Question

which of the following would most likely result in tungsten contamination during gtaw? a holding the torch at a slight angle from vertical b using pure argon as the shielding gas c touching the tungsten to the weld puddle d setting the gas flow to 20 cfh

Explanation:

GTAW (Gas Tungsten Arc Welding) uses a tungsten electrode. Tungsten contamination occurs when the electrode contacts the molten weld puddle, transferring tungsten particles to the weld. Option A (torch angle) affects weld penetration, not contamination. Option B (pure argon) is a standard shielding gas. Option D (20 CFH gas flow) is a typical setting; incorrect flow may cause porosity but not tungsten contamination.

Answer:

C. touching the tungsten to the weld puddle