Forging is the process of forming metal through the use of heat and force to get the desired shape. Force can be applied through pressing or manually on the molten metal, compressively in operation. In many industries today, manufacturing units need forged metals for their activities.
Forging consists of two main operations based on force,
- The drawing down process
In the drawing down process of forging, the cross-section area of the workpiece and the elongated length is reduced. Therefore, there is an increase in length and a decrease in the cross-sectional area. A wire drawing process involves the use of a comprehensive force which is applied at the perpendicular direction of its axis.
- The Upsetting process
The upsetting process is the opposite method to the drawing down approach. It entails a decrease in the workpiece and an increase in the cross-section. This process applies force in a parallel direction to the length axis.
Types of Forging:
These are the various classifications of forging;
1. Temperature:
Hot forging: The process of hot forging means the workpiece will be heated to a temperature beyond recrystallization after which force will be applied.
The recrystallization of most metals is achieved at half their melting point temperature.
- Warm Forging: This is done at a temperature of 40% of the metal’s melting point temperature.
- Cold Forging: The process of forging at room temperature is called cold forging. This is the process that gives the highest mechanical properties.
2. According to the arrangement of Die:
- Open Die Forging: An open die forging process uses a flat die or no die, and it produces a rough product. In this process, the workpiece is hammered to obtain the desired result.
- Close Die Forging: A closed die forging process applies higher force and a set of impression to produce the desired piece from a workpiece.
3. Based on the Forging equipment:
- Smith forging: The smith forging method is an aged old method that makes use of an open die method in which the workpiece is placed on a stationary anvil while it is being struck with a hammer till the desired shape is achieved. The needed force can be applied manually or through power hammers.
- Drop Forging: In this process, an automatic hammer is applied in a series of blow by what is normally called dropping action.
- Press Forging: A press forging process is similar to the drop forging method with an exception to the use of continuous squeezing force of the hydraulic press, which it uses to increase the length, and decreases the cross section area of the workpiece.
- Machine Forging: The machine forging process is an upsetting process that achieves a decrease in length and a substantial increase in the cross-sectional area.
Uses of forged products
Forged products are used in the mechanical industry for many things such as; Large turbine rotor, generator rotor, Crankshafts, camshafts, chisels, and in shipbuilding. Hollow forgings like large oil tubes are used in refineries and gas processing plants. Heavy machinery industries also make use of forged products.
Applications of forged products are unlimited. However, this information will suffice for anyone who needs a quick knowledge of the uses and methods of forgings.
