subject: The Hot Extrusion Process - The Way It Is Performed And Its Sub-processes [print this page] The extrusion process can be classified into hot extrusion, warm extrusion and cold extrusion. These three forms differ in the temperatures to which metals are put through and many other aspects. To make things clearer, let me start by describing the word extrusion.
What is extrusion?
Extrusion is a procedure used in metals to convert them into different shapes. The end products are then used in several sectors such as automobile and aircraft firms. The process of transforming the metal is accomplished by punching it into a number of dies until the desired shape is achieved. Machineries and equipment that come in various sizes and functionalities are used in order to do things easier and more efficiently.
What is Hot Extrusion?
Hot extrusion can also be referred to as hot working. It is the technique where a piece of metal is deformed or melted by using heat higher than its recrystallization temperature.
Hot extrusion may involve various sub-processes and they include drawing, forging, rolling and rotary perforating.
In drawing, tensile forces are used to stretch a metal. You could do any of the following drawing types: sheet, bar, tube or wire drawing.
In forging, localized compressive pressure do the job. There are around seven most popular types and they are: drop, roll, press, upset, automatic hot, net-shape, near-net-shape, and induction forging.
In rolling, a pair or number of rolls are used where a metal stock can easily penetrate. Flat, ring, and foil rolling are basically three of the common rolling processes used today.
In rotary piercing, smooth tubing that has thick walls is created. This procedure has two types: the Stiefel process and the Mannesmann process.
What are the benefits of hot extrusion over the other extrusion techniques?
Some of the benefits of doing hot extrusion are the following:
1. The material created via hot extrusion is more ductile than the material produced via other procedures.
2. It is much easier to perform hot extrusion since it requires less force and energy.
3. During the deformation process, the pores seen in the metal are reduced in size or are thoroughly closed up.
4. Because this process is carried out at quite high temperatures, chemical inhomogeneities are curtailed or are totally eliminated.
But, just like other things in this world, hot extrusion also has drawbacks. Here are some:
1. There might be undesirable reactions that may result from the exposure of the metal to the atmosphere of the surroundings.
2. You may need to purchase costly equipments for example an induction heater or a diesel furnace.
