Internal Corrosion Technologist Certification
Exam
1. Internal corrosion requires three primary elements:
A. Metal, electrolyte (water), and oxidizer/acids
B. Sunlight, soil, plastic
C. Stainless steel, nitrogen, concrete
D. Coating, paint, sand
✅ Answer: A
Explanation: Water + steel + corrosive species (O₂, CO₂, H₂S,
acids) are required for corrosion to start.
2. Which gas forms carbonic acid when dissolved in pipeline
water?
A. CO₂
B. N₂
C. He
D. H₂
✅ Answer: A
Explanation: CO₂ + H₂O → H₂CO₃ → corrosive environment
for carbon steel.
3. The major product of CO₂ corrosion is:
A. Iron carbonate (FeCO₃)
B. Iron sulfide
,C. Iron oxide only
D. Aluminum oxide
✅ Answer: A
Explanation: CO₂ corrosion often produces FeCO₃ scale which
can be protective or porous.
4. H₂S corrosion commonly forms:
A. Iron sulfide scale
B. Iron carbonate scale
C. Plastic film
D. Nitrogen oxide
✅ Answer: A
5. Internal MIC is most likely found:
A. In stagnant water or under deposits
B. In perfectly dry gas
C. In plastic pipe only
D. Where no water accumulates
✅ Answer: A
Explanation: SRB and other microbes thrive where stagnant
water and deposits remain.
6. The component that most accelerates internal corrosion in
wet gas:
A. Free water
B. Dry methane
,C. Plastic coating
D. Line markers
✅ Answer: A
7. ER (electrical resistance) probes measure:
A. Reduction in metal thickness due to corrosion
B. Gas volume
C. CO₂ pressure
D. Pig location
✅ Answer: A
Explanation: A thin metal element’s resistance increases as
corrosion reduces its cross-section.
8. Coupon corrosion rate is typically expressed in:
A. Mils per year (mpy)
B. Volts per meter
C. Joules per second
D. Ohm-meters
✅ Answer: A
9. High solids content in produced water often causes:
A. Erosion-corrosion
B. UV attack
C. Hydrogen embrittlement only
D. Plastic failure
✅ Answer: A
, 10. Internal inhibitors prevent corrosion by:
A. Forming a protective film on metal surface
B. Increasing pipe pressure
C. Removing water
D. Increasing solids
✅ Answer: A
11. What increases CO₂ corrosion rate?
A. Higher temperature and free water
B. Only CO₂ gas without water
C. Plastic pipe
D. Low velocity dry gas
✅ Answer: A
12. Low spots in gas pipelines are critical because:
A. Water accumulates and becomes an electrolyte
B. No corrosion occurs
C. Flow is too fast
D. Only solids accumulate
✅ Answer: A
13. Batch inhibition programs work best when followed by:
A. Cleaning pig runs
B. Painting the pipe
Exam
1. Internal corrosion requires three primary elements:
A. Metal, electrolyte (water), and oxidizer/acids
B. Sunlight, soil, plastic
C. Stainless steel, nitrogen, concrete
D. Coating, paint, sand
✅ Answer: A
Explanation: Water + steel + corrosive species (O₂, CO₂, H₂S,
acids) are required for corrosion to start.
2. Which gas forms carbonic acid when dissolved in pipeline
water?
A. CO₂
B. N₂
C. He
D. H₂
✅ Answer: A
Explanation: CO₂ + H₂O → H₂CO₃ → corrosive environment
for carbon steel.
3. The major product of CO₂ corrosion is:
A. Iron carbonate (FeCO₃)
B. Iron sulfide
,C. Iron oxide only
D. Aluminum oxide
✅ Answer: A
Explanation: CO₂ corrosion often produces FeCO₃ scale which
can be protective or porous.
4. H₂S corrosion commonly forms:
A. Iron sulfide scale
B. Iron carbonate scale
C. Plastic film
D. Nitrogen oxide
✅ Answer: A
5. Internal MIC is most likely found:
A. In stagnant water or under deposits
B. In perfectly dry gas
C. In plastic pipe only
D. Where no water accumulates
✅ Answer: A
Explanation: SRB and other microbes thrive where stagnant
water and deposits remain.
6. The component that most accelerates internal corrosion in
wet gas:
A. Free water
B. Dry methane
,C. Plastic coating
D. Line markers
✅ Answer: A
7. ER (electrical resistance) probes measure:
A. Reduction in metal thickness due to corrosion
B. Gas volume
C. CO₂ pressure
D. Pig location
✅ Answer: A
Explanation: A thin metal element’s resistance increases as
corrosion reduces its cross-section.
8. Coupon corrosion rate is typically expressed in:
A. Mils per year (mpy)
B. Volts per meter
C. Joules per second
D. Ohm-meters
✅ Answer: A
9. High solids content in produced water often causes:
A. Erosion-corrosion
B. UV attack
C. Hydrogen embrittlement only
D. Plastic failure
✅ Answer: A
, 10. Internal inhibitors prevent corrosion by:
A. Forming a protective film on metal surface
B. Increasing pipe pressure
C. Removing water
D. Increasing solids
✅ Answer: A
11. What increases CO₂ corrosion rate?
A. Higher temperature and free water
B. Only CO₂ gas without water
C. Plastic pipe
D. Low velocity dry gas
✅ Answer: A
12. Low spots in gas pipelines are critical because:
A. Water accumulates and becomes an electrolyte
B. No corrosion occurs
C. Flow is too fast
D. Only solids accumulate
✅ Answer: A
13. Batch inhibition programs work best when followed by:
A. Cleaning pig runs
B. Painting the pipe
