Millwright Certification Welding and Cutting Processes 1

Question 1

Which welding process uses a non-consumable tungsten electrode and a separate filler rod?

Accepted Answer

GTAW (TIG welding)

Answer

GTAW (TIG) uses a non-consumable tungsten electrode to create the arc while filler metal is added manually with a separate rod, making it ideal for precise, high-quality welds on thin or critical materials.

Question 2

What is the correct sequence for shutting down an oxy-acetylene torch at the end of a job?

Accepted Answer

Close the acetylene valve first, then the oxygen valve, then bleed the lines

Answer

Closing acetylene first extinguishes the flame safely and prevents a backfire or soot deposit in the tip. Oxygen is then closed, and lines are bled to relieve pressure and prevent hose deterioration.

Question 3

In SMAW (stick) welding, what is the purpose of the flux coating on the electrode?

Accepted Answer

To shield the weld pool from atmospheric contamination and form slag

Answer

The flux coating burns and vaporizes to produce a shielding gas cloud around the arc and molten pool, keeping out oxygen and nitrogen. It also forms a slag layer over the bead that protects the weld as it cools.

Question 4

A millwright notices porosity in a completed weld bead. What is the most likely cause?

Accepted Answer

Contamination or moisture in the weld zone

Answer

Porosity (gas pockets trapped in the solidified weld) is almost always caused by contaminants such as oil, moisture, rust, or paint releasing gases into the molten pool faster than they can escape before solidification.

Question 5

When cutting with a plasma arc system, what material conducts the return current path back to the power supply?

Accepted Answer

The work clamp (ground) attached to the workpiece

Answer

The work clamp completes the electrical circuit. Current flows from the power supply through the torch electrode, through the plasma arc into the workpiece, and returns via the work clamp cable. Without a solid work connection the arc will not transfer.

Blog Practice Test

Blog Practice Test

Millwright Certification Welding and Cutting Processes 1