For semi-automatic
When considering this issue, attention should be focused on argon compounds with hydrogen and helium, which are widely used for welding nickel, high-alloy and stainless steels and their alloys. Each of these mixtures is classified specifically as a semi-automatic welding gas, however, in certain situations, they can be used simply for molding
Another option for a welding mixture designed for welding in semi-automatic mode is a combination of argon and CO2 (carbon dioxide). The basis for the use of this combined composition is the principle of maximum protection of the metal and minimization of harmful side effects for it.
At the beginning of work with this composition, first of all, the burner is ignited, through the nozzle of which the welding mixture of argon and carbon dioxide is fed into the working area.
After starting the burner and heating the material with a tungsten-coated infusible electrode, an electric arc is ignited. At the same time, a special button turns on the supply of melting wire, for the protection of which this mixture of gases is used.
High-quality welding by all of the above methods requires a competent calculation of the volumes of the required gas, as well as the choice of the optimal feed rate of the welding melting wire. For this purpose, schedules and typical modes of metal processing have been developed, calculated individually for each type of gaseous mixture.
The combustion temperature of the welding mixture is chosen so that the metal itself and the wire do not melt from it, so it is not at all necessary to turn off the burner at a single distance from the bath.
Upon completion of the formation of the seam, for its gradual cooling, they often use the method of short-term heating with the same combustible composition (if necessary).
The table data on welding mixtures recommended for working with a semiautomatic device can be found in the table:
| Raw material | Thickness, mm | Recommended Blend | , mm | Welding speed, mm/min | Welding currentIsv, A | Arc voltage Ud, V | Wire feed speed, m/min | Gas consumption, l/min |
| Carbon structural steels | 1,0 | K-3.1 | 0,8 | 350-600 | 45-65 | 14-15 | 3,5-4,0 | 12 |
| 1,6 | K-3.1 | 0,8 | 400-600 | 70-80 | 15-16 | 4,0-5,3 | 14 | |
| 3,0 | K-3.2 | 1,0 | 280-520 | 120-160 | 17-19 | 4,0-5,2 | 15 | |
| 6,0 | K-3.2 | 1,0 | 300-450 | 140-160 | 17-18 | 4,0-5,0 | 15 | |
| 6,0 | K-3.2 | 1,2 | 420-530 | 250-270 | 26-28 | 6,6-7,3 | 16 | |
| 10,0 | K-3.2 | 1,2 | 300-450 | 140-160 | 17-18 | 3,2-4,0 | 15 | |
| 10,0 | K-2 | 1,2 | 400-480 | 270-310 | 26-28 | 7,0-7,8 | 16 | |
| 10,0 | K-2 | 1,2 | 300-450 | 140-160 | 17-18 | 3,2-4,0 | 15 | |
| 10,0 | K-3.3 | 1,2 | 370-440 | 290-330 | 26-31 | 10,0-12,0 | 17 | |
| Alloy steels | 1,6 | NP-1 | 0,8 | 410-600 | 70-85 | 19-20 | 6,5-7,1 | 12 |
| 3,0 | NP-2 | 1,0 | 400-600 | 100-125 | 16-19 | 5,0-6,0 | 13 | |
| 6,0 | NP-2 | 1,0 | 280-520 | 120-150 | 16-19 | 4,0-6,0 | 14 | |
| 6,0 | NP-2 | 1,2 | 500-650 | 220-250 | 25-29 | 7,0-9,0 | 14 | |
| 10,0 | NP-3 | 1,2 | 250-450 | 120-150 | 16-19 | 4,0-6,0 | 14 | |
| 10,0 | NP-3 | 1,2 | 450-600 | 260-280 | 26-30 | 8,0-9,5 | 14 | |
| 10,0 | NP-3 | 1,2 | 220-400 | 120-150 | 16-19 | 4,0-6,0 | 15 | |
| 10,0 | NP-3 | 1,2 | 400-600 | 270-310 | 28-31 | 9,0-10,5 | 15 | |
| Aluminum alloys | 1,6 | NP-1 | 1,0 | 450-600 | 70-100 | 17-18 | 4,0-6,0 | 14 |
| 3,0 | NP-1 | 1,2 | 500-700 | 105-120 | 17-20 | 5,0-7,0 | 14 | |
| 6,0 | NP-1 | 1,2 | 450-600 | 120-140 | 20-24 | 6,5-8,5 | 14 | |
| 6,0 | NP-2 | 1,2 | 550-800 | 160-200 | 27-30 | 8,0-10,0 | 14 | |
| 10,0 | NP-2 | 1,2 | 450-600 | 120-140 | 20-24 | 6,5-8,5 | 16 | |
| 10,0 | NP-2 | 1,6 | 500-700 | 240-300 | 29-32 | 7,0-10,0 | 16 | |
| 10,0 | NP-2 | 1,2-1,6 | 400-500 | 130-200 | 20-26 | 6,5-8,0 | 18 | |
| 10,0 | NP-3 | 1,6-2,4 | 450-700 | 300-500 | 32-40 | 9,0-14,0 | 18 |
In conclusion, it should be recalled that gas mixtures are an integral part of some types of welding work, which, according to the specification, belongs to the category of consumables.
When using them, it is very important to establish the exact ratio of the components, thanks to which it is possible to achieve high performance of the welding process. This rule is true for both novice welders and professionals with extensive experience in gas environments.
Description
Special offer for gas mixers VM-2M! 1 euro = 56 rubles! The offer is limited!
Mixer for 2 gases, designed for the food industry or welding technology.
Mixer for 2 gases
VM-2M is intended for flanged direct connection (high
pressure) and is most often used for welding equipment or for
Food Industry. This kind of gas mixer is very easy to use.
operation. By means of rotary knobs with a scale marked in
percent, and thanks to the proportional mixing valve, the gas
the VM-2M mixture is continuously adjustable.
