SAW Advanced Diagnostics & Troubleshooting 2

Question 1

A SAW bead shows a convex crown with sharp toes and no fusion at the edges. Which parameter change is most likely to correct this?

Accepted Answer

Increase voltage

Answer

Increasing arc voltage widens and flattens the bead, improving toe wetting and fusion at the edges.

Question 2

Porosity is found exclusively on the start of every weld run in a production SAW operation. The most probable cause is:

Accepted Answer

Flux moisture at the leading edge before arc stabilizes

Answer

At arc start, flux has not yet been fully melted and degassed, trapping moisture-released hydrogen that causes start porosity.

Question 3

During tandem SAW, the trail wire arc becomes unstable and wanders. Which adjustment should be tried first?

Accepted Answer

Increase trail wire inductance setting

Answer

Increasing inductance on the trail wire dampens current fluctuations and stabilizes arc wandering in tandem configurations.

Question 4

A longitudinal crack appears in the weld metal centerline of a high-strength steel joint welded with SAW. This is most consistent with:

Accepted Answer

Hot cracking due to high sulfur and high weld crown width-to-depth ratio

Answer

Centerline hot cracking results from low-melting sulfide films combined with a narrow, deep weld bead geometry that focuses stress at the centerline.

Question 5

A SAW procedure produces consistent undercut on the advancing side of a fillet weld made on a rotating cylinder. The best corrective action is:

Accepted Answer

Rotate the part so the weld puddle is slightly on the downhill slope

Answer

Repositioning the weld so gravity helps support the molten pool eliminates undercut caused by the puddle flowing away from the toe.

(SAW) Submerged Arc Welding Certification Practice Test