API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 11:

  ___________ cooling water outlet temperatures and/or process side outlet temperatures tend to __________ corrosion rates as well as fouling tendency.

  A. Increasing, decrease
  B. Decreasing, decrease
  C. Decreasing, increase
  D. Increasing, increase
  D. Increasing, increase

• Question 12:

  Sulfidation of iron-based alloys usually:

  A. Occurs in equipment handling sour water
  B. Occurs only when moisture contacts the surface scale
  C. Causes wet hydrogen sulfide cracking of hard welds
  D. Occurs at metal temperatures above 500癋 (260癈)
  D. Occurs at metal temperatures above 500癋 (260癈)

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  API RP 571 and RP 939-C define sulfidation conditions as:

  "Sulfidation of iron-based alloys generally becomes significant at temperatures above 500癋 (260癈) in hydrocarbon streams with sulfur but without hydrogen."

  "For hydrogen-containing environments, this threshold may be reduced to 450癋 (230癈)."

  API RP 571, Section 4.2.1.1 - Sulfidation; API RP 939-C, Section 3.1) Therefore, the correct answer is D.

• Question 13:

  The effects of hydrogen embrittlement ___________ with _________ temperatures.

  A. Increase, increasing
  B. Decrease, decreasing
  C. Increase, decreasing
  D. Decrease, increasing
  D. Decrease, increasing

• Question 14:

  Contrary to a pure mechanical fatigue, there is no _________ load in corrosion-assistant fatigue. Corrosion promotes failure at a lower stress and number of cycles than the materials normal endurance.

  A. Tensile
  B. Stress
  C. Ductile
  D. Fatigue limit
  D. Fatigue limit

• Question 15:

  In most cases, brittle fracture occurs only at temperatures below the Charpy impact transition temperature. Steel cleanliness and ________ have a significant influence on toughness and resistance to brittle fracture.

  A. Alloy composition
  B. Tensile strength
  C. Grain size
  D. Pressure
  C. Grain size

• Question 16:

  At what minimum level of nickel content does an alloy become nearly immune to chloride stress corrosion cracking?

  A. 12%
  B. 20%
  C. 35% D. 45%
  C. 35% D. 45%

  ---

  API RP 571 states under Chloride Stress Corrosion Cracking (Cl-SCC): "Nickel contents above approximately 35% provide significant resistance to chloride stress corrosion

  cracking. Alloys such as Alloy 625 and Alloy 825 exhibit excellent resistance."

  "Austenitic stainless steels with lower nickel contents, such as 304 and 316, are more susceptible to Cl-SCC."

  Hence, option C (35%) is correct.

• Question 17:

  Which of the following is most susceptible to chloride stress corrosion cracking?

  A. Non-stress-relieved admiralty brass U-bends
  B. Inadequately heat-treated 1.25 Cr-0.5 Mo low-alloy steel
  C. Non-stress-relieved 304 stainless steel
  D. Non-postweld heat-treated carbon steel
  C. Non-stress-relieved 304 stainless steel

  ---

  API RP 571 on Chloride Stress Corrosion Cracking (Cl-SCC) clearly states:

  "Austenitic stainless steels such as 304 and 316 are highly susceptible to Cl-SCC when subjected to tensile

  stress and exposed to chloride-bearing environments."

  "Susceptibility is greatest in non-stress-relieved weldments or cold-worked areas."

  Brass and carbon steels are not typical Cl-SCC candidates; low alloy steels such as 1.25Cr-0.5Mo are also not commonly affected.

  Thus, option C is the correct answer.

• Question 18:

  Components that have been carburized may have a change in the level of ________.

  A. Carbon
  B. Chromium
  C. Ferromagnetism
  D. Stress
  C. Ferromagnetism

• Question 19:

  Cadmium and lead will cause LME on _____________.

  A. Copper alloys
  B. 300 Series SS
  C. Aluminum alloys
  D. High strength steel
  D. High strength steel

• Question 20:

  SSC is a form of hydrogen stress cracking resulting from the absorption of ________ that is produced by the sulfide corrosion process on the metal surface.

  A. Sulfur dioxide
  B. Hydrogen sulfide
  C. Atomic hydrogen
  D. Hydrogen chloride
  C. Atomic hydrogen