GOST 26469-85 palladium-tungsten alloy wire. technical conditions

Characteristics of nichrome wire

Nichrome wire.

The presented alloy is distinguished by the presence of two main components - nickel and chromium. Silicon, aluminum, manganese, iron, titanium, zirconium can also be included in the composition of nichrome as filler elements. The quantitative ratio of these ligatures makes it possible to judge a certain type of nichrome.

At present, the production of two grades of wires based on alloys has been established: Х20Н80 and Х15Н60. Kh20N80 contains about 70-75% nickel, 20-25% chromium and 0.8-1% iron. It has the following properties:

• working temperature - 1250-1300 С;
• resistivity for wire over 3 mm in diameter. - 13 Ohm * mm / m;
• density - 8.5 g / cm3;
• specific heat capacity - 0.44 kJ / kg · K.

The insignificant iron content in this alloy indicates its low magnetic properties. This has a positive effect on its corrosion resistance and wear resistance.

Kh15N60 is also characterized by the predominance of nickel - 60-65% and chromium - 15-18%. The presented alloy is noticeably inferior to its analogue in terms of basic technical indicators.

• working temperature - 1000-1100 С;
• resistivity for wire with a diameter over 3 mm. - 12 Ohm * mm / m;
• density - 8.0-8.5 g / cm3;
• specific heat capacity - 0.46 kJ / kg · K.

Due to the high content of iron, the concentration of which can reach 3%, this type of nichrome is endowed with magnetic susceptibility, which does not allow us to speak of a high corrosion resistance of the alloy. Nevertheless, due to the low density of the nichrome wire made of this alloy, it becomes possible to produce specimens with a smaller cross-section, characterized by greater ductility.

Ferronichrome is characterized by high mechanical strength and is not inferior to more alloyed alloys in terms of heat resistance when used in aggressive environments.

Peculiarities

For the manufacture of tungsten wire - GOST 18903-73 - forged rods are used. In the course of drawing, a gradual decrease in the temperature regime is carried out. After that, the product is cleaned by annealing and electrolytic polishing.

The raw material for the manufacture of this type of wire products is the most refractory metal. This material is heat-resistant and durable, it is not afraid of acidic and alkaline environments. Such characteristics make it possible to use tungsten wire for the production of parts intended for operation under heating conditions, as a result of which they do not lose their original properties.

Mechanical parameters characteristic of this type of wire products (increased hardness, resistance to wear during heating, low value of thermal expansion), exceeding many similar materials, make tungsten products very popular.

This type of rolled metal is distinguished by a high modulus of elasticity, excellent ohmic resistance, and good thermal conductivity. It is a durable and reliable material that can withstand extreme operating conditions, making it indispensable in a variety of manufacturing industries.

There are several brands of such wire. The classification is carried out in accordance with the cross-sectional diameter and the percentage of tungsten in the composition of the material.

The wire diameter can be from 12.5 to 500 microns.

The most popular brand is VA. The BPH brand is used for the production of cathodes for electronic devices.

The brands of tungsten rolled metal VM, VT are also in demand.

It is the brand that determines the scope of the material.

Applications

Tungsten wire is used in various spheres of production and the national economy. It is used to make spirals and spring elements for incandescent light bulbs.

The tungsten-rhenium variety (BPH) is used for the production of traverses.

Tungsten is a refractory metal, therefore, wire products based on it are indispensable for creating resistance elements in heating devices. It is contained in thermoelectric converters, loop heaters.

The process of manufacturing tungsten rolled metal is rather complicated with the use of powder metallurgy techniques. It is very popular in the electrical and radio engineering industries. It is actively used in the creation of LCD television screens. The most demanded wire products are tungsten anhydride and are obtained from the salts of this metal.

On its basis, parts of X-ray equipment are made, which during operation are subjected to vibrations and strong heating. Meshes and filtering mechanisms based on it are used in the chemical industry.

