Electrodes: types, characteristics, which is better, the producers

The electrode pin is coated with lubricative used for welding metals. Molten core, absorbing oxygen and nitrogen, becomes brittle during operation.

It is therefore necessary slag covering (coating) to protect the molten weld metal or curable by atmospheric influences.

Coating determines cleanability, weld strength, the quality of the ball, and the composition of the weld metal and electrode specification. It protects the metal from damage, improves the quality of welding and creates a number of benefits, which include:

• controlled size and spray penetration;
• stability of the arc;
• increasing deposition rate;
• aligned weld surface;
• easy slag removal.

types of electrodes

Products are classified on several parameters: melting behavior, the coating composition of the coating.

by melting

Melt (metal or otherwise) electrodes - a consumable material which transforms into the weld part. Non-consumable variations are made of carbon and graphite, they are metal.

nonconsumable electrode

Major variations - coal-based and tungsten.

• Carbon electrodes - a machine without the filler, is used for cutting or arc welding, it consists of carbon graphite rod, which may be coated with copper or other metals.
• Tungsten electrode - defined as no filler metal electrode used in the arc welding or cutting. Produced most of tungsten.

Also included torirovannyj, itrirovanny and lanthanised electrodes.

It contains information about the size and tolerance requirements and selection of pilot tests. Application area:

• carbon and the usual double-arc welding,
• cutting and gouging.

meltable

The metal electrodes are divided into coated (cast iron, brass, bronze, aluminum) and uncovered. The second type was used in the early stages of development of welding industry, it is now used as a wire for welding in a gaseous environment.

covered electrodes distinguished by the thickness of the applied layer as defined GOST 9466-75:

• Thin - A Russian markings identical to the international;
• Medium - Russian labeling, international - In;
• Thick - Russian markings D International - R;
• Especially thick - Russian markings D, international - S.

There are 4 types of possible operating positions:

• all positions;
• all except the vertical position;
• lower, horizontal and vertical;
• lower.

classification of electrodes

Consider the Russian and American systems.

Western manufacturers have established methods of identifying electrodes used in arc welding type E1234:

1. E - arc welding.
2. The two first digits - the tensile strength is indicated in lbf / in² (thousand psi. inch) of the deposited metal.
3. The third digit indicates the position of the welding: 0 - is the classification; 1 - for all positions; type 2 - only for the horizontal position; 3 - only for horizontal welding.
4. The latter figure - indicates the polarity, along with the type of current.

For example, the number of electrode E6010 is suitable for arc welding with a minimum tensile strength of 60,000 lbf / in²; used in all positions; It requires direct current reverse polarity.

Types of coatings, current and polarity assigned to the fourth position of the classification.

Russian classification It has differences. The symbol indicates the appointment, type of coating and mechanical properties of the weld. Determined by GOST 9467-75.

• E38-E50 - a range of classes for working with low-alloy steels. This type of metal stronger than carbon analogs standard components: Chromium, Nickel, tear rate of at least 50 kgf per millimeter.
• Variations with the letter A to 50 (e.g., E50A) are applicable for welding of carbon steels.

The material of lower strength than the previous one, with a reduced carbon content - generally up to 2.14%. Consumables, indicated A, used for demanding metal ductility or toughness.

• E55, E60 - average category are suitable for first and second kinds of materials, but the resistance to rupture, held in the range 50-60 kgf / mm.
• E70-E150 - for alloyed steels (high strength and high), tear strength exceeds 60 kgf / mm.
• Basic type E-09M or variations with the addition of other abbreviations and with the letter M in binding designation, and the types of e-10H1M1NFB, e-10H3M1BF - for welding alloy steel heat resistant type.

Each type number of requirements for compliance with the standards of the mechanical properties and chemical composition.

By coating mind

The division into the following types:

• sour (Denoted by A) - to work in all positions with the use of any kind of current. Not applicable when the carbon content is increased, or sulfur in the metal.
• rutile (Denoted F) - work with alternating or direct current, used in all positions.
• main (Denoted by B) - all spatial positions, suitable for welding thick metal. Working with a constant current, the polarity is reversed.
• cellulose (Denoted U) - electrode is resistant to overheating. Working with direct or alternating current in all positions.
• blended (Denoted RTSZH) - all provisions in addition to the ceiling, low consumption, are composed of iron powder.

According to the composition of pack

It consists of 6-12 ingredients:

• Cellulose - created by the decomposition of the material gas with the reducing agent shield surrounding the arc.
• Metal carbonates - adjustable base slag gazozaschita created by melting organic components.
• Calcium fluoride - electrolyte improves flowability when applied to metal oxides, released gas for arc protection.
• Mineral silicates - considered slag-forming, are used to ensure that the alloy content and bases, are responsible for the strength of the electrode coating.

