Welding Processes and Equipment Flashcards

What is the primary advantage of using DCEN (straight polarity) in SMAW?

Answer: Greater heat at the electrode, less at the base metal

DCEN directs more heat to the electrode end rather than the base metal, which can be useful for specific electrodes and thin materials.

Which GMAW transfer mode produces the least spatter and is characterized by very small droplets transferred across the arc?

Answer: Spray transfer

Spray transfer uses high voltage and amperage to project tiny droplets axially across the arc with minimal spatter.

What is the function of the contact tip in a GMAW welding gun?

Answer: It transfers welding current to the wire electrode

The contact tip conducts welding current to the continuously fed wire electrode as it passes through the tip.

In resistance spot welding, what creates the heat needed to fuse the metal?

Answer: Electrical resistance at the interface when current flows through the parts

Resistance spot welding generates heat through the electrical resistance at the contact point between workpieces when high current is applied.

Which shielding gas mixture is most commonly used for GMAW of carbon steel with spray transfer?

Answer: 75% Argon / 25% CO2

A 75% Ar / 25% CO2 mixture (C25) is the most common blend for GMAW of carbon steel, providing good arc stability and penetration.

What does OCV (Open Circuit Voltage) refer to in a welding power source?

Answer: The voltage present at the output terminals when no arc is established

OCV is the voltage measured at the output terminals of the power source when it is energized but not welding (no arc).

For which base metal is it most critical to use a dry, low-hydrogen SMAW electrode to prevent weld cracking?

Answer: High-strength, high-carbon, or alloy steel

High-strength and high-carbon steels are susceptible to hydrogen-induced (cold) cracking, making low-hydrogen electrodes essential.