API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 121:

  A brittle fracture:

  A. Is caused by stress cycles.
  B. Is always the result of thermal stresses.
  C. Grow very rapidly with minimum deformation prior to failure.
  D. Grows slowly and is dependent on time and stress.
  C. Grow very rapidly with minimum deformation prior to failure.

• Question 122:

  Susceptibility to temper embrittlement is largely determined by the presence of the alloying elements manganese and _______.

  A. Chromium
  B. Moly
  C. Silicon
  D. None of the above
  C. Silicon

• Question 123:

  With high temperature sulfide corrosion (Sulfidization), noticeable increases may be found downstream of _________ injection points.

  A. Hydrogen
  B. Caustic
  C. Ammonia
  D. Water
  A. Hydrogen

• Question 124:

  (Corrosion of carbon steel in sulfuric acid increases significantly below what percent acid concentration?)

  A. 65
  B. 75
  C. 86
  D. 95
  A. 65

  ---

  Comprehensive and Detailed From Exact Extract:

  According to API RP 571, carbon steel exhibits a minimum corrosion rate in sulfuric acid at concentrations around 65-70 wt% due to formation of a protective iron sulfate film.

  When sulfuric acid concentration drops below approximately 65%, this protective film becomes unstable

  and corrosion rates increase dramatically.

  Referenced Documents (Study Basis): API RP 571 - Section on Sulfuric Acid Corrosion

• Question 125:

  With sulfuric acid corrosion, carbon steel corrosion rates increases significantly if the flow velocity exceeds about ________m fps or at acid concentrations below _________.

  A. 6-9, 80%
  B. 5-7, 75%
  C. 2-3, 65%
  D. 4-6, 85%
  C. 2-3, 65%

• Question 126:

  A form of corrosion that can occur at the junction of dissimilar metals when they are joined together in a suitable electrolyte is __________.

  A. Galvanic corrosion
  B. Anodic corrosion
  C. Cathodic corrosion
  D. All of the above
  A. Galvanic corrosion

• Question 127:

  Changing to a more corrosion resistant and/or higher hardness material _________ improve cavitation resistance.

  A. Will
  B. May
  C. Will not
  D. May not
  D. May not

• Question 128:

  Which of these materials are not susceptible to Spheroidization?

  A. Carbon steel
  B. 9Cr-1Mo
  C. 316 SS
  D. Both A and B
  C. 316 SS

• Question 129:

  The most effective protection of carbon steel pilings from soil-side corrosion is a combination of a:

  A. Corrosion-resistant coating and a cathodic protection system
  B. Galvanizing and a cathodic protection system
  C. Corrosion-resistant coating and a clean sand backfill
  D. Clean sand backfill and a cathodic protection system
  A. Corrosion-resistant coating and a cathodic protection system

  ---

  Comprehensive and Detailed From Exact Extract: According to API RP 571 and corrosion control best practices, maximum protection of buried or soil-exposed carbon steel is achieved by combining: A protective coating (primary barrier) Cathodic protection (CP) (secondary, active protection) This dual system: Minimizes current demand Protects coating defects Extends service life significantly Neither coatings nor CP alone provide equivalent long-term reliability.

  Referenced Documents (Study Basis): API RP 571 - Section on Soil-Side Corrosion API Corrosion Control Study Guide

• Question 130:

  Steel cleanliness and _______ have a significant influence on toughness and resistance to brittle fracture.

  A. Composition
  B. Alloy
  C. Grain size
  D. None of the above
  C. Grain size