The recommended postflow time when welding at 140 amps is approximately

The recommended postflow time when welding at 140 amps is approximately

• A. 15 seconds
• B. 20 seconds
• C. 10 seconds
• D. 5 seconds

Answer: (A)

Postflow time is the period after you finish welding during which shielding gas keeps flowing to protect the hot weld and heat-affected zone as it cools. The idea is to prevent oxidation, porosity, and contamination while the weld surface is still reactive. When you’re welding at higher amperage, like around 140 A, you’re putting more heat into the metal, so the weld pool and surrounding area stay hot longer and remain susceptible to a lapse in shielding. The postflow needs to be long enough to cover that cooling phase, so a longer postflow—about 15 seconds—helps ensure the weld finishes with proper shielding. If the postflow is too short, air can creep in as the weld cools and cause defects; if it’s longer than needed, gas use increases but doesn’t harm the weld quality.

Postflow time is the period after you finish welding during which shielding gas keeps flowing to protect the hot weld and heat-affected zone as it cools. The idea is to prevent oxidation, porosity, and contamination while the weld surface is still reactive. When you’re welding at higher amperage, like around 140 A, you’re putting more heat into the metal, so the weld pool and surrounding area stay hot longer and remain susceptible to a lapse in shielding. The postflow needs to be long enough to cover that cooling phase, so a longer postflow—about 15 seconds—helps ensure the weld finishes with proper shielding. If the postflow is too short, air can creep in as the weld cools and cause defects; if it’s longer than needed, gas use increases but doesn’t harm the weld quality.