General characteristics and design features of surfacing electrodes type T590

T-590 electrodes with a special coating are used to restore parts subject to abrasive wear. The rods have a diameter of 4 or 5 mm and are manufactured in accordance with GOST 9466-75 and 10051-75.

The standard provides for the use of alternating or direct current, metal surfacing is carried out at an angle or in a horizontal position.

Welding with T-590 electrode.

General description of T-590 electrodes

Electrodes are used for the refurbishment of parts subjected to medium-level shock loads and abrasive wear.

The rods make it possible to restore the functionality of teeth in buckets of road equipment, cutting elements of plows in agricultural installations or rotating augers of mixing machines. The technology of applying a metal layer allows you to reduce the cost of maintaining and restoring equipment.

Design features

The metal core of round cross-section is made of wire SV-08 or SV-08A, corresponding to the standards of the GOST 2246-70 standard. The outer part is coated with a basic type of coating; the material contains boron and chromium compounds that alloy the weld metal.

The addition of chromium prevents mixing of the deposited layer with the material from which the part being repaired is made.

The boron additive increases the plasticity of the weld and reduces the solubility of carbon in the melt.

Specifications

Technical parameters of LEZT T-590:

• mass consumption of rods for applying 1 kg of metal – 1.4 kg;
• deposition factor – 9 g/A*h;
• current in the circuit – from 200 to 280 A;
• diameter – 4 or 5 mm;
• weight – 62.5 and 92.5 g (depending on the cross-section);
• application productivity (with a diameter of 4 mm) – 1.9 kg per hour;
• rod length – 450 mm.

Principle of operation

To apply the coating you need:

1. Place the electrode in the holder, put on a protective apron, gloves and a mask.
2. Connect the power supply to the welding machine (with direct current, reverse switching polarity is used).
3. Excite an arc and apply a layer of molten metal to the base (for example, in the area of ​​an abrasive excavation).
4. Wait for the material to cool and clean the surface of the seam from slag with a wire brush.
5. Apply a second layer by passing the electrode in the opposite direction, and then remove the slag layer.

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Weld.

Advantages of surfacing elements

Advantages of the technology for repairing parts using T-590 electrodes:

• easy arc excitation;
• the slag crust does not stick to the base and metal of the weld;
• restoration of the original geometry of products;
• increased hardness of the surface layer;
• restoration of parts made of alloy steels and cast iron is allowed;
• good adhesion of the deposited metal to the base material;
• the applied material has increased corrosion resistance and is not saturated with hydrogen vapor;
• The technique makes it possible to reduce the list of spare parts in convoy warehouses.

Features of work

To obtain a high quality final result of the work, it is necessary to strictly adhere to the entire technological process. It is imperative to carry out preliminary preparation of the filler material. It consists of preheating the electrodes in the temperature range from 300 to 350 degrees Celsius. Preheating should be done for approximately sixty minutes.

When working with filler material model T-590, you can use equipment that operates on both direct and alternating electric current. In the first case, absolutely any equipment will do; in the second, the unit voltage should not exceed seventy volts.

You also need to choose the correct size of filler material. This model is produced in rods and can have two types of diameter: 4 or 5 mm. Regardless of the size and model, the chemical composition of the filler material is identical, therefore, the operating mode must be selected solely on the basis of the required electric current required to melt the working surface of the product and the filler material itself. For the four-millimeter version, an electric current of approximately 200-220 Amps is sufficient. For the five-millimeter version, it will require slightly more - from 250 to 270 Amperes. If you do not comply with the above framework, the quality of the final result of the work will not satisfy the required parameters.

Special properties

When using T-590, you should take into account the features of the rods:

1. The applied restoration layer is characterized by high strength and hardness (from 58 to 64 on the HRC scale), but is not designed for high impact loads. The material is prone to cracking, but defects do not reduce the performance of the restored parts.
2. When repairing steel products, you should not apply more than 2 successive layers of metal (due to an increased risk of chipping fragments); for cast iron parts, 1 pass with an electrode is allowed. To apply an additional layer, it is necessary to use rods with a different chemical composition that is compatible with the base material.

Content of chemical elements in the deposited layer

Percentage composition of the applied metal layer:

• chromium – from 22 to 27%;
• carbon – from 2.9 to 3.5%;
• silicon – from 2 to 2.5%;
• manganese – from 1 to 1.5%;
• boron – from 0.5 to 1.5%;
• sulfur – less than 0.035%;
• phosphorus – no more than 0.04%.

Application area

Surfacing electrodes T-590 are used in the repair industry. They are suitable for restoring the working surface of metal products. These are mainly industries such as mechanical engineering, machine tool manufacturing, agriculture, and various branches of production. They can be useful not only in large and small enterprises, but also in the private sphere. Electrodes will help restore the worn working surface of parts to extend their service life, and such things may be required in many applications.

Production Features

Production lines consist of several sections:

• drawing and cutting wire into pieces of the required length;
• applying a layer of protective coating under pressure followed by drying;
• packaging of finished products.

During manufacturing, special requirements are placed on the chemical composition of the coating, which protects the melt zone from exposure to atmospheric air and saturates the metal with alloying additives.

On the Russian market there are electrodes under the brand name T-590 or E-320X25S2GR, produced by Lincoln Electric, Zeller Welding, Volgodonsk or Zelenograd plants, as well as several dozen other enterprises located in the Russian Federation or neighboring countries.

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T-590 from different manufacturers.

Work principles

The electrodes of the presented brand have properties that are worth considering. You will be able to use alloys that will be resistant to destruction.

At the same time, the metal does not have high reliability indicators. Small kinks may appear in it. You shouldn’t spend a lot of time on this point, because it has little effect on the quality of the metal.

