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Welding materials and equipment for arc

Technique arc welding Welding works suggest a certain preparation of parts, which includes several operations: - editing that is carried out on machines or manually. For example, for editing sheet and strip metal apply various

High-performance welding methods To improve the performance of manual arc welding, several methods have been developed. One of them is called deep-pressed welding (thanks to this method, labor productivity increases by about 50-70%),

Technology welding in protective gases Arc welding in the protective gases environment is becoming increasingly distributed, because there is a number of technological advantages: - ensures high productivity and the degree of heat source concentration.

Features of welding of various materials Gas welding can be applied to welding various materials.1. Welding alloy steel. It includes titanium, molybdenum, chrome, nickel, etc. from the presence of certain alloying components depend on the features

Safety technique for gas welding and cutting gas welding and cutting are associated with a certain risk, so if they are implemented, it is necessary to strictly follow the safety regulations: 1. Before work, you must carefully read the instructions for use.

Reservation technology Reservation is a method based on applying a waxy or fat layer according to the product planned on its glazing. Skipididid is added to the bees wax and heated to dissolution. With the help of brushes impose the composition to the place, not

The technique of shtchevyvyi take a little putty on the spatula and apply it to the surface of the wall with strokes of the middle thickness, then press the spatula's blade slightly stronger and smash the spacion layer by vertical movements. Spacely roll up to getting very thin

Technique Painting When painting ceilings and walls draw attention to the direction of light falling out of the window. If painting is made with a brush, the penultimate layer of paint is necessarily applied against the direction of the sun's rays, and the last on the contrary. Otherwise, after

Cold welding method at home Welding joints of the linoleum panels produce in the following ways: - heat, that is, infrared rays and hot air; - a cold. The first welding method is mainly used in production, and at home - only

Safety Each professional electrician before crossing the practice directly to practice, gives a special safety exam. This exam includes questions about the operation of electrical installations and ways to work with them that would

There are several types of welding, differing from each other by obtaining a high-temperature welding bath, designed for cutting or compounds of various metals and alloys: electric arc, ultrasound, gas flame. The principle of operation lies in the fact that the edges of the designs of the reunion to be reunited are melted, and a completely new structural unit is formed at the place of their joint - welding seam.

Welding gases

The temperature indicator depends primarily on which gas is used during welding. For example, as a result of water reaction with calcium carbide, acetylene is released, which interacts with oxygen, makes it possible to obtain a flame temperature of more than 3000 degrees. The welding gases include all varieties of propanes, butanov, Maf (alternative to acetylene), benzenes, kerosens and others.

The presence of oxygen, which is a combustion catalyst, is necessarily in the process of applying any welding gases. The oxygen supplied to the burner must have high quality and purity. The maximum temperature obtained during operation depends on these indicators.

Gas mixes elements

Regardless of which gas is used during welding, it is important to remember that it is possible to obtain a high combustion temperature and certain flame properties, only when used in a mixture of technically pure oxygen. Fullness of combustion or evaporation of combustible elements depends on the quality of the component, and on the amount of the properties obtained by the flame: restorative or oxidative.

Special requirements are presented to the storage and submission conditions. The use of special separate cylinders is necessary in this case:

• technical oxygen is a powerful catalyst;
• many gases used for welding are very toxic.

If atmospheric oxygen is used, it is hardly possible to get perfectly smooth seams. It will change the properties of the metal found in the melting and compound process, which will significantly reduce the quality of the seam made.

It is considered not effective use in a welding gas mixture of conventional oxygen contained in the atmosphere. The presence of impurities existing in the air significantly reduces the combustion rate of the elements, which is reflected in the flame temperature.

Welding gases

Regardless of which gas is used during welding, inert or carbonate, it should be remembered for compliance with the proportions in the mixture. A specific choice depends on the metal. For example, carbon dioxide gas prevails in welding steel structures (about 18%), and when working with stainless steel - argon (almost 98%).

During welding, inert and active gases are used. Inert elements are usually not poisonous, do not interact with the metal and do not dissolve in them.

• Argon (AR) - does not have colors and odor, it does not burn, heavier than air is one and a half times. Distinguish two varieties. The highest grade is used to welding loaded metal structures from active and rare metals and alloys. The first grade is necessary for aluminum and steel products.
• Helium (He) - without color, smell, lighter than air. Two types are distinguished: high purity and technical element. Rare Helia's use is due to its high cost. Recommended for pure and active metals, aluminum and steel.
• Nitrogen (N2) - does not have colors, smell. It is used for copper and copper alloys. There are 4 varieties of nitrogen with different content of substance.

