Types of Forging according to Temperature
Forged metal is used by many industries today. From Aviation to Defence, forging is used to give the metal a desired shape and added strength and flexibility. This article discusses three broad types of forging on the basis of temperature.
Forging is a process of shaping the work piece by applying forces through tools and giving it the desired shape. The work piece is processed by a hammer or by pressing it. Smiths invented this process thousands of years ago. The first forging was processed with the help of the hammer and anvil. It is the process of deformation of material with compressive stress. Earlier, forging was used for making coins, jewellery, weapons and many more things. Now, various companies are involved in forging. Today, you can contact any forge company for any kind of forging.
Based on the temperature of the work piece, forging can be classified into three groups: cold forging, warm forging and hot forging. All of these kinds are explained in detail:
Cold forging is performed at the temperature of the metal, which is going to be forged. This method is used for the metals that are usually soft even at room temperature. This kind of forging is usually used for carbon, aluminium and alloy steels. It is the least expensive method. Additionally, it requires either no or little finishing work.
The advantages of cold forging are it is least expensive, lubrication process is very easy, oxidation is not required in it, and it creates very less friction between the work piece surface and the die surface. Additionally, it is the faster process; hence, it saves your time.
The disadvantages of the process are, it requires expensive and powerful tools, it requires powerful equipment and designing is critical in this type of forging.
In warm forging, the temperature is kept high above the room temperature. The temperature varies from material to material, but the above range should be less than the recrystallization temperature. For e.g., steel is heated to 700 to 800 Celsius. In this forging, fewer tools are used as compared to the cold forging. Even the forging is more powerful.
The advantage of this kind of warm forging are; provides a good surface finish to the parts, less powerful tools are required and production rate is high. Whereas the disadvantage is, it has very less precise tolerance.
Very high temperature is required for hot forging. The temperature is kept above the recrystallization temperature. Excessive heat is required in it to protect the metal from hardening during the forging.
Recrystallisation is the temperature at which new grains are developed in the metal.
The advantages of hot forging are, as the temperature is very high; hence, the object flows very easily. It saves time and energy. The forged products are very sturdy and strong.
Disadvantages of hot forging are it is very costly, surface finish is very poor, and it is possible that the object will be wrapped during the forging process.
Now forging has become very easy with the help of heavy tools and machines. Various techniques employed now contribute to saving the time of forging and make it easy. One can easily find a forge company that takes up forging projects giving the desired results to its clients.