If it is necessary to perform surfacing, there is no need to use more than two electrode layers. If you are using cast iron, then one coating will be sufficient.

Application nuances

Before use, the electrodes must be calcined in an electric oven. The use of rods with chipped or cracked coating is not allowed (due to the risk of disturbing the chemical composition of the deposited layer).

The surfaces to be treated must be cleaned of dirt, traces of paint or primer, corrosion and degreased with volatile solvents.

The melt is applied horizontally or at an angle. Since the coating of the electrodes conducts electric current, accidental contact with the part may initiate an arc.

Welding at an angle.

Selecting the float mode

The electrodes are designed for use with alternating current or direct voltage with any polarity. When using alternating current, a transformer is required to maintain the open circuit voltage at 70 V.

When the deposited layer is in the lower position and an electrode with a diameter of 4 mm is used, the current strength is set to 200-220 A. Violation of the mode leads to poor adhesion of the layer or burning of the part.

Conditions of use

Types and characteristics of monolith electrodes

In order to perform surfacing, it is necessary to clean the part being welded from dirt, oil and rust. Also, surfacing should not be carried out in more than two layers on steel parts, and in one layer on cast iron parts.

If the wear of the part is significant, it is better to use other electrodes for the lower layers, depending on the metal composition of the product.

You can deposit a preliminary layer with “Standard RC” and “Monolit RC” electrodes on steels such as low-alloy carbon steels. For steels alloyed with manganese, electrodes UONI 13/55 “Plasma” can be used.

The electrodes deposit metal with high wear resistance. It is prone to the formation of various small cracks approximately 2 mm in size. However, this does not reduce the quality and durability of the restored part.

T-590 electrodes are widely used in the mining, agricultural and transport industries.

Packaging and storage rules

The products are packaged in packs weighing 1 or 5 kg with a shell made of thick corrugated cardboard, covered on the outside with a protective polyethylene film.

Information labels are pasted on the outside, packs are stacked in 6 pieces. in boxes, large quantities are shipped by factories on Euro standard wooden pallets.

Products are stored in a dry place. Before use, the rods are calcined for an hour in an electric oven heated to a temperature of +240°...+260°C.

Packages with electrodes.

Nuances of surfacing work

• prepare products for surfacing. They must be heated at the temperature indicated on the packaging. The moisture content of the coating cannot exceed 0.8%;
• monitor the condition of the electrode coating. It should not have cracks, delaminations or contamination;
• prepare surfaces for surfacing. They must be thoroughly cleaned from any kind of contamination to a metallic sheen;
• select the correct surfacing mode. The strength of the welding current, where the process of applying the layer will be carried out, is selected taking into account the diameter of the consumable material. These data are indicated on the packaging and in accompanying documents;
• Surfacing can be carried out for products made of steel in no more than 2 layers, for cast iron - only in 1 layer.

The surfacing process can be seen in this video:

Advantages and disadvantages

Regardless of the main purpose of any product or material, it has advantages and disadvantages. Model T-590 electrodes are no exception. The advantages of filler material, of course, include the fact that with their help you can easily restore working parts of construction equipment, whose working activity is directly related to constant loads.

The repaired part is practically no different from the factory version; this can be achieved thanks to the excellent characteristics of the T-590 surfacing electrodes.

If during the repair process of a product or part the work area is not subjected to high heat treatment, then the final result of the connection acquires a high level of strength. In addition to the basic chemical composition, various additional elements can be added to the structure of the material, making it very easy to select the composition for a specific part. It is worth noting that the surfacing material must be selected based on the chemical composition of the part to be worked with.

There are far fewer disadvantages than advantages. These include the following factors. The most important disadvantage is that the deposited material has a low level of ductility, therefore, due to this property, the area of ​​use of the electrode is quite narrowed (it cannot be used in working with parts whose working activity involves constant changes in shape, etc.).

Also, filler material cannot be used in two layers, as this significantly increases the chance of cracks. However, they can also play a useful role by relieving the entire structure. Getting rid of them is quite easy after completing the basic procedure by brewing them.

Application

The main area of ​​application of electrodes is repair. With their help it is quite easy to restore metal parts. Most often, this process occurs at the industrial level, but if you have specialized equipment, electrodes of this model can be used at home. With the help of surfacing material, it is quite easy to restore the surface of a failed product or part, if you have certain knowledge, therefore, there is no need to purchase new equipment. A product repaired using model T-590 electrodes is almost in no way inferior to the factory version.

Advantages and disadvantages

The advantages of the products include the fact that they perfectly restore worn parts of working machines, which must meet special hardness conditions while maintaining the necessary characteristics. Thus, even after restoration, they will have good performance, as they did before the repair. In the absence of heat treatment, the weld material receives a high hardness of HRC 58-64. The presence of alloying elements allows you to more accurately select electrodes for the materials that require surfacing. All this increases operational efficiency and reduces downtime during repairs. It also reduces the need to keep spare parts in stock.

The disadvantages include the lack of ductility of the deposited material. Also, these electrodes are highly targeted and cannot be used universally for other purposes. When surfacing more than two layers of material, there is a risk of cracks, so other types should be used for subsequent surfacing. Cracks can have a beneficial effect, as they relieve stress from certain areas of the part, and once a crack has formed, it can be welded.

Calcination before welding

Under normal storage conditions, they do not require calcination before welding.
In case of moistening, calcination: 240-260C for 60 minutes. Chemical composition of the directed metal, %

Hardness of deposited metal

Surfacing is carried out in the lower and inclined positions using direct current of reverse polarity using narrow beads or with slight vibrations of the electrode.
Surfacing can also be carried out with alternating current at no load (no more than 60 V). Packaging details