Canadian Welding Bureau
L AU S I V • 2 L B W C
✦CWB ✦
L2 Welding Inspector Level 2 · Visual Weld Inspector Examination
S E T T I N G T H E S TA N D A R D I N W E L D I N G C E R T I F I C AT I O N
CANADA
CWB Level 2 — Visual Weld Inspector Examination
W E L D I N G P R O C E SS E S · CO N S U M A B L E S · M E TA L LU R G Y · D I STO RT I O N · N DT · STA I N L E SS ST E E LS ·
M E C H A N I C A L T E ST I N G
ORGANIZATION Canadian Welding Bureau (CWB) CERTIFICATION Welding Inspector Level 2
EXAM TYPE Visual Weld Inspector Comprehensive TOTAL QUESTIONS 50 Questions
SUBJECT AREAS Processes · Metallurgy · NDT · Distortion · FORMAT Multiple Choice & True/False — Select the
Testing · Stainless Steels Single Best Answer
VISUAL WELD INSPECTOR EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question based on the CWB Level 2 Visual Weld Inspector curriculum.
▸ Content covers all modules: welding processes and consumables, metallurgy and material properties, weld discontinuities and
defects, distortion and residual stress control, non-destructive testing methods (LPI, MPI, RT, UT, ET), mechanical testing,
inspection roles and responsibilities, and welding of stainless steels.
▸ Key formulas: Energy Input = (V × A × 60) / (Speed × 1000) kJ/mm; Ug = Ft/d; Stress = Load / Original CSA; % Elongation =
[(L2−L1)/L1] × 100.
SECTION I — WELDING PROCESSES, METALLURGY, NDT & INSPECTION Questions 1 – 50
1. A consumable electrode is defined as:
A. An electrode that carries current but does not melt.
B. An electrode which melts and provides metal to fill the joint.
C. An electrode used exclusively in the GTAW process.
D. A tungsten electrode used for non-consumable arc welding.
CORRECT ANSWER B — An electrode which melts and provides metal to fill the joint.
RATIONALE A CONSUMABLE ELECTRODE melts and provides filler metal. The Heat Affected Zone (HAZ) is the base metal
region adjacent to the weld whose properties changed from welding heat. Electrons flow CATHODE to ANODE.
Magnetic pinch force increases as the SQUARE of current, producing smaller droplets. Welding current
transforms from HIGH voltage/LOW amperage to LOW voltage/HIGH amperage. Electron beam welding
achieves full penetration in ONE PASS on thick material. Electroslag welding progresses VERTICAL UP.
Explosion welding is a SOLID STATE process using controlled detonation. Thermite welding joins RAILS. GTAW
without filler is AUTOGENOUS welding.
,2. Once a box of E49XX low hydrogen electrodes has been opened, the electrodes may remain at ambient
temperature for a maximum of:
A. 2 hours.
B. 4 hours.
C. 8 hours.
D. 24 hours.
CORRECT ANSWER B — 4 hours.
RATIONALE Opened low hydrogen electrodes may remain at ambient temperature for up to 4 HOURS. After that, they
must be stored in holding ovens at minimum 120°C. Electrodes that NEVER go in ovens: CELLULOSIC. SMAW
uses CONSTANT CURRENT; GMAW uses CONSTANT VOLTAGE. The main function of slag: protecting weld metal
from contamination, reducing oxygen/impurities, and controlling bead shape. Cellulose in electrode coating
primarily provides GASEOUS PROTECTION. The "-1" suffix on E4918/E4924 indicates IMPROVED IMPACT
PROPERTIES. A stainless electrode E316-25 is BASIC flux, usable for flat grooves and horizontal fillets only.
FCAW position "2" means flat grooves and horizontal fillets only.
3. In GMAW welding, the spray mode of metal transfer is achieved with:
A. Low amperage, low voltage, and CO2 shielding.
B. High amperage, high voltage, and argon-rich shielding gas.
C. Medium amperage, medium voltage, and helium shielding.
D. Low amperage, high voltage, and nitrogen shielding.
CORRECT ANSWER B — High amperage, high voltage, and argon-rich shielding gas.
RATIONALE SPRAY transfer requires HIGH amperage, HIGH voltage, and ARGON-RICH shielding (typically 95% Ar / 5%
CO2). Spray has a large weld pool difficult to control out of position. GLOBULAR transfer has excessive spatter.
SHORT CIRCUIT transfer has the lowest amperage and may cause lack of fusion. Short circuit is used for CAST
IRON; spray for ALUMINUM ALLOYS. The most common FCAW gas is 75% Ar / 25% CO2. Self-shielded FCAW
wires are best for field work and tolerate air currents. Gas-shielded FCAW with basic ingredients is NOT suited
for out-of-position welding. For MCAW, a 15° travel angle using PUSH technique gives flat profile and good
penetration.
