Learn more about the pros and cons of each method
Steels are the most commonly used metal forging method. The reason for the popularity of this method in production is that compared to other methods, we will see more savings in raw materials.
Cold forging or cold pressing
Cold forging, also known as cold pressing, is one of the oldest methods in the metalworking industry. To perform the cold forging method, the craftsmen press the metal ingots and shape them to their desired shape with the help of a tool.
Hot and cold forging comes in a variety of methods, including forging or hammering, hydraulic and impact pressing, rolling and head forging, and upsetting.
Forging process classification
If we want to consider categories for the forging process, we have to present them in both open and closed die. The open die process is typically used to form components that have higher or more dimensional tolerances. To better understand, we give an example. Forging is used for rebar when it is intended to reduce the diameter or deformation, or if a person intends to turn the rebar into a square or hexagonal cross section, etc., he should use this method.
Closed die forging process
But you should know about the closed die forging process that this method is usually used to produce parts with pre-designed shapes and dimensions. Components that have more precise dimensional tolerances. For example, the production of industrial bolt from rebar is a clear example of the use of this method.
Low and high temperature forging
Another category is low temperature and high temperature forging, which is the main topic of this article. Low temperature forging is called cold forging and high temperature forging is called hot forging.
Cold Forging
Cold forging leads to changes in the shape and appearance of the metal and other properties. In this way, the ductility, strength and durability of the metal are changed.
It is important to know that in the cold pressing process, the time required to change the state of the metal ingot and convert it to other shapes is different. You will also see differences in higher geometric accuracy, better surface quality and erosion strength.
Components made by cold forging will be used in various industries. Most of the industries that use this method for metalworking are rocket and aerospace industries. In general, it can be said that industries that depend on human security use this method.
Why do we need forging and pressing?
Reducing costs depends on the use of this method of metalworking. Also, if you have delays in the production of your products, it is better to refer to companies and factories that are equipped with forging and pressing industry and outsource the production of your intermediate products as much as possible.
Another reason that leads you to outsource products is that the initial performance design of forging processes is a trial and error, and these trial and error are done on forging tools.
If you want to use numerical simulation for the nonlinear forging process, you will definitely need optimal numerical methods. Of course, it should be noted that classical development methods are very practical for simulating and optimizing forging. In the forging industry, you can use FORGE software. In fact, this software is one of the most widely used software in this field.
Advantages of cold forging
Cold forging has several advantages, the main of which are very high dimensional accuracy and no The most important is the very high dimensional accuracy and lack of surface oxidation of the metal.
- In high mass production, less energy is consumed and it is more economical.
- Using cold forging method, many very small parts can be produced.
- It is also possible to produce medium-sized parts and objects in several stages with very high speed and accuracy.
- You will need less operator power.
- If you need to produce more complex parts, this need is met by a machine
.Disadvantages of cold forging method
- You have to pay a lot of money to produce molds.
- The operators you hire must be skilled and able to work with the device.
- This method is not able to produce parts larger than 39 mm.
- If the amount of parts you produce is small and limited, using this method will not be economical.
- Cold forging method can not produce parts with long length and thin diameter.
Hot forging
Each metal has its own characteristics and is prepared for forging at a specific temperature. As you know, most metals are suitable for forging. Metals such as carbon steels and alloy steels or aluminum and its alloys are suitable for forging. Brass and copper and their alloys will also change shape with this method.
In the hot forging method, the part is heated above the recrystallization temperature. The method of producing hot forging can be considered as a modified method in comparison with cold forging and hot forging. The hot forging process will be between the two methods. It is important to know that in the hot forging method, heat is transferred from the hot part to the die. This process leads to a drop in the temperature of the piece and will cause variable properties during the process.
Advantages of hot forging
- It can be boldly said that the disadvantages of cold forging are among the advantages of hot forging method, because in this method, production of parts with medium to very large sizes is possible and the price will be affordable.
- The production process of parts will be less.
Bolts are usually made in one step.
- Easy forming of strong metals by hot forging method is possible.
- Unlike the cold forging method, which had a limit on the number of parts produced, there is no specific limit on the size of the length and the size of the parts.
Disadvantages of hot forging method
- Accurate control of the heating process among workers is important.
- Surface oxidation of the metal is common and requires shot blasting or acid washing.
- This method has dimensional accuracy and speed, more limited production volume than cold forging.
