API API Certifications API-571 Questions & Answers

• Question 61:

  300 series stainless steel heater tubes in an oil-burning furnace in the hydrocracker began to leak and the furnace was brought down. What was the probable cause of the cracking?

  A. Chloride stress corrosion

  B. Polythionic acid stress corrosion

  C. Amine stress corrosion

  D. Stress oriented hydrogen induced cracking

  Correct Answer: B

• Question 62:

  In most cases, brittle fracture occurs only at temperatures _________ the Charpy impact transition temperature.

  A. Above

  B. Below

  C. Around

  D. Inside

  Correct Answer: B

• Question 63:

  ________ eliminates the susceptibility of most common steels to SCC.

  A. Preheat

  B. High temperature

  C. PWHT

  D. All of the above

  Correct Answer: C

• Question 64:

  Cavitation is a form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles. Temperatures approaching the boiling point of the liquid are _________ to result in bubble formation.

  A. Less likely

  B. More likely

  C. Not likely

  D. None of the above

  Correct Answer: B

• Question 65:

  Corrosion rates of the anode can be high if there is a _______ anode to cathode ratio.

  A. Large

  B. Small

  C. Severe

  D. None of the above

  Correct Answer: B

• Question 66:

  Hydrogen stress cracking is the same mechanism that is responsible for sulfide stress corrosion cracking in wet H²S environments except that HF acid is generating the __________.

  A. Sulfide

  B. Corrosion

  C. Hydrogen

  D. None of the above

  Correct Answer: C

• Question 67:

  Surface initiated cracks caused by environmental cracking of 300 Series SS and some nickel based alloys under the combined action of tensile stress, temperature and an aqueous chloride environmental is called ________. The presence of dissolved oxygen ___________ the propensity for cracking.

  A. Cl SCC, Increases

  B. Stress cracking, Increases

  C. Cl SCC, Decreases

  D. Stress cracking, Decreases

  Correct Answer: A

• Question 68:

  Which of these materials is not susceptible to amine cracking?

  A. Carbon steel

  B. 300 Series SS

  C. 400 Series SS

  D. Both B and C

  Correct Answer: D

• Question 69:

  Amine corrosion depends on the design, operating practices, the type of amine, amine concentration, temperature and _________.

  A. Pressure

  B. Velocity

  C. Stress

  D. None of the above

  Correct Answer: B

• Question 70:

  ____________ are characterized by a localized loss in thickness in the form of pits, grooves, gullies, waves, rounded holes and valleys. These losses often exhibit a directional pattern.

  A. Erosion

  B. Corrosion/Erosion

  C. Environmental corrosion

  D. Both A and B

  Correct Answer: D