API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 201:

  Which of these materials are susceptible to creep damage?

  A. Carbon steel
  B. Stainless steel
  C. Low alloy steel
  D. All of the above
  D. All of the above

• Question 202:

  ________ eliminates the susceptibility of most common steels to SCC.

  A. Preheat
  B. High temperature
  C. PWHT
  D. All of the above
  C. PWHT

• Question 203:

  A fatigue fracture is brittle and the cracks are most often __________.

  A. Parallel
  B. Transgranular
  C. Intergranular
  D. Transverse
  B. Transgranular

• Question 204:

  What structure is 304 stainless steel?

  A. Martensitic
  B. Austenitic
  C. Duplex
  D. Ferritic
  B. Austenitic

• Question 205:

  Which type of corrosion is most likely to occur in hydroprocess reactor effluent streams in units producing alkaline sour water?

  A. Amine
  B. Ammonium bisulfide
  C. Caustic
  D. Ammonium chloride
  B. Ammonium bisulfide

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  From API RP 571 and RP 932-B:

  "In hydroprocessing reactor effluent systems, the most common corrosion mechanism is ammonium bisulfide (NH#HS) corrosion, which forms in the presence of hydrogen sulfide and ammonia."

  "NH#HS attacks carbon steel aggressively under turbulent flow and at low pH."

  Correct answer is B - ammonium bisulfide corrosion.

• Question 206:

  Alloy 400 is susceptible to LME when it comes in contact with molten ________.

  A. Cadmium
  B. Mercury
  C. Zinc
  D. Lead
  B. Mercury

• Question 207:

  _________ material sections also have a ___________ resistance to brittle fracture due to higher constraint, which increases triaxial stresses at the crack tip.

  A. Thinner, Lower
  B. Thicker, Lower
  C. Thinner, Higher
  D. Thicker, Higher
  B. Thicker, Lower

• Question 208:

  Titanium Hydriding damage occurs primarily in sour water strippers and amine units in the overhead condensers, heat exchanger tubes and other titanium equipment operating above _________.

  A. 300?F
  B. 270?F
  C. 210?F
  D. 165?F
  D. 165?F

• Question 209:

  300 series austenitic stainless steels susceptible to polythionic acid stress corrosion cracking (PTA SCC) can become sensitized when heated in the range of:

  A. 400癋 to 675癋 (204癈 to 357癈)
  B. 750癋 to 1500癋 (400癈 to 815癈)
  C. 1650癋 to 1725癋 (899癈 to 941癈)
  D. 1200癋 to 1650癋 (622癈 to 900癈)
  B. 750癋 to 1500癋 (400癈 to 815癈)

  ---

  In API RP 571, under the section Polythionic Acid Stress Corrosion Cracking, it is stated: "Sensitization of austenitic stainless steels occurs when the material is exposed to temperatures in the range of 800癋 to 1500癋 (427癈 to 816癈), which causes chromium carbide precipitation at grain boundaries, depleting the adjacent areas of chromium."

  "Once sensitized, the steel becomes susceptible to attack in the presence of polythionic acids, particularly in

  environments containing sulfides and oxygen."

  API RP 571, Section 4.2.2.5 - PTA SCC)

  This makes option B (750癋 to 1500癋 / 400癈 to 815癈) the most accurate and standard-aligned answer.

• Question 210:

  With sulfuric acid corrosion, the presence of oxidizers can _______ the corrosion rate.

  A. Increase
  B. Decrease
  C. Stabilize
  D. Eliminate
  A. Increase