Gas are active serve as the protection of the welding zone from the air, they enter into chemical interaction with metals and dissolve in them.

• Oxygen (O2) - does not have colors, odor, taste. Oxygen does not burn, but is a powerful catalyst that supports burning. It is used in mixtures with inert or active ingredients.
• Carbon dioxide (CO2) has a smell and pronounced oxidative properties. It is perfectly soluble in water and weighs 1.5 times heavier than air. There are 3 grades of substances that are used to connect cast iron, low and medium carbon metals and alloys, low-alloy structures and corrosive steels. It should be remembered that carbon dioxide in welding does not apply.

Improve the process and welding quality with welding mixtures. The most claimed mixtures:

• helium and argon;
• argon and oxygen;
• carbon dioxide and argon;
• oxygen and carbon dioxide;
• argon, carbon dioxide, oxygen.

Choosing which gas for welding is suitable in a particular case, it is necessary to take into account several factors: the characteristics of the metal combined, the type of equipment, the desired seam shape, the conditions for performing work, the properties of the chemical composition.

Gas welding is more expensive than electric, because the price of acetylene and oxygen is significantly higher than the cost of the electrical energy required during contact or arc welding.

Gas welding with full responsibility can be called the queen of welding fields.

Everything is good in it: it is easy to perform, equipment for gas welding is quite inexpensive, economical in the consumption of electrical energy, the list of advantages can be continued.

If you started with the advantages, it will be honest to stop at the minuses. The disadvantage in the speed of metal heating is low.

In addition, the working plot with such a "melt" method is a very large zone of metal heating, which is lost a lot of thermal energy. There is also such an unpleasant phenomenon as a warping.

Thus, the performance of the workflow is not very high, and with an increase in the thickness of the edges of the welded blanks decreases even more.

Therefore, if the thickness of your metal sheet is more than six millimeters, start thinking about the use of gas welding somewhere else. And the thick edge is better to cook, for example, arc method.

Injector and uninterruptible burner.

Gas welding - not the most expensive welding method, it is well known. But gas for welding - acetylene and oxygen, which love to use as a welding gas mixture, are still more expensive than electricity.

And if you add a fairly high risks of explosions and a serious fire. Danger that instantly occurs with the improper handling of combustible liquids, gases, oxygen cylinders and elementary calcium carbide, enthusiasm is slightly reduced.

Gas welding technology is excellent for a wide range of welding: from the connection of parts from aluminum and steel to work on bronze and cast iron.

Immediately, we note that almost all metals, including such a capricious as copper, lead or cast iron, can be powered by gas welding: they are easier than gas technology than any other.

Technical sides of the gas welding process

Features of gas welding - the democraticity of its seams, which can be done in all positions in space - from the lower to the ceiling.

The hardest thing accounted for the ceiling seams, since in this case the molten metal needs to be maintained and quickly distributed over the entire length of the seam by the high pressure of the gas mixture from the flame.

The most popular seams in this method are butkovy. It is not friendly gas welding with seams of a mustache and brand. The fact is that for both types of seams you need an extremely strong heating of the metal. In addition, this method is high risk of pronounced warp.

If the edges of the billets are thin and bent, they are boiled without the use of filled wire with the formation of continuous or intermittent seams, which can also be single and multi-layered.

It is clear that before welding it is necessary to clean the edges and surfaces of metal blanks in the most careful way.

One of the most important technical components of the GS - manipulation with a gas burner. Gas welding technique implies that the flame is kept at a distance of about 5 mm from the end of the core, without touching the metal surface.

The welding bath is formed under the pressure of the gases on the liquid metal, they seem to swell it around the edges.

The additive wire is immersed in the welding bath. The intensity of the heating of the working area can be changed. This is done by changing the corner of the tilt of the copper mouthpiece of the burner to the surface of the workpiece. The dependence here is straight and understandable: the greater the angle of inclination, the higher the heating of the metal from the flame.

The torch mouthpiece should move along the seam. At the same time, it is necessary to monitor the condition of the welding bath: the metal in it should be protected by gas pressure from the unwanted effects of ambient air. It is necessary to do this to protect the metal from the oxide film.

