Ulteriori criteri di scelta dell'elettrodo per la saldatura ad elettrodo (MMA) - Tecnista

How do I choose the right coated electrode for the welding work I have to do? If you missed the first part of this article then Click here!

High efficiency electrodes
These electrodes are characterized by a yield generally greater than 150%, due to the presence of a large amount of iron dust in the upholstery. In some cases the weight of the iron powder can exceed that of the soul. High-yield electrodes have considerable economic interest since they have a melting speed much higher than that of ordinary electrodes.
High efficiency electrodes can be basic, acid or rutile coating and the mechanical characteristics of the metal deposited are equivalent to those of the corresponding traditional electrodes. High efficiency electrodes find their application in frontal floor welds where it is possible to use strong current intensity and then realize high welding speeds.

Electrodes with cellulosic coating
These electrodes contain in the coating a high percentage of cellulose that gives them a very powerful, but easily controllable arc, which allows you to have a very good and regular penetration. The combustion of cellulose creates a protective atmosphere that prevents the oxidation of the bathroom. The slag is of limited thickness and comes off very easily. The cord has a smooth, regular and slightly convex appearance.

Specially designed for the welding of the tubes, these electrodes find application in all carpentry work.

3) approvals and certifications.

The electrodes can be approved according to various approval bodies, each manufacturer can also have more than one. Classifications can be different between one nation and another.
Currently the most widespread is the American Welding Welding (AWS) to which all producers refer and mark the related abbreviations on their products.

4) Choice of current intensity.

The maximum and minimal value is normally indicated on the package, a specific electrode must be paid. The current to be used depends largely on the size of the piece to be welded, from the welding position and the type of joint. Small pieces require a lower current intensity, while large pieces require higher current intensity due to the different heat dissipation speed.

By welding the higher current intensities, within the descending power level, within the interval of values ​​assigned for a certain electrode and a certain diameter must be used.

Welding above head, medium current intensity must be used, while the lower intensity values ​​must be used for vertically ascending vertical welding. Lower intensity values ​​must be used, as well as small pieces even when the piece is preheated.

5) Electrode storage

The electrodes that are not packaged in airtight containers must be stored in a dry place and at a temperature not less than 10 ° C. For basic electrodes, the minimum temperature must be at least 15 ° C and relative humidity less than 40%

When a certain humidity is observed in the coating it is necessary to dry the electrodes, an operation that can be carried out in the special bathrooms at a temperature of 200/250 ° C for 3 hours. This data is also normally indicated on the electrode package or the technical sheet.

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