What is Metal Heat treatment?
What is Metal Heat treatment?
How should I do heat treatment for my workpieces to meet my technical requirements and characteristics for precise and long-life use?
Metal heat treatment has been lasting for more than 3000 years. Since then, the process has changed dramatically, from traditional open flame heating to heating the workpiece in special furnaces capable of controlling the temperature in a vacuum, gas, or chemical environment. Heat treatment equipment is improved year by year to increase enterprise efficiency, reduce comprehensive costs, and optimize process management. Heat treatment of various metals is a complex and responsible process. Violation of technical operations will not achieve the required quality and performance of the product.
Why is a metal heat treatment furnace needed?
Metal heat treatment is a group of processes that give workpieces or parts the desired properties. Most commonly, this involves parameters such as hardness, flexibility, and improved formability. The properties of the material are also often changed under the influence of chemical processes, for example, the surface of the part is filled with nitrogen or carbon compounds to increase strength and wear resistance, as well as the ability to work in a corrosive environment.
Heat treatment equipment allows you to perform the following series of processes.
· Hardening – the hardness of the metal increases after heating to a certain temperature, depending on the composition. After this, the metal is rapidly cooled. In the process, special hot furnaces are used to harden the metal.
· Tempering – a process carried out after the material has hardened to reduce brittleness and relieve stress. It also increases the flexibility of the part, thus simplifying its further processing. The material of the part is uniformly heated to a temperature that changes the metal structure.
· Annealing – during the heating to a given temperature, the physical-mechanical properties change, which then slowly decrease with the furnace temperature.
· Normalizing – the operation is the same as annealing, except that the cooling process is carried out in the open air, which significantly speeds up the process compared to annealing.
The main types of furnaces for the heat treatment of metals
Depending on the task, industrial enterprises use the following types of furnaces for processing metals:
1. Vacuum furnaces. The material is heated in a vacuum, which increases the efficiency of processing – the heated material does not come into contact with the air, eliminating surface oxidation. Among the advantages, it is worth noting that this furnace allows uniform heating of the part, due to the uniform distribution of heat in the furnace chamber. Depending on the design, they can be vertical or horizontal.
2. Box furnaces for heat treatment of metals. They are most often used to harden metals, but due to a wide range of temperature conditions, they can solve many other problems, including laboratory research. The heating process of the workpiece takes place in an air environment at a temperature of 50 to 1250°C.
3. Salt bath furnace. In this type of furnace, the metal is in molten salt. This allows high equipment efficiency and uniform heat distribution. Using active ingredients, many chemical processes can be carried out, including nitriding, carbonitriding, carburizing, and light burning.
4. Quenching furnace in a gas environment. Heating in a gas environment is characterized by precise and uniform heating. Using this method, the production process can be significantly accelerated.