Hardfacing Electrodes - page 1

Are you looking for proven MMA electrodes for build-up welding? Check our offer of MMA electrodes designed for rebuilding worn surfaces and regenerating parts exposed to abrasion and other damage.

Description of MMA coated electrodes for surfacing:

1. Construction:

The electrode consists of a metal core and a coating. The coating is a mixture of various substances that melts during welding, creating a shielding gas that protects the weld and slag covering the weld.

1. Functions of the coating:

• Creates a shielding gas that protects the filler metal from oxidation and nitriding.
• Affects the stability of the welding arc.
• Forms slag that insulates the weld and facilitates the removal of impurities.
• Affects the mechanical properties of the weld.

1. Application:

MMA coated electrodes are used for welding various metals, including steel, cast iron, and non-ferrous metals, in various welding positions.

Types of MMA coated electrodes for surfacing:

1. Rutile electrodes (R):

Universal, easy to use, provide smooth welds with easily removable slag.

Suitable for welding in various positions, including thin sheets.

Do not always require drying unless white deposits are visible on the coating.

2. Basic electrodes (B):

Characterized by high ductility of the weld and resistance to cracking.

Require drying before use at a temperature of 300-350°C for 1-3 hours.

Mainly used for welding with direct current with positive polarity.

3. Cellulosic electrodes (C):

Used for welding in difficult field conditions, including vertical downhand welding.

Welding with alternating or direct current with positive polarity.

Do not require drying before use and even benefit from slight moisture in the coating.

4. Acid electrodes (A):

Provide welds with a smooth surface but average mechanical properties.

Used in various positions, except vertical upward welding.

Welding with alternating or direct current with negative polarity.

Do not require drying with proper storage.

5. Special electrodes:

Rutile-acid coatings (RA), rutile-basic (RB), rutile-cellulosic (RC).

Thick rutile electrodes (RR).

Selecting the electrode for surfacing depends on:

• Type of material: Steel, cast iron, non-ferrous metals.
• Material thickness: It is recommended to select the electrode diameter according to the thickness of the welded material.
• Welding position: Different types of electrodes perform well in different positions.