stainless steel, copper, titanium, aluminum, bronze and other non-ferrous metals and alloy steels - all metals, parts of which are just not welded together.But in life there are different situations: it is necessary to weld pipes made of stainless steel, the aluminum parts of the car or simply weld dumps foot of a bronze statuette.By the above metals require special treatment - argon arc welding, work on which are not cheap, if not pretty "bite" when ordering them from a specialist.So the question arises of the owners, and whether it is possible welding with argon their own hands and that it needs.If you've never cooked anything, it is strictly not necessary to begin with the welding of non-ferrous metals, it was too time-consuming and complicated process is designed for certain professional skill and experience.But if the experience of the conventional arc welding is available and you are confident in their abilities, then the information in this
- Welding argon: technology and general principles
- Technology TIG
- What is needed for welding with argon
- Various modes of welding with argon
- welding aluminum welding copper Features
- Argon arc welding: the advantages and disadvantages
- Welding argon: Video - User
Welding argon: technology and general principles
Argon arc welding is a hybrid of electric (arc) and gas welding.On the technology of electric welding, it is similar in that the electric arc, and gas - like the use of gas and operation of the welder.
arc a source of heat, that it melts the edges of the metal, thanks to its welding occurs.
But why do we need the gas argon ?The fact is that when welding non-ferrous metal and alloy steel by reacting with oxygen are oxidized, either as they adversely affect other impurities that are in the air, because this seam is obtained fragile filled bubbles, and aluminum, for example, generally burnsoxygen.To protect the metal from exposure to various contaminants and gases using inert argon gas.This gas is 38% heavier than air, so it is easy and quickly displaces oxygen from the welding zone and reliably isolates the labor pool from any influence of the atmosphere.To begin to supply gas to the welding area must be 20 seconds before ignition of the arc and stop at 7 - 10 seconds after the completion of the work.Argon is almost does not react with the base metal and other gases in the area of the arc, so called inert.But there are some nuances: the welding on the reverse polarity of the argon atoms are easily separated electrons through this entire medium is transformed into argon plasma conductivity.
argon welding can be performed as a consumable electrode , and non-consumable , as the last tungsten electrode is used because this material is very refractory.It makes tungsten filament lamp.The diameter and the electrode material is entirely dependent on the alloying metal, these figures can be easily found in the manuals.
are three types of TIG welding:
- RAD - a manual welding consumable electrode argon.
- AMA - automatic argon arc welding using a consumable electrode.
- AADP - automatic argon arc welding using a consumable electrode.
If you are looking for a ready machine for welding with argon tungsten looking machines TIG (Tungsten Inert Gas (Welding)).That is denoted welding tungsten inert gas.
What is the torch for welding with argon?Its heart is a non-consumable tungsten electrode , which should extend beyond the body of the burner is only 2 - 5 mm, max.The diameter of the electrode is selected according to the table based on the parameters of the welded materials.Inside the burner there is a holder that can be inserted in and fix the electrode of any desired diameter.
around the electrode is worn ceramic nozzle , from him, and will come argon gas during welding.
For welding we need filler wire of the same material as the parts to be welded, the diameter is chosen according to the tables.
Consider how to work with manual welding with argon, and when the torch and filler wire are in the hands of the welder.
Before working surface of parts to be welded must be cleaned of oxides, dirt and grease.This can be done mechanically or chemically.
first step on the workpiece is fed so-called "mass" as a normal arc welding.If the parts are too small, it can be applied to a desktop or iron bath.The filler wire in the circuit does not turn on, it will be submitted separately.
right hand welder must take the torch and filler wire to the left.On the burner should be a button, and the current supply of gas, turn off the gas in advance for 20 seconds.The strength of the current is selected depending on the materials to be welded, or by personal experience through trial and error.Omit torch electrode as close as possible to the surface of the welded metal, the ideal distance of 2 mm.The arc is generated between the tip of the electrode and the metal, it melts the edges of welded parts and filler wire.
How is welding with argon: photo - an example.
Important!A non-consumable tungsten electrode should be kept as close as possible to the surface of the welded metal to create the shortest arc.The larger arc, the less depth of penetration of metal and wider and less aesthetic seam.With a large arc voltage increases and worsens the quality of the weld.
slowly drawing torch along the seam, making no transverse movements, the welder must gradually feeding the filler wire.It is up to the master skill will depend on the quality and accuracy of the resulting weld.
Important!Sharp Welding wire leads to spatter.Therefore, it should be fed smoothly and accurately, which is achieved only through practice.It is best to have the filler wire ahead of the torch at an angle to the work piece without making transverse movements.This will ensure a smooth and narrow seam.
Please note that the ignition when welding consumable electrode can not be produced by touching on the work piece.And here are the reasons:
- high ionization potential of argon does not allow well-ionize the gap between the welding electrode and by sparks from contact.When welding consumable electrode situation is somewhat different: after touching an electrode on the surface of the cooking zone in the pair appear iron ionization potential which is much (by 2.5 times) lower than that of argon, it allows you to ignite the arc.
- Due touch the electrode surface of the welded metal as it becomes dirty.
