Certified Welder Welding Process Application 4

Question 1

Which condition would cause porosity in a GMAW weld?

Accepted Answer

All of the above

Answer

Porosity can result from excessive turbulence (too-high gas flow), contaminants releasing gas into the weld pool, or drafts disturbing shielding gas coverage.

Question 2

The term 'keyhole' welding technique is associated with which process operating at high power?

Accepted Answer

Plasma Arc Welding (PAW) and Laser Beam Welding (LBW)

Answer

Keyhole welding is used in high-energy-density processes like PAW and LBW, where the beam fully penetrates the material and the molten metal flows around a cylindrical void.

Question 3

An E7018 electrode in SMAW is classified as a:

Accepted Answer

Low-hydrogen, iron powder electrode suitable for all positions

Answer

E7018 is a low-hydrogen, iron powder electrode rated for all positions that produces a sound, ductile weld when kept dry.

Question 4

What is the main reason preheating is applied before welding high-carbon or alloy steels?

Accepted Answer

To reduce the cooling rate and prevent hydrogen-induced cracking in the HAZ

Answer

Preheating slows the cooling rate of the heat-affected zone (HAZ), reducing the risk of martensite formation and hydrogen-induced (cold) cracking.

Question 5

In GMAW, increasing wire feed speed (WFS) without changing voltage will primarily:

Accepted Answer

Increase amperage (current) and decrease arc length

Answer

In constant-voltage GMAW, faster WFS causes more wire to enter the arc, increasing current consumption and shortening the arc length.

Certified Welder Practice Test

Certified Welder Practice Test

Certified Welder Welding Process Application 4