shaping them into the desired configuration through the hammering or pressing of the work piece.
CGC Kymon’s open die forging never completely confines or restrains the metal in the dies. Most open die forgings are produced on flat dies. However, round swaging dies, V‐dies, mandrels, pins and loose tools are also used depending on the desired part configuration and size.
CGC Kymon’s advanced forging process helps produce high‐strength, long‐life parts optimised in terms of mechanical properties as well as structural integrity in sizes ranging from a few kilos to many tonnes in weight. Additionally, the forging technique allows shapes that could not earlier be produced by the open die forging process.
Pictured above is a representation of the steps involved in open die forging a typical stepped bar. The procedure is as follows:
- Rough forging a heated billet between flat dies to the maximum diameter dimension
- Forging or "drawing" down the first step to size
- The second step is drawn down to size. Note how the part elongates with each process step as the material is being displaced
- "Planishing" the rough forging for a smoother surface finish and to keep stock allowance to a minimum