Where to get it at home?

Many are interested in where to find tungsten wire at home. It is a component of all heating parts of household appliances.

It is present in old versions of irons, electric kettles. If you have an old fan heater at home, remove the wire strands from the heaters. It's easy to get it out of broken toasters. It is also found in the heating elements of washbasins. To remove the wire, the heating elements are carefully opened with a grinder. It will only be necessary to clear the wire products from insulation.

Tungsten rolled metal, resistant to wear and adverse external influences, has proven itself well. Its deliveries are carried out not only in coils, but also in coils.

Areas of application of nichrome wire

The specific properties of nichrome have found their application in various fields of activity, both domestic and industrial.

All kinds of this alloy are used as heating elements for various devices: electric ovens, dryers, thermocouples, as well as in ceramic products, playing the role of a supporting frame.

Nichrome wire, as the main actuator of electric heating devices, in most cases is a spiral through which an electric current of a given value is passed. This form is recognized as the most optimal for these devices, since it allows you to achieve greater heat transfer by increasing the length of the conductive element. The high degree of plasticity of the presented material significantly increases the service life of such devices, due to the high resistance to deformation.

Where to get nichrome wire at home? This alloy is widely used in various household appliances. Examples include electric heaters, hair dryers, soldering irons, toasters, and ovens. In addition, they are used in electronic cigarettes.

Nichrome wire: selection criteria

The implementation of the project for the creation of various types of electrothermal equipment presupposes a thorough analysis of the nominal operating parameters, which will serve as a starting point in calculating the key indicators of nichrome wire.

First of all, it is necessary to calculate the electrical resistance of the working element. It depends on three physical quantities, namely: the resistivity of the material, its length and cross-sectional area. The formula for calculating active resistance is as follows: R = ρ l / S.

To obtain the missing data, it is necessary to calculate the length of the spiral. Depending on the voltage applied to it, you should dwell on the most optimal value for the length of the wire, its diameter, and the size of the core.In order to save yourself from time-consuming calculations, you can use the pivot table, which gives the values ​​of the length of the spiral, depending on the diameter of the wire and core for nichrome with a diameter of 0.2 to 0.5 mm.

The presented table is applicable for calculating the length of the spiral when using a voltage of 220 V. For example, for a wire with a diameter of 0.4 mm and a core diameter of 3 mm, the length of the spiral for a household electrical network will be 40 cm.It should be noted that using this table it will not be difficult to calculate the desired value for a voltage of 380 V. To do this, it is enough to select the necessary data and make a proportion of the following form: 220 V - 40 cm / 380 V - x.

In the event that a measuring tool was not at hand and it is not possible to determine the diameter of the wire, you can always use a simple, but at the same time effective method. To do this, it is enough to take an ordinary pencil and wind a wire around it, tightly pressing turn by turn. In the event that 10 turns of the spiral fit into 1 mm. the length of the pencil, then the diameter of the wire will be 1 \ 10 mm.

About the nuances of tungsten wire production

For the manufacture of tungsten wire, powder bars are used, which are rolled on a rotary forging machine. The workpieces are heated and drawn by the drawing method. This produces a tungsten wire with a diameter of 1 to 10 mm. Rolled metal can be thinner. It is called a tungsten filament. Some grades of tungsten wire can be alloyed with cobalt, chromium, carbon. The presence of such impurities improves the strength of the rolled metal.

The production of drawn wire of groups A, B, C (it is called black) is carried out by the method of powder metallurgy. Such rolled metal products include VA, VNR and VCh brands. From one kilogram of tungsten, it is possible to obtain a filament, the length of which is 3.5 km and it is enough for the manufacture of filaments of 20,000 lamps with a nominal power of 60 watts.