• Ferrosilicon and ferromanganese - complement the weld seam of silicon and manganese, helps its deoxidation.
• Titanium dioxide - forms bystrootverdevayuschy slag material characterized by increased fluidity during welding.
• Clay and gum - provide strength and elasticity of the coating material during extrusion.
• Iron powder - welding productivity increases due to the additional precipitation of the metal in the weld, the arc stabilizes and improves the flow properties of the slag.

Details of electrodes

Features functional coating patterns depend on the applied surface composition.

rutile electrodes

Among them are combined varieties: rutile, iron powder, sodium or potassium.

• If, rutile, iron powder, allowed welding position depend on the percentage. Up to 50% of the powder - the electrode is suitable for use in all positions.

A higher percentage is only used for the production of horizontal fillet welds.

• The content of the rutile titanium dioxide or relatively high in relation to the sodium component that provides a reduced spatter, the controllability of the slag and quiet arc.

• In models with sodium flux it has a smooth surface and the penetration of less than cellulose analogs, but the mechanical properties of the weld metal is lower than that of cellulose type.
• The high deposition rate and low voltage arc are common to all rutile-sodium plasters, it depends on the amount of iron in the coating.
• Formulations of potassium used for arc ionization.
• Rutile used with any of the current view, but in a straight polarity.

cellulosic electrodes

Produced from recycled materials, low alloy components or cellulose-type sodium addition, paper content reaches 30%.

• Fusing rough, and increased spatter compared with other types of material makes it inconvenient for a permanent job.
• Pulp and potassium view suggests replacing sodium potassium, of weld (arc penetration) close in quality to the pulp and sodium type.
• The gas shield with carbon dioxide and hydrogen produces a uniform arc which ensures deep penetration.

This is an early type, designed for pipe lines cross. Usually it is used together with a constant current at a reverse polarity. Cellulose potassium suitable for AC welding.

The cellulose types permissible in the presence of small amounts of iron powder. It stabilizes the arc, and slightly increases the rate of deposition.

Basic and variations nizkovodorodistye

Lime-calcium coating conforms to the main. The whole group plasters characterized by the absence of organics, is released during the decomposition of hydrogen. Besides the main, these properties are inherent in mixtures with sodium and potassium.

• Unused resources containing the crystallized water: asbestos, cellulose.
• Calcium fluoride provides minimal hydrogen content at the arc, whereby an increased weld ductility achieved.
• The arc is smooth, but the average deposition rate, with moderate penetration.

The type of a constant current, need reverse polarity.

acidic electrodes

The basis wash ore with oxides of iron and manganese. Oxidative character mixtures caused evolution of oxygen during melting.

• The composition is obtained of about 0.15% carbon content corresponds to the boiling steel.
• Deoxidized metals are prone to increased pore formation, coating is not suitable for use with high-alloy steel.
• Moderate toughness.
• Metal treated with an acid wash, is brittle and prone to cracking.

With iron in the composition

This includes a mixture of hydrogen-iron (more than 50% of the powder) and iron oxide-sodium. Wash with this composition creates a large amount of slag during operation.

• average penetration and reduced spatter levels;
• obtain a weld having a smooth surface;
• complication of slag formation control;
• deposition occurs at a high speed;
• It is used only for making horizontal fillet welds;
• work with any type of current and polarity.

There are types other than those mentioned, most of them - the combination and intended for aerial work.

typical characteristics

naked

Made from the composite wire for specific applications.

• Drawing coatings have slight stabilizing effect on the arc.
• Applied to welding of manganese steel and other operations where the coating is not required or desirable.
• Practically inapplicable for manual welding - arc unstable.
• Nitriding seam causes a decrease of its mechanical properties.
• When operating at low currents, characterized by the appearance globular advantage.

chalk

Light coating improves the flow characteristics of the arc:

• reduces the impurity phosphorus oxides or sulfur;
• changing the tension of the metal - the droplets emerging from the tip of the electrode, small size and high frequency;
• Controlled flow uniformity;
• Increased arc stability;
• in the joint increases the oxygen content of 5-10 times.

Physical and mechanical characteristics of the weld metal when entering the modified alloy electrode materials into plaster. The slag in this case enhances the quality of the metal joints and their suitability for high-speed welding.

pros

Advantages electrodes are considered type of coating.

rutile

• Reduced toxicity;
• arc stability, regardless of the type of current applied;
• increased deposition rate at the input of iron powder;
• resistance to pore formation;
• quality weld formation due to the smooth transition metal;
• low sensitivity to arc elongation,
• Small spray ratio.

main

• high ductility;
• reduced risk of damage and crystallization cracks;
• High toughness of the weld;
• resistance to cold brittleness;
• increases the deposition rate when administered iron powder;
• low oxidizing ability;
• toxicity in comparison with acidic coatings reduced.

sour

• with arc extension or working with the material containing dross, there is no tendency to form pores;
• stable combustion to different types of current;
• High-performance heat provided in oxidation reactions;
• acidic slags ability to bind iron oxide, transforming them into silicates and titanates;
• deposition rate reaches 11-12 g / Ah.

cellulose

• a reduced amount of slag;
• Gas metal protection;
• allow to carry out the work without the formation of pores;
• high quality root weld penetration;
• suitability for welding in confined spaces and all positions;
• compliance with the chemical composition of the weld semi-killed or killed steel.

