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 production of electrical engineering.
Basic qualities of nichrome
Nichrome different:
- high heat resistance. At high temperatures, its mechanical properties do not change;
- plasticity, which allows the production of nichrome spirals, wires, tapes, threads from the alloy;
- easy handling. Products made of nichrome are well welded, stamped;
- high resistance to corrosion in various environments.
- nichrome resistance is high.
Basic Features
- Densityis 8200-8500 kg/m3.
- Nichrome melting point - 1400 C.
- Maximum operating temperature - 1100°C.
- Strength - 650-700 MPa.
- Nichrome resistivity 1.05-1.4 Ohm.
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 appliance has elements made of nichrome.
Letter wire marking:
- "H" - usually used in heating elements.
- "C" - used in resistance elements.
- "TEN" - intended for tubular electric heaters.
According to domestic standards, there are several main brands:
- Double wire Х20Н80. The composition of the alloy includes: nickel - 74%, chromium - 23%, as well as 1% each of iron, silicon and manganese.
- Triple Х15Н60. The alloy consists of 60% nickel and 15% chromium. The third component is iron (25%). The saturation of the alloy with iron makes it possible 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 workability is improved.
- The cheapest version of nichrome is Х25Н20. It is an iron-rich alloy in which the mechanical properties are maintained, but the service temperature is limited to 900°C.
Use of nichrome
Thanks to its quality andunique characteristics of nichrome products can be used where reliability, strength, resistance to chemically aggressive environments and very high temperatures are needed.
Nichrome coils and wires are an integral part of almost all types of heating appliances. Nichrome is present in toasters, bakeries, heaters, ovens. The alloy has also found use in resistors and rheostats operating at high temperatures. There is nichrome in electric lamps and soldering irons. Nichrome coils are heat-resistant and highly resistant, making them suitable for use in high-temperature drying and firing ovens.
Finds use and scrap nichrome. It is melted down, and the material is used again. An alloy of nickel and chromium is used in chemical laboratories. This composition does not react with most alkalis and acids. Deformed nichrome heating coils are used in electronic cigarettes.
Compared to the iron previously used for these purposes, nichrome products are safer, do not spark, do not rust, do not have melted areas.
The melting point of nichrome is 1400°C, so when cooking, no odors and fumes are felt.
Engineers are still exploring the unique properties of this material, constantly expanding its scope.
At home, nichrome wire is used to make homemade equipment, jigsaws and cutters, such as a foam cutting machineor wood, soldering iron, wood burner, welding machines, household heaters, etc.
The most popular wire is X20H80 and X15H60.
Where can I buy nichrome wire
This product is sold in rolls (coils, coils) or in the form of a tape. The cross section of nichrome wire can be in the form of an oval, a circle, a square, and also a trapezoid, the diameter ranges from 0.1 to 1 mm.
Where can I get or buy nichrome products? We suggest considering the most common and possible options:
- First of all, you can contact the organization that manufactures these products and place an order. You can find out the exact address of such enterprises in special references for goods and services, which are available in almost all major cities and towns. The operator will be able to suggest where to purchase, and will give a phone number. In addition, information about the range 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 who sell radio components, spare parts and other metal products.
- Any hardware store.
- On the market you can buy some old device, for example, a laboratory rheostat, and take nichrome.
- Nichrome wire can also be found at home. For example,it is from it that the spiral of the electric tile 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 marking.
Nichrome spiral winding
Today, the nichrome coil is one of the main elements of many heating devices. After cooling, nichrome is able to retain its plasticity, so that a spiral of such material can be easily removed, changed its shape or, if necessary, adjusted to a suitable size. Spiral winding 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, when winding, you can make a calculation, so to speak, “by eye”. To do this, select the required number of turns depending on the heating of the nichrome wire, while periodically including the spiral into 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 calculating the winding of the spiral, you can use a special online calculator.
Having calculated the required number of turns, you can start winding on the rod. Without cutting the wire, carefully connect the nichrome coil to the voltage source. Then check the correctness of the calculations for the winding of the spiral. It is important to consider that for closed-type spirals, the winding length must be increased by a third of the value obtained in the calculation.
To ensure the same distance between adjacent turns, you need to wind the winding into 2 wires: one is nichrome, the second is any copper or aluminum, with a diameter that is equal to the desired gap. When winding is completed, the auxiliary wire should be carefully wound.
Nichrome cost
The only drawback that nichrome has is the price. So, a two-component alloy when purchased at retail is estimated at about 1,000 rubles per kilogram. The cost of nichrome stamps 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, the physical characteristics of the diameter, cross section, length, etc. It is also important to take an interest in the documentation of compliance. In addition, you need to be able to visually distinguish the alloy from its, so to speak, “competitors”. The correct choice of material is the key to the reliability of electrical engineering.