Volume control is also very smooth due to the handle with
scale.
Thanks to the built-in
constant pressure regulator provides a constant
quality level VM-2M. That is why the mixer does not depend on
packing speed, pre-pressure fluctuations or fluctuations
gas supply volume. ArCO gas mixer2 mainly used for welding technology and in the food industry
industry. Features and benefits of the arco2 faucet:
- by means of two integrated safety valves, the connected system is protected from dangerous high pressure;
- compact;
- differs in simple installation;
- economical - does not require additional components, such as a pressure regulator.
Mixer ArCO2 very
easy to maintain. Smooth adjustment of ArCO2 provides
proportional mixing valve with percentage scale.
Mixer for 2 gases N2CO2 also used primarily for
food industry or welding technology. Benefits and
advantages of mixer N2CO2:
- has a compact design;
- simple installation;
- low-cost - does not require additional components, such as a pressure regulator;
- Easy to operate: thanks to the proportional mixing valve and the % scale, continuously adjustable.
Gas mixer N2CO2 does not depend on pressure fluctuations in the gas supply and the volume of gas supply, as well as on the packing speed.
Advantages:
• low-cost, because no additional components needed
such as a pressure regulator • compact design • simple installation • protection of the connected system against hazardous high
pressure through two integrated
safety valves
Consistent quality
• does not depend on pressure fluctuations in the gas supply; • does not depend on the packing speed; • does not depend on fluctuations in the volume of gas supply (within permissible
limits)
Technical details
| A type | BM-2 M (with two integrated relief valves) |
| gases | N2/CO2 (0-100%) or Ar/CO2 (0-25%) |
| Inlet pressure | min. 4.5 bar, max. 230 bar |
| outlet pressure | Max. 3 bar |
| Capacity (air) | 8 - 25 l/min. |
| Adjustment accuracy | ±1% at 0-25% or ±2% at 0-100% |
| Mixing accuracy | better ±1% |
| Gas connection - inlet - outlet | flange connection DIN 477G 1/4 DIN 8542 |
| Frame | aluminium, lined |
| Weight | approx. 3.2 kg |
| Dimensions (HxWxD) | e.g. 220 x 160 x 140 mm (without connections) |
| Approval for operation | The company is ISO 9001:2000 and ISO 14001 certified |
Productivity BM-2M - up to 111 normal l / min. Infinitely variable capacity adjustment via dosing valve.
Productivity BM-2V - up to 142 normal l / min. Mixture outlet pressure adjustment via equalization pressure.
Features of argon and carbon dioxide compounds
Before deciding which gas to use in the mixture, it is necessary to consider the features of the use of each of them.
According to TU 2114-001-99210100-09, all of the above compositions can be formed in a variety of proportions, differing in the percentage of each of the components. In the vast majority of such proportions, argon or oxygen is contained in volumes that make up the bulk of the substance (from 88 to 98%). Supplementing them additives (carbon dioxide, in particular) rarely exceed 5-15% in volume terms.
Argon in proportion to helium is most often used for the purpose of processing non-ferrous metals and their derivatives. The main types of workpieces for which argon-arc welding is used are copper, aluminum, nickel, and chromium-nickel alloys.
Welding mixtures from a combination of argon and carbon dioxide are often used to heat the metal before welding or gradually cool it down after work is completed. As a rule, such a procedure is organized in cases of emergency.
The process of welding metal blanks in mixtures with a high content of carbon dioxide requires special attention. The fact is that when it combines with oxygen in the air, carbon monoxide is formed, which is dangerous for human health, to protect against which the operator must work in a special mask.
Thus, argon and carbon dioxide in combination with a number of active additives are universal welding gas mixtures used when working with most grades of ferrous and non-ferrous metals. Their combination, along with high efficiency of use, is characterized by a relatively low price.
Varieties
Taken in the ratio established by technical standards, the above components can form the following gas mixtures:
- argon plus carbon dioxide;
- argon in combination with helium and oxygen (hydrogen);
- combination of carbon dioxide and oxygen.
Some of these combinations are optimally suited for a semi-automatic, which is already designed for the possibility of their effective use. However, it will be more convenient to consider this issue after a more detailed acquaintance with the main welding mixtures.
Argon and carbon dioxide
Prepared in a certain proportion, this mixture of gases is most productive when working with carbon and low alloy steels. When comparing the effectiveness of this combination with similar performance of pure gas welding, it is found that this welding composition facilitates the jet transfer of the electrode substance.
In addition, the seams on the finished product, in contrast to welding on pure carbon dioxide, are more even and plastic. When working with this mixture of gases, the possibility of pore formation is markedly reduced.
Argon combined with oxygen
Argon-oxygen mixture is very often required for effective alloying of alloyed and low-alloyed steels. A small addition of oxygen to the working combination not only eliminates the formation of pores, but also significantly expands the possibilities of welding procedures.
First of all, this concerns changing the current adjustment limits, as well as the use of a wider range of welding wire varieties. Naturally, the quality of the weld formed in this case increases markedly, as a result of which mixtures of this composition are in high demand.
carbon dioxide and oxygen
The use of this welding mixture of gases allows you to get the desired positive effect, which is manifested in the following:
- metal spatter observed during welding is significantly reduced;
- as a result, the quality of the formed seam is improved;
- the temperature in the working area rises, which in a certain way affects the efficiency of the work being carried out (their productivity increases sharply).
However, this welding reagent has one significant drawback associated with increased metal oxidation in the welding zone. As a result, the mechanical parameters of the formed joint deteriorate noticeably. In addition, this compound produces carbon monoxide, which is harmful to humans.