4. The minimum chromium content required to make steel "stainless" is:
A. 5%
B. 8%
C. 10%
D. 12%
CORRECT ANSWER C — 10%.
RATIONALE Minimum 10% CHROMIUM for stainless steel. The four main types: FERRITIC, AUSTENITIC, MARTENSITIC, and
DUPLEX. Nickel stabilizes FCC (austenite); chromium stabilizes BCC (ferrite). "L" means LOW CARBON (max
0.03%). SENSITIZATION is chromium depletion at grain boundaries from carbide precipitation. To avoid
sensitization: use STABILIZED grades (321/347 with Ti/Nb) or low-carbon grades. Duplex has 50%
austenite/50% ferrite. Martensitic preheat depends on CARBON CONTENT. Austenitic stainless has the BEST
low-temperature toughness. GMAW of stainless with 100% CO2 is NOT recommended — carbon pickup
occurs. Oxy-acetylene cannot cut stainless. For buttering carbon steel to stainless, use E309. Weld decay
prevention: solution treatment at 1100°C with rapid cool.
, 5. What is the fundamental cause of distortion in welding?
A. Excessive welding current.
B. Localized shape change from heating and cooling.
C. Poor welder technique.
D. Incorrect filler metal selection.
CORRECT ANSWER B — Localized shape change from heating and cooling.
RATIONALE Distortion is fundamentally caused by LOCALIZED SHAPE CHANGE from heating and cooling. Metal expands
VOLUMETRICALLY when heated. DISTORTION = physical shape change by bending/twisting/warping. STRAIN
= shape change from stress. PLASTIC DEFORMATION = permanent shape change not reversible when forces
removed. RESIDUAL STRESSES are locked inside metal after cutting/welding. Longitudinally, residual stress
can equal YIELD STRESS of base metal. To reduce angular distortion: increase travel speed, reduce
preparation angle, preheat. Decreasing weld beads REDUCES transverse shrinkage. Flame straightening max
temperature for low alloy steels: 650°C. The neutral axis has neither tension nor compression when flexed.
Pre-setting plates allows recovery from angular distortion with least residual stress effect.
6. Ultrasonic testing of welds typically utilizes sound frequencies in the range of:
A. 1–3 kHz
B. 2.5–5 kHz
C. 1.5–3.5 MHz
D. 2.5–5 MHz
CORRECT ANSWER D — 2.5–5 MHz.
RATIONALE UT frequencies: 2.5–5 MHz (megahertz). UT uses two main wave types: LONGITUDINAL and SHEAR
(transverse). Piezoelectric crystals convert electrical to mechanical energy and vice versa. The A-scan displays
AMPLITUDE (vertical) and TIME/distance (horizontal). COUPLANT increases energy transmission into material.
For angle probe, first calibrate EXIT/INDEX POINT using IIW block. To inspect upper weld portion, bounce
beam off BACK WALL. DAC = Distance Amplitude Correction curve. CSA W59 acceptance: based on AMPLITUDE
and LENGTH. ASME rejects cracks, lack of fusion, and incomplete penetration regardless of length. Electroslag
welds need LOW frequencies due to large grain size. Radiography: CO-60 has SHORTER wavelengths (more
penetrating) than Ir-192. IQI thickness = 2% of material thickness. X-rays are safer because they can be
TURNED OFF. Film density range: 1.5–3.5.
7. Liquid penetrant inspection (LPI) can only detect:
A. Subsurface discontinuities up to 6 mm deep.
B. Surface discontinuities and defects open to the surface.
C. Volumetric discontinuities throughout the material.
D. Both surface and subsurface defects in ferrous materials.
CORRECT ANSWER B — Surface discontinuities and defects open to the surface.
RATIONALE LPI detects SURFACE-ONLY discontinuities. It relies on CAPILLARY ACTION. The most sensitive system:
FLUORESCENT POST-EMULSIFIABLE. Halogen content must be limited on austenitic stainless — can cause
STRESS CORROSION CRACKING. False indications come from POOR CLEANING. Continuous line = crack;
rounded = porosity. Don't use grinder for LPI — it can flow metal and conceal cracks. MPI: AC has NO
subsurface capability; DC can detect near-surface defects. Yoke must lift 4.5 kg (AC) or 18 kg (DC). Prods are
restricted due to ARC STRIKE risk. AC yoke placed ACROSS weld detects fusion boundary cracks.
DEMAGNETIZATION occurs at 770°C (Curie temperature). Eddy current max depth: 6 mm in non-ferrous
metals. Potential drop measures FATIGUE CRACK GROWTH.