About the application of tungsten wire

Tungsten wire of the VM brand is used in radio electronics and X-ray engineering for the production of cathodes and heaters for electronic devices designed for operation at high temperatures (2100 ° C) in harsh conditions. The BPH brand is chosen for the manufacture of springs, hooks, cathodes of electronic and gas-discharge devices and other parts that, in addition to the properties of tungsten, must have additional characteristics obtained by adding special additives to the composition.

The high ohmic resistance and unique light output of tungsten makes it indispensable in the production of incandescent lamps. The production of tungsten filament from grades VA, VCh, VRN is carried out in accordance with GOST 19671-9. The diameter of rolled metal can vary from 19.5 microns to 1.5 mm. Tungsten wire is also required for the production of helical and non-helical cathodes and springs for electrical appliances, loop cathodes, heaters. The chemical industry needs a variety of tungsten wire screens and filters. It is also needed in surgery, rocketry, mechanical engineering and aircraft construction, and the textile industry. The most critical parts and assemblies are made from tungsten wire.

Non-consumable tungsten electrodes are distinguished by exceptional heat resistance, thermal stability and operational reliability. With their help, steel, aluminum, copper, brass sheet metal products are welded. The weld seam is thin and even.

Scope of metal and alloys with it

Tungsten is a very common metal in industry and everyday life. The range of its application is very wide.It is used in areas such as:

• medicine;
• Automotive industry;
• military equipment;
• space industry;
• Appliances;
• temperature and radiation monitoring devices;
• metalworking industry.

At home, it can be found in the filaments of lighting fixtures, which consist of almost pure tungsten.

There is a lot of this non-ferrous metal in:

• cathode-ray tube picture tubes;
• X-ray machines;
• in the cathodes of vacuum tubes.

Hard alloys of tungsten with titanium and cobalt are used in metalworking due to their wear resistance. These include:

• VK8 and VK6 with a content of 92 and 94 percent tungsten, respectively;
• TK alloys with a tungsten content from 65 to 85 percent;
• TTK alloys - 81-82 percent.

Heavy alloys of tungsten with the ability to absorb gamma radiation are used for the manufacture of containers for radioactive substances. Rotors and gyroscopes are made from copper alloys, since they are non-magnetic.

Heavy alloys include:

• VD, VND, VNM - alloys of tungsten with copper, as well as tungsten and copper with nickel. The price per kg of such alloys depends on the amount of the main element (tungsten), which ranges from 75 to 98 percent.
• Residence permit - an alloy of tungsten with iron. About 90 percent of the metal we need is present.

Tungsten in the composition of alloys is contained in industrial tools:

The content of the metal of interest to us in these tools is much lower, but such alloys are still readily accepted by buyers.

In the names of high-speed alloys, the letter R is put at the beginning. Examples - Р6М5, Р18. They contain 6 to 18 percent tungsten.

In the automotive industry, this metal is used to make the electrical contacts of the ignition distribution system.

In the military industry, tungsten is used as the cores of projectiles and tungsten bullets due to its high density, which is almost 2 times higher than that of lead.

In this case, residence permit stamps are used.

Varieties of wire for stainless steel 12x18n10t

To weld stainless steel parts, it is necessary to use argon arc welding and an additive made of the same material. It can have different properties, which may be suitable for other cases. Long products are produced from 12 × 18N10T steel. The filler material of this grade must meet the requirements of GOST 18143-72.

Welding filler wire has found its application in the machine-building and food industries, at construction sites, etc. It has not only high corrosion resistance, but also resistance to the effects of chemically aggressive environments. It contains a sufficient amount of chromium, which protects it from rust.

For welding, products made using cold drawing technology are used. It has a fairly low price and at the same time, such processing retains all its properties. This wire ensures the quality of the seam when processing any material.

Stainless wire 12X18H10T

So, water supply systems are often assembled from pipeline fittings made from this steel grade. When assembling and repairing, the use of a welding additive of 12X18H10T grade is considered optimal.

This steel grade is available in several versions. Hot or cold rolling technologies are used for its production. They make it possible to obtain a product with a diameter of 0.2 to 6 mm. When using wire of this brand, it must be borne in mind that it can change some of its parameters based on the diameter.

