chapter 29 Flashcards
American Welding Society (AWS) classification
What does the classification E-70 1 8 on an electrode mean?
* The E means that the electrode is used for electric arc welding.
* The first two digits indicate the tensile strength in thousands of pounds per square inch (i.e., 70 means 70,000 psi).
* The fourth digit indicates the special characteristics of the electrode, such as type and general content of the coating, weld quality, amount of penetration, and the type of arc or electrical current.
o The fourth digit may be any number between 0 and 8. It is important to note that the fourth digit cannot be considered individually but must be considered in conjunction with the third digit to identify both the polarity and position of the electrode.
Electrodes are classified into five main groups: 1) mild steel, 2) high-carbon steel, 3) special alloy steel, 4) _________ and 5) non-ferrous.
Preheating is especially important when welding brittle metals such as _____________.
cast iron
deposition
the act of depositing
When making a vertical or overhead weld, a fast freeze type electrode with a diameter of 1/8” would normally be used. Regardless of the base metal size, an electrode diameter of 3/16” is the maximum size used.
fast freeze type electrode
metallurgical properties
properties of the metal
(The electrode should produce a weld metal with approximately the same metallurgical properties as the parent metal.)
Electrodes are classified into five main groups: 1) mild steel, 2) high-carbon steel, 3) special alloy steel, 4) cast iron, and 5) ____________.
non-ferrous (without iron, non megnetic)
The electrode should produce a weld metal with approximately the same metallurgical properties as the ________________. A top quality weld should be as strong as the _________________.
parent metal
root pass
the first weld bead.
shielded electrodes
thin metal rods having approximately the same composition as the metal to be welded. They are coated with a wide variety of types of flux.
tensile strength
What does the classification E-70 1 8 on an electrode mean?
- The first two digits indicate _______________in thousands of pounds per square inch (i.e., 70 means 70,000 psi).
properties of the metal
(The electrode should produce a weld metal with approximately the same metallurgical properties as the parent metal.)
metallurgical properties
the first weld bead.
root pass
What does the classification E-70 1 8 on an electrode mean?
- The first two digits indicate _______________in thousands of pounds per square inch (i.e., 70 means 70,000 psi).
tensile strength
