CCC Welding & Metalworking Techniques 2 — Questions and Answers
Question 1: Which personal protective equipment (PPE) is mandatory when performing MIG welding in a collision repair facility?
- Safety glasses and leather gloves only
- Welding helmet with appropriate lens shade, gloves, and flame-resistant clothing (Correct answer)
- Face shield and rubber gloves
- Standard shop coat and tinted safety glasses
Correct answer: Welding helmet with appropriate lens shade, gloves, and flame-resistant clothing
OSHA and industry standards require a welding helmet with appropriate auto-darkening or fixed lens shade, heat-resistant gloves, and flame-resistant clothing to protect against UV radiation, sparks, and molten spatter.
Question 2: What does the term 'heat-affected zone' (HAZ) mean in the context of collision repair welding?
- The area of the shop requiring ventilation during welding
- The zone around a weld where metal properties are altered by heat without melting (Correct answer)
- The temperature range at which filler wire melts
- The area on the panel that must be preheated before welding
Correct answer: The zone around a weld where metal properties are altered by heat without melting
The heat-affected zone (HAZ) is the area adjacent to a weld where the base metal's microstructure and properties are changed by welding heat without actually melting, potentially weakening high-strength steel.
Question 3: Why is it especially important to control heat input when welding Advanced High-Strength Steel (AHSS) in modern vehicles?
- AHSS requires higher voltage settings than mild steel
- Excessive heat destroys the engineered microstructure of AHSS, reducing its strength (Correct answer)
- AHSS must be welded only with TIG welding equipment
- High heat improves AHSS weldability
Correct answer: Excessive heat destroys the engineered microstructure of AHSS, reducing its strength
AHSS panels are thermally processed to achieve specific strength properties; excessive heat during repair destroys these properties, compromising structural integrity and crash performance.
Question 4: What is the correct lens shade range recommended for MIG welding at currents between 60–160 amps?
- Shade 5–6
- Shade 7–8
- Shade 10–11 (Correct answer)
- Shade 13–14
Correct answer: Shade 10–11
AWS and OSHA guidelines recommend lens shade 10–11 for MIG welding at 60–160 amp current levels to adequately protect eyes from arc radiation.
Question 5: Before welding galvanized or zinc-coated steel panels, what should a technician do to the weld area?
- Apply flux to prevent oxidation
- Remove the zinc coating from the immediate weld zone to prevent toxic fumes and porosity (Correct answer)
- Increase wire feed speed to compensate for the coating
- Preheat the panel to 400°F to burn off the coating during welding
Correct answer: Remove the zinc coating from the immediate weld zone to prevent toxic fumes and porosity
Zinc coating must be removed from the weld area because burning zinc produces toxic fumes and causes weld porosity; the coating should be re-applied after welding for corrosion protection.
Question 6: Which destructive test is used in a collision repair shop to verify spot weld quality and penetration?
- Bend test
- Tensile pull test
- Peel or chisel test (Correct answer)
- Hardness test
Correct answer: Peel or chisel test
The peel or chisel test physically separates welded panels to inspect nugget size and penetration, confirming that spot welds meet strength requirements before production use.
Question 7: What is the primary reason for applying weld-through primer to bare metal flanges before welding overlapping panels?
- To increase conductivity for resistance welding
- To prevent corrosion between mating surfaces that cannot be reached after welding (Correct answer)
- To improve the appearance of the finished weld bead
- To reduce the welding temperature required
Correct answer: To prevent corrosion between mating surfaces that cannot be reached after welding
Weld-through primer provides corrosion protection to the mating surfaces between panels that will be permanently sealed by the weld and inaccessible for future coating.
CCC Welding & Metalworking Techniques 2
Which personal protective equipment (PPE) is mandatory when performing MIG welding in a collision repair facility?