The most sought-after ways

Welding in the lower position.

Gas welding methods can be described and listed in several thick volumes.

Take the most common of them:

Left welding

The left method of gas welding is the most common among masters of any qualification. Used to connect metals with a thin edge and a low level of melting point. Left and right welding - two sides of the same medal, remember it easy.

Right welding

The right welding method is suitable for working with metals with a thickness of more than 3 mm and high thermal conductivity. It should be noted that the welding seam with right welding is obtained better due to the best protection of metal with flame.

The use of the heat of the flame with the right way is more economical, and the speed of the process is above almost 20%. In the same popular potty, you can add gas cost savings about 10%.

A twisted wire must be taken with a diameter less than exactly two times the thickness of the metal blank. Wire can not be thicker 8 mm.

Welding using through roller

This technology of gas welding involves gradual, step by step, moving the flame with the melting of the upper edge of the hole in the workpiece and the layer of the molten metal layer on the lower edge of the same hole.

Pre-sheet metal sheets are fixed vertically, leaving a gap between them half the thickness of the workpiece itself. The seam is formed in the shape of a roller, which connects the items. It is distinguished by density, without any pores or slag residues.

Welding with baths

Here the name speaks for itself. The principle of the method lies in the formation of new and new baths along the seam. As soon as one of them is formed, the end of the additive wire is introduced into it, it melts there, and then moves to the refurbishment of the burner fire.

Meanwhile, the mouthpiece of the nozzle moves further along the seam - the next site. Each new bath overlaps the previous one third of the wire diameter.

This method connects thin sheets when you need to perform butt or angular types of seams. This is a favorite type of welding for pipes from steel low-alloyed or small-carbon alloys.

Multilayer gas welding

It is used with very responsible types of work, as it is characterized by rather low performance, and the welding gases are required here in a large volume - the method is not cheap. It occurs an annealing of the lower layers when the upper is surfacing.

As a result, there is an excellent duty of each layer before the formation of the next seam. This method significantly improves the quality of the seam metal.

The process goes in short plots. Special attention is paid to clean the surface of the underlying layer before overlaying the following.

Welding with oxidative flame and deoxidation

Gas welding cylinders.

This technology is designed to connect parts from small-carbon steel alloys. The flame here has a sharp oxidative character, as a result of which iron oxides are formed in the welding bath. If there is oxidation, it is necessary and the so-called deoxidation.

It is achieved using a special additive wire with high shares of manganese and silicon. An excellent productivity is higher than 10% than the remaining methods.

Nuances with different seams and different metals

Horizontal seams are formed using the right method of gas welding. There are situations where the process lead to the right to left with the mouthpiece at the bottom of the bath, and the wire from above. So the seam is formed faster and easier, and the molten metal in the bath does not flow down.

Vertical seams on the contrary, are produced by the left in the bottom-up direction. If the metal is thick, apply the seam with a double roller.

Ceiling seams are one of the most difficult for execution. Here you need to first heat the edges of the workpiece, then until the time for their melting, the wire is placed, which is quickly melted.

The liquid metal in the bath is held from the flow of down the pressure of gases from the burner. Welding makes the right way. It is best to use multilayer seams with multiple passages.

Low carbon steel can be prepared with almost any gases. It is important to choose the right twisted wire: it must also be made of steel with low carbon content.

Alloyed steel are with very different compositions. Therefore, the unified method of gas welding for them is not and cannot be. If the heat-resistant stainless steel alloy, the parts are cut from it with a wire with a nickel and chromium content.

There are separate stamps that can only be prepared using molybdenum as part of the additive wire.

Copper and its alloys always require a strong flame. During melting, it is extremely fluid, so the gap must be made minimal. In addition to copper wire, flux mixes for deoxidation of metal weld are used.

Brass is a very difficult metal for work due to its composition. Here is the high risk of pore formation in the welding seam due to the volatility of zinc. This risk can be significantly reduced by feeding more oxygen into the mixer and applying brass wire as a additive.

Bronze - another capricious alloy. During welding, it is important not to smear from the composition of its important elements: tin, silicon and aluminum. Therefore, the flame should be reducing, and the additive is bronze with a silicon additive, which will help in the further deoxidation of the seam.

