How much copper is in a welding machine

Copper welding: electrodes and technology, is it possible to weld using arc welding?

Copper welding is widely used in various fields of human activity. It is thanks to this that the technology for joining this material, like other non-ferrous metals, is constantly being improved.

It has a number of properties that make it special compared to other simple materials. Let's look at the work process in more detail.

Properties

First of all, it should be said about the dependence of welding quality on the purity of the material. The purer the copper, the better the connection will be.

Electrical circuit of a welding machine for copper welding.

In addition to the noted quality, a number of features of this element should be highlighted that influence the welding process:

• like many other elements, cuprum interacts with oxygen, that is, it oxidizes;
• Cu has a high linear expansion coefficient;
• ability to adsorb hydrogen and oxygen;
• dependence of the metal structure on heat treatment;
• high thermal conductivity, seven times higher than that of steel;
• high turnover.

Earlier it was noted about a simpler connection of pure material. Of course, this option is quite rare, so welding is performed in a protective atmosphere or using flux.

Copper Welding Technology

When working with this element, special copper electrodes are used. They have special properties that make them most effective in forming seams using various methods.

Copper welding technology has developed and improved in all areas of welding - this includes argon arc welding technology, resistance welding, etc. Let's look at each of them in more detail.

Manual welding

This method is perhaps one of the most common. It is the one that is most widely used in everyday life. The connection can be made semi-automatically or automatically.

Electrodes for copper welding can also be of several types: metal, carbon. At the same time, the electrode rod must be made of copper or an alloy based on it - bronze.

Gas

Copper arc welding is also widely used. The connection is made using direct current of direct polarity. Tungsten is used as the base of the rod, but the additive is made from cuprum or alloys based on it.

After forming the joint using this method, forging is usually carried out. This significantly improves the quality and reliability of the joint.

In the case of connection with a gas torch, a mixture of acetylene and oxygen is used. This allows you to achieve a high combustion temperature. As a result, the weld pool is maintained at optimal dimensions.

If it is necessary to connect a part with a thickness of more than ten millimeters, not one burner is used, but two. The second is necessary in order to warm up the product.

There is no need for double-sided welding in the second torch, since heating is not needed in this option.

Contact

This option is widespread in pipe connections. It should be noted that in this case it is not the copper itself that is bonded, but its alloys.

Copper resistance welding technology.

A special feature of this technology is electrodes for copper, made of metals with a high melting point.

This is necessary to ensure that heat removal from the contact point is minimal. It is also worth noting the low casting characteristics of cuprum. As a result, its connection is carried out only with the use of special additives that help obtain a strong and reliable joint.

As for working with alloys based on this material, things are the same here. High thermal conductivity makes it difficult to heat the product to the required temperature.

In addition, to form a high-quality joint, the base material and alloys based on it are mechanically cleaned and then etched in acids to obtain a clean surface.

Bottom line

Welding copper is accompanied by some peculiarities. For example, welding copper to copper can only be done using rods made of metals with a high melting point, otherwise, due to high heat dissipation, it will not heat up to the required temperature.

Source: https://tutsvarka.ru/vidy/svarka-medi

We perform copper welding at home

Welding of metal parts is a technological procedure that makes it possible to obtain permanent connections by forming a bond between intermolecular and interatomic particles of the material under significant heating until melting and plastic deformation. Spot welding of copper at home is used, as a rule, to join many metals and their alloys in all industrial fields, even medicine.

To carry out welding work, different energy sources can be used: friction, ultrasound, electric arc, electric current. Modern technologies are so advanced that work related to welding joints of metal structures can be performed not only in industrial enterprises, but also in the field, on reservoirs, under water, even in space.

But, as in any type of activity, there are nuances, advantages and disadvantages, requirements for the safety of work, etc.

Thus, when organizing welding work at home with workpieces made of copper, aluminum, brass, and stainless steel, it is necessary to follow the established precautions.

This type of activity is particularly dangerous to human health: there is a danger of damage to the organs of vision by ultraviolet radiation, contact with molten metal on the skin, electric shock, etc.

Copper Gas Welding Technology

Gas welding of copper at home is the most common technology used in domestic conditions. The resulting weld using this technique is highly durable. It is thanks to this parameter that gas welding is in great demand among home craftsmen. To connect copper products at home, you need to have on hand:

• Welding machine
• Gas-burners
• Gas cylinders (acetylene)
• Copper wire
• asbestos

Some advice from experienced welders

• If the thickness of the copper product is no more than 1 cm, the connection can be made with one torch.
• If the thickness of the copper sample is more than 1 cm, it is necessary to use two burners at once, the second will serve for heating.
• To reduce the outflow of thermal energy in this case, additional asbestos sheets will be needed.
• When welding copper products, it is recommended to use electrical wire made of copper, previously cleaned of paint and varnish insulating coatings.
• Cleaning must also be carried out on the welded edges of the products. This condition should not be neglected, since the possibility of cuprous oxide formation depends on it.

All necessary conditions for preliminary preparation for welding work have been completed. This means you can proceed directly to connecting the prepared copper products.

Recommendations

• You should try not to overheat the heated sections of the connection that are located close to each other.
• The concentrated flame must be directed perpendicular to the seam directly to the edge of the wire.
• The wire should melt before the edges of the product. The cooking process continues until the entire seam is completely formed.
• It must be remembered that stopping an unfinished connection can lead to overheating of some areas of the product, resulting in cuprous oxide and the formation of cracks.
• The completed weld must be forged.
• For small thicknesses of products, the wire must be kept cold.
• If the thickness of the product is more than 0.5 cm, then the wire must be heated to a temperature of 200 degrees. Higher temperatures are also allowed, but not more than 500 degrees, since the grain of the metal will form, which will subsequently become quite brittle.
• The welded, forged seam must be brought to a temperature of 500 degrees and cooled instantly.

At this point, the connection of copper parts can be considered complete.

