IMM Welding & Fabrication 3

Question 1

In the electrode classification E7018, what does the last digit '8' indicate?

Accepted Answer

The coating type and compatible current/polarity

Answer

The diameter of the electrode in sixteenths of an inch

Answer

The minimum yield strength of the weld deposit

Answer

The number of weld passes required for full penetration

Question 2

Which NDT method magnetizes ferromagnetic components and uses iron particles to reveal surface and near-surface discontinuities?

Accepted Answer

Magnetic particle testing (MT)

Answer

Ultrasonic testing (UT)

Answer

Radiographic testing (RT)

Answer

Liquid penetrant testing (PT)

Question 3

What is the purpose of a weld test coupon?

Accepted Answer

To qualify a welding procedure or certify a welder's proficiency

Answer

To measure heat input in joules per inch during production welding

Answer

To determine the correct electrode diameter for a given base metal thickness

Answer

To calibrate welding power source output

Question 4

What is the primary advantage of GTAW (TIG welding) compared to GMAW (MIG welding)?

Accepted Answer

Superior weld quality and precise control, especially on thin materials and reactive alloys

Answer

Higher electrode deposition rate

Answer

Lower operator skill requirement

Answer

Better performance in outdoor or drafty environments

Question 5

What are the primary goals of post-weld heat treatment (PWHT)?

Accepted Answer

To relieve residual stresses and improve heat-affected zone toughness

Answer

To increase weld hardness and wear resistance

Answer

To remove surface oxidation and scale from the weld

Answer

To increase the carbon content of the weld deposit

Question 6

What is weld distortion, and which technique is commonly used to minimize it?

Accepted Answer

Dimensional change from non-uniform heating and cooling; minimized by tacking, clamping, or back-step welding

Answer

Arc instability from moisture; minimized by electrode pre-drying

Answer

Electrode coating failure; minimized by proper storage conditions

Answer

Slag entrapment; minimized by increasing travel speed

Question 7

Which weld joint type is formed when one piece of metal is welded perpendicular to the flat surface of another piece, forming a 90° angle?

Accepted Answer

T-joint

Answer

Butt joint

Answer

Lap joint

Answer

Edge joint