Welding stainless steel parts is a complex technological process and if you violate its rules, the result can be a large number of substandard products. To avoid this, it is necessary to make the right choice of wire material.Wire made of steel 12X18H10T is a specific product and may not be suitable for most types of alloy steel. The main rule for choosing a material for welding is the identity of the chemical composition. The wire made from this wire is good because the industry produces a wide range and, as a rule, there are no problems with the choice. By the way, when welding, preheating and smooth cooling may be required. Heating is performed using a gas burner.

Major sources of scrap

The paradox of this rare metal is that it can be found even in an ordinary residential building.

It is found in incandescent light bulbs and in the windings of electric furnaces. These are the main sources of tungsten for ordinary citizens and individuals.

However, it is very, very difficult to accumulate a sufficient amount for the delivery of this non-ferrous metal from these sources.

Therefore, those who want to profit from several dozen bulbs usually turn to resellers.

Recently, tungsten incandescent lamps have become unpopular. This is because energy-saving light bulbs or LED bulbs that do not contain this metal have come into use.

Also, tungsten is contained in the victorious soldering of concrete drills, which are also found in everyday life. It contains more of the basic element, but it is not a pure metal, but one of its alloys - "win" or VC with cobalt.

Recyclable materials are handed over by state and private enterprises that specialize in metalworking. Used tools from high-speed steels are taken from them:

• incisors;
• cutters;
• borax;
• cutting discs and so on.

Do not forget that tungsten is distributed in the form of a finished product:

And also in the form of production waste:

Tungsten dust is weighed in grams and, accordingly, the price is also set per gram.

Usage

The VM brand is used in X-ray technology and radio electronics, for the manufacture of heaters and cathodes for electronic devices, which are designed for operation under vibration, shock, t ° 2100 ° C. The VRN brand is used for the manufacture of springs, hooks, cathodes of gas-discharge and electronic devices, bushings, traverses and other parts that do not require tungsten with special additives.

High resistance and unique light output allow the use of a thin tungsten filament in incandescent lamps. A tungsten filament for lighting devices is made in accordance with GOST 19 671-91 from VA, VRN, VCh, ∅ 19.5 μm - 1.5 mm. Also, springs of electronic devices, spiral and non-spiral (loop) cathodes for electronic devices, grids, heaters are made from it. Various filters, tungsten wire mesh are used in the chemical industry. This wire is used for the production of surgical instruments, rocket parts, aircraft, and textile equipment.

Tungsten wire (GOST 18 903−73)

Provider

The company "Auremo" offers to buy a tungsten wire, thread, the price is the most favorable today. A large selection of high quality products is always available in the warehouse. Compliance with GOST and international quality standards. Availability of goods and efficiency of delivery are ensured by representative offices located in Moscow, St. Petersburg, cities of Eastern Europe. Always available tungsten wire, thread, the price depends on the volume of the order and additional terms of delivery. Preferential discounts are available for bulk purchases.

Tungsten-carbon compounds

Tungsten carbides are considered to be very important from a practical point of view. They are used for the manufacture of hard alloys. Compounds with carbon have a positive coefficient of electrical resistance and good metal conductivity. Tungsten carbides are formed of two types: WC and W₂C. They differ in their behavior in acids as well as in their solubility in other compounds with carbon.

Two types of hard alloys are made on the basis of tungsten carbides: sintered and cast. The latter are obtained from a powdery compound and carbide with a C deficiency (less than 3%) by casting. The second type is made from tungsten monocarbide WC and a cementing metal-bond, which can be nickel or cobalt. Sintered alloys are produced only by powder metallurgy. The cementitious metal powder and tungsten carbide are mixed, pressed and sintered. Such alloys have high strength, hardness and wear resistance.