L AU S I V • 2 L B W C
✦CWB ✦
L2 Welding Inspector Level 2 · Visual Weld Inspector Examination
S E T T I N G T H E S TA N D A R D I N W E L D I N G C E R T I F I C AT I O N
CANADA
CWB Level 2 — Visual Weld Inspector Examination
W E L D I N G P R O C E SS E S · CO N S U M A B L E S · M E TA L LU R G Y · D I STO RT I O N · N DT · STA I N L E SS ST E E LS ·
M E C H A N I C A L T E ST I N G
ORGANIZATION Canadian Welding Bureau (CWB) CERTIFICATION Welding Inspector Level 2
EXAM TYPE Visual Weld Inspector Comprehensive TOTAL QUESTIONS 50 Questions
SUBJECT AREAS Processes · Metallurgy · NDT · Distortion · FORMAT Multiple Choice & True/False — Select the
Testing · Stainless Steels Single Best Answer
VISUAL WELD INSPECTOR EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question based on the CWB Level 2 Visual Weld Inspector curriculum.
▸ Content covers all modules: welding processes and consumables, metallurgy and material properties, weld discontinuities and
defects, distortion and residual stress control, non-destructive testing methods (LPI, MPI, RT, UT, ET), mechanical testing,
inspection roles and responsibilities, and welding of stainless steels.
▸ Key formulas: Energy Input = (V × A × 60) / (Speed × 1000) kJ/mm; Ug = Ft/d; Stress = Load / Original CSA; % Elongation =
[(L2−L1)/L1] × 100.
SECTION I — WELDING PROCESSES, METALLURGY, NDT & INSPECTION Questions 1 – 50
1. A consumable electrode is defined as:
A. An electrode that carries current but does not melt.
B. An electrode which melts and provides metal to fill the joint.
C. An electrode used exclusively in the GTAW process.
D. A tungsten electrode used for non-consumable arc welding.
CORRECT ANSWER B — An electrode which melts and provides metal to fill the joint.
RATIONALE A CONSUMABLE ELECTRODE melts and provides filler metal. The Heat Affected Zone (HAZ) is the base metal
region adjacent to the weld whose properties changed from welding heat. Electrons flow CATHODE to ANODE.
Magnetic pinch force increases as the SQUARE of current, producing smaller droplets. Welding current
transforms from HIGH voltage/LOW amperage to LOW voltage/HIGH amperage. Electron beam welding
achieves full penetration in ONE PASS on thick material. Electroslag welding progresses VERTICAL UP.
Explosion welding is a SOLID STATE process using controlled detonation. Thermite welding joins RAILS. GTAW
without filler is AUTOGENOUS welding.
,2. Once a box of E49XX low hydrogen electrodes has been opened, the electrodes may remain at ambient
temperature for a maximum of:
A. 2 hours.
B. 4 hours.
C. 8 hours.
D. 24 hours.
CORRECT ANSWER B — 4 hours.
RATIONALE Opened low hydrogen electrodes may remain at ambient temperature for up to 4 HOURS. After that, they
must be stored in holding ovens at minimum 120°C. Electrodes that NEVER go in ovens: CELLULOSIC. SMAW
uses CONSTANT CURRENT; GMAW uses CONSTANT VOLTAGE. The main function of slag: protecting weld metal
from contamination, reducing oxygen/impurities, and controlling bead shape. Cellulose in electrode coating
primarily provides GASEOUS PROTECTION. The "-1" suffix on E4918/E4924 indicates IMPROVED IMPACT
PROPERTIES. A stainless electrode E316-25 is BASIC flux, usable for flat grooves and horizontal fillets only.
FCAW position "2" means flat grooves and horizontal fillets only.
3. In GMAW welding, the spray mode of metal transfer is achieved with:
A. Low amperage, low voltage, and CO2 shielding.
B. High amperage, high voltage, and argon-rich shielding gas.
C. Medium amperage, medium voltage, and helium shielding.
D. Low amperage, high voltage, and nitrogen shielding.
CORRECT ANSWER B — High amperage, high voltage, and argon-rich shielding gas.
RATIONALE SPRAY transfer requires HIGH amperage, HIGH voltage, and ARGON-RICH shielding (typically 95% Ar / 5%
CO2). Spray has a large weld pool difficult to control out of position. GLOBULAR transfer has excessive spatter.
SHORT CIRCUIT transfer has the lowest amperage and may cause lack of fusion. Short circuit is used for CAST
IRON; spray for ALUMINUM ALLOYS. The most common FCAW gas is 75% Ar / 25% CO2. Self-shielded FCAW
wires are best for field work and tolerate air currents. Gas-shielded FCAW with basic ingredients is NOT suited
for out-of-position welding. For MCAW, a 15° travel angle using PUSH technique gives flat profile and good
penetration.
