Types of Forging Dies
Forging dies are used to shape and form metals in mass production, sometimes with and sometimes without heating the workpiece. Forging dies are divided into three categories
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Closed-die forging: In this method, the workpiece is placed between two die halves and is given the shape of the die under the compressive force or impact of hydraulic or mechanical presses or drop hammers. Forging dies are made of hot-working steels with high toughness and yield strength. Sometimes, several dies and multiple forging stages are used to achieve the final shape, as a single pressing operation cannot produce a complete part.
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Open-die forging: In open-die forging, the dies have a simple shape, and sometimes the dies are simply two flat surfaces. In the forging operation, the workpiece is rotated between the two die surfaces so that the compressive force of the press shapes it into the desired form. Large parts weighing more than 150 tons can be deformed using this method. Rolling forging is also used. In this method, a hole is created in a thin, circular metal sheet. After rolling or even compression and impact, a ring with a lower height and larger diameter is obtained. This method is a combination of rolling and forging and is used to produce rings between 0.5 grams and 180 tons.
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Flash-free forging: In flash-free forging, the process is similar to die casting, except that the temperature is lower. Two die halves are placed on the initial workpiece. Ultimately, the final part is obtained and no further finishing processes such as machining are required.