Argon-arc welding of copper samples

Argon-arc welding at home is performed using welding equipment using direct current, non-consumable tungsten electrodes. The procedure is reminiscent of soldering products: the electrode is heated to a high temperature. As a result, the copper begins to melt.

With this welding technique, it is important to instantly cool the areas being joined. Argon-arc welding involves the use of argon and copper filler wire, which is pre-cleaned from the paint and varnish insulating coating.

Copper welding: area of ​​application of technology

Argon welding is used to repair structures made of copper. It has proven itself to be quite effective when performing welding work in hard-to-reach areas.

Argon-arc welding is quite in demand at manufacturing enterprises, and if you have the appropriate equipment, it can also be successfully used in domestic conditions.

If you have inverter welding equipment and special fusible electrodes, the procedure for joining copper samples can be carried out using the technology of welding steel products. There are practically no fundamental differences in this case.

But, with this joining method it is much more difficult to make a vertical seam than a horizontal one.

What you need to know about electrodes used for welding copper parts

To ensure a high quality weld, it is recommended to use electrodes coated with a special compound. Such a coating is necessary for the production of slag formed with metal oxides. It will prevent air from coming into contact with the weld.

The coating fills the voids formed during welding of parts due to burnout of components and subsequently introduces new components into the seam. This coating contributes to better stability of the electric arc.

The slag layer produced by this coating will slow down the cooling of the molten copper, causing more gases to escape from the weld.

Electrodes used in the welding process are divided into two types:

• melting - wire made of copper, steel, aluminum, cast iron is used for their production;
• non-melting - synthetic graphite and electrical coal are used for their production.

When choosing electrodes, you need to look at their color:

• yellow electrodes are intended for samples made of heat-resistant, corrosion-resistant steels;
• red - used for electric arc welding of copper products;
• gray – for blanks made of non-ferrous metals;
• blue - designed for connecting heat-resistant components.

Welding brass structures

Welding brass at home is a rather complicated procedure, since brass contains zinc, which evaporates when heated, as a result of which the product loses its original strength.

Brass itself is an alloy with zinc. The technology for joining parts made of brass is considered difficult due to the evaporation of zinc at high temperatures; this chemical element instantly oxidizes, resulting in the formation of a toxic, refractory oxide. Therefore, welding of brass samples should be carried out in specially equipped places equipped with an exhaust hood; welders should work in respirators.

Basic requirements for welding brass

• Cleanliness of the process when using argon-arc welding. Before starting work, the products are thoroughly cleaned to a characteristic metallic shine on the surface.
• There should be no oxides on the surface of the parts being welded; if present, they must be removed. Nitric acid is used for this. After this cleaning is completed, the product is washed in hot water and then dried.

When welding parts with argon, a characteristic continuous crackling sound is felt, and the welding arc has an amazing color. This is all due to the presence of zinc in the alloy. During the joining process, brass does not burn out or fly off in separate pieces, as it melts. Experienced welders advise welding brass in separate sections and not melting it in a continuous layer.

When the material melts completely, there is a possibility of burning through the metal.

If it is necessary to weld a crater, then it is recommended to gradually reduce the welding voltage, increase the length of the arc and subsequently move it away from the workpiece.

In the process of such a connection, the seam is filled in full; roasting of the zinc leads to its evaporation, resulting in the formation of defects in the metal.

To reduce the evaporation of this chemical element, it is necessary to increase the presence of oxygen in the flame and use filler materials alloyed with boron, aluminum, and silicon.

Advice! When connecting brass parts, carry out welding work outdoors, do not neglect safety requirements!

Source: https://electrod.biz/hobbi/vyipolnyaem-svarku-medi.html

Copper welding technology

Copper melting point 1883°C

Brand	Weldability	Technological features of welding
Copper cathode	Additives BrKMts 3-1 MNZhKT-5-1-0.2-0.2 BrOTs 4-3, BrKh 0.7 For a thickness of more than 8-10 mm, preheating to 200-300°C is required
M00k, M0k, M1k	good
Deoxidized copper
M1r, M2r, M3r	good
Refined copper
M2, M3	good
Bronze tin castings	Additives of the same brand as the base metal For a thickness of more than 10-15 mm, preheating to 500-600°C is required
Br03Ts12S5 Br05Ts5S5, Br08Ts4 Br010F1, Br010Ts2	Satisfactory
Br03TS7S5N1 Br04TS7S5Br010S10	Bad
Tin-free bronze castings
BrA9Zh3L	good
BrA9Mts2L BrA10Zh3Mts2 BrAPZh6N6BrA7Mts15ZHZN2ts2	Satisfactory
Bronzes are deformable
Br0f7-0.2, BrKh1 BrKMtsZ-1, BrB2	good
BrAMts9-2 BrAZh9-4, BrSr1	Satisfactory
BrA5, BrA7	Bad
Brass deformable	Additives BrOTs4-3 BrKMts 3-1, LK62-0.5 LK80-3, LMTs 59-0.2 For a thickness of more than 12 mm, preheating to 300-350°C is required
L96, LA77-2, LK80-2	good
LMtsS58-2, LS3 L062-1	Satisfactory
LS59, LS60-1	Bad

Welding difficulties

The high thermal conductivity of copper (6 times higher than that of iron) requires the use of a welding arc with increased thermal power and symmetrical heat removal from the welding zone. Recommended types of welded joints are butt joints and those with similar heat dissipation characteristics.

The high fluidity of copper (2-2.5 times higher than that of steel) complicates the welding of vertical and ceiling seams. It is possible only with minimal weld pool sizes and a short residence time of the metal in the liquid state. When welding butt joints in the lower position with guaranteed penetration, in order to avoid burn-through, it is necessary to use pads made of graphite, dry asbestos, flux pads, etc.

The active ability to absorb gases (oxygen and hydrogen) during melting, leading to weld porosity and hot cracks, requires reliable protection of the weld metal and welding materials from contamination with harmful impurities.

Due to the tendency of copper to oxidize with the formation of refractory oxides, it is necessary to use filler material with deoxidizing gels, the main ones being phosphorus, silicon and manganese.

