Electric Welding: Advantages of Coated Electrodes

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Coated Electrode

A coated electrode is made of a metallic wire (called core wire) coated uniformly with flux material. While fluxing, the electrode about 20 mm of its length is left bare at one end for mounting it into the electrode holder. The flux material used for coating of the electrode is a bad conductor of electricity.

Coated electrodes are used these days because the flux coated on the core wire is composed of special element which protects both the arc and the weld metal that passes through range of liquid action and solidification during welding.

Advantages of Coated Electrodes

The coated electrodes are preferred in the metallic arc welding for getting the good quality of the weld. The advantages of using coated electrodes are given as follows −

Can be Used with AC Supply

The coated electrodes can be used with AC metal arc welding. When the AC supply is used for welding process, the arc cools at zero current position. This tends to deionize the path of the arc. However, the shielding gases keep the arc space ionized. Therefore, the coated electrodes can also be used with the AC supply.

Helps in Maintaining the Arc

The coated electrode helps in maintaining the electric arc because the coating flux consists of arc stabilizing materials like titanium and potassium compounds, calcium carbonate, etc.

Shielding the Molten Metal from Oxidization

The gases which are formed around the arc protect the weld metal from oxidation by the atmospheric oxygen and nitrifying the effect of nitrogen of air. Consequently, we get a ductile weld of goof quality.

Can be Used for High Welding Current

The coated electrode can be used for the higher welding currents as compared to the bare electrode. The coating of the flux makes the electrode insulated at its outer cover and hence, this electrode can be used at higher welding currents without getting red hot.

Prevents the Spattering of Metal

By using the coated electrode for welding process, the spattering of metal during the welding process is prevented.

Overhead and Vertical Welding is Easy

With the coated electrode, the welding in overhead and vertical positions become very easy. It is because, with the coated electrode, the slag made by the flux is quick freezing and by solidifying immediately prevents the liquid metal from falling down on the operator or earth.

Sudden Cooling of the Weld is Prevented

The basic salts of magnesium, silicon and calcium in the covering slag which floats on the surface of the metal, prevents sudden cooling of the weld. Thus, it also prevents the welds from becoming brittle.

raja
Updated on 16-Mar-2022 05:03:01

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