In the modern metallurgical industry, they are used for metal cutting and for the manufacture of drilling tools. One of the most common alloys are VK6 and VK8. They are used for the manufacture of cutters, cutters, drills and other cutting tools.

The field of application of tungsten carbides is quite voluminous. So, they are used for making:

• armor-piercing supplies;
• parts of engines, aircraft, spaceships and rockets;
• equipment in the nuclear industry;
• surgical instruments.

In the West, tungsten carbides are especially widely used in jewelry, especially for making wedding rings. The metal looks beautiful, aesthetically pleasing, and is easy to process.

This is because they are incredibly durable. It will take a lot of effort to scratch such a product. Even after a few years, the ring will look like new. It will not fade, the relief pattern will not be damaged, and the polished part will not lose its luster.

Tungsten and rhenium

The alloy of these two elements is widely used for the manufacture of high-temperature thermocouples. Tungsten - what metal? Like rhenium, it is a heat-resistant metal, and the alloying of elements reduces this property. But what if you take two almost identical substances? Then their melting point will not decrease.

If rhenium is used as an additive, an increase in the heat resistance and ductility of tungsten will be observed. This alloy is obtained by melting in powder metallurgy. Thermocouples made from these materials are heat resistant and can measure temperatures above 2000 ° C, but only in an inert environment.Of course, such products are expensive, because only 40 tons of rhenium are mined in one year and only 51 tons of tungsten.

* depends on the course $

LLC "Snab-Resource" buys out tungsten scrap for recycling on favorable terms. Many of us are familiar with this element from incandescent lamps - thanks to the tungsten silver filament, they give light. The prices for tungsten scrap acceptance are high, because this material is very valuable and in demand.

The high price of tungsten is directly related to its unique properties and rarity in nature. Its features are hardness, refractoriness and high specific gravity. The main field of application is metallurgy. The metal is used for the preparation of alloys, the manufacture of parts. About 95% of the tungsten used in industry is in the metallurgical industry.

LLC "Snab-Resource" accepts tungsten scrap from individuals and organizations. It can be waste, illiquid assets and even marriage.

Varieties of wire for semiautomatic devices

The selection of welding wire for semiautomatic devices should be carried out for a specific type of metal to be joined. The use of an additive consumable material significantly improves the quality of the seam, prevents the formation of pores and irregularities in the joint.

The main advantages of using the additive when performing welding are presented:

• acceleration of the welding process;
• ease of use in the industrial field;
• a significant decrease in the likelihood of defects due to the lack of additive coating;
• a large selection of consumables, allowing you to select the optimal additive for each specific case;
• low level of slag formation during welding.

Disadvantages of using a filler component when welding:

• the need for constant protection;
• difficulty in storing large skeins;
• difficulty in selecting the optimal diameter of the additive;
• the need to constantly use flux.

Wire grades table.

All types of welding wire are generally divided into:

1. Copper-plated.
   This type of wire is used for welding carbon and low alloy steel parts. Copper-plated steel fillers ensure a good weld and low metal spatter.
2. Powder.
   Additive components of these grades are made in the form of a hollow tube made of mild steel. Deoxidizers and slag-forming substances are placed inside the tank, ensuring comfortable use of semi-automatic welding without shielding gas. Flux-cored filler wires help to significantly reduce slag formation and reduce the time required to work the weld.
3. Solid section.
   This type of wire differs from the usual one in that welding electrodes are made from it.
4. Non-copper plated.
   Additives of this type are used primarily for working with low-carbon steel products.
5. Activated.
   Powder additives used when welding in a carbon dioxide atmosphere.
6. Gas welding.
   For carbon and low carbon steel grades, it is best to use gas welding consumables.
7. Aluminum.
   One of the few wire types suitable for welding aluminum parts. When working with an aluminum additive, the porosity of the welds is low. Such additives are actively used in the shipbuilding and dairy industries.
8. Stainless steel.
   The filler component allows welding stainless steel products and prevents corrosion of the resulting weld.
9. Flux.
   This type of filler wire is widely used for joining medium carbon, low carbon and carbon steel grades. Due to the presence of a built-in flux, such additives can be used when welding without shielding gas.
10. Doped.
    One of the best components for welding in any gas mixture and with any kind of metal.