The large coefficient of linear expansion of copper (1.5 times higher than that of steel) entails significant deformations and stresses, and the formation of hot cracks. They can be eliminated by preheating structures: copper up to 250-300°C, bronze up to 500-600°C

Preparation for welding

Copper or its alloys are cut into dimensional pieces using a grinding machine, pipe cutters, lathes and milling machines, as well as plasma arc cutting. Edges for welding are prepared mechanically.

The parts to be welded and the filler wire are cleaned of oxides and contaminants to a metallic shine and degreased. The edges are treated with fine sandpaper, metal brushes, etc. The use of coarse abrasives is not recommended.

It is possible to etch edges and wires in an acid solution:

75 cm3 per 1 liter of nitrogen water;

100 cm3 per 1 liter of sulfuric water;

1 cm3 per 1 liter of salt water

followed by washing in water and alkali and drying with hot air. Structures with a wall thickness of 10-15 mm are preheated with a gas flame, a dispersed arc and other methods.

The assembly of joints of parts for welding is carried out either in fixtures or with the help of tacks. The gap between the joined workpieces is kept the same throughout. The tacks must have a minimum cross-section so that they can be remelted during the welding process.

The surface of the tacks must be cleaned and ensured that there are no surface hot cracks.

If welding is carried out in the lower position, then special devices made of graphite or copper are used to improve heat removal

When welding in the open air, the joint is equipped with removable screens

1 - gas flow; 2 - seam; 3 - screen.

Selecting mode parameters

Welding is carried out on a constant hoc of straight polarity. Welding current (A) is approximately determined by the formula:

Isv=100×S,

where S is the metal thickness, mm

Shielding gases can be argon, helium, nitrogen and mixtures thereof. The arc length in argon and helium should be no more than 3 mm. In nitrogen it is increased to 12 mm. Therefore, the arc voltage and its power increase (3-4 times) compared to welding in argon. In helium, the arc power doubles compared to welding in argon.

Shielding gas consumption:

• argon - 8-10 l/min
• helium -10-20 l/min
• nitrogen - 15-20 l/min

The welding speed is selected from the conditions for forming a seam with the desired geometry. Structures with a thickness of 4-6 mm are welded without preheating in argon, and up to 6-8 mm - in helium and nitrogen. To weld thicker metal, preheating from 200 to 300°C is required.

Welding technique

Welding in argon with a “forward angle” when releasing the electrode 5-7mm. The following are used as filler wire:

• deoxidized copper
• copper-nickel alloy MNZHKT-5-1-0.2-0.2
• bronze BrKMts 3-1, Br OTs 4-3
• special alloys with effective deoxidizers.

To increase the resistance of the weld metal against hot cracks, welding wires are used:

• BrAZhNMn 8.5-4-5-1.5
• BrMts AZHN 12-8-3-3
• M Mts 40

To prevent molten metal from getting to the end of the W-electrode, the filler wire is not inserted into the arc column, but is fed to the edge of the weld pool and slightly to the side

APPROXIMATE MODES FOR WELDING COPPER IN ARGON

Type of edge preparation	Metal thickness, mm	Welding current, A	Electrode diameter, mm	Additive diameter, mm	Argon consumption, l/min	Number of passes without weld seam
1,21,52,53	120-130140-150220-230230-240	2,5-32,5-33,5-43,5-4	1,6233	7-87-88-98-9	1
10	1st pass 200-3502nd pass 200-3503rd pass 200-400 Underwelding seam 250-350	4-4,5	356 3	7-8777	3
12	1st pass 250-3502nd pass 250-4003rd pass 300-4504th pass 300-450 Underwelding seam 250-350	35663	8-10	4
20	1st and 2nd passes 250-4003 and 4th passes 250-4505 and 6th passes 300-550 Underweld seam 250-350	5-5,5	3563	10-12	6
25	1st and 2nd passes 250-4003 and 4th passes 300-4505 and 6th passes 300-5507 and 8th passes 350-600 Underweld seam 250-350	35663	12-14	8

Welding in nitrogen , which is an inert gas in relation to copper, is carried out with a carbon or graphite rod. It is not advisable to use W-electrodes, since their consumption in nitrogen is too high. Nitrogen arc welding with a carbon electrode is carried out using direct current of straight polarity at an arc voltage of 22-30 V. At a current of 150-500 A, the diameter of the electrode should be 6-8 mm. Nitrogen consumption - 3-10 l/min

Source: https://weldering.com/tehnologiya-svarki-medi

Welding copper: argon, inverter, semi-automatic, how to weld at home, than welding with other metals

Several basic copper welding methods have been developed and are widely used. Modern technologies make it possible to avoid the appearance of hot cracks, pores and other types of defects. Welding of copper and its alloys is carried out using argon, an inverter, wire and electrodes. Having considered the main methods, you can choose the most suitable one and avoid many problems.

Welding copper and its alloys: technology

Before you start welding copper and its alloys, you must carefully prepare the product . Measured blanks are cut using a grinder, lathe or milling machine. For copper with a thickness of 6-18 millimeters, you need to prepare the edges. They should be V- or X-shaped. (For large volumes, it would be advisable to purchase an edger-beveler.)

Before starting work, the seams are thoroughly cleaned of contamination and oxidation. For copper welding to be successful, it is necessary to protect the bath from exposure to oxygen. For this, it is recommended to use electrode wire, which must be alloyed with aluminum and phosphorus. In some cases it is necessary to heat the copper .

It connects well when working with consumable electrodes. It is important to know that the length of the arc should be 4-5 millimeters. Using pulsed-arc welding technology in argon, you can make any types of seams, even ceiling ones, and weld very thin metal. It is recommended to place padding elements under it.

How to cook copper: methods

For successful and high-quality copper welding, inverters, semi-automatic machines, gas machines, and argon machines are most often used. Manual, semi-automatic and automatic welding of cuprum and its connections can be performed with consumable and non-consumable electrodes. To work with copper and steel, automatic arc technology and flux are used.

