1, simple equipment, low price and convenient maintenance. The welding operation does not need complicated auxiliary equipment, but only simple auxiliary tools, which is convenient to carry.

2. No auxiliary gas protection is needed, and the wind resistance is strong.

3. Flexible operation and strong adaptability, and welding can be carried out everywhere in covered electrode. Covered electrode arc welding is suitable for welding single pieces or small batches of workpieces, as well as irregular, arbitrary spatial position and difficult mechanization welding.

4. Wide application range, which can weld most metals and alloys in industrial applications, such as carbon steel, low-alloy structural steel, stainless steel, heat-resistant steel, low-temperature steel, cast iron, copper alloy, nickel alloy, etc. In addition, covered electrode arc welding can also be used for welding dissimilar metals, repairing welding of cast iron and surfacing welding of various metal materials.

Disadvantages:

1. Welders have high labor intensity and poor working conditions. When welding, the welder always carries out manual operation and naked eye observation in high temperature baking and toxic smoke and dust environment. ?

2. Low production efficiency. Compared with the automatic welding method, covered electrode arc welding uses less welding current, and the covered electrode needs to be replaced frequently. ?

Extended data:

Process principle of manual arc welding;

Welding process: Manual arc welding consists of welding power supply, welding cable, electrode holder, covered electrode, weldment and arc. When welding, use covered electrode to contact the workpiece to ignite the arc, then lift covered electrode and keep a certain distance. Under the condition of suitable arc voltage and welding current provided by welding power supply, the arc burns stably, resulting in high temperature, which locally heats covered electrode and weldments to a molten state.

The molten metal at the end of covered electrode and the molten weldment metal fuse together to form a molten pool. When welding, the arc moves with covered electrode, and the liquid metal in the molten pool gradually cools and crystallizes to form a weld, and the two weldments are welded together.

During the welding process, the covered electrode flux core melts and is transferred to the molten pool in the form of droplets, while the covered electrode flux core produces a certain amount of gas and liquid slag. The generated gas fills the arc and molten pool to isolate the air. The density of liquid slag is less than that of liquid metal and floats on the molten pool, thus protecting the molten pool.

When the metal in the molten pool cools and solidifies, the slag also solidifies to form welding slag covering the weld surface, which prevents the high-temperature weld metal from being oxidized and reduces the cooling speed of the weld. In the welding process, complex metallurgical reactions such as deoxidation, desulfurization, dephosphorization and dehydrogenation are carried out between liquid metal and liquid slag and gas, so that the weld metal can obtain appropriate chemical composition and structure.

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