IMM Welding & Fabrication 2

Question 1

In the electrode designation E7018, what does the number '70' represent?

Accepted Answer

Minimum tensile strength of the deposited weld metal in ksi

Answer

The digits '70' in E7018 indicate a minimum tensile strength of 70,000 psi (70 ksi) for the weld deposit in the as-welded condition.

Question 2

What type of oxy-acetylene flame is used when welding cast iron?

Accepted Answer

Carburizing (reducing) flame

Answer

A slightly carburizing flame is used for cast iron to add carbon to the weld zone and compensate for carbon burn-off during the welding process.

Question 3

What does FCAW stand for?

Accepted Answer

Flux-Cored Arc Welding

Answer

FCAW stands for Flux-Cored Arc Welding, which uses a tubular wire electrode with a flux-filled core to shield and protect the weld pool.

Question 4

What is the primary purpose of a backing bar (backing strip) placed behind a weld joint?

Accepted Answer

To support the molten weld pool and ensure full root penetration on single-sided welds

Answer

A backing bar supports the molten root pass from below, allowing full-penetration welds to be made from one side without burn-through.

Question 5

What causes porosity in a completed weld?

Accepted Answer

Gas entrapped in the solidifying weld metal forming voids

Answer

Porosity occurs when gases such as hydrogen, nitrogen, or oxygen become trapped in the solidifying weld pool before they can escape, forming voids or bubbles.

IMM - Industrial Maintenance Mechanic Certified Practice Test

IMM - Industrial Maintenance Mechanic Certified Practice Test

IMM Welding & Fabrication 2