Advantages and disadvantages of welding with gas burner

Gas welding of metals has a solid list of advantages:

• The method does not imply the purchase and use of complex and expensive equipment. It is not necessary for him, for example, an inverter or semi-automatic.
• Consumables used in gas welding are widely offered on the market, you can find any composition or model without difficulties.
• Special protective agents are not required, even with gas welding of pipes.
• The main parameters of the welding are well regulated: the flame of any required power, the level of metal heating temperature.

Gas burner welding method.

There are disadvantages where without them:

• Too slow metal heating, especially in comparison with the electric arc.
• A too extensive heating zone around the gas burner, as a result of which a lot of energy is lost.
• Heat from the burner of scattered type, it is difficult to concentrate.
• The method is still more expensive than the electric arc: the price of gases is higher than the cost of electricity.
• With an increase in the thickness of the edges of the blanks, the speed of the workflow is reduced due to high heat dissipation.
• It is almost impossible to automate the process.

Couple words about consumables

What gas is used during welding - the question is not unavailable, in which you need to understand to make the right choice. Types of gases used are different, the choice depends on several factors.

Oxygen

Oxygen, for example, is distinguished by the complete absence of color and smell. His role is special, it performs the function of the catalyst for the melting of metals during welding. Storage and transportation of oxygen are made in constant pressure cylinders. This is a difficult thing, but quite fulfilled.

The main thing is to know and implement the safety rules in handling oxygen cylinders and gas itself. For example, the presence of technical oil can lead to ignition: therefore, it is necessary to categorically exclude the slightest contact with such oil.

Flame of gas burner.

In the premises where cylinders are stored, in no case should there be a source of heat or direct sunlight.

How welding oxygen is obtained: this is done quite simply - from atmospheric air with the help of specialized equipment.

Oxygen is divided into three types of purity:

• highest grade with gas concentration of 99.5%;
• first grade from 99.2%;
• the second is from 98.5%.

Acetylene

This is the second most popular gas used in the GS for welding and cutting. It is also without color and smell. With elevated pressure or heating, acetylene may explode. It is produced from carbide calcium and water.

Acetylene is not the cheapest gas, but its advantage makes it very popular among welders. It's all about combustion temperatures - it has acetylene is remarkably high, especially in comparison with such cheaper gases as methane, propane or kerosene couple.

Flux and Flushing Wire

These are the main participants in the process of forming the welding seam. The additive wire must be absolutely purified from the slightest signs of dirt or corrosion. Sometimes instead of wire, it is possible to use a strip from the same metal as blanks for welding.

Flusics are necessary to protect the welding bath from the harmful effects of external factors. Most often, a boiler and boric acid are taken as composite elements of flux mixtures, which can be applied directly to the welded blanks or on the additive wire.

The only metal that can do without flux mixes is carbon steel. Well, a special need in the presence of a flux occurs when welding copper, aluminum and their alloys.

Necessary equipment for gas welding

Water shutter

This is a simple and effective protection of the pipe, the acetylene generator and other elements from the fire in the form of a reverse thrust from the gas burner. Water in this gate should be at the level of which you need to follow. It is usually located between the burner and acetylene pipe.

Gas cylinders

These cylinders of different color depending on the type of gas. All cylinders apply strict rule: never paint the top so that the paint and gas contact does not happen. Another technical nuance: the acetylene cylinders should not be made copper valves due to the high risk of explosion from the interaction of acetylene and copper.

Miscellaneous hoses

Hoses need a lot for what: gases and hot liquids. In addition, they must work under pressure, so this is not at all garden hoses for irrigation of vegetation, but serious devices with special technical characteristics.

• with a red stripe for pressure up to 6 atmospheres;
• with a yellow stripe for combustible substances;
• with a blue pressure strip up to 20 atmospheres.

Gas-burners

Gases and pairs from flammable liquids are mixed in a burner mixer. They are produced in a huge variety, sharing injectors and burners without it, different power, and so on.

Reducer

The necessary thing is where there is a high gas pressure.

Reducers reduce gas pressure leaving the cylinder. They are two types: direct and reverse action. Advanced silver models are available for operation with liquefied gas: they do not allow such a gas to freeze at the outlet of the cylinder.

Gas post

This is a special desktop for welding. The best way Post - a tabletop with the possibility of turning it and fixed. A good post is equipped with exhaust ventilation and a good warehouse tool and storage system.

Gas welding: hybrid version with semi-automatic

In this technique, the use of an electrical arc and protective gas is added - most often argon. With this scenario, the technology can be called hybrid.