To ignite the arc when welding with argon non-consumable tungsten electrode is used oscillator, which is connected parallel to the power supply.
Oscillator supplies the high-frequency electrode high voltage pulses by which ionizes the arc gap.If the network frequency is typically 55 Hz and 220 V, the oscillator converts them, and supplies the voltage to 2000 - 6000 with frequency 150 - 500 kHz.This makes it easy to light the electrode.
What is needed for welding with argon
TIG enough usual devices for arc welding, but it is possible to upgrade or add other required elements.Consider what we need for welding in argon:
- transformer.Suitable conventional welding transformer, which is used for arc welding with open circuit voltage of 60 - 70 V. Of course, the power it needs to meet the technological features of the process.
- Power contactor, which will supply the welding voltage to the burner.
- Oscillator.For what it is, we have already found.
- device that will adjust the time of argon blowing.We in fact need to light it in advance, and that after the completion of the welding gas is supplied even seconds 20. This delay is needed and control.
- burner for welding with argon.
- cylinder argon, always with a gearbox.
- Tungsten electrodes, rods of the required diameter.
- auxiliary transformer, which will be used to power switching devices.
- rectifier power switching devices for DC 24 V
- electrogas valve (24 V DC or 220 V AC).
- on-off switch and contactor oscillator.
- LC filters, which is necessary for the protection of the welding transformer of the pulse (high) sent to the oscillator.
- ammeter to measure the welding current.
- car battery (55 - 75 Ah), or faulty work is not important.It is connected in series into the circuit in order to reduce the DC component that inevitably occurs when AC welding (in more detail in the literature).
- welding glasses.
All elements of this scheme you can buy on the market and raise their hands, get makeshift welding with argon, more circuitry can be greatly improved if have the appropriate knowledge.
also aids TIG can be purchased ready-made equipment, they connect the gas cylinder, torch, grounding and control buttons burner and gas supply.The price of these devices start at 250 USD
Various modes of welding with argon
For better weld metal is necessary to choose the right welding mode.
polarity and current direction should be selected based on the properties of welded metal.Basic steel and alloys are welded with direct current, which has a direct polarity.Aluminum, beryllium, magnesium, and other non-ferrous metals for better welding of reverse polarity or alternating current, it contributes to a more rapid breakdown of the oxide film.During the DC welding is unequal heat at the anode and cathode of 70% to 30% of the anode and the cathode.To reheat minimum electrode and thus a good product is melted, use a straight polarity.
Important!When welding with alternating current oscillator after lighted arc enters stabilizer.To prevent the deionization of the arc gap during the change of polarity and ensure steady burning arc, the oscillator supplies pulses to the arc at the time of polarity reversal.
welding current is selected depending on the properties of the weld metal and the size of the parts, as well as electrodes.To select the amperage of the tables can be in reference books, and can be empirically.
argon consumption depends on the feed rate and the speed of the razing of air flow.If welding is going on inside the building without drafts, consumption will be minimal.Welding work in conditions of strong crosswind requires increasing the distance between the electrode and the material, as the air flow can endure argon, then the metal surface will be unprotected.In such cases, use special nozzles (convergent) with fine mesh.
In addition to the gas mixture of argon is sometimes added oxygen , about 3 - 5%.Argon is not able to protect against moisture, dirt, and other additives, which may appear on the surface of the parts to be welded in the molten metal.Oxygen also reacts with harmful impurities, whereby they either burn or float in the resulting compound of the weld pool surface.The use of oxygen - a good way of dealing with the porosity of the weld.
Features aluminum welding
When heated, the aluminum on the surface there is a refractory film.When welding at a reverse polarity, or with alternating current source that can destroy the film.When the aluminum part has a positive charge, when welding with reverse polarity argon ions bombard the surface of the aluminum, destroying the oxide film.In this case, argon already serves not simply a protective gas, and plasma is electrically conductive, simplify and improve the welding work.
during AC welding similar process occurs when the aluminum parts is the cathode.
Features welding copper
copper readily reacts with oxygen to form copper oxide.This leads to the fact that the seam turns patchy and insufficiently robust.An even greater problem is that the resulting copper oxide reacts with the hydrogen in the air, forming water vapor, which tends to break out and form pores in the weld.It is therefore imperative to protect the weld zone with argon.
Argon arc welding: the advantages and disadvantages
Like any process in welding with argon has its advantages and disadvantages that are associated with the technology and devices used.
- weld argon protection from the environment.This provides a strong connection, without pores and impurities.
- metal is heated a little, the heating area is very small, so you can easily welded blanks of complex design, not afraid to change their shape.
- Welding of metals and alloys that can not cook anyway.
- relatively rapid execution of works, thanks to the high-temperature arc.
- is enough sophisticated equipment that requires fine-tuning.
- relative complexity welding, requires experience and skill.
Welding argon is good because it ensures that the seam of high quality, with the same depth of penetration.This is very important when welding thin metal with access from only one side, for example, orbital butt tubes.Incidentally, when welding non-ferrous metal of small thickness the filler wire can be omitted.
Welding argon: Video - User