In our life, electric heating wire is the most common heating element. It is a functional alloy material that generates heat after power on and converts electric energy into heat energy. Its maximum working temperature can reach more than 1000 degrees Celsius. Electric heating wire will be used as heating element in metallurgy, construction, military industry, household appliances and other fields. Let's follow Xiaobian to understand the classification and quality identification methods of electric heating wires.
The classification of electric heating wires is based on the different chemical element content and organizational structure of electric heating wires. Electric heating wires are divided into iron chromium aluminum alloy electric heating wires and nickel chromium alloy electric heating wires. These two kinds of electric heating wires, as electric heating elements, have different functional characteristics.
1. Iron chromium aluminum alloy heating wire
Advantages: high operating temperature, up to 1400 ℃. Fe Cr Al alloy heating wire has long service life, high resistivity, high surface load and good oxidation resistance.
Disadvantages: the strength is low in high temperature environment. With the increase of temperature, the plasticity of iron chromium aluminum alloy heating wire will increase, that is to say, iron chromium aluminum alloy heating wire is easy to deform at high temperature and is not easy to repair after deformation.
2. Nickel chromium alloy heating wire
Advantages: it has high strength in high-temperature environment, is not easy to deform and change the structure after long-term high-temperature operation, and the normal temperature plasticity of Ni Cr alloy heating wire is good, and the repair after deformation is relatively simple. In addition, nickel chromium alloy heating wire has high emissivity, no magnetism, good corrosion resistance and long service life.
Disadvantages: nickel needs to be used in the manufacture of nickel chromium alloy heating wire. The price of this metal is higher than that of iron, chromium and aluminum. Therefore, the manufacturing cost of nickel chromium alloy heating wire is high, which is not conducive to cost control.
Quality identification method of electric heating wire:
First of all, we should know that the heating wire reaches the red hot state, which is related to the structure of the heating wire. Cut off a section of electric heating wire and use 8V 1A transformer. The resistance value of electric heating wire or electric heating wire of electric blanket shall not be less than 8 ohms, otherwise the transformer will be easy to burn. With a 12V 0.5A transformer, the resistance of the heating wire should not be less than 12 ohms, otherwise the transformer is easy to burn out. If the electric heating wire reaches the red hot state, the more red it is, the better. 8V 1A transformer should be used, and its power is greater than 12V 0.5A transformer. In this way, we can better test the advantages and disadvantages of the electric heating wire.
