API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 61:

  The remaining life of a component susceptible to creep damage can be cut in half by a/an:

  A. sudden change in temperature.
  B. increase in operating unit throughput.
  C. increase in temperature of 25癋 (15癈).
  D. increase in stress of 10%.
  C. increase in temperature of 25癋 (15癈).

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  According to API RP 571 Section 5.3.2.1 (Creep):

  "Creep damage is exponentially dependent on temperature. A small increase in temperature (e.g., 25癋 or 15?C) can reduce remaining life by more than half. This is because the creep rate increases rapidly with temperature, especially above design limits."

  Stress is a contributing factor, but the dominant and most sensitive variable is temperature.

  Thus, Option C (increase in temperature of 25癋/15癈) is the correct answer.

• Question 62:

  Carburization can be confirmed by a substantial increase in hardness and a _______ in ductility.

  A. Loss
  B. Gain
  C. Change
  D. None of the above
  A. Loss

• Question 63:

  Which of the materials listed are not susceptible to Chloride Stress Corrosion Cracking?

  A. 400 Series Stainless Steel
  B. 300 Series Stainless Steel
  C. 8% Nickel Alloys
  D. Duplex Stainless Steel
  A. 400 Series Stainless Steel

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  Chloride Stress Corrosion Cracking (Cl-SCC) is a serious form of corrosion primarily affecting austenitic stainless steels and some duplex stainless steels, particularly when exposed to chloride-containing environments at elevated temperatures.

  According to API RP 571 Section 5.1.2.3 (Chloride Stress Corrosion Cracking - Cl-SCC) :

  "Austenitic stainless steels (e.g., 300 series such as Types 304 and 316) are the most susceptible to Cl-SCC... Duplex stainless steels have greater resistance but are not immune, especially at temperatures >150癋 (65?C)... Ferritic stainless steels (400 series) are generally not susceptible." Thus, Option A (400 Series Stainless Steel) is not susceptible to chloride SCC, making it the correct answer.

• Question 64:

  With thermal fatigue, time to failure is a function of the magnitude of the stress and the number of cycles and decreases with _________ stress and ________ cycles.

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

• Question 65:

  High temperature H?/ H睸 corrosion damage is minimized by using alloys with high _________ content.

  A. Carbon
  B. Molybdenum
  C. Chromium
  D. Stainless
  C. Chromium

• Question 66:

  __________ testing is the best method to determine the susceptibility of a material to hydrogen stress cracking.

  A. Hardness
  B. Acoustic
  C. SWUT
  D. AUT
  A. Hardness

• Question 67:

  300 Series SS, 5Cr, 9Cr and 12Cr alloys are not susceptible to ________ at conditions normally seen in refineries.

  A. Cl SCC
  B. SOHIC
  C. HTHA
  D. HTLA
  C. HTHA

• Question 68:

  At elevated temperature, the carbide phases in certain carbon steels are unstable and may decompose into _______. This decomposition is known as graphitization.

  A. Silicon
  B. Graphite nodules
  C. Carbon dust
  D. Graphite dust
  B. Graphite nodules

• Question 69:

  Ammonium chloride salts are hydroscopic and readily absorb water. A ________ amount of water can lead to very aggressive ammonium chloride corrosion.

  A. Large
  B. Small
  C. Proper
  D. Improper
  B. Small

• Question 70:

  _________ acid is most often used as a catalyst in polymerization units.

  A. Polythionic
  B. Naphthenic
  C. Phosphoric
  D. Sulfuric
  C. Phosphoric