Problems

Disadvantages are also tied to the types.

rutile

• silicon dioxide causes a reduction in toughness;
• reduced ductility;
• small hydrogen sulfide stress cracking resistance;
• instability to the crystallization cracks;
• High oxidation of iron and alloying elements;
• high phosphorus content, causes a tendency to cold brittleness;
• unsuitability for designs with high operating temperatures.

main

• tendency to cavitation at the increased arc length or the presence of rust on edges;
• requires preparatory work with pictures - cleaning, calcination prior to welding;
• unstable arcing due to fluorine in the composition;
• ionization probability;
• required for operation with direct current reverse polarity.

sour

• hydrogenation and diffusion of the weld metal;
• limited the possibility of applying for a hardenable alloy and carbon steels;
• increasing deoxidizing metal favors the formation of pores due to hydrogen evolution;
• the tendency to form the weld hot cracking at a carbon content exceeding 0.15%;
• unsuitability for manual welding steels containing more than 0.3% carbon;
• tendency to strain aging, which reduces toughness;
• increased spatter;
• Toxicity of manganese compounds.

cellulose

• spattering up to 15% - a higher rate;
• high surface tension of molten metal;
• the hydrogen content of the weld is increased, which reduces its strength.

How to choose

Among factors considered in choosing the right electrode, the main is its composition. It must meet the stated objectives and the type of metal with which to work.

• The bare wire electrodes models uniformity is responsible for monitoring the stability of the arc.
• It is important to choose the material, similar to the composition of the weld metal.
• The presence of a mixture of certain components causes arc instability. This ferric sulfate, aluminum oxide or its (at least 0.01%) and silicon dioxide and. At the same time, the iron oxides of manganese and calcium stabilized arc.
• Phosphorus causes grain growth, brittleness and cold brittleness. Sulfur acts as a slag, is particularly harmful in the electrodes of low carbon steel with a low content of manganese.

The surface should be free of dirt and roughing compounds. Is checked using a light fabric. A large number of layers creates unstable welding conditions.

What better electrodes

Universal values ​​there, the main thing - to pick up matching types and sizes.

• Cellulose and base coat is applied only for manual welding with direct current, suitable for designs with oversized durability requirements.
• Sour and rutile is applied with a voltage of 50 volts welding machine. The tolerance of 5 volts.
• UONI 13/55 - universal type with basic coating, MP-3 - rutile.
• Electrode diameter is selected for the metal thickness, which will cook. Allowable difference in width in the range 0.1-0.5 mm.

• Soft arc (designation) - for thin metal or imperfect structures or clearance fit parameters.
• It is important to pay attention to the relevant statements of the welding position (horizontal, and so on. D.).
• The presence of iron powder increases the volume of molten metal available to the weld (in the heat turns steel powder).

Exploitation

The electrodes should be stored in dry. Moisture adversely affects the characteristics of the coating, and can lead to excessive splashing. It often leads to porosity, excessive formation of cracks in the welded area.

The electrodes are exposed to moist air or liquid for more than 2-3 hours, it must be dried by heating in a suitable furnace - for two hours at a temperature of 260 ° C. After drying require storage in sealed containers or packages.

Bending electrode can lead to the fact that the rod will escape from wash. Electrodes damaged coating should not be used for welding.

electrodes manufacturers

Warranty conditions manufacturers do not apply to consumables, which include electrodes.

BlueWeld - Italian manufacturer of welding equipment. Available electrodes for plasma cutting, which differ in form from the ordinary.

Brima - the German manufacturer. Accessories for welding dissimilar steels, rutile and austenitic-ferrite model. Comply with Russian and international classifications.

Deka - manufacturer of Spain, specializing in metalworking machinery and machine tools. Welding components are available in the form of wire.

ESAB - Swedish manufacturer of equipment for welding and cutting metals. The coated electrodes with main daubing.

FUBAG - the German manufacturer. It specializes in various types of equipment for power stations, pumps, compressor and welding tool. Models are available electrodes with rutile and basic coating.

Kedr - for this is the company brand manufacturer of inverters and cooking accessories. Tungsten electrodes are available models.

Monolit - trademark rutinovyh and cellulosic electrodes. Produced "PlazmaTek" Ukrainian company.

Telwin - Italian manufacturer of welding equipment and accessories. The warranty on the welding equipment 12 months.

Wester - complete with rutile daubing. The company poorly represented on the Internet, under the same brand are the other manufacturers.