The service life of FeCrAl wire

The service life of FeCrAl wire heating wire is affected by multiple factors. The following is a specific analysis:
I. In terms of material purity
1. High purity advantage: When FeCrAl wire heating wires are made from high-purity raw materials, the impurity content is extremely low. Impurities often trigger local chemical reactions or form weak points during the operation of the heating wire. For instance, certain impurities may react more easily with oxygen in the air, accelerating the oxidation rate. High-purity FeCrAl wire heating wires, due to their low impurity content and more uniform and stable internal structure, can effectively reduce defects caused by impurities, thereby extending their service life. In some industrial heating equipment with extremely high requirements for the lifespan of heating wires, high-purity FeCrAl wire heating wires are selected, and their service life can be extended by 2 to 3 times compared to products of ordinary purity.
2. Impurity influence: If the purity of the raw materials is insufficient and they contain a large amount of impurities, in a high-temperature environment, the impurities will accelerate the deterioration of the heating wire. For instance, some sulfide impurities can react with iron, chromium and aluminum to form low-melting-point compounds. During the heating process of the heating wire, these low-melting-point areas are prone to melt first, causing the heating wire to break and significantly shortening its service life.
Ii. Working Temperature level
1. Advantage of low-temperature operation: When FeCrAl wire heating wire works at a relatively low temperature, the thermal motion of the atoms inside it is relatively slow. This results in a relatively small change in the microstructure of the heating wire and a relatively slow oxidation rate. For instance, when operating below 800℃, the oxide film formed on the surface of iron, chromium and aluminum is relatively dense and stable, which can effectively prevent the internal metal from further oxidation, thereby extending the service life of the heating wire. Some low-temperature heating devices in laboratories use FeCrAl wire electric heating wires at 600-700 ℃ for a long time, and their service life can reach several years.
2. High-temperature hazard: When the working temperature exceeds a certain range, such as reaching above 1200℃, the oxidation rate of FeCrAl wire heating wire will accelerate sharply. At high temperatures, the thermal motion of atoms intensifies, the growth rate of the oxide film accelerates but its structure becomes loose, losing effective protection for the internal metal. Meanwhile, the grains of the heating wire grow rapidly, leading to a decline in its mechanical properties and making it fragile and prone to breakage. When used continuously in such a high-temperature environment, the heating wire may be damaged within just a few hundred hours.
Iii. From the perspective of working environment
1. Good environmental advantage: In a dry, clean and non-corrosive gas working environment, the service life of FeCrAl wire heating wire will be relatively long. A dry environment can reduce electrochemical corrosion caused by water vapor, and a clean environment prevents dust and other impurities from adhering to the surface of the heating wire, which may affect heat dissipation or cause local corrosion. For instance, in the heating equipment of electronic device manufacturing workshops, the environment is relatively clean, and the service life of FeCrAl wire heating wires can be effectively guaranteed. Generally, they can be used for 1 to 2 years longer than similar heating wires used in harsh environments.
2. Hazards from harsh environments: If the working environment contains a large amount of corrosive gases, such as chlorine and sulfur dioxide in a chemical production workshop, these gases will undergo chemical reactions with iron, chromium and aluminum, accelerating the corrosion of the heating wire. In addition, a humid environment can also trigger electrochemical corrosion, causing rust spots to appear on the surface of the heating wire, which in turn reduces its electrical conductivity and mechanical strength, and shortens its service life. In such a harsh environment, FeCrAl wire heating wires may need to be replaced every few months.
Iv. Rationality of Design and Installation
1. Advantages of reasonable design and installation: When designing electric heating equipment, if the selection of FeCrAl wire electric heating wires is reasonable, fully considering factors such as their load-bearing capacity and uniform heating, and the installation process is standardized, it can ensure that the electric heating wires have good heat dissipation conditions and appropriate stretching degrees, etc. For instance, a reasonable wire winding method can ensure that the heating wire heats up evenly, avoiding local overheating. An appropriate installation spacing can guarantee good heat dissipation. In this case, the service life of the FeCrAl wire heating wire can meet the design expectations and it can generally be used normally for 3 to 5 years.
2. Hazards of unreasonable design and installation: If the design and selection are inappropriate and the heating wire operates under overload for a long time, it will cause its temperature to be too high, accelerating aging and damage. During the installation process, if the heating wire is stretched excessively or its bending radius is too small, stress concentration will form in these areas. As the heating wire expands and contracts due to heat, it is prone to break from these stress concentration points, seriously shortening its service life.

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