Resistance calculation

Electrical resistance is of particular importance in situations where wire is used as a winding for transformers and generators. After all, if the resistance is too large, then in the event of an emergency, the winding may ignite, which can lead to catastrophic consequences.

Resistance formula

For an accurate calculation of resistance, the following formula is used: R = (P x L) / S. It stands for this:

• R is the total resistance. We need to find this parameter as a result of calculations (units of measurement - Ohm).
• P is the resistivity of the material. This indicator is a physical constant, and it depends on the type of chemical element. For copper, the constant P will be 0.0175 (units - (Ohm x mm x mm) / m).
• L is the total length in meters. The larger it is, the higher the resistance of the conductor will be.
• S is the cross-sectional area in square millimeters. This parameter also affects the final resistance - the less it is, the higher the resistance will be.

Please note that the S parameter is usually indicated in the technical documentation, however, instead of the cross-sectional area, sometimes only the wire cross-sectional diameter is indicated. In this case, it is necessary to calculate the area using the formula: S = (Pi x d x d) / 4

This formula is deciphered as follows:

• Pi is a mathematical constant that is approximately 3.14.
• d is the cross-sectional diameter of the conductor in millimeters.

As a result, the resistance of the copper wire is measured by two formulas: R = (P x L) / S = (4 x P x L) / (Pi x d x d).

Examples of tasks

Let's try to solve a few simple problems:

• Task 1. Determine the resistance of a wire, the length of which is 100 meters, and the cross-sectional area is 5 square millimeters. In our problem, the area parameter is known, so we will use the first formula R = (P x L) / S. Substitute our values: R = (0.0175 x 100) / 5 = 0.35 ohms.
• Task 2. Determine the resistance of a wire with a length of 500 meters and a cross-sectional diameter of 2 millimeters. In this problem, the diameter is known, so we will use the second formula R = (4 x P x L) / (Pi x d x d). Substitute our values: R = (4 x 0.0175 x 500) / (3.14 x 2 x 2) = 2.78 ohms.

Tungsten Acceptance Conditions

It is important to note that different companies have different approaches to the reception of recyclable materials. However, despite this, there are a number of general rules that enterprises of all types try to adhere to.

Both individuals and legal entities have the right to hand over tungsten scrap when posting scrap metal at the enterprise. When it is received, an analysis is carried out and the exact content of pure metal and impurities is determined. This procedure is carried out using special instruments - analyzers of metals and alloys.

The final price may vary depending on the composition of the tungsten alloy and the presence of various additives in it.

However, the cost in any case remains very high, since rare non-ferrous metals are used as impurities.

Recyclable materials with different content of the main element from 5 to 99% are accepted.

Large enterprises that ensure safe and documented transactions place increased demands on the quality of scrap and for individuals or legal entities who hand over the metal, namely:

1. Reception of scrap is carried out in accordance with state standards, and the transaction must not contradict regulatory enactments.
2. Metal can be accepted from an individual only upon presentation of an identity document.
3. Recyclable materials are accepted only in their pure form without any dirt and impurities.

Military, nuclear and aerospace products are being evaluated more carefully, with particular emphasis on radiation monitoring

It is important to understand that many companies that accept tungsten scrap set a minimum weight of one kilogram, and large ones - from 50 and more. Of course, there is an opportunity to find small buyers through ads, but the price can be much lower

Of course, there is an opportunity to find small buyers through ads, but the price can be much lower

It is important to understand that many companies that accept tungsten scrap set a minimum weight of one kilogram, and large ones - from 50 and more. Of course, there is an opportunity to find small buyers through ads, but the price can be much lower