Electrode Selection and Identification in MMA Welding

Flashcards covering electrode selection criteria, designation syntax, coating types, mechanical property symbols, welding positions, and current specifications for MMA welding based on standardized technical data.

Coated Electrode Selection Factors

Key considerations for selecting an electrode, including base metal nature, section dimensions, welding machine current type, welding position, joint type/fixation, required deposit properties (corrosion resistance, tensile strength, ductility), and standards compliance.

Letter E (Electrode Symbol)

The symbol at the start of an electrode specification indicating that it is a coated electrode for electric arc welding.

Electrode Identification Code Structure

A standardized sequence of numbers and letters designating electrode specifications: Letter E, 1st digit, 2nd digit, 3rd digit, intermediate letter, 4th digit, and 5th digit.

Mechanical Property Digits (1st, 2nd, and 3rd Digits)

Numerical values specifying mechanical properties: minimum tensile strength in $\text{kg/mm}^2$, elongation percentage over $5 \times D$, and impact strength at $+20^\circ\text{C}$ in $\text{kgm/cm}^2$.

Coating Type A

Designation for an Acid coating ($\text{Ácido}$) on an electrode.

Coating Type B

Designation for a Basic coating ($\text{Básico}$) on an electrode.

Coating Type C

Designation for a Cellulosic coating ($\text{Celulósico}$) on an electrode.

Coating Type O

Designation for an Oxidizing coating ($\text{Oxidante}$) on an electrode.

Coating Type R

Designation for a Rutile coating ($\text{Rutilo}$) on an electrode.

Coating Type T

Designation for a Titanium coating ($\text{Titanio}$) on an electrode.

Coating Type V

Designation for other coating types ($\text{Otros tipos}$) on an electrode.

Welding Position Symbol 1 (4th Digit)

Indicates that the electrode is suitable for all welding positions.

Welding Position Symbol 2 (4th Digit)

Indicates that the electrode is suitable for all positions except vertical downward.

Welding Position Symbol 3 (4th Digit)

Indicates that the electrode is suitable for flat horizontal, horizontal cornice, and horizontal angle positions.

Welding Position Symbol 4 (4th Digit)

Indicates that the electrode is suitable for horizontal angle and horizontal on an inclined plane.

Welding Current Symbol (5th Digit)

Designates the recommended direct current (C.C.) polarity and the open-circuit voltage in volts for alternating current (C.A.).