Nichrome was invented in 1905 by Albert Marsh, who combined nickel (80%) and chromium (20%). Today, there are about ten modifications of alloys of various grades. Aluminum, manganese, iron, silicon, titanium, molybdenum, etc. are added as additional alloying impurities. Due to its outstanding qualities, this metal has become widely used for the manufacture of electrical engineering.
The main qualities of nichrome
Nichrome is different:
- high heat resistance. At high temperatures, its mechanical properties do not change;
- ductility, which makes it possible to produce nichrome spirals, wires, ribbons, threads from an alloy;
- ease of processing. Nichrome products are well welded, stamped;
- high resistance to corrosion in various environments.
- Nichrome resistance is high.
Basic properties
- The density is 8200-8500 kg / m3.
- The melting point of nichrome is 1400 C.
- The maximum working temperature is 1100 ° C.
- Strength - 650-700 MPa.
- The resistivity of nichrome is 1.05-1.4 ohms.
Nichrome wire marking
Nichrome wire is an excellent material for various electric heating elements, which are used in almost all industries. Almost every household heating device has elements made of nichrome.
Literal wire marking:
- "N" - is used, as a rule, in heating elements.
- "C" - is used in resistance elements.
- "TEN" - is intended for tubular electric heaters.
According to domestic standards, there are several main brands:
- Double wire X20H80. The composition of the alloy includes: nickel - 74%, chromium - 23%, as well as 1% of iron, silicon and manganese.
- Triple X15H60. The alloy consists of 60% nickel and 15% chromium. The third component is iron (25%). The saturation of the alloy with iron allows you to significantly reduce the cost of nichrome, the price of which is quite high, and at the same time maintain its heat resistance. In addition, its machinability is increased.
- The cheapest version of nichrome is X25H20. It is an iron-rich alloy in which mechanical properties are retained, but the operating temperature is limited to 900 ° C.
The use of nichrome
Due to its high-quality and unique characteristics, nichrome products can be used where reliability, strength, resistance to chemically aggressive environments and very high temperatures are needed.
Nichrome spirals and wire are an integral part of almost all types of heating devices. Nichrome is present in toasters, bakeries, heaters, ovens. The alloy has also found application in resistors and rheostats operating under strong heating. There is nichrome in electric lamps and soldering irons. Nichrome spirals have heat resistance and considerable resistance, which allows them to be used in high-temperature drying and calcining furnaces .
Finds the use and scrap of nichrome. It is smelted, and the material goes back to business. Nickel-chromium alloy is used in chemical laboratories. This composition does not react with most alkalis and acids. Deformed heating nichrome spirals are used in electronic cigarettes.
Compared to iron previously used for these purposes, nichrome products are safer, do not spark, do not rust, and do not have melted areas.
The melting point of nichrome is 1400 ° C, so when cooking food, odors and burning are not felt.
Engineers are still exploring the unique properties of this material, constantly expanding the scope of its application.
At home, nichrome wire is used to make home-made equipment, jigsaws and cutters, such as, for example, a machine for cutting foam or wood, a soldering iron, a device for burning wood, welding machines, household heaters, etc.
The most popular is the wire X20H80 and X15H60.
Where can I get nichrome wire
The implementation of this product is carried out in rolls (bays, coils) or in the form of a tape. The cross section of the nichrome wire can be in the form of an oval, circle, square, or trapezoid, the diameter is in the range from 0.1 to 1 millimeter.
Where to get or buy nichrome products? We suggest considering the most common and possible options:
- First of all, you can contact the organization manufacturing this product and place an order. You can find out the exact address of such enterprises in special reference books on goods and services that are available in almost all major cities and towns. The operator will be able to tell where to buy, and give a phone number. In addition, information on the assortment of such products can be found on the official websites of manufacturers.
- You can buy nichrome products in specialized stores, for example, selling radio components, material for craftsmen such as Skillful Hands, etc.
- Buy from individuals selling radio components, spare parts and other metal products.
- In any hardware store.
- On the market you can buy some old device, such as a laboratory rheostat, and take nichrome.
- Nichrome wire can also be found at home. For example, it is from her that the spiral of the electric stove is made.
If you need to make a large order, then the first option is most suitable. If you need a small amount of nichrome wire, in this case you can consider all the other items on the list. When buying, be sure to pay attention to the labeling.
Nichrome spiral winding
Today, a nichrome spiral is one of the main elements of many heating appliances. After cooling, nichrome is able to maintain its plasticity, so that a spiral of such a material can be easily removed, changed its shape or, if necessary, adjusted to a suitable size. Winding spirals in industrial conditions is carried out automatically. At home, you can also carry out manual winding. Let's take a closer look at how to do this.
If the parameters of the finished nichrome spiral in its working condition are not too important, during winding it is possible to calculate, so to speak, “by eye”. To do this, you need to choose the right number of turns depending on the heating of the nichrome wire, while periodically including a spiral in the network and reducing or increasing the number of turns. This winding procedure is very simple, but it can take a lot of time, and part of the nichrome is wasted.
To increase the simplicity and accuracy of the calculation of spiral winding, you can use a special online calculator.
Having calculated the required number of turns, you can proceed to winding on the rod. Without cutting the wire, carefully connect the nichrome spiral to the voltage source. Then check the correctness of the calculations for winding the spiral. It is important to note that for closed spirals, the length of the winding should be increased by a third of the value obtained in the calculation.
To ensure the same distance between adjacent turns, it is necessary to introduce a winding into 2 wires: one is nichrome, the second is any copper or aluminum, with a diameter that is equal to the required gap. When winding is finished, the auxiliary wire should be carefully rewound.
The cost of nichrome
The only drawback that has nichrome is the price. So, a two-component alloy when buying at retail is estimated at about 1000 rubles per kilogram. The cost of nichrome brands with a ligature is about 500-600 rubles.
Conclusion
When choosing products from nichrome, it is necessary to take into account data on the chemical composition of the product of interest, its electrical conductivity and resistance, physical characteristics of the diameter, cross section, length, etc. It is also important to take an interest in documentation of compliance. In addition, you must be able to visually distinguish the alloy from his, so to speak, “competitors”. The correct choice of material is the key to the reliability of electrical engineering.