Question

22 why is maintaining the proper arc length critical when carbon dioxide is used for gmaw? answer: 23 why is a pull - type gun used for aluminum electrode wire? answer: 24 what do the letters “er” at the beginning of a gmaw electrode designation mean, and how can such an electrode be used? answer: 25 what electrodes are commonly recommended for the following? a. gmaw welding of stainless steel. answer: b. fcaw welding of low - alloy steel. answer: c. gmaw welding of carbon steel. answer:

Explanation:

1. Maintaining proper arc length in GMAW with CO2 is crucial for stable arc, good penetration, and minimizing spatter.
2. Pull - type guns are used for aluminum electrode wire as aluminum is soft and can be fed more smoothly to prevent wire jams.
3. "ER" in GMAW electrode designation stands for "electrode - rod". These are solid filler metals used for welding by providing filler material to the weld joint.

25.A: For GMAW welding of stainless steel, 308L or 316L electrodes are commonly recommended.
25.B: For FCAW welding of low - alloy steel, E71T - 1 electrodes are often recommended.
25.C: For GMAW welding of carbon steel, ER70S - 6 electrodes are commonly used.

Answer:

1. Maintaining proper arc length ensures stable arc, good penetration, and minimizes spatter.
2. Aluminum is soft, and pull - type guns prevent wire jams by feeding wire smoothly.
3. "ER" means "electrode - rod". They provide filler material for the weld joint.

25.A. 308L or 316L electrodes
25.B. E71T - 1 electrodes
25.C. ER70S - 6 electrodes