4. The minimum chromium content required to make steel "stainless" is:
A. 5%
B. 8%
C. 10%
D. 12%
CORRECT ANSWER C — 10%.
RATIONALE Minimum 10% CHROMIUM for stainless steel. The four main types: FERRITIC, AUSTENITIC, MARTENSITIC, and
DUPLEX. Nickel stabilizes FCC (austenite); chromium stabilizes BCC (ferrite). "L" means LOW CARBON (max
0.03%). SENSITIZATION is chromium depletion at grain boundaries from carbide precipitation. To avoid
sensitization: use STABILIZED grades (321/347 with Ti/Nb) or low-carbon grades. Duplex has 50%
austenite/50% ferrite. Martensitic preheat depends on CARBON CONTENT. Austenitic stainless has the BEST
low-temperature toughness. GMAW of stainless with 100% CO2 is NOT recommended — carbon pickup
occurs. Oxy-acetylene cannot cut stainless. For buttering carbon steel to stainless, use E309. Weld decay
prevention: solution treatment at 1100°C with rapid cool.
, 5. What is the fundamental cause of distortion in welding?
A. Excessive welding current.
B. Localized shape change from heating and cooling.
C. Poor welder technique.
D. Incorrect filler metal selection.
CORRECT ANSWER B — Localized shape change from heating and cooling.
RATIONALE Distortion is fundamentally caused by LOCALIZED SHAPE CHANGE from heating and cooling. Metal expands
VOLUMETRICALLY when heated. DISTORTION = physical shape change by bending/twisting/warping. STRAIN
= shape change from stress. PLASTIC DEFORMATION = permanent shape change not reversible when forces
removed. RESIDUAL STRESSES are locked inside metal after cutting/welding. Longitudinally, residual stress
can equal YIELD STRESS of base metal. To reduce angular distortion: increase travel speed, reduce
preparation angle, preheat. Decreasing weld beads REDUCES transverse shrinkage. Flame straightening max
temperature for low alloy steels: 650°C. The neutral axis has neither tension nor compression when flexed.
Pre-setting plates allows recovery from angular distortion with least residual stress effect.
6. Ultrasonic testing of welds typically utilizes sound frequencies in the range of:
A. 1–3 kHz
B. 2.5–5 kHz
C. 1.5–3.5 MHz
D. 2.5–5 MHz
CORRECT ANSWER D — 2.5–5 MHz.
RATIONALE UT frequencies: 2.5–5 MHz (megahertz). UT uses two main wave types: LONGITUDINAL and SHEAR
(transverse). Piezoelectric crystals convert electrical to mechanical energy and vice versa. The A-scan displays
AMPLITUDE (vertical) and TIME/distance (horizontal). COUPLANT increases energy transmission into material.
For angle probe, first calibrate EXIT/INDEX POINT using IIW block. To inspect upper weld portion, bounce
beam off BACK WALL. DAC = Distance Amplitude Correction curve. CSA W59 acceptance: based on AMPLITUDE
and LENGTH. ASME rejects cracks, lack of fusion, and incomplete penetration regardless of length. Electroslag
welds need LOW frequencies due to large grain size. Radiography: CO-60 has SHORTER wavelengths (more
penetrating) than Ir-192. IQI thickness = 2% of material thickness. X-rays are safer because they can be
TURNED OFF. Film density range: 1.5–3.5.
7. Liquid penetrant inspection (LPI) can only detect:
A. Subsurface discontinuities up to 6 mm deep.
B. Surface discontinuities and defects open to the surface.
C. Volumetric discontinuities throughout the material.
D. Both surface and subsurface defects in ferrous materials.
CORRECT ANSWER B — Surface discontinuities and defects open to the surface.
RATIONALE LPI detects SURFACE-ONLY discontinuities. It relies on CAPILLARY ACTION. The most sensitive system:
FLUORESCENT POST-EMULSIFIABLE. Halogen content must be limited on austenitic stainless — can cause
STRESS CORROSION CRACKING. False indications come from POOR CLEANING. Continuous line = crack;
rounded = porosity. Don't use grinder for LPI — it can flow metal and conceal cracks. MPI: AC has NO
subsurface capability; DC can detect near-surface defects. Yoke must lift 4.5 kg (AC) or 18 kg (DC). Prods are
restricted due to ARC STRIKE risk. AC yoke placed ACROSS weld detects fusion boundary cracks.
DEMAGNETIZATION occurs at 770°C (Curie temperature). Eddy current max depth: 6 mm in non-ferrous
metals. Potential drop measures FATIGUE CRACK GROWTH.