Sews with gas welding.

These are the steps of actions:

• connecting the device to the network;
• fixation of the foaming wire through the hole in the burner;
• gas pressure adjustment using gearbox;
• definition and setting the feeder feed rate;
• regulation of the remaining parameters - the forces of welding current and voltage;
• fixation of the burner at an angle to the surface of the blanks before igniting the burner;
• start welding.

It should be noted that specifications All consumables, as well as equipment elements, clearly and clearly spelled out in GOSTs. In other words, the gas welding process is perfectly regulated.

Fall under Gosty, for example, the following parameters:

• characteristics of acetylene generator;
• types of hoses;
• gas pressure adjustable by gear;
• type of gas burner;
• types of additive wire;
• standards for gas cylinders, etc.

Gas welding process

TO Manager:

Welding metals

Gas welding process

Gas, or gas-plasive welding refers to the group of welding methods of melting and occupies the most important place in this group, yielding to the practical value of only arc electric welding. To carry out the welding process, it is possible to use different combustible, respectively, which can be distinguished by welding hydrogen-oxygen, gasoline-oxygen, etc. Acetylane-oxygen welding has a predominant value; Other types of combustible have limited use. The essential technological difference of gas welding from arc welding is a smoother and slow metal heating.

This is the main difference between the welding gas flame from the welding arc is in some cases the disadvantage, in others, the advantage of the gas flame and determines the following main areas of its use for welding:
1) steels of small thickness, 0.2-5 mm;
2) non-ferrous metals;
3) metals requiring a gradual soft heating and slow cooling, for example, many instrumental steels;
4) metals requiring heating during welding, for example cast iron and some varieties of special steels;
5) for solid soldering;
6) for some types of surfacing work.

Thanks to the versatility, the comparative simplicity and portability of the necessary equipment, gas welding is very appropriate for many types of repair work. Comparatively slow metal heating with a gas flame quickly reduces the capacity of gas welding with an increase in metal thickness, and with thickness steel above 8-10 mm gas welding is usually economically unprofitable, although the welding of 30-40 mm thick is technically possible. In slower heating, a large volume of the main metal adjacent to the weld bath is heated, which, in turn, causes significant deformations (warping) of the products of the products. This important circumstance makes gas welding technically inappropriate, not to mention economic disadvantage for such, for example, objects, such as building metal structures, bridges, wagons, hulls of ships, beds of large machines, etc. Slow heating also causes a long residence of metal in the zone High temperatures, which entails overheating, consolidation of grain and some decrease in the mechanical properties of metals.

Significant metal deformations arising from gas welding limit the possibility of choosing rational forms of welded joints. From the diverse forms of welded joints performed by arc welding, with gas welding use, as a rule, only the simplest butt compound. Corner seams and compounds of fattest and brazers for gas welding are used only in cases of necessity due to the difficulties created by significant metal deformations inherent in gas welding. The butt connections are used as without a bevel of edges, without flaming and with the kneading edges (a particularly convenient compound for gas welding) and with single and double-sided bevel edges.

Qualified welders can use more powerful burners, increasing the rate of flame promotion along the seam and increasing welding performance.

The burner is usually adjusted to work on a normal flame. The thermal effect of the flame on the metal depends not only on the power of the flame, but also on the angle of the flame axis to the metal surface. The flame is most intense when its axis is normal to the metal surface. With a decrease in the angle of inclination, the thermal effect of the flame is weakening and is distributed for the larger area. Thus, besides the selection of the appropriate burner size, the welder can smoothly adjust the heat action of the flame metal, making the flame to be softer or tough, changing the angle of inclination of the flame to the surface of the product. With an increase in metal thickness, it is customary to increase the angle of inclination of the flame and reduce it with a decrease in metal thickness. In the process of welding, the burner is reported by oscillatory movements, and the end of the mouthpiece describes a zigzag path, similar to the path, the end of the metal electrode under arc welding. The burner the welder holds in his right hand, if the addition of the additive metal is required, then the welder holds a frowning rod in the left hand. The prudent bar is located at an angle of 45 ° to the metal surface, and the end should be immersed in the molten metal bath. The end of the bar reports zigzag vibrational movements in the direction opposite to the movements of the burner, so that the rods and the burner mouthpiece always move towards each other.

