Electric arc welding of metal

Electric arc welding of metal Arc welding is a method of welding metals, which involves heating and melting the metal with an electric arc. It is one of the most common welding methods. It was first discovered by scientist N.G. Slavyanov in 1888. He used a consumable metal electrode. Welding took place under a layer of flux. Electric arc welding of metal It is carried out using direct current. The positive terminal is on the piece being welded, and the negative terminal is on the electrode. Electric welding can be performed with either a consumable electrode or a non-consumable electrode. This welding method is widely used in repair work, installation work, mechanical engineering, construction, and other fields.

Electric arc welding with a consumable electrode

Electric arc welding with a consumable electrode The process involves melting the metal surface and the electrode. The electrode serves as the material for producing the weld. To prevent weld oxidation, gases such as helium, argon, carbon dioxide, and their mixtures are used. During welding, they are supplied from the welding head. Easily ionizable elements in the electrode make the electric arc more stable. Such elements may include sodium, potassium, and calcium. The advantage of DC welding is that the weld is cleaner. This is due to the fact that the amount of spatter produced during electrode melting is minimal. Electric arc welding of metal with a consumable electrode includes:

• Preparing the metal surface to be welded. Cleaning it from dirt and oil stains;
• To form a welding arc, electric current is supplied to the electrode and the workpiece;
• An arc is formed. It reaches 7000 ⁰C and begins to melt the metal;
• A weld pool is formed from the molten electrode and the metal surface. The slag rises to the surface and forms a protective film. The weld then solidifies, forming a weld joint.

When welding with a consumable electrode in a shielding gas, the welding wire is similar in chemical composition to the metal being welded. Inert gases such as helium, argon, and their mixtures are used for welding non-ferrous metals and their alloys.

Current parameters affect the depth of penetration. Increasing the current penetrates the metal deeper, while decreasing it does the opposite. Current magnitude does not affect the weld width, but the type of current does. The weld is narrower when using direct current.

The welding arc also affects the quality of the weld. The smaller the arc, the cleaner the weld. The metal melts smoothly, and the number of metal droplets is significantly reduced. This allows for deeper penetration. Electric arc welding of metal with a consumable electrode has its advantages:

• the ability to weld in any place and any position;
• You can weld a wide variety of steel types;
• Welding is quite simple and easy to transport.

Disadvantages of this welding method:

• harmfulness of gases during work;
• low efficiency and, in comparison with other types of welding, low productivity;

The quality of the weld depends on the qualifications of the welder.