Covered by ESAB Welding Electrodes

At the present time for manual arc welding of stainless steel electrodes are used with different types of coverage:

• principal;
• rutile;
• coating that provides a high degree of surfacing and
• a special coating for gravity welding and weld "the trigger."

Type of coverage affects:

• welding characteristics;
• weldability;
• type of metal transfer (inkjet or drop);
• formation of the slag system and, consequently, the scope of the position of the electrode and welding;
• and the mechanical properties of weld metal and weld metal.

Rutile electrodes - the most common electrode for welding stainless steels.

Electrode brand OK 63.30 - a typical electrode of this class, which provides atomized metal transfer, high arc stability and minimal spatter.

The property of self releasing slag removing it makes the operation very easy.

The appearance of the seam turns nice and smooth, as, for example, shown below in welding fillet welds.

Welding of rutile electrodes is performed both at constant and alternating current. Welding electrodes of small diameter from 1.6 to 3.2 mm can be cooked in all positions, but because of the high fluidity of the slag is preferable to use them for welding in the lower positions.

Rutile electrodes are also available with a daubing providing a high degree of cladding to improve the performance of welding, such as the electrode marks OK 63.41.

These electrodes have the same properties as conventional rutile electrodes, but due to the presence of metal powder in the coating deposition rates are much higher than they have.

Such electrodes produced a greater length, because there is no danger of overheating, coating and, therefore, one electrode can impose a longer seam. This reduces the time to replace the ignition electrode and the next.

Photos. The length of welds when welding electrode OK 63.30 and OK 63.41

Rutile electrodes with a high degree of deposition is usually only used for welding in the down position.

They come with a diameter of 1.6 mm, but in practice mostly used a larger diameter electrodes. These electrodes are easy to cook, because the welding is carried out by the support on the plaster.

And the arc is also very easy to ignite.

Welding electrodes with basic coating , such as stamps OK 61.35 , characterized by the properties of rutile electrodes. They are only used when welding with direct current, and preferably in different spatial positions, such as for welding in the vertical position, or for pipe welding, because the basic slag makes it easier to control the weld pool and root penetration weld.

The slag is not so easily removed, as in the case of rutile electrodes, and the weld is obtained less than smooth.

The main type of coating provides a high purity weld metal and is used in cases where the required high plastic properties at cryogenic temperatures.

Electrodes for welding stainless steels can be produced with a rod of mild steel with the addition of alloying elements in plaster. These welding electrodes are called synthetic . They are mainly used for welding dissimilar steels, such as mild steel with stainless steel.

Due to the high conductivity of the rod of mild steel electrodes can produce such great lengths, up to 700 mm with a diameter of 5 mm and used for gravity welding.

Photos. Welding electrode ESAB OK 67.72

For the production of electrodes for welding, "the trigger" used a special rutile. To this species belongs electrode ESAB OK 63.34.

Slag system was developed in order to ensure a seamless weld "the trigger" as a constant and alternating current. With these electrodes can be welded thin sheets and easy to follow the penetration of the root weld thicker plates.

These electrodes can perform welding and other spatial positions, but here they can not compete with conventional rutile electrodes.

Another special form of rutile coating welding electrodes is used for the so-called welding "points" . An example of such an electrode ESAB OK 63.20 .

Welding technique is to periodically brief excitation and quenching of the arc, which allows to control the weld pool when welding in various positions of the sheet metal and pipes.

Specially designed coating composition provides easy re-excitation of the arc on the electrode.

Maintain the quality of the electrodes can be only when they are stored properly. For example, a packet must always be sealed, because the electrodes are in open boxes absorb moisture. Wet the electrode coating gives the porosity in the weld seam.

Wet electrodes are dried at a temperature of 250-300 º C for two hours.

To obtain high-quality welding needs the correct choice of welding equipment. The power supply is chosen based on the type of electrodes used and the nature of work. Welding electrode on the package indicated:

• constant or alternating current,
• polarity
• open-circuit voltage and
• welding current.

The cheapest sources are welding transformers, generating an alternating current welding.

Producing a constant welding current generators and rectifiers have high welding performance. On construction sites are not equipped with a supply of electricity, commonly used welding DC generators. Modern inverter DC sources provide high welding performance, combined with low weight and dimensions of the source itself.

See also:
welding electrode
manual arc welding