The electroslag method is recommended for joining products with a thickness of 30-55 millimeters. Using an inverter, you can use a carbon electrode, for example, ESAB OK Carbon, Weldline CARBONAIR PLUS . The store offers a wide selection of manufacturers. Welding copper with a graphite type of electrode has proven itself to be excellent. Below are several subheadings that provide more detailed descriptions of the best methods for welding copper and its alloys.

Inverter

You can select the electrodes most suitable for copper welding using inverters by visiting the corresponding section of the website. The recommended brand is Komsomolets 100. The inverter is designed to create a constant voltage, current of reverse or direct polarity. You need to work with a short break. Weld sections of 30-40 millimeters, after which they should cool naturally. The angle of inclination of the electrode should be 10-20 degrees.

Semi-automatic

When working semi-automatically, welding is carried out with copper wire; although it is thin, it is of very high quality and allows you to achieve good results. If the metal thickness is more than 6 millimeters, then it is recommended to prepare the edges with a grinder or chamfer. They should be V-shaped with a blunting of up to 4 millimeters. To ensure that the seam is not porous, welding is performed without transverse vibrations.

When working on a semi-automatic machine, you can use M2 wire with a thickness of 2 mm. Recommended voltage 30 V, 300 A. Work is done with transverse movements. In this case, flux K-13, AN26, wire M1-3 can be used. The strength of a copper weld made on a semi-automatic machine is not inferior in terms of performance to the base metal.

Argon

Argon serves as an excellent protective agent. Tungsten types of electrodes are used in the work. The role of the additive is performed by the wire. The work is carried out on direct current of reverse polarity. Thin copper products are connected without heating. Welding is recommended to be done from right to left. It is necessary to maintain an inclination angle of 90 degrees for the electrode and 15 degrees for the rod. Depending on the thickness of the metal, gas consumption ranges from 7-18 liters per minute. Welding current is set from 80 to 500 amperes.

Gas welding

In order for the weld to be strong and of high quality when gas welding copper, it is necessary to monitor gas consumption. If the copper is thinner than 10 mm, 150 liters per hour of work will be enough, and if it is thicker, then 200 liters will be required.

Welding must be done quickly , preferably without stopping, which will avoid the appearance of defects and cracks. The filler material must melt before the base material.

If the workpiece is thicker than 10 millimeters, then two burners can be used. The technology involves the use of fluxes. They contain boron. Alloying of the metal and its deoxidation using filler wire are allowed. The method is also suitable for joining copper alloys. It is important to know that the filler wire must be identical in composition to the base metal being welded .

You can watch a short video that clearly shows the process close-up.

Source: https://WeldElec.com/info/kak-pravilno-varit/svarka-medi/

Features of copper welding

Copper welding is used in various industries due to the special properties of the metal. However, to obtain reliable welds, you must strictly comply with all technology requirements and use suitable equipment and consumables.

Features of copper welding

Features of welding copper structures:

• heated metal reacts with oxygen and forms a refractory oxide film, so it is necessary to use various methods to counteract the occurrence of such a reaction;
• copper has a high coefficient of thermal expansion, 1.5 times higher than that for steel alloys, therefore, after cooling, the deposited metal is subject to significant shrinkage;
• in direct contact with oxygen, molten copper absorbs oxygen and hydrogen, which leads to the formation of a heterogeneous brittle phase with pores and defects;
• due to good thermal conductivity, copper structures quickly heat up and cool down, which negatively affects the mechanical properties of the weld;
• high fluidity complicates the process of welding massive parts - it is impossible to ensure complete fusion on one side of the structure, as well as to create a vertical or ceiling seam;
• When the heating temperature increases above +2000C, the plastic and strength characteristics decrease and are completely lost by +5500C.

The influence of impurities on the weldability of copper

Impurities in copper negatively affect its properties, as they can lead to embrittlement, reduced ductility, and the creation of internal defects. When welding, the material may contain phases with a melting point different from pure metal, which increases the complexity of welding work.

Impurities are almost always present in pure metal, so in fact, welding of alloys is necessarily carried out in a protective atmosphere or using fluxes. It is important to use additives based on aluminum, manganese, and silicon. They will allow you to obtain a homogeneous structure and achieve the necessary technical characteristics of the weld.

Basic copper welding methods

To weld copper structures, it is necessary to comply with the requirements of copper welding technologies. The following welding methods are available for copper workpieces:

• inverter;
• semi-automatic;
• argon;
• gas;
• carbon electrodes.

Argon welding TIG mode

The TIG mode is used for automatic or semi-automatic welding. Advantages:

• small heating zone;
• eliminating the formation of defects in the structure;
• high speed of weld creation;
• simplicity of technology.

Carbon electrode

The process of welding with carbon electrodes is universal, since it is possible to ignite an arc between two electrodes, a workpiece and an electrode, an electrode and a mass. The technology is similar to the torch welding process.

BrKMts3-1 brand wire is used. Current and voltage parameters are selected depending on the technical features of the structures and their composition.

Carbon electrodes for welding

Carbon electrode inverter

Welding copper with carbon electrodes requires skills in carrying out such work. The features of the process are as follows:

• the inclination of the electrode above the workpiece surface is no more than 300;
• range of welding currents from 35 to 130 A.

Materials and equipment

To weld copper, you will need the following equipment and materials:

• inverter or welding machine;
• electrodes;
• solder or protective gas cylinders.

What you need to know about copper welding electrodes

Copper welding is performed using electrodes with protective coatings. Rods alloyed with bronze, silicon or manganese are used. Such compositions make it possible to eliminate copper deoxidation and ensure uniformity of the metal.

Protective coatings are selected that ensure stable arc burning and prevent metal deoxidation and the formation of cavities or slags.

Copper Welding Machine

The following equipment can be used to perform welding work:

• automatic or semi-automatic devices;
• inverters;
• TIG equipment.

It is recommended to use devices from the following manufacturers:

• ESAB;
• Fubag;
• Resanta;
• Svarog.

