CRI Welding Processes & Techniques 2 — Questions and Answers
Question 1: Which welding process uses a non-consumable tungsten electrode and an inert shielding gas to produce a weld?
- SMAW
- GTAW (Correct answer)
- FCAW
- SAW
Correct answer: GTAW
Gas Tungsten Arc Welding (GTAW), also known as TIG welding, uses a non-consumable tungsten electrode with inert shielding gas such as argon or helium.
Question 2: In Submerged Arc Welding (SAW), what covers the arc and molten weld pool to protect it from atmospheric contamination?
- Flux-coated electrode
- Granular flux (Correct answer)
- Inert gas
- Slag coating
Correct answer: Granular flux
In SAW, a granular flux blanket completely submerges the arc and weld pool, providing both shielding and metallurgical benefits.
Question 3: What type of weld joint is formed when two members are positioned at an angle greater than 30° but less than 135° to each other?
- Butt joint
- T-joint
- Corner joint (Correct answer)
- Lap joint
Correct answer: Corner joint
A corner joint is formed when two members meet at a corner, typically at approximately 90°, forming an L-shape.
Question 4: Which welding discontinuity is most commonly associated with insufficient heat input during the Submerged Arc Welding process?
- Porosity
- Incomplete fusion (Correct answer)
- Underfill
- Hot cracking
Correct answer: Incomplete fusion
Insufficient heat input in SAW leads to incomplete fusion because the base metal does not reach the required temperature to bond with the weld metal.
Question 5: What is the primary purpose of preheat in welding?
- Increase weld speed
- Reduce the risk of hydrogen-induced cracking (Correct answer)
- Improve arc stability
- Reduce shielding gas consumption
Correct answer: Reduce the risk of hydrogen-induced cracking
Preheat slows the cooling rate of the weld and heat-affected zone, reducing the risk of hydrogen-induced (cold) cracking, especially in hardenable steels.
Question 6: In Flux-Cored Arc Welding (FCAW), what is the function of the flux contained within the tubular electrode?
- Conducts electrical current
- Provides shielding and alloying elements (Correct answer)
- Cools the weld pool
- Increases travel speed only
Correct answer: Provides shielding and alloying elements
The flux core generates shielding gases, forms slag for protection, and can introduce alloying elements to the weld pool.
Question 7: Which destructive test method is used to evaluate the ductility of a weld by bending a specimen around a specified radius?
- Tensile test
- Guided bend test (Correct answer)
- Charpy impact test
- Hardness test
Correct answer: Guided bend test
The guided bend test evaluates weld ductility and soundness by bending a specimen (face, root, or side bend) to a specified radius without cracking.
CRI Welding Processes & Techniques 2
Which welding process uses a non-consumable tungsten electrode and an inert shielding gas to produce a weld?