API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 391:

  Graphitization occurs in:

  A. Aluminum
  B. Stainless steel
  C. Carbon steel
  D. Monel
  C. Carbon steel

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  Comprehensive and Detailed From Exact Extract:

  According to, is a high-temperature degradation mechanism that occurs in API RP 571 graphitization carbon and carbon-molybdenum steels exposed for long periods at temperatures typically above 800 癋 (425 癈).

  In this process: Iron carbides decompose into free graphite nodules The steel loses strength, ductility, and pressure-retaining capability Failures can occur without significant wall loss Graphitization does not occur in aluminum, stainless steels, or nickel-copper alloys such as Monel. Referenced Documents (Study Basis): API RP 571 - Section on Graphitization

• Question 392:

  Key factors affecting thermal fatigue are the magnitude of the temperature and the __________.

  A. Number of cycles
  B. Pressure
  C. Stress
  D. Alloy composition
  A. Number of cycles

• Question 393:

  Which of the following materials is least affected by brittle fracture?

  A. Carbon steel
  B. Chromes
  C. 300 series stainless steel
  D. 400 series stainless steel
  E. All stainless steels
  C. 300 series stainless steel

• Question 394:

  An inspector has discovered significant cracking in a T-joint where hot and cold hydrogen-containing streams are mixing in a hydroprocess unit. What damage mechanism should the inspector suspect is the cause?

  A. Mixing point corrosion
  B. Injection point corrosion
  C. Thermal fatigue
  D. Hydrogen embrittlement
  C. Thermal fatigue

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  API RP 571 on Thermal Fatigue:

  "Mixing of hot and cold streams, particularly where hydrogen is present, can induce thermal cycling

  stresses, leading to thermal fatigue cracking, especially at fittings like tees."

  "Hydrogen embrittlement typically affects stressed zones, but this pattern strongly indicates thermal fatigue."

  So the correct answer is C - Thermal fatigue.

• Question 395:

  __________ is a change in the microstructure of steels after exposure in the 850?F to 1400?F range, where the carbide phases in carbon steels are unstable and may agglomerate from their normal plate-like appearance.

  A. Carburization
  B. Spheroidization
  C. Graphiding
  D. 885?Embrittlement
  B. Spheroidization

• Question 396:

  What treatment is used to prevent boiler feed water corrosion?

  A. Oxide scavengers are added to process
  B. Oxygen scavengers are added to process
  C. Sulfide scavengers are added to process
  D. Sulfur scavengers are added to process
  B. Oxygen scavengers are added to process

• Question 397:

  Nitriding is usually confined to the surface of most components and will have a dull, ______ appearance. In more advanced stages, the material will exhibit very hard surface hardness.

  A. Gray
  B. Black
  C. Brown
  D. White
  A. Gray

• Question 398:

  Which of the following materials are affected by mechanical fatigue cracking?

  A. Only carbon steel
  B. Only carbon steel and chromes
  C. Only carbon steel, and high nickel alloys
  D. All materials
  B. Only carbon steel and chromes

• Question 399:

  ____________ is often found in piping and equipment that handles caustic, including H睸 and mercaptan removal units, as well as equipment that uses caustic for neutralization in sulfuric acid and HF acid units.

  A. Carburization
  B. Sulfide corrosion
  C. Caustic embrittlement
  D. Hydrogen cracking
  C. Caustic embrittlement

• Question 400:

  Inspecting for high-cycle fatigue can be difficult since:

  A. The cracks are extremely tight.
  B. Predicting the location of cracking is difficult.
  C. Once the crack begins, only a few cycles are needed for the crack to lead to failure.
  D. Often the equipment is vibrating making non-destructive evaluations difficult.
  C. Once the crack begins, only a few cycles are needed for the crack to lead to failure.