Types of solders

Welding copper blanks using fluxes can improve the quality of seams, increase their strength, and reduce the number of defects. Depending on the heating temperature, there are the following types of solders:

• low temperature;
• high temperature.

Low temperature solders

Low-temperature solders are used at heating temperatures up to +4500C for welding low-melting copper alloys. They are made on a tin or lead base, with the addition of antimony. In order to increase corrosion resistance, zinc is present in the composition.

High temperature solders

Fluxes for high-temperature welding are capable of maintaining their properties up to +11000C. The following elements are used in the composition: phosphorus, zinc, copper, silver, silicon. Most compounds are suitable for welding copper with other metals.

Material preparation and cleaning

Before welding, you need to prepare the metal as follows:

• Clean the surface along and near the seam with a solvent;
• use an abrasive tool to remove the oxide film;
• remove dust, dirt, remove contacting foreign objects or materials;
• for a thickness of 6–10 mm, cut off the chamfers on one side, and for more than 10 mm, cut off the chamfers on both sides of the seam.

Welding stages

Steps for welding copper at home:

1. An electrical circuit is assembled: an electrode is connected to the holder, wires are connected for welding with reverse polarity current.
2. A protective screen is laid around the part to prevent rapid heating or cooling. This is required so that the seam is uniform and there are no cracks on it after cooling.
3. An inverter with parameters suitable for operation is turned on, which is supposed to weld two copper workpieces.
4. The arc is ignited outside the area with the workpiece.
5. Flux is applied to the rod.
6. The seam is formed in one pass.
7. The inverter turns off.
8. Natural cooling of the part is carried out.

When welding copper workpieces with a thickness of up to 5 mm, preheating is not required. Massive structures require mandatory warm-up before welding.

Source: https://metalloy.ru/obrabotka/svarka/medi-osobennosti

Mini welding machine 12 V

With this simple welding machine you can cut thin metals, weld copper wires, and engrave metal surfaces.
Other applications can be found without any problems. This mini welding machine can be powered with a voltage of 12-24 V. The welding machine is based on a high-voltage high-frequency converter.

Built on the principle of a blocking oscillator with deep transformer feedback. The generator generates short-term electrical pulses, repeated at relatively large intervals. The clock frequency is in the range of 10-100 kHz. The transformation ratio of this circuit will be 1 to 25. This means that if a voltage of 20 V is applied to the circuit, then the output should be about 500 V. This is not entirely true.

Since any pulse transformer source or generator without load has powerful high-voltage pulses reaching a voltage of 30,000 V! Therefore, if you disassemble any Chinese pulse charger, you will see a soldered resistor parallel to the output capacitor. This is also a network load; without a resistor, the output capacitor will quickly leak due to excess voltage, or worse, it will explode.

Therefore, attention! The voltage at the transformer output is dangerous to life!

Mini welding machine diagram

Required parts:

• The transformer is homemade, the manufacturing procedure is described below.
• Resistors - 0.5-2 W power.
• The transistor used was FP1016, but it is difficult to find due to its specificity. Can be replaced with transistor 2SB1587, KT825, KT837, KT835 or KT829 by changing the polarity of the power supply. Another transistor with a collector current of 7 A, a collector-emitter voltage of 150 V, and a high gain (composite transistor) is also suitable.

The transistor must have a heat sink installed.

Although this is not on the diagram, it would be a good idea to place a filter capacitor in parallel with the source so that all interference from the operation of the blocking generator does not penetrate the source.

Transformer manufacturing

The transformer is wound on a piece of ferrite rod from a radio receiver.

• The collector winding is 20 turns of 1 mm wire.
• Base winding - 5 turns with a 0.5-1 mm rein.
• High-voltage winding - 500 turns with a drive of 0.14-0.25 mm.

All windings are wound in one direction. First is the collector winding, followed by the base winding. This is followed by three layers of white electrical tape insulation.

Next, we wind the high-voltage winding, 1 layer of 125 turns, then insulation, then repeat. In total, you should get 4 layers, which is equal to 500 turns. We also insulate the top with white electrical tape in several layers.

Let's put together a diagram. If everything is in order, everything should start without problems.

Since the operating frequency of the generator exceeds the sound frequency, you will not hear a squeak during operation, so do not touch the output of the transformer with your hands. Start the generator with a voltage of 12 Volts and increase if necessary. The arc ignites from a distance of 1 cm, which indicates the voltage 30 kV. The high frequency does not allow the burning arc to break, as a result of which the arc burns very stably.

When using a copper electrode in close contact with another electrode, a plasma medium (copper plasma) is formed, resulting in an increase in the temperature of arc welding and cutting.

Welding machine testing by cutting and welding

We cut a razor blade with an arc. We fuse copper wires up to 1 mm thick. Thick copper wire was used as an electrode. It is clamped in a wooden match, since dry wood is also a good insulator.

If you liked this small welding machine, then you can make it larger in size and power. But be extremely careful.

Also, to increase the power, you can assemble a generator using a push-pull circuit, and even using field-effect transistors, like here - Simple 12 V induction heater. In this case, the power will be decent.

Also, do not look at the bright arc discharges with the naked eye; use special safety glasses.

Watch a video of making a welding machine using a blocking generator

The author of the homemade video is Artym Kositsyn

Source: https://SdelaySam-SvoimiRukami.ru/3848-mini-svarochnyy-apparat-12-v.html

Copper welding

Copper materials are used in conditions with increased requirements for ductility and corrosion resistance.

Copper welding is carried out when used in various areas of production, decorative parts due to their increased aesthetic properties.

The thermal conductivity of the material is twice as high as that of aluminum alloys; there are many ways to join copper products. Modern technologies make it possible to avoid hot cracks, porous formations and other non-compliances with standards during operation.

Copper welding

Welding technology of copper and its alloys

Copper alloys, in contrast to the pure metal, have reduced thermal conductivity, as a result of which elevated temperatures are not required. There are several types of alloys, the best option being oxygen-free copper. Copper welding technology involves the use of pre-prepared products. Before welding, parts of the appropriate size are made; for components up to 18 mm in length, chamfer edges are prepared.