Fig. 1. Form of compounds used for gas welding

Fig. 2. The applied corners of the tilt of the burner depending on the thickness of the metal

Gas welding can be produced in the lower, vertical and ceiling positions. There are two methods for performing gas welding, so-called left and right ways.

With the usually applied by the left welding method, the additive rod moves ahead, followed by the burner. Welded seam remains behind the burner, the flame is directed forward, on the main metal. Most convenient for the welder in this case, move the burner along the seam to the right left.

With the right way of welding ahead moves the burner, it follows the additive rod located between the seam and burner. The seam is located ahead of the burner, counting in the direction of the flame, the flame is directed backwards on the weld. With the right method, the burner is usually moving from left to right.

The right method gives the best to. P. D. The use of heat of the flame, and therefore increases the productivity of welding and, accordingly, reduces the specific consumption of gases by 15-20%. Despite the specified advantage, the right method is applied quite rarely; This is due to the fact that the advantage of this method is noticeably manifested only when welding metal with a thickness of more than 5 mm, which rarely occurs during gas welding. When welding the metal of small thicknesses, the right way, not giving noticeable benefits, increases the risk of processing the metal, why it does not apply. In order to increase the productivity of gas welding, it is advisable to divide the flame into several separate independent flames located along the seam axis. Despite the undoubted increase in welding productivity given by multifamilate burners, they have not yet received a noticeable distribution in our industry due to the complexity of the design and maintenance, cumbersome and inconvenience in work compared to a normal single-flame burner.

Fig. 3. Scheme of transverse oscillatory movements Mouthpiece burner

Fig. 4. Methods for performing gas welding: A - left; B - right

The fastening wire for gas welding steels is used as for electrodes under arc welding, and is manufactured according to GOST in 2246-60. For gas welding of low carbon steel, the wire brands of SV-08, SV-08A and SV-15G are used. For welding cast iron produced special cast cast iron rods with high carbon and silicon content. For the surfacing of solid wear-resistant coatings, the rods of cast solid alloys are produced, for example, a solid alloy of the sample, developed by the Sorma Plant.

Instead of electrode coats used in arc welding, gas welding is quite widely used by fluxes whose use is necessary for gas welding of cast iron, non-ferrous metals and some special steels. Fluses are added to the bath for dissolving oxides and the formation of low-melting slags that pop-up to the surface of the bath. Fluses can introduce reducing agents and additives alloying the filtered metal. Fluses are used in the form of powders and pastes applied to the main metal or on the additive rod. The effect of fluxes on oxides can be chemical and physical, but often between them is difficult to carry out a clear boundary.

The chemical effect of fluxes is to form with oxides of metals of low-melting compounds resistant at high temperatures. For chemical fluxes of metal metal oxides, such as iron oxides FEO, acidic acids are injected into fluxes, such as silicon dioxide Si02 (quartz sand, crushed window glass) and boric anhydride B203 (boor, boric acid). For acidic acid oxides, such as silicon dioxide Si02, compounds giving major oxides are used. To this end, Na2C03 and Potash K2C03 are usually used, which gives the main oxides of NA20 and K20, respectively in the welding zone.

For solvent fluxes, there is mainly halogen salts of alkali and alkaline earth metals NaCl, KS1, LICL, CAC12, NAF, KF, CAF2, etc., as well as carbon dioxide and phosphorous sodium salts. To enhance the effects of solvent fluxes in them, sodium or potassium bisulfates or KHS04 are often added.

The resulting free acid translates metal oxides into halide salts, reinforcing their solubility in the flux and lowering the melting point of the resulting slag.

The use of gas welding is vast and varied. Gas welding is used in aircraft construction, which prevails welding of small thicknesses (1-3 mm), in the production of chemical equipment. Important It has gas welding in the laying and installation of pipelines of a wide variety of appointments, especially small diameters, up to 100 mm. Gas welding is an indispensable powerful tool during repair and, for this purpose, is widely used in repair shops for all types of transport, in agriculture, etc.

The quality of welded compounds performed by gas welding is higher than with arc electrodes with a thin ionizing coating, but somewhat inferior to arc welding made by high-quality electrodes. The main reason for a certain reduction in the strength of welded compounds is that at gas welding there is no doping of the weld metal, while in arc welding, high-quality electrodes containing ferroalloys are made of fairly significant doping. Thus, gas protection provided by the reduction zone of the welding flame to obtain a high-quality welded joint is less effective than the action of high-quality electrode coats for arc welding.

