The metal welding process is widely used not only in industry, but also at home. The most popular at present is electric electrode welding. This popularity is due to the simplicity of welding equipment, as well as the quality of the connection of various metals.
A high-strength and high-quality weld can be obtained only using electrodes with a special coating that protects the weld pool from oxygen. The best brands of rutile-coated electrodes are very popular not only among experienced welders, but also among home craftsmen. The main thing is to know their features and basic properties of the application.
Welding Electrode Selection
The high level of strength of the welded joint is completely dependent on the correct choice of consumables (electrode). Therefore, the solution of such a problem should meet the basic requirements for high-quality welding.
The correct choice of electrode for welding must meet the following conditions:
- the mechanical properties of the weld pool metal should correspond to the base material;
- the weld should not have cold and hot cracks, i.e., have high technological strength;
- the versatility of the electrode provides welding in various positions, as well as on any kind of current;
- when joining alloy steels, the material of the electrode should provide high corrosion resistance of the weld and its heat resistance;
- minimum level of toxic substances emission during welding.
Rutile-coated electrodes correspond to all these properties, therefore they are the most common when welding various types of steel.
Electrode Features
The welding electrode consists of two parts. The core of the electrode is a metal bar of a specific material. A special coating is applied to this bar, which significantly affects the welding process. The main objective of powder coating is to protect the weld pool from the harmful effects of oxygen.
As an additive for rutile-coated electrodes, SV-08 or SV-08A wire is used, which is characterized by a low carbon content.
Quality electrodes must be dry and free from mechanical damage. Therefore, the welding rods must be stored in a dry and warm place. When dampness occurs, the rutile-coated welding electrodes are dried in special ovens. At home, ovens can be used for this purpose.
The chemical composition of the electrode coating
A certain brand of electrodes, for effective connection of metal structures, is selected depending on the protective coating of the additive. The most common are four types of coverage:
- the main coating contains titanium, ferromanganese, quartz sand and smelter;
- oxides of manganese, iron and silica are part of the acid coating;
- rutile-coated electrodes comprise about 50% titanium dioxide (rutile);
- the composition of the cellulose coating includes talc, resin of organic origin, cellulose and various ferroalloys.
The chemical composition of rutile electrodes contains a number of additional components, which are distributed in the following ratio:
- dextrin - 3%;
- magnesite - 10%;
- ferromanganese - 15%;
- feldspar - 25%;
- rutile - 47%.
Advantages of rutile electrodes
Of course, the percentage of components that make up the rutile-coated electrodes may vary slightly, depending on the manufacturer.
The choice of the necessary consumables for the high-quality performance of electric manual arc welding depends on the positive properties of the electrodes used.
The main advantages of rutile-coated electrodes include the following properties:
- emitted gases during the combustion of rutile electrodes are low toxic, which almost does not harm the health of the welder;
- the ability to weld on surfaces without pre-treatment, as the components are not susceptible to moisture or rust;
- soot that occurs during welding, has the properties of a semiconductor, so the ignition of the electrode is carried out without prior cleavage of slag;
- the welding arc has stable combustion both when working on direct current and on alternating current;
- the weld has a finely scaly structure, therefore it is resistant to cracks;
- low metal spatter saves consumables;
- the ability to create a weld in any position.
The technological parameters of rutile electrodes are much better than those of consumables with a different coating.
Disadvantages of rutile coating
According to experts, there are some disadvantages of using rutile-coated electrodes, which are more related to the technological features of the welding process.
The weaknesses of rutile electrodes include:
- the need for drying and calcining damp products;
- strict control over the magnitude of the welding current, since its increase significantly increases the spatter of the metal;
- the impossibility of high-quality welding of high-carbon metals, which is mainly due to the characteristics of the core of the product.
Such a small number of disadvantages of rutile coating, almost does not affect the wide distribution of this consumable.
The main brands of rutile electrodes
Marking of rutile electrodes is indicated by the letter P, according to the name of the material. In this case, electrodes with a rutile cellulose coating are often found, which relate to a consumable of a mixed type. In such products, part of the rutile is replaced by a cellulosic component, which mainly burns during the welding process, significantly reducing the formation of slag. Using mixed electrodes is much easier to weld in an upright position.
Among the most popular brands of rutile-coated electrodes, the following products can be distinguished:
Having studied the main characteristics of these electrodes, it is not difficult to choose a consumable material for a specific task.
Electrodes MR-3
These electrodes are considered the most common for welding. The main advantages of the MP-3 electrodes are as follows:
- ease of forming a seam in various positions;
- steady burning of an arch;
- the ability to weld in various modes;
- a small percentage of metal loss during spraying.
Electrodes are widely used for both high-quality welding and metal deposition on the friction units of assemblies. For the efficient use of products, it is necessary to pre-bake them at a temperature of 160 ℃.
Electrodes OK 46.00
Electrodes are produced by the Swedish concern, which has branches in Russia.
Electrodes OK 46.00 have the following positive properties:
- the ability to weld wet surfaces;
- the weld has high strength;
- the electrodes are calcined at low temperature (80 ℃);
- high arc stability is carried out at low current.
Remember that rutile-coated electrodes are used most efficiently when welding low-carbon steels, but in some cases non-ferrous metals can also be combined. Many brands of rutile electrodes are often used by inexperienced welders, while the connection is of high quality weld.