When dealing with large volumes, processing speed is achieved using a chamfer, which is capable of processing the part in the desired shape.

In addition, the joints are thoroughly cleaned of dirt and oxidation to avoid the formation of defects. Welding of copper takes place in an oxygen-protected environment; for this purpose, wire made of aluminum alloys with the addition of phosphorus is used.

The part cleared of impurities requires preheating, otherwise the flux layer will spread unevenly over the seams.

Arc welding

High-quality production is carried out using electrodes, the arc length is no more than 5 mm. The pulse-arc connection allows for the production of various seams and the use of thin metal. In difficult situations, in order to avoid breaking and cracking, a stop is placed, which helps to securely fasten the parts.

How to cook copper

A guaranteed connection is obtained by using various methods of connecting nodes. For docking the following is used:

• gas apparatus;
• inverter;
• semi-automatic;
• tool for manual arc welding.

The connection is made with consumable and non-consumable wire electrodes, automatically or manually using flux. When working with materials of large diameter, the electroslag method is used.

Gas welding of copper

The inverter connection method implies the presence of a high-quality metal melting device. The construction trade aisles offer a wide range of products, allowing you to choose the right tool for the appropriate site. Among others, it is worth noting graphite electrodes, which allow the production of crafts at different temperature conditions.

Welding nichrome with copper

Nichrome parts are usually joined using graphite electrodes. The arc burns in a stable manner, the length varies depending on the current voltage parameters, reaching up to 55 mm.

Melting of the electrode is excluded, the tip is able to heat up to the temperature necessary for melting copper. The structure is such that a thermionic reaction occurs, allowing action to be performed by a heated device at a power of 10A or more. The advantages include ease of use due to the lack of sticking, as well as cost-effectiveness.

Carbon welding at home

It is quite difficult to make the device yourself. An inexpensive inverter offered on the construction market will allow you to weld copper at home. The model range offers distinctive characteristics of power and output voltage of the variety; this condition allows you to choose a device that suits your pocket.

When welding small copper parts, a low power inverter is sufficient. The connection is made from the home network; modern devices do not put increased loads on household wiring.

The most affordable graphite devices allow you to connect wiring and repair a damaged car radiator at home.

Technology and methods for welding copper at home

Mankind mastered copper, as well as its alloys (bronze, brass) long before iron. Today, the main consumer of this metal is the electrical industry. It is also in demand in other industries, as well as for household needs.

Copper alloys are easily soldered, but welded joints are preferable. They are twice as strong and resistant to high temperatures. However, cooking it is no less difficult than parts made of stainless steel or cast iron.

It is fusible (1080-1083ºС), has a thermal conductivity six times higher than iron and one and a half times aluminum. Its melting fluidity can rival that of water. At three hundred degrees it becomes highly brittle.

In addition, it is easily oxidized and actively dissolves hydrogen, with the subsequent formation of water vapor. All this causes residual stress and forms cracks.

Welding copper workpieces is more difficult than for other metals.

However, all these problems can be solved, and copper welding is a common way to produce products from it.

Manual arc with metal electrodes

The most common joining method is arc welding with fusible electrodes. It is carried out using a conventional welding machine or inverter.

Before starting work, parts along the entire length of the joint are cleaned to a metallic shine and degreased. Parts up to 4 mm thick are cooked without cutting edges, thicker parts from 5 to 10 mm are cut.

Workpieces of greater thickness are cut in an X-shaped manner, i.e. not only from above, but also from the reverse side.

Before welding copper into thin sheets “butt-to-butt”, first perform the so-called flanging. This operation will consist of bending the edges of the sheets 3-5 mm at a right angle to prevent burning of the workpieces.

The electrodes are a copper rod coated with rutile that has the main reaction (as a rule).

For a long time, the main type recommended by GOST were Komsomolets - 100, ANC-1 and 2, developed back in the USSR. For bronze and other alloys ANC-3, ANC-3M. Today, the market, in addition to them, offers products from foreign companies. These are mainly ZELLER and ESAB.

They operate on direct current. The polarity is reversed, i.e. “+” to the electrode, “–” to the workpiece, on a “short” arc, high current.

It is recommended to preheat thick workpieces (from 6 mm) to 250-400ºС.

The quality of the joint greatly depends on the qualifications of the welder, so they prefer not to connect critical parts using this method.

A feature of copper is its high fluidity, which is why the seam is made in the lower position or at a slight angle. For the same reason, when welding pipelines, it is desirable to ensure rotation of the parts. If such an operation is impossible, it is better not to use manual electrode sutures.

Carbon or graphite electrodes

A similar technique is used to create products that do not experience significant loads, up to 15 mm thick . The work is carried out on a long arc, to reduce the degree of contact of the deposited metal with the carbon monoxide formed during work.

The filler material is not immersed directly into the weld pool, but is fed into the arc 5-6 mm from its surface.

Sheets up to 3 mm are welded by flanging; for thicker metal, an additional filler rod is used. In addition, to reduce the appearance of oxides, pre-coating the joint with a flux of borax, boric acid and boric anhydride is used.

Massive workpieces are cooked with graphite using direct current of direct polarity . To obtain an accurate arc, they are sharpened at 30 degrees.

Plates from 5 mm are connected with preliminary cutting of the edges. To prevent metal from leaking out of the melt, graphite or asbestos pads are used.

To improve the quality of the finished seam, it is forged in one, less often twice . In this case, thick workpieces are preheated to 600-800ºС, and upon completion of forging they are quickly cooled.

Using a carbon or graphite electrode, you can quickly and conveniently weld the end of a twist of copper wires by simply melting it. The contact provided in this way is superior in reliability to soldering.[/stexbox]

Argon-arc

This type of workpiece connection is superior in reliability to manual welding with fusible electrodes, as well as conventional arc welding . Using this method, it is also possible to weld steel with copper at home, which allows you to repair most types of household appliances.

