CWB Welding Inspector Level 3 Exam
Prep 2025/2026 Update – Complete Study
Material and Practice Questions
2025/2026 Updates: Increased focus on NDT (UT/RT for aluminum), sustainability (low-
emission welding), and digital inspection (drones for pipelines).
Questions (50 Questions)
Question: Which alloy would give the highest risk of hot cracking? (a) Al-0.1%Cu (b) Al-
3%Cu (c) Al-8%Cu Answer: (c) Al-8%Cu. Rationale: Wide freezing range in high-Cu
alloys promotes liquation in HAZ (Unit 5; AWS D1.2).
Question: What is the primary purpose of preheat in welding low-alloy steels? Answer: To
slow cooling rate and prevent brittle martensite. Rationale: Reduces HAZ hardness (Unit
2; CSA W59 Table 5).
Question: For gray cast iron welding, recommended filler is? Answer: ENi-CI (Ni-based).
Rationale: High Ni for crack resistance (Unit 3; AWS D11.2).
Question: Carbon equivalent (CE) formula for steels? Answer: CE = C + Mn/6 +
(Cr+Mo+V)/5 + (Ni+Cu)/15. Rationale: Predicts weldability; CE >0.4 high risk (Unit 2;
IIW formula).
Question: What is lamellar tearing? Answer: Separation of inclusions in through-thickness
welds. Rationale: High restraint in thick plates (Unit 2; BS 7910).
Question: Preheat temp for P91 steel? Answer: 200-250°C. Rationale: Prevents cracking in
9Cr-1Mo (Unit 2; ASME Section IX).
Question: Which aluminum series is heat-treatable? Answer: 6xxx and 7xxx. Rationale:
Age-hardenable (Unit 5; AWS D1.2).
Question: Liquation cracking in aluminum occurs in? Answer: HAZ due to low-melting
eutectics. Rationale: Mg-Si phases melt (Unit 6; AWS D1.2).
Question: Sensitization in 5xxx aluminum? Answer: Beta phase precipitation causing IGC.
Rationale: >3% Mg, 100-260°C (Unit 6; MIL-HDBK-5).
Question: ISO 9001 requires? Answer: Documented QMS with continual improvement.
Rationale: Clause 4-10 (Unit 7; ISO 9001:2015).
Prep 2025/2026 Update – Complete Study
Material and Practice Questions
2025/2026 Updates: Increased focus on NDT (UT/RT for aluminum), sustainability (low-
emission welding), and digital inspection (drones for pipelines).
Questions (50 Questions)
Question: Which alloy would give the highest risk of hot cracking? (a) Al-0.1%Cu (b) Al-
3%Cu (c) Al-8%Cu Answer: (c) Al-8%Cu. Rationale: Wide freezing range in high-Cu
alloys promotes liquation in HAZ (Unit 5; AWS D1.2).
Question: What is the primary purpose of preheat in welding low-alloy steels? Answer: To
slow cooling rate and prevent brittle martensite. Rationale: Reduces HAZ hardness (Unit
2; CSA W59 Table 5).
Question: For gray cast iron welding, recommended filler is? Answer: ENi-CI (Ni-based).
Rationale: High Ni for crack resistance (Unit 3; AWS D11.2).
Question: Carbon equivalent (CE) formula for steels? Answer: CE = C + Mn/6 +
(Cr+Mo+V)/5 + (Ni+Cu)/15. Rationale: Predicts weldability; CE >0.4 high risk (Unit 2;
IIW formula).
Question: What is lamellar tearing? Answer: Separation of inclusions in through-thickness
welds. Rationale: High restraint in thick plates (Unit 2; BS 7910).
Question: Preheat temp for P91 steel? Answer: 200-250°C. Rationale: Prevents cracking in
9Cr-1Mo (Unit 2; ASME Section IX).
Question: Which aluminum series is heat-treatable? Answer: 6xxx and 7xxx. Rationale:
Age-hardenable (Unit 5; AWS D1.2).
Question: Liquation cracking in aluminum occurs in? Answer: HAZ due to low-melting
eutectics. Rationale: Mg-Si phases melt (Unit 6; AWS D1.2).
Question: Sensitization in 5xxx aluminum? Answer: Beta phase precipitation causing IGC.
Rationale: >3% Mg, 100-260°C (Unit 6; MIL-HDBK-5).
Question: ISO 9001 requires? Answer: Documented QMS with continual improvement.
Rationale: Clause 4-10 (Unit 7; ISO 9001:2015).
