Practice Test Geeks(API 510) API 510 Inspector Certification Practice Test
← All API 510 Flashcard Decks

Corrosion Assessment Flashcards

7 cards from real API 510 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Corrosion Assessment flashcards as text

  1. What type of corrosion involves the preferential attack of one phase in a multi-phase alloy, such as the removal of zinc from brass?

    Answer: Dealloying (selective leaching)

    Dealloying, or selective leaching, involves the preferential removal of one element from an alloy, such as dezincification of brass.

  2. According to API 510, how should a corrosion rate be established for a new vessel with no prior inspection history?

    Answer: Use published data, experience from similar services, or process engineering estimates

    For new vessels, API 510 allows use of published corrosion data, similar service experience, or process engineer estimates to establish an initial corrosion rate.

  3. Which condition is required for erosion-corrosion to be a significant degradation mechanism in a pressure vessel?

    Answer: High-velocity flow, especially with entrained solids or vapors

    Erosion-corrosion requires high-velocity flow that mechanically removes protective oxide layers, with entrained solids or phase changes accelerating the damage.

  4. What is the purpose of establishing a short-term corrosion rate in API 510 assessments?

    Answer: To capture recent changes in process conditions that may differ from historical rates

    Short-term rates reflect the most recent inspection interval, capturing changes in process conditions that may not be represented by historical long-term data.

  5. A pressure vessel inspector discovers blistering on the inner surface of a vessel in H2S service. What damage mechanism does this MOST likely indicate?

    Answer: Hydrogen blistering

    Hydrogen blistering occurs when atomic hydrogen diffuses into the steel and accumulates at inclusions, forming blisters visible on the surface.

  6. Which factor most significantly increases the susceptibility of austenitic stainless steel to chloride stress corrosion cracking?

    Answer: Elevated temperature above approximately 140 degrees F (60 degrees C)

    Chloride SCC in austenitic stainless steel is significantly accelerated at elevated temperatures, typically above 140 degrees F, in the presence of chlorides and tensile stress.

  7. Per API 510, if a vessel's corrosion rate doubles after a process change, what is the MOST appropriate inspector action?

    Answer: Revise the inspection interval based on the new, higher corrosion rate

    A significant change in corrosion rate warrants revising the inspection interval using the new rate to ensure the vessel remains within safe limits.