For argon arc technology, non-consumable tungsten electrodes are used. Metal is welded using direct current of direct polarity.

To ensure complete penetration, the edges of the workpieces are cut in a V or X-shaped manner, at an angle of up to 70 degrees.

The integrity of the weld pool is ensured by asbestos or graphite shells and linings.

Taking into account the easy oxidation of metal, to improve quality, filler rods and wires are used with deoxidizing additives - tin, zinc, phosphorus, etc.).

For work, filler rods of the following brands are used:

• MNZHKT-5 is a copper-nickel alloy, optimal for working on pure copper;
• BrKMtsZ-1 and BrKMtsZ-2 - bronze alloy, used for working on alloys (brass, bronze);
• DT-CuZn , and analogues - for making combinations with other metals, working on copper and its alloys;
• TIG CuSi3 and analogues (e.g. BARS CuSi3 ) - application on pure copper, alloys, work on surfacing a layer on low-alloy steels.

In addition to argon, helium or a helium-argon mixture is used for welding work, where the second gas contains about 70%.

On automatic or semi-automatic machines under flux

Submerged arc welding provides the highest quality weld compared to the above methods.

Semi-automatic welding of copper is carried out in a carbon dioxide environment. Flux is supplied with this method using a special filler wire.

Automatic submerged arc welding requires stationary, expensive equipment; therefore, in terms of speed and quality, it is used only in enterprises.

Technologically, the process is extremely simple: the future joint is covered with flux powder, after which the process is carried out with the supply of filler wire. In this case, part of the powder melts, forming a layer of slag. Excess flux is collected for reuse.

The technological mode of semi-automatic welding is determined by the worker himself, based on the thickness of the workpieces, grade of metal, environmental conditions, type of joint, as well as other parameters. This includes:

• electrode diameter;
• electrode feed speed;
• speed of movement of the welding torch;
• volume and characteristics of flux
• pulse dimension (when using pulse current), etc.

Automatic welding makes it possible to use not one, but two or more electrodes. Thus, even a massive seam is completed in one pass . In addition, the flux pad helps keep the molten metal of the weld pool in place.

Both unfused and fused fluxes are used for welding. The first, also called ceramic, is a mixture of powders of various substances. The latter are made by grinding the melt of pre-mixed additives. Fused fluxes are more stable in properties, so they are more often used for copper and its alloys. The most popular type A20 consists of silica, alumina, magnesium oxide, sodium fluoride and deoxidizing additives.

The strength of the joint obtained under submerged arc is not inferior to that of the base metal.

Welding alloys containing zinc is accompanied by the release of toxic fumes. In addition, the flux itself produces harmful gaseous substances when melted. The presence of effective ventilation or an insulating gas mask in such cases is a prerequisite.

Gypsies, non-ferrous metal and our accountant

Do you want to sell non-ferrous scrap metal at the price of regular iron? Then don't read this story.

In the early 2000s, I was asked to set up production of welding products. The company inherited, in addition to the accountant and welders, old-style welding stations. Type TDM-317.

Welding machine TDM-317 U2. Brief information

TDM-317 is a hard worker from the times of the USSR. Alas, by 2000 it was obsolete. The price for electricity has increased significantly, and he ate it in huge portions. Tens of times more than an inverter. The only thing that still inspired respect for the old man was his weight. Not less than 124 kg.

Welding machine TDM-317 U2

Modern welding inverters weighed no more than 7 kg. I allocated funds and we bought an inverter for each welder. They decided to scrap the old ones so as not to clutter up the storage area.

About the accountant

Dear Nadenka worked as an accountant at the company. Slender, unknown age, sociable. She loved to talk on the phone and was in the category of essential workers. Any tax inspectors avoided Nadezhda. She submitted reports the first time and was well aware of all the new trends in legislation.

But apparently her friendship with the exact sciences did not work out. What copper, what aluminum, what plastic, what iron - these terms for Nadezhda were “Terra incognito”. In addition to all this, it should be noted that the welders were written off and the documents for them were lost.

Only this is what I know now, about the characteristics of an accountant. Then my brain could not even imagine that Nadezhda did not know about the internal contents of the old people in the warehouse. How much scrap copper is in welding machines, how much iron there is, does not even remotely understand the difference in the price of components.

"Partners"

Monday, autumn morning, I’m in my second week in a new place, what should I do? Don’t look for a scrap metal removal company yourself. Moreover, there were more than 100 of them in our city, glorious Nikolaev, at that time.

Considering the accountant’s love for telephone conversations, I assigned this task to her. Find a metal removal partner. Such that he himself could load the welding machines (posts) and take them to the receiving point. He repeated that he could only find several options from the list in the newspaper.

I set the task for Nadezhda and went to a cozy restaurant to meet with a client to negotiate the terms of the contract. I have my cell phone with me and am expecting a call from my accountant in the evening with a report.

The call came in exactly at one o'clock in the afternoon. Nadezhda reports that about 10 companies arrived and she chose the best one. The one that offered free shipping and handling. The money is on her table, the devices are being loaded into transport.

The thought crept into my mind that I didn’t seem to be needed. The task was completed and exceeded. Nadya showed organizational skills, rounded up the available scrap metal collectors and organized an auction. Well done!

And I liked the service in the city. For the export of metal. How quickly they arrived. There are movers, there is transport, and there is even cash.

But everything is too smooth. I digested the information and in the return call I tell them to stop loading, not let the car out, and I’ll be right there. I called the security guard to tell him not to let anyone in or let anyone out with the cargo.

Scandal

Had arrived. I greeted the smiling gypsies who were briskly discussing our bins.

I go into the reception apartment. There is wine and sweets on the table. A tall, gray-haired gypsy sows compliments to Nadenka. Nadezhda is as happy as a thousand elephants. In general, she radiates genuine human happiness and joy with her entire being.