The performance of gas welding, significant with small thicknesses of the base metal, is rapidly decreasing with an increase in its thickness. With small thicknesses (0.5-1.5 mm), gas welding can exceed arc. With an increase in metal thickness up to 2-3 mm, the speed of gas and arc welding is equalized, and then the difference in speeds quickly, increases with an increase in the thickness of the metal in favor of arc welding. With small thicknesses, the absolute consumption of gases per 1 m weld is small; The total cost of 1 m of the weld may be less than with other welding methods. With an increase in the thickness of the base metal, the cost of gases and the consumption of time for welding 1 m seam and gas welding becomes more expensive than arc; The difference in value is rapidly increased with an increase in the thickness of the base metal. Thus, economically gas welding is most appropriate for welding small metal thicknesses.

The peculiarities of gas welding should also include almost exceptional execution of welds in one pass. Execution of seams for. Domestic passes, i.e. In several layers, widely practiced in arc welding, almost does not find applications for gas welding, where the patch of the seam in the hot state is quite often used, which gives good results in some cases - an increase in the density of the weld metal and the safety strength.

The gas flame is less bright than the welding arc, the flame radiation does not burn the skin of the face, therefore the protection of the eye of the welder's eye with colored glasses is sufficient.

Gas welding

Gas welding

compound of parts with heating (melting) of welding places of gas flames obtained by burning various combustible substances in oxygen. There are hydrogen-oxygen, gasoline-oxygen, acetylene-oxygen and other types of welding. The greatest industrial use received acetylene-oxygen. Unlike electrical arc or other sources of energy, the gas flame heats the material slower and more smoothly. This determines the expediency of using gas welding to connect parts from cast iron, tool steels, when heated or slow cooling in the process of compounding the metal is needed. For gas welding, complex equipment is required (welding torches and gas from the cylinder are used), so this welding method is often used during repair work. A variety of gas welding is gas cover weldingproduced with precipitating (squeezing) after heating the connected parts - pipes, rails, etc.

Encyclopedia "Technique". - M.: Rosman. 2006 .

Watch what is "Gas Welding" in other dictionaries:

gas welding - Welding of melting, in which heat flames of a mixture of gases burning with a burner is used for heating. [GOST 2601 84] [Terminological dictionary on construction in 12 languages \u200b\u200b(VNIIIS Gosstroita USSR)] Gas welding welding with melting, with ... ... ... Technical translator directory

Modern encyclopedia

Gas welding - Gas welding, melting welding with a flame formed by burning a mixture of combustible gas (acetylene, hydrogen, gasoline vapor, etc.) with oxygen in the welding burner. The creation of gas welding contributed to the use of processes ... ... Illustrated Encyclopedic Dictionary

See welding. Technical railway dictionary. M.: State Transport Railway Publishing House. N. N. Vasilyev, O. N. Isaakyan, N. O. Roginsky, Ya. B. Smolyansky, V. A. Sokovich, T. S. Khachaturov. 1941 ... Technical Railway Dictionary

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The method of welding metal products with a gas flame formed during combustion of a combustible gas (acetylene, hydrogen, gasoline vapor, etc.) with oxygen. Apply for welding thin-walled products made of steel, non-ferrous metals and alloys ... encyclopedic Dictionary

gas welding - Dujinis Suvirinimas Statusas T Sritis Chemija apibrėžtis Neišardomas Metalinių Detalių Sujungimas Dujų Liepsna. Atitikmenys: Angl. Gas Welding Rus. Gas Welding Ryšiai: Sinonimas - Autogeninis Suvirinimas ... Chemijos Terminų aiškinamasis žodynas

Welding with melting, when the heat of flames of a combustible gas (acetylene, hydrogen, gasoline vapor, etc.) is used for heating (acetylene, hydrogen, vapor of gasoline, etc.) with oxygen burned with a welding burner. The greatest tempo (approx. 3200 ° C) has acetylane oxygen ... Big Encyclopedic Polytechnic Dictionary

gas welding - Welding of melting at which the welded surfaces are heated by a gas flame, the nutrition of the gas burners in gas flame welding is carried out from cylinders (O2 and C2H2) and directly from the combustible gas generators. Such gases ... Encyclopedic dictionary for metallurgy

Books

• Gas welding and cutting of metals, I. I. Sokolov. Reproduced in the original author's spelling of the publication of 1975 (Publisher`Moscow`). AT…