I greet the chief of the gypsy camp, politely apologize for my absence and invite Nadya to my place. I'm asking about the price. Nadenka boasts that the gypsies offered the best conditions and a price 10% more than at the metal collection point. Plus the price is free loading and transportation.

Just what metal? You guessed it. Regular, black . And there is more than 80 kg of copper in that welding machine!

In the 2000s, copper was almost 12 times more expensive than ferrous metal!!!

The situation has become complicated. The accountant took the money. There are 10 times fewer of them than there should be. The amount is not small, the dispute could be serious. There is a gypsy camp in the yard of the enterprise. How to avoid a scandal and hours-long debate? That is the question.

I didn’t say anything to Nadya. He could not destroy her happy state with his own hands. I call a taxi, go out to the guest room and send Nadezhda to the store for champagne, sweets, and other tasty treats of her choice. I speak deliberately loudly so that the gypsy can hear.

I smile at the gypsy and at the same time apologize - I ask you to pause for about 30 minutes. It’s not appropriate, they say, to celebrate events without our financial participation. Nadya will return with a net from the market - we will continue.

Submachine gunners

Then everything is simple. I call the machine gunners from the security service. According to the contract, I have this opportunity - once a month for any reason. At least check combat readiness.

Friends in bulletproof vests arrived 7 minutes later. Twice as fast - well done. I take the elder into the reception room, call the gypsy and suggest that we continue the banquet. I ask when the additional payment will be and with whom to draw up a deferred payment agreement.

Perhaps it was not a gypsy at all. Because he understood everything. He grinned and said that he took mine. He thanked me for sending Nadenka - she’s a wonderful woman, let her not know what she’s doing.

The camp chief did not agree to continue the banquet and discuss the new price. He ordered the unloading of the two vehicles that had already been loaded. And the camp left.

About 5 minutes later the machine gunners also left.

Double banquet for two

Everyone left. That left me and the guard. Yes, welding machines that never left their lair. After 20 minutes Nadya returned. With a bottle of my favorite champagne, a box of chocolates and coffee.

What did I tell her? He opened the champagne and said that the gypsies, having learned how much copper was in the devices, refused to take them. They don't need copper. Need ferrous metal. They left with the money.

In the evening I took Nadenka home. I wrote down how much copper is in the welder. He asked me to find a client specifically for copper, and the metal could be sold as a bonus. The next day I arrived at lunchtime. On the table there was a bottle of cognac, my favorite coffee and a list of copper buyers. With price.

Nadenka played the scenario I proposed. I even hugged her a little. He asked which wine she liked best. We continued the celebration.

Friends

A year later, Nadezhda married a gypsy. I made new friends. Gypsy and accountant.

As for the welding machines, they remained in the warehouse for another three months. Until they were taken apart. Copper is separate, iron is separate. The other option always led to a dead end. The buyer didn't believe me. They wanted to pay for the device by weight, like for ferrous metal.

Dear friend. If you have motors, cables or other products with copper, disassemble them. This makes it much easier to sell scrap metal. And you won't go wrong.

Source: http://xlom.ru/istorii/svarochnyj-apparat-tdm-317-u2/

Devices for welding copper wires: main features and types, technical characteristics and nuances of application

Welding copper cables has a number of features: a metal such as copper becomes brittle at a temperature of 300°C, and begins to melt only at 1080°C. In this regard, you need not only to have experience working with this material, but also to have a high-quality welding machine on hand.

What types of machines are there for welding copper wires?

There are 3 main groups of machines for welding wires made of non-ferrous metals.

Narrow-profile devices

Such equipment can be either Russian (TS-700-2) or imported. The devices are compact in size and equipped with straps for more convenient carrying. Carbon electrodes are used as consumables for welding copper wires (high temperature). Despite its high ergonomics, with the help of such equipment it is possible to solder both rigid conductors with a cross-section of 1.5 mm2 and above, as well as wires consisting of a large number of thin copper conductors.

General purpose inverter devices

This is a familiar modern welding equipment that can also be used to weld copper. However, for this you will need:

• adjust the current - due to the refractoriness of copper, more power will be required at the contact of the electrode with the melt. Therefore, here the current strength (direct) will be needed more - up to 160 Amperes;
• use copper-carbon electrodes.

Modern examples of classic welding equipment are also distinguished by their compactness and thoughtfulness: the devices are initially designed to be as easy to carry as possible, and the connection of the device wire to the object being welded (twisted) is made using a clamp.

Homemade wire welding machines

Wanting to save money, numerous craftsmen quite successfully create their own equipment for welding copper wires, using coils of used transformers. The power of such equipment is very modest - 0.3-0.8 kW, and the voltage on the secondary winding is 9-36 Volts. The holder is assembled from individual wires so that the total cross-section is at least 15 mm2, and the carbon rods of used batteries are used as electrodes.

What you need to pay attention to when choosing a welding machine

It is best to select a suitable device based on the required functional features. Therefore, you need to focus, first of all, on the following characteristics:

• household or professional device . A specialized welding machine costs much more than a compact household welding machine, whose resource is tens of times less.
• Is specialized equipment required ? The inverter welding machine is universal. Using classic electrodes, you can weld or cut carbon steel, and using copper-carbon electrodes, you can solder strands of copper cables. If highly specialized work is not required in non-trivial conditions (which require increased ergonomics from the equipment), then it is recommended to purchase a modern version of an inverter welding machine.
• power . If the arrays of materials that are supposed to be welded are large and the machine is supposed to be used frequently, it is advisable to buy powerful equipment (for example, 10 or 12 kW). However, for common household purposes, 4-5 kW will be sufficient.
• additional functions . It’s good if the welding machine has a “hot start” option, protection against electrode sticking, and smoothing out power supply fluctuations. In addition, especially for inverter devices, it is extremely important to have the ability to regulate the current strength. Important parameters are the compact size and the presence of a reversible belt. The modern welding process has become much more efficient, and in connection with this, the device must be easy to handle and light in weight.

Description of machines for welding copper wires

Source: https://elsvarkin.ru/svarochnoe-